Science.gov

Sample records for joint surface lesions

  1. Osteochondral Lesions of Major Joints

    PubMed Central

    Durur-Subasi, Irmak; Durur-Karakaya, Afak; Yildirim, Omer Selim

    2015-01-01

    This paper provides information about osteochondral lesions (OCL) and example cases of OCL occurring in major joints, some of which are rarely seen. This simple tutorial is presented in question and answer format. PMID:26180500

  2. First Metatarsophalangeal Joint Arthroscopy for Osteochondral Lesions.

    PubMed

    Sherman, Thomas I; Kern, Michael; Marcel, John; Butler, Alexander; McGuigan, Francis X

    2016-06-01

    Small-joint arthroscopy has supplanted open procedures because it offers the potential for improvement in joint visualization, reduced scarring, and accelerated recovery. Despite these advantages, arthroscopy of the first metatarsophalangeal joint is not commonly performed and reports of its use are lacking. The reason for this is not clear but may be because of perceived technical complexity and poorly defined indications. In our experience, however, arthroscopy of the first metatarsophalangeal joint is a versatile procedure that facilitates treatment of many different pathologic processes through a minimally invasive approach with few complications. We present our technique for arthroscopic management of osteochondral lesions of the hallux. PMID:27656371

  3. Cystic lesion around the hip joint

    PubMed Central

    Yukata, Kiminori; Nakai, Sho; Goto, Tomohiro; Ikeda, Yuichi; Shimaoka, Yasunori; Yamanaka, Issei; Sairyo, Koichi; Hamawaki, Jun-ichi

    2015-01-01

    This article presents a narrative review of cystic lesions around the hip and primarily consists of 5 sections: Radiological examination, prevalence, pathogenesis, symptoms, and treatment. Cystic lesions around the hip are usually asymptomatic but may be observed incidentally on imaging examinations, such as computed tomography and magnetic resonance imaging. Some cysts may enlarge because of various pathological factors, such as trauma, osteoarthritis, rheumatoid arthritis, or total hip arthroplasty (THA), and may become symptomatic because of compression of surrounding structures, including the femoral, obturator, or sciatic nerves, external iliac or common femoral artery, femoral or external iliac vein, sigmoid colon, cecum, small bowel, ureters, and bladder. Treatment for symptomatic cystic lesions around the hip joint includes rest, nonsteroidal anti-inflammatory drug administration, needle aspiration, and surgical excision. Furthermore, when these cysts are associated with osteoarthritis, rheumatoid arthritis, and THA, primary or revision THA surgery will be necessary concurrent with cyst excision. Knowledge of the characteristic clinical appearance of cystic masses around the hip will be useful for determining specific diagnoses and treatments. PMID:26495246

  4. Generalized Models for Rock Joint Surface Shapes

    PubMed Central

    Du, Shigui; Hu, Yunjin; Hu, Xiaofei

    2014-01-01

    Generalized models of joint surface shapes are the foundation for mechanism studies on the mechanical effects of rock joint surface shapes. Based on extensive field investigations of rock joint surface shapes, generalized models for three level shapes named macroscopic outline, surface undulating shape, and microcosmic roughness were established through statistical analyses of 20,078 rock joint surface profiles. The relative amplitude of profile curves was used as a borderline for the division of different level shapes. The study results show that the macroscopic outline has three basic features such as planar, arc-shaped, and stepped; the surface undulating shape has three basic features such as planar, undulating, and stepped; and the microcosmic roughness has two basic features such as smooth and rough. PMID:25152901

  5. Generalized models for rock joint surface shapes.

    PubMed

    Du, Shigui; Hu, Yunjin; Hu, Xiaofei

    2014-01-01

    Generalized models of joint surface shapes are the foundation for mechanism studies on the mechanical effects of rock joint surface shapes. Based on extensive field investigations of rock joint surface shapes, generalized models for three level shapes named macroscopic outline, surface undulating shape, and microcosmic roughness were established through statistical analyses of 20,078 rock joint surface profiles. The relative amplitude of profile curves was used as a borderline for the division of different level shapes. The study results show that the macroscopic outline has three basic features such as planar, arc-shaped, and stepped; the surface undulating shape has three basic features such as planar, undulating, and stepped; and the microcosmic roughness has two basic features such as smooth and rough.

  6. Leg lesions and cleanliness of finishing bulls kept in housing systems with different lying area surfaces.

    PubMed

    Schulze Westerath, H; Gygax, L; Mayer, C; Wechsler, B

    2007-07-01

    The influence of the quality of different lying surfaces on lesions and swellings at the joints as well as on the cleanliness of finishing bulls throughout the fattening period was studied. On 17 farms (623 bulls), pens with fully slatted concrete floors (CONCRETE), with rubber coated slats (RUBBER), with cubicles (CUBICLES, provided with five different types of soft lying mat) and with a littered lying area (STRAW) were compared. Bulls kept on STRAW developed the smallest lesion scores at the joints. In CUBICLES, there was a huge variability in the lesion scores depending on the type of lying mat, ranging from values comparable to STRAW up to and greater than the values for CONCRETE. The highest lesion scores at the carpal joints were found on CONCRETE, with intermediate values on RUBBER and in CUBICLES. At the tarsal joints, lesion scores were similar on CONCRETE and RUBBER and in the same range or worse on most mats in the CUBICLES. Swelling scores were highest on CONCRETE and intermediate on RUBBER and in CUBICLES compared to STRAW. In general, there was a steady increase in the lesion scores of the leg joints throughout the fattening period on CONCRETE, RUBBER and STRAW, whereas on some of the mats in CUBICLES these scores were at a high level from early on in the fattening period. Animals in all the housing systems were clean over the whole fattening period. Littering the lying area in CUBICLES affected neither the lesion scores nor the swelling scores at the joints nor animal cleanliness. In conclusion, both rubber coated slats and cubicles provided with soft lying mats were favourable with regard to the levels of lesions and swellings of the leg joints of finishing bulls compared to concrete slats. However, these levels were even lower in pens with a straw bedded lying area.

  7. Osteochondral lesions in distal tarsal joints of Icelandic horses reveal strong associations between hyaline and calcified cartilage abnormalities.

    PubMed

    Ley, C J; Ekman, S; Hansson, K; Björnsdóttir, S; Boyde, A

    2014-03-25

    Osteochondral lesions in the joints of the distal tarsal region of young Icelandic horses provide a natural model for the early stages of osteoarthritis (OA) in low-motion joints. We describe and characterise mineralised and non-mineralised osteochondral lesions in left distal tarsal region joint specimens from twenty-two 30 ±1 month-old Icelandic horses. Combinations of confocal scanning light microscopy, backscattered electron scanning electron microscopy (including, importantly, iodine staining) and three-dimensional microcomputed tomography were used on specimens obtained with guidance from clinical imaging. Lesion-types were described and classified into groups according to morphological features. Their locations in the hyaline articular cartilage (HAC), articular calcified cartilage (ACC), subchondral bone (SCB) and the joint margin tissues were identified and their frequency in the joints recorded. Associations and correlations between lesion-types were investigated for centrodistal joints only. In centrodistal joints the lesion-types HAC chondrocyte loss, HAC fibrillation, HAC central chondrocyte clusters, ACC arrest and ACC advance had significant associations and strong correlations. These lesion-types had moderate to high frequency in centrodistal joints but low frequencies in tarsometatarsal and talocalcaneal-centroquartal joints. Joint margin lesion-types had no significant associations with other lesion-types in the centrodistal joints but high frequency in both the centrodistal and tarsometatarsal joints. The frequency of SCB lesion-types in all joints was low. Hypermineralised infill phase lesion-types were detected. Our results emphasise close associations between HAC and ACC lesions in equine centrodistal joints and the importance of ACC lesions in the development of OA in low-motion compression-loaded equine joints.

  8. Bipolar radiofrequency lesion geometry: implications for palisade treatment of sacroiliac joint pain.

    PubMed

    Cosman, Eric R; Gonzalez, Christian D

    2011-01-01

    Ex vivo photographic temperature mapping of bipolar radiofrequency (RF) lesions in animal tissue is performed over a wide range of electrode tip spacings, tip lengths, tip diameters, tip temperatures, and lesion times. In vivo temperature measurements collected during clinical treatment of sacroiliac joint (SIJ) pain corroborate those collected ex vivo. Generation of a "strip lesion" connecting two separated bipolar electrode tips is demonstrated ex vivo for tip spacings as large as 20 mm. A rounded rectangular bipolar lesion with midline dimensions 12 mm × 15 mm × 8 mm (L × W × D) is demonstrated using 10 mm parallel tip spacing, 10 mm tip lengths, 20 gauge cannulae, 90°C tip temperature, and 3-minute lesion time. Lesion length can be increased to 18 mm by using 15 mm tip lengths. Lesion width can be increased to 17 mm by using 12 mm tip spacing. The size of conventional bipolar lesions can exceed the size of lesions produced both by conventional monopolar RF (12 mm × 7 mm × 7 mm ellipsoidal) and by cooled monopolar RF as used in spinal pain management (10 mm × 10 mm × 10 mm spherical). SIJ pain is treated by placing 5 to 7 straight RF cannulae perpendicular to the dorsal sacrum and producing 4 to 6 overlapping bipolar RF lesions between the dorsal sacral foramina and the ipsilateral SIJ. This bipolar "palisade" (a defensive fence) creates a continuous lesion spanning the region through which multiple sacral lateral branch nerves travel along irregular, branching paths to reach the SIJ.

  9. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Finish of surface joints. 18.33 Section 18.33... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a flame... § 18.31(a)(6). All metal surfaces forming a flame-arresting path shall be finished during...

  10. Preliminary results of automated removal of degenerative joint disease in bone scan lesion segmentation

    NASA Astrophysics Data System (ADS)

    Chu, Gregory H.; Lo, Pechin; Kim, Hyun J.; Auerbach, Martin; Goldin, Jonathan; Henkel, Keith; Banola, Ashley; Morris, Darren; Coy, Heidi; Brown, Matthew S.

    2013-03-01

    Whole-body bone scintigraphy (or bone scan) is a highly sensitive method for visualizing bone metastases and is the accepted standard imaging modality for detection of metastases and assessment of treatment outcomes. The development of a quantitative biomarker using computer-aided detection on bone scans for treatment response assessment may have a significant impact on the evaluation of novel oncologic drugs directed at bone metastases. One of the challenges to lesion segmentation on bone scans is the non-specificity of the radiotracer, manifesting as high activity related to non-malignant processes like degenerative joint disease, sinuses, kidneys, thyroid and bladder. In this paper, we developed an automated bone scan lesion segmentation method that implements intensity normalization, a two-threshold model, and automated detection and removal of areas consistent with non-malignant processes from the segmentation. The two-threshold model serves to account for outlier bone scans with elevated and diffuse intensity distributions. Parameters to remove degenerative joint disease were trained using a multi-start Nelder-Mead simplex optimization scheme. The segmentation reference standard was constructed manually by a panel of physicians. We compared the performance of the proposed method against a previously published method. The results of a two-fold cross validation show that the overlap ratio improved in 67.0% of scans, with an average improvement of 5.1% points.

  11. Unusual lesions mimicking impingement syndrome in the shoulder joint - Think medially.

    PubMed

    Singh, Rohit; Malhotra, Akshay; Cribb, Gillian; Cool, Paul; Hay, Stuart

    2016-09-01

    Impingement syndrome is usually caused by irritation of the rotator cuff within the sub acromial space and this includes the coraco-acromial arch (Acromion and Coraco-acromial ligament), the acromio-clavicular joint and occasionally the coracoid. Iatrogenic causes such as sutures, pins, plates or wires left from previous surgery can cause similar symptoms. We present a series of four cases mimicking "classical" impingement symptoms/signs in which the causal pathology was identified outside the sub-acromial space. Magnetic Resonance Imaging (MRI) showed lesions that were present in the supra-spinatus fossa but were causing pressure effects on the sub-acromial space, namely - a ganglion cyst in one case, lipomata in two other cases, and a glomus tumour. A ganglion cyst and glomus tumour mimicking impingement syndrome is a rare reported case to our knowledge. These are unusual causes that should be considered when investigating classical impingement syndrome and particularly those who may have failed to respond to decompression surgery. They highlight the potential value of looking beyond the sub-acromial space for causal lesions and in these cases, at a time when limited ultrasound investigation has become increasingly popular; MRI has clearly played an important and was essential in planning surgery as these lesions would not have been identified on USS. Even though the symptoms were classical. PMID:27594993

  12. Differences in injury pattern and prevalence of cartilage lesions in knee and ankle joints: a retrospective cohort study.

    PubMed

    Aurich, Matthias; Hofmann, Gunther O; Rolauffs, Bernd; Gras, Florian

    2014-10-27

    Osteoarthritis (OA) is more common in the knee compared to the ankle joint. This can not be explained exclusively by anatomical and biomechanical differences. The aim of this study is to analyze and compare the injury pattern (clinically) and the cartilage lesions (arthroscopically) of knee and ankle joints in a cohort of patients from the same catchment area. A retrospective study of the clinical data of 3122 patients (2139 outpatients and 983 inpatients) was performed, who were treated due to an injury of the knee and ankle joint. Statistical analysis was performed using SigmaStat 3.0 (SPSS Inc, Chicago, USA). There is a higher prevalence of injuries in the ankle as compared to the knee joint in this population from the same catchment area. In contrast, high-grade cartilage lesions are more prevalent in the knee, whereas low grade cartilage lesions are equally distributed between knee and ankle. From this data it can be concluded that the frequency of injuries and the injury pattern of knee versus ankle joints do not correlate with the severity of cartilage lesions and may therefore have no direct influence on the differential incidence of OA in those two joints.

  13. Fine-needle aspiration of pigmented villonodular synovitis of the temporomandibular joint masquerading as a primary parotid gland lesion.

    PubMed

    Yu, G H; Staerkel, G A; Kershisnik, M M; Varma, D G

    1997-01-01

    The fine-needle aspiration findings in a case of pigmented villonodular synovitis of the temporomandibular joint are presented. The characteristic cytomorphologic and clinical features of this uncommon, benign fibrohistiocytic lesion are discussed. In addition, due to the initial clinical impression of a primary parotid gland lesion, the differential diagnosis for the cytomorphologic features observed (histiocytoid cells admixed with osteoclast-like giant cells) are discussed within the context of a primary salivary gland mass.

  14. A repetitive, steady mouth opening induced an osteoarthritis-like lesion in the rabbit temporomandibular joint.

    PubMed

    Fujisawa, T; Kuboki, T; Kasai, T; Sonoyama, W; Kojima, S; Uehara, J; Komori, C; Yatani, H; Hattori, T; Takigawa, M

    2003-09-01

    Although excessive mechanical stress is assumed to be one of the factors contributing to pathogenesis of temporomandibular joint (TMJ) osteoarthritis (OA), no pure mechanical-stress-induced OA model has been developed without surgical manipulation or puncture of the joint cavity. The purpose of this study was to establish a genuine mechanical-stress-induced OA model of the rabbit TMJ. In the experimental rabbits, repetitive, forced jaw-opening, 3 hrs/day for 5 days, was applied with the use of a general anesthesia protocol. By histological assessment of the TMJ articular tissues, partial eburnation of the articular cartilage, reactive marginal proliferation of the articular cartilage chondrocytes, and nested proliferation of chondrocytes in the subchondral bone area were observed at 7 days after the repetitive, forced-jaw-opening period. These results suggest that the repetitive, forced-jaw-opening protocol without surgical intervention can induce evident OA-like lesions in the rabbit TMJ, and this OA model may greatly contribute to the elucidation of the cartilage degradation mechanism in TMJ OA. PMID:12939359

  15. Lubricin Protects the Temporomandibular Joint Surfaces from Degeneration

    PubMed Central

    Purcell, Patricia

    2014-01-01

    The temporomandibular joint (TMJ) is a specialized synovial joint essential for the mobility and function of the mammalian jaw. The TMJ is composed of the mandibular condyle, the glenoid fossa of the temporal bone, and a fibrocartilagenous disc interposed between these bones. A fibrous capsule, lined on the luminal surface by the synovial membrane, links these bones and retains synovial fluid within the cavity. The major component of synovial fluid is lubricin, a glycoprotein encoded by the gene proteoglycan 4 (Prg4), which is synthesized by chondrocytes at the surface of the articular cartilage and by synovial lining cells. We previously showed that in the knee joint, Prg4 is crucial for maintenance of cartilage surfaces and for regulating proliferation of the intimal cells in the synovium. Consequently, the objective of this study was to determine the role of lubricin in the maintenance of the TMJ. We found that mice lacking lubricin have a normal TMJ at birth, but develop degeneration resembling TMJ osteoarthritis by 2 months, increasing in severity over time. Disease progression in Prg4−/− mice results in synovial hyperplasia, deterioration of cartilage in the condyle, disc and fossa with an increase in chondrocyte number and their redistribution in clusters with loss of superficial zone chondrocytes. All articular surfaces of the joint had a prominent layer of protein deposition. Compared to the knee joint, the osteoarthritis-like phenotype was more severe and manifested earlier in the TMJ. Taken together, the lack of lubricin in the TMJ causes osteoarthritis-like degeneration that affects the articular cartilage as well as the integrity of multiple joint tissues. Our results provide the first molecular evidence of the role of lubricin in the TMJ and suggest that Prg4−/− mice might provide a valuable new animal model for the study of the early events of TMJ osteoarthritis. PMID:25188282

  16. Lubricin protects the temporomandibular joint surfaces from degeneration.

    PubMed

    Hill, Adele; Duran, Juanita; Purcell, Patricia

    2014-01-01

    The temporomandibular joint (TMJ) is a specialized synovial joint essential for the mobility and function of the mammalian jaw. The TMJ is composed of the mandibular condyle, the glenoid fossa of the temporal bone, and a fibrocartilagenous disc interposed between these bones. A fibrous capsule, lined on the luminal surface by the synovial membrane, links these bones and retains synovial fluid within the cavity. The major component of synovial fluid is lubricin, a glycoprotein encoded by the gene proteoglycan 4 (Prg4), which is synthesized by chondrocytes at the surface of the articular cartilage and by synovial lining cells. We previously showed that in the knee joint, Prg4 is crucial for maintenance of cartilage surfaces and for regulating proliferation of the intimal cells in the synovium. Consequently, the objective of this study was to determine the role of lubricin in the maintenance of the TMJ. We found that mice lacking lubricin have a normal TMJ at birth, but develop degeneration resembling TMJ osteoarthritis by 2 months, increasing in severity over time. Disease progression in Prg4-/- mice results in synovial hyperplasia, deterioration of cartilage in the condyle, disc and fossa with an increase in chondrocyte number and their redistribution in clusters with loss of superficial zone chondrocytes. All articular surfaces of the joint had a prominent layer of protein deposition. Compared to the knee joint, the osteoarthritis-like phenotype was more severe and manifested earlier in the TMJ. Taken together, the lack of lubricin in the TMJ causes osteoarthritis-like degeneration that affects the articular cartilage as well as the integrity of multiple joint tissues. Our results provide the first molecular evidence of the role of lubricin in the TMJ and suggest that Prg4-/- mice might provide a valuable new animal model for the study of the early events of TMJ osteoarthritis.

  17. Textured bearing surface in artificial joints to reduce macrophage activation

    NASA Astrophysics Data System (ADS)

    Nakanishi, Yoshitaka; Nishi, Naoki; Chikaura, Hiroto; Nakashima, Yuta; Miura, Hiromasa; Higaki, Hidehiko; Mizuta, Hiroshi; Iwamoto, Yukihide; Fujiwara, Yukio; Komohara, Yoshihiro; Takeya, Motohiro

    2015-12-01

    Micro slurry-jet erosion has been proposed as a precision machining technique for the bearing surfaces of artificial joints in order to reduce the total amount of polyethylene wear and to enlarge the size of the wear debris. The micro slurry-jet erosion method is a wet blasting technique which uses alumina particles as the abrasive medium along with compressed air and water to create an ideal surface. Pin-on-disc wear tests with multidirectional sliding motion on the textured surface of a \\text{Co}-\\text{Cr}-\\text{Mo} alloy counterface for polyethylene resulted in both a reduction of wear as well as enlargement of the polyethylene debris size. In this study, primary human peripheral blood mononuclear phagocytes were incubated with the debris, and it was elucidated that the wear debris generated on the textured surface regulated secretion of the proinflammatory cytokines IL-6 and TNF-α, indicating a reduction in the induced tissue reaction and joint loosening.

  18. The lubricative function of artificial joint material surfaces by confocal laser scanning microscopy. Comparison with natural synovial joint surface.

    PubMed

    Kobayashi, Masanori; Oka, Masanori

    2003-01-01

    The purpose of this study was to observe and compare the effect of the behavior of different lubricating surfaces, including articular cartilage and several artificial joint materials, under the physiological loading by confocal laser scanning microscopy (CLSM) to clarify the mechanism of lubrication in natural joints and subsequently improve the quality of artificial joints. In our experiment, even with considerable loading, natural articular cartilage exhibited a synovial fluid area and an area of direct and solid contact. In the region between these two areas, a liquid crystal layer was observed. On the other hand, the materials used for artificial joints (metal and polyethylene, which are now in use, and polyvinyl alcohol-hydrogel polymer which is being developed), did not exhibit neither a clear fluid pool area nor the intermediary area with liquid crystal formation. These results suggest that natural articular cartilage surface has a particular characteristic which builds up a synovial pooling area and liquid crystal formation in the third area by interaction with macromolecules in synovial fluid under the loading condition. These characteristics give natural articular cartilage its excellent lubricative function. To improve the quality of artificial joints, the characteristics of the implant material surface and the synovial macromolecules must be considered. PMID:14646057

  19. 0.2-Tesla magnetic resonance imaging of internal lesions of the knee joint: a prospective arthroscopically controlled clinical study.

    PubMed

    Riel, K A; Reinisch, M; Kersting-Sommerhoff, B; Hof, N; Merl, T

    1999-01-01

    The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 244 patients. A dedicated system for MRI of limbs and peripheral joints--the 0.2-T Artoscan (Esaote, Italy)--was used for imaging knee joint lesions. T1-weighted spin-echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of the femoropatellar joint were acquired. Paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments and medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 h after imaging, the sensitivity, specificity, and accuracy were respectively 93%, 97%, and 95% for tears of the medial meniscus; 82%, 96%, and 93% for tears of the lateral meniscus; 100%, 100%, and 100% for tears of the posterior cruciate ligament; 98%, 98%, and 97% for tears of the anterior cruciate ligament; and 72%, 100%, and 92% for full-thickness articular cartilage lesions. The examination can be performed within 30-45 min at lower cost than diagnostic arthroscopy. MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning.

  20. Localization of subsurface fluorescent lesions using surface spectral measurements

    NASA Astrophysics Data System (ADS)

    Kolste, Kolbein

    Localization of Subsurface Fluorescent Lesions using Surface Spectral Measurements Sponsored by the National Institute of Health, Bethesda, Maryland Kolbein Kolste, Ph.D. Keith Paulsen In neurosurgical tumor resection, maximizing extent of resection plays a major role in the care of cancer patients. To date, ALA is being researched as a technique to guide tumor resection by inducing the accumulation of the endogenous fluorophore PpIX. Most research has focused on the use of blue light excitation of PpIX to visual the tumor. However, due to the high attenuation of blue light by in vivo chromophores, such as oxy- and deoxy-hemoglobin, the source of collected fluorescence emissions is confined to the top layer of cells, and the signal is subject to masking by blood on the surface of the surgical field of view. This issue is particularly a problem at the end of the resection, when the surgeon is evaluating the margin for remaining tumor, but the blue-signal is insensitive to residual tumor that may be located several millimeters beneath the surface. PpIX has an absorption band in the near infrared (NIR), where the absorption due to blood is orders of magnitude lower, enabling the excitation of a fluorophore at depth. In this work, we created a hyperspectral imaging system that attaches to a neurosurgical microscope and is capable of detecting PpIX fluorescence that has been excited at 635 nm. We utilize a dual-waveband technique from the hyperspectral to estimate depth of fluorescence origin and characterize the inherent limitations of the estimated depth. One of the major benefits of this technique is that the estimation is independent of the concentration and size of the fluorophore. This is first demonstrated in phantom studies, where the depths of multiple separate inclusions at various depths are accurately estimated. The technique is verified in animal tumor models and translated into the clinical theater, with pilot data showing the first estimation of depth of

  1. Automated inspection of solder joints for surface mount technology

    NASA Technical Reports Server (NTRS)

    Savage, Robert M.; Park, Hyun Soo; Fan, Mark S.

    1993-01-01

    Researchers at NASA/GSFC evaluated various automated inspection systems (AIS) technologies using test boards with known defects in surface mount solder joints. These boards were complex and included almost every type of surface mount device typical of critical assemblies used for space flight applications: X-ray radiography; X-ray laminography; Ultrasonic Imaging; Optical Imaging; Laser Imaging; and Infrared Inspection. Vendors, representative of the different technologies, inspected the test boards with their particular machine. The results of the evaluation showed limitations of AIS. Furthermore, none of the AIS technologies evaluated proved to meet all of the inspection criteria for use in high-reliability applications. It was found that certain inspection systems could supplement but not replace manual inspection for low-volume, high-reliability, surface mount solder joints.

  2. A new approach for surface fitting method of articular joint surfaces.

    PubMed

    Hirokawa, Shunji; Ueki, Takashi; Ohtsuki, Ayaka

    2004-10-01

    The application of joint contact mechanics requires a precise configuration of the joint surfaces. B-Spline, and NURBS have been widely used to model joint surfaces, but because these formulations use a structured data set provided by a rectangular net first, then a grid, there is a limit to the accuracy of the models they can produce. However new imaging systems such as 3D laser scanners can provide more realistic unstructured data sets. What is needed is a method to manipulate the unstructured data. We created a parametric polynomial function and applied it to unstructured data sets obtained by scanning joint surfaces. We applied our polynomial model to unstructured data sets from an artificial joint, and confirmed that our polynomial produced a smoother and more accurate model than the conventional B-spline method. Next, we applied it to a diarthrodial joint surface containing many ripples, and found that our function's noise filtering characteristics smoothed out existing ripples. Since no formulation was found to be optimal for all applications, we used two formulations to model surfaces with ripples. First, we used our polynomial to describe the global shape of the objective surface. Minute undulations were then specifically approximated with a Fourier series function. Finally, both approximated surfaces were superimposed to reproduce the original surface in a complete fashion. PMID:15336930

  3. Joint inversion of surface and borehole magnetic amplitude data

    NASA Astrophysics Data System (ADS)

    Li, Zelin; Yao, Changli; Zheng, Yuanman; Yuan, Xiaoyu

    2016-04-01

    3D magnetic inversion for susceptibility distribution is a powerful tool in quantitative interpretation of magnetic data in mineral exploration. However, the inversion and interpretation of such data are faced with two problems. One problem is the poor imaging results of deep sources when only surface data are inverted. The other is the unknown total magnetization directions of sources when strong remanence exists. To deal with these problems simultaneously, we propose a method through the joint inversion of surface and borehole magnetic amplitude data. In this method, we first transform both surface and borehole magnetic data to magnetic amplitude data that are less sensitive to the directions of total magnetization, and then preform a joint inversion of the whole amplitude data to generate a 3D susceptibility distribution. The amplitude inversion algorithm uses Tikhonov regularization and imposes a positivity constraint on the effective susceptibility defined as the ratio of magnetization magnitude over the geomagnetic field strength. In addition, a distance-based weighting function is used to make the algorithm applicable to joint data sets. To solve this positivity-constraint inversion problem efficiently, an appropriate optimization method must be chosen. We first use an interior-point method to incorporate the positivity constraint into the total objective function, and then minimize the objective function via a Gauss-Newton method due to the nonlinearity introduced by the positivity constraint and the amplitude data. To further improve the efficiency of the inversion algorithm, we use a conjugate gradient method to carry out the fast matrix-vector multiplication during the minimization. To verify the utility of the proposed method, we invert the synthetic and field data using three inversion methods, including the joint inversion of surface and borehole three-component magnetic data, the inversion of surface magnetic amplitude data, and the proposed joint

  4. Nonproliferative and Proliferative Lesions of the Rat and Mouse Skeletal Tissues (Bones, Joints, and Teeth).

    PubMed

    Fossey, Stacey; Vahle, John; Long, Philip; Schelling, Scott; Ernst, Heinrich; Boyce, Rogely Waite; Jolette, Jacquelin; Bolon, Brad; Bendele, Alison; Rinke, Matthias; Healy, Laura; High, Wanda; Roth, Daniel Robert; Boyle, Michael; Leininger, Joel

    2016-01-01

    The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is an initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the skeletal tissues and teeth of laboratory rats and mice, with color photomicrographs illustrating examples of many common lesions. The standardized nomenclature presented in this document is also available on the internet (http://www.goreni.org/). Sources of material were databases from government, academic and industrial laboratories throughout the world.

  5. Nonproliferative and Proliferative Lesions of the Rat and Mouse Skeletal Tissues (Bones, Joints, and Teeth)

    PubMed Central

    Fossey, Stacey; Vahle, John; Long, Philip; Schelling, Scott; Ernst, Heinrich; Boyce, Rogely Waite; Jolette, Jacquelin; Bolon, Brad; Bendele, Alison; Rinke, Matthias; Healy, Laura; High, Wanda; Roth, Daniel Robert; Boyle, Michael; Leininger, Joel

    2016-01-01

    The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is an initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the skeletal tissues and teeth of laboratory rats and mice, with color photomicrographs illustrating examples of many common lesions. The standardized nomenclature presented in this document is also available on the internet (http://www.goreni.org/). Sources of material were databases from government, academic and industrial laboratories throughout the world.

  6. Nonproliferative and Proliferative Lesions of the Rat and Mouse Skeletal Tissues (Bones, Joints, and Teeth).

    PubMed

    Fossey, Stacey; Vahle, John; Long, Philip; Schelling, Scott; Ernst, Heinrich; Boyce, Rogely Waite; Jolette, Jacquelin; Bolon, Brad; Bendele, Alison; Rinke, Matthias; Healy, Laura; High, Wanda; Roth, Daniel Robert; Boyle, Michael; Leininger, Joel

    2016-01-01

    The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is an initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the skeletal tissues and teeth of laboratory rats and mice, with color photomicrographs illustrating examples of many common lesions. The standardized nomenclature presented in this document is also available on the internet (http://www.goreni.org/). Sources of material were databases from government, academic and industrial laboratories throughout the world. PMID:27621538

  7. Nonproliferative and Proliferative Lesions of the Rat and Mouse Skeletal Tissues (Bones, Joints, and Teeth)

    PubMed Central

    Fossey, Stacey; Vahle, John; Long, Philip; Schelling, Scott; Ernst, Heinrich; Boyce, Rogely Waite; Jolette, Jacquelin; Bolon, Brad; Bendele, Alison; Rinke, Matthias; Healy, Laura; High, Wanda; Roth, Daniel Robert; Boyle, Michael; Leininger, Joel

    2016-01-01

    The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is an initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the skeletal tissues and teeth of laboratory rats and mice, with color photomicrographs illustrating examples of many common lesions. The standardized nomenclature presented in this document is also available on the internet (http://www.goreni.org/). Sources of material were databases from government, academic and industrial laboratories throughout the world. PMID:27621538

  8. Treatment efficacy of etanercept and MTX combination therapy for ankylosing spondylitis hip joint lesion in Chinese population.

    PubMed

    Lian, Fan; Yang, Xiuyan; Liang, Liuqin; Xu, Hanshi; Zhan, Zhongping; Qiu, Qian; Ye, Yujin

    2012-06-01

    To investigate the efficacy of etanercept and MTX (methotrexate) combination therapy in Chinese patients with ankylosing spondylitis hip joint lesion, the possible courses and maintenance protocol, altogether 97 ankylosing spondylitis patients fulfilling the modified New York criteria with hip joint lesion were enrolled in a 12-month trial treated with combined etanercept and MTX. All these patients were required to be poor responders to SSZ (Sulfasalazine) or MTX therapy for 6 consecutive months or the longer. Etanercept was administered subcutaneously twice a week at a fixed dosage of 25 mg for the first six months, followed by 25 mg once a week in patients with good control of both symptoms and radiological progression, or twice a week for another six months in patients with BASDAI > or = 4. Combined MTX was administered intravenously once a week at the dosage of 15 mg. Demographics, clinical and laboratory features, physical function and quality of life using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), Harris hip score, and radiological assessment using the BASRI-hip index were recorded. Most patients achieved pain release at the end point of assessment. Significant improvement in Bath AS Disease Activity Index (BASDAI) (P < 0.05), Bath AS Functional Activity Index (BASFI) (P < 0.05), and Harris hip score (P < 0.05) was demonstrated. Radiographic progression was recorded as no exacerbation or alleviated. Larger interval between two etanercept administrations would provide similar advantages to standard method and possibly less adverse events if MTX was combined. Etanercept and MTX combination therapy was beneficial to ankylosing spondylitis patients with hip joint lesion, and staged dosage deduction in the long term proved to be effective as well as adverse event preventing.

  9. Comparison of ultrasound and magnetic resonance imaging for diagnosis and follow-up of joint lesions in patients with haemophilia.

    PubMed

    Sierra Aisa, C; Lucía Cuesta, J F; Rubio Martínez, A; Fernández Mosteirín, N; Iborra Muñoz, A; Abío Calvete, M; Guillén Gómez, M; Moretó Quintana, A; Rubio Félix, D

    2014-01-01

    Haematomas and recurrent haemarthroses are a common problem in haemophilia patients from early age. Early diagnosis is critical in preventing haemophilic arthritis, and recent years have seen excellent advances in musculoskeletal ultrasound as a diagnostic tool in soft tissue lesions. In this study, we compared the results of ultrasound imaging for the diagnosis of musculoskeletal injuries in haemophilia patients with scores obtained using magnetic resonance (MRI) scans. A total of 61 haemophilia patients aged 4-82 years were included in this study. Both knees and ankles of each patient were assessed using the Gilbert (clinical assessment) and Pettersson scores (X-ray assessment). Patients with severe haemophilia (n = 30) were examined using ultrasound and MRI (Denver scoring system). Results obtained with ultrasound and MRI in severe patients were correlated using the Pearson test. In patients with severe haemophilia, normal joints were similarly assessed with MRI and ultrasound (κ = 1.000). By component of joint assessment, haemarthrosis was similarly diagnosed with both techniques in all joints (κ = 1.000). A good positive correlation was found between these techniques in detecting and locating synovial hyperplasia (κ = 0.839-1.000, knees and ankles respectively), and erosion of margins (κ = 0.850-1.000). The presence of bone cysts or cartilage loss was better detected with MRI (κ = 0.643-0.552 for knees and ankles, and κ = 0.643-0.462 respectively). Ultrasound is useful in detecting joint bleeds, synovial hyperplasia and joint erosions, with results comparable to those of MRI. A quick and affordable technique, ultrasound imaging may be useful for monitoring joint bleeds and structure normalization and maintenance in routine practice.

  10. Surface Roughness of Initial Enamel Caries Lesions in Human Teeth After Resin Infiltration

    PubMed Central

    Arnold, Wolfgang H.; Meyer, Ann-Kathrin; Naumova, Ella A.

    2016-01-01

    Background: Low viscosity resin infiltration of initial caries lesions is a modern microinvasive method to treat initial cries lesions. However, only scarce information is available about the long-term surface alterations of infiltrated lesions. Methods: Twenty-eight premolar teeth exhibiting non-cavitated initial caries lesions (International Caries Detection and Assessment System (ICDAS code 1&2)) were divided into two groups, one of which was infiltrated with resin, and the other remained untreated. The teeth underwent two thermocycling procedures. The surface roughness was determined quantitatively, and the results were evaluated statistically. In addition, the surfaces of the lesions were investigated by scanning electron microscopy (SEM), and the surface was analyzed visually with respect to surface irregularities. Results: The results showed a reduction in the surface roughness that was significant after 2500 thermocycles compared to the untreated surface. In the control specimens, no change in the surface roughness was found. The qualitative SEM data also showed a smooth surface after thermocycling, which supported the statistical findings. Conclusion: After thermocycling, resin-infiltrated enamel surfaces become smoother and had no additional risk for plaque accumulation. PMID:27733877

  11. Multi-component joint analysis of surface waves

    NASA Astrophysics Data System (ADS)

    Dal Moro, Giancarlo; Moura, Rui Miguel Marques; Moustafa, Sayed S. R.

    2015-08-01

    Propagation of surface waves can occur with complex energy distribution amongst the various modes. It is shown that even simple VS (shear-wave velocity) profiles can generate velocity spectra that, because of a complex mode excitation, can be quite difficult to interpret in terms of modal dispersion curves. In some cases, Rayleigh waves show relevant differences depending on the considered component (radial or vertical) and the kind of source (vertical impact or explosive). Contrary to several simplistic assumptions often proposed, it is shown, both via synthetic and field datasets, that the fundamental mode of Rayleigh waves can be almost completely absent. This sort of evidence demonstrates the importance of a multi-component analysis capable of providing the necessary elements to properly interpret the data and adequately constrain the subsurface model. It is purposely shown, also through the sole use of horizontal geophones, how it can be possible to efficiently and quickly acquire both Love and Rayleigh (radial-component) waves. The presented field dataset reports a case where Rayleigh waves (both their vertical and radial components) appear largely dominated by higher modes with little or no evidence of the fundamental mode. The joint inversion of the radial and vertical components of Rayleigh waves jointly with Love waves is performed by adopting a multi-objective inversion scheme based on the computation of synthetic seismograms for the three considered components and the minimization of the whole velocity spectra misfits (Full Velocity Spectra - FVS - inversion). Such a FVS multi-component joint inversion can better handle complex velocity spectra thus providing a more robust subsurface model not affected by erroneous velocity spectra interpretations and non-uniqueness of the solution.

  12. Treatment of articular cartilage lesions of the knee joint using a modified AMIC technique.

    PubMed

    Pascarella, Antonio; Ciatti, Riccardo; Pascarella, Fabio; Latte, Carmine; Di Salvatore, Mariano Giuseppe; Liguori, Luciano; Iannella, Germano

    2010-04-01

    This study describes a modified AMIC technique consisting of perforations according to Pridie, rather than microfractures, and the covering of the focus of the lesion with a biological collagen patch enriched with bone marrow blood drawn through the knee itself. This technique allows advantages of both the Pridie technique and the in situ proliferation of mesenchymal cells beneath a biological collagen membrane, 'augmented', with bone marrow blood. The collagen membrane forms the roof of a 'biological chamber', and serves to protect and contains the stem cells as they differentiate into chondrocytes, which will form a healthy regenerative cartilage.

  13. Registration of knee joint surfaces for the in vivo study of joint injuries based on magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Cheng, Rita W. T.; Habib, Ayman F.; Frayne, Richard; Ronsky, Janet L.

    2006-03-01

    In-vivo quantitative assessments of joint conditions and health status can help to increase understanding of the pathology of osteoarthritis, a degenerative joint disease that affects a large population each year. Magnetic resonance imaging (MRI) provides a non-invasive and accurate means to assess and monitor joint properties, and has become widely used for diagnosis and biomechanics studies. Quantitative analyses and comparisons of MR datasets require accurate alignment of anatomical structures, thus image registration becomes a necessary procedure for these applications. This research focuses on developing a registration technique for MR knee joint surfaces to allow quantitative study of joint injuries and health status. It introduces a novel idea of translating techniques originally developed for geographic data in the field of photogrammetry and remote sensing to register 3D MR data. The proposed algorithm works with surfaces that are represented by randomly distributed points with no requirement of known correspondences. The algorithm performs matching locally by identifying corresponding surface elements, and solves for the transformation parameters relating the surfaces by minimizing normal distances between them. This technique was used in three applications to: 1) register temporal MR data to verify the feasibility of the algorithm to help monitor diseases, 2) quantify patellar movement with respect to the femur based on the transformation parameters, and 3) quantify changes in contact area locations between the patellar and femoral cartilage at different knee flexion angles. The results indicate accurate registration and the proposed algorithm can be applied for in-vivo study of joint injuries with MRI.

  14. Indian Hedgehog in Synovial Fluid Is a Novel Marker for Early Cartilage Lesions in Human Knee Joint

    PubMed Central

    Zhang, Congming; Wei, Xiaochun; Chen, Chongwei; Cao, Kun; Li, Yongping; Jiao, Qiang; Ding, Juan; Zhou, Jingming; Fleming, Braden C.; Chen, Qian; Shang, Xianwen; Wei, Lei

    2014-01-01

    To determine whether there is a correlation between the concentration of Indian hedgehog (Ihh) in synovial fluid (SF) and the severity of cartilage damage in the human knee joints, the knee cartilages from patients were classified using the Outer-bridge scoring system and graded using the Modified Mankin score. Expression of Ihh in cartilage and SF samples were analyzed with immunohistochemistry (IHC), western blot, and enzyme-linked immunosorbent assay (ELISA). Furthermore, we detected and compared Ihh protein levels in rat and mice cartilages between normal control and surgery-induced osteoarthritis (OA) group by IHC and fluorescence molecular tomography in vivo respectively. Ihh expression was increased 5.2-fold in OA cartilage, 3.1-fold in relative normal OA cartilage, and 1.71-fold in OA SF compared to normal control samples. The concentrations of Ihh in cartilage and SF samples was significantly increased in early-stage OA samples when compared to normal samples (r = 0.556; p < 0.001); however, there were no significant differences between normal samples and late-stage OA samples. Up-regulation of Ihh protein was also an early event in the surgery-induced OA models. Increased Ihh is associated with the severity of OA cartilage damage. Elevated Ihh content in human knee joint synovial fluid correlates with early cartilage lesions. PMID:24786088

  15. 3D surface roughness measurement for scaliness scoring of psoriasis lesions.

    PubMed

    Ahmad Fadzil, M Hani; Prakasa, Esa; Asirvadam, Vijanth Sagayan; Nugroho, Hermawan; Affandi, Azura Mohd; Hussein, Suraiya Hani

    2013-11-01

    Psoriasis is an incurable skin disorder affecting 2-3% of the world population. The scaliness of psoriasis is a key assessment parameter of the Psoriasis Area and Severity Index (PASI). Dermatologists typically use visual and tactile senses in PASI scaliness assessment. However, the assessment can be subjective resulting in inter- and intra-rater variability in the scores. This paper proposes an assessment method that incorporates 3D surface roughness with standard clustering techniques to objectively determine the PASI scaliness score for psoriasis lesions. A surface roughness algorithm using structured light projection has been applied to 1999 3D psoriasis lesion surfaces. The algorithm has been validated with an accuracy of 94.12%. Clustering algorithms were used to classify the surface roughness measured using the proposed assessment method for PASI scaliness scoring. The reliability of the developed PASI scaliness algorithm was high with kappa coefficients>0.84 (almost perfect agreement).

  16. Resultant knee joint moments for lateral movement tasks on sliding and non-sliding sport surfaces.

    PubMed

    Nigg, Benno M; Stefanyshyn, Darren J; Rozitis, Antra I; Mundermann, Annegret

    2009-03-01

    The aim of this study was to compare ankle and knee joint moments observed when playing on sport surfaces that slide slightly relative to the ground with the moments observed when playing on conventional sport surfaces. Three-dimensional resultant internal joint moments and kinematic characteristics of the lower extremity were quantified for 21 university basketball players when performing v-cut and side-shuffle tasks on three types of sliding surface (interlocking tiles) and on two types of conventional surface (maple wood and rolled vinyl). Translational and rotational friction between the five test surfaces and a test shoe were also quantified. The five sport surfaces moved horizontally between 0.2 and 1.6 mm during the landing phase of the two tasks. The medio-lateral ground reaction forces were lowest for the surfaces with the highest horizontal movement. Resultant ankle joint moments were lower and resultant knee moments were higher on the sliding surfaces than the conventional surfaces. Sport surfaces that allow a few millimetres of horizontal movement during ground contact may reduce joint loading at the ankle joint, but increase joint loading at the knee joint, when compared with conventional sport surfaces, and thus may influence the prevalence of knee injuries.

  17. The spatial organisation of joint surface chondrocytes: review of its potential roles in tissue functioning, disease and early, preclinical diagnosis of osteoarthritis.

    PubMed

    Aicher, Wilhelm K; Rolauffs, Bernd

    2014-04-01

    Chondrocytes display within the articular cartilage depth-dependent variations of their many properties that are comparable to the depth-dependent changes of the properties of the surrounding extracellular matrix. However, not much is known about the spatial organisation of the chondrocytes throughout the tissue. Recent studies revealed that human chondrocytes display distinct spatial patterns of organisation within the articular surface, and each joint surface is dominated in a typical way by one of four basic spatial patterns. The resulting complex spatial organisations correlate with the specific diarthrodial joint type, suggesting an association of the chondrocyte organisation within the joint surface with the occurring biomechanical forces. In response to focal osteoarthritis (OA), the superficial chondrocytes experience a destruction of their spatial organisation within the OA lesion, but they also undergo a defined remodelling process distant from the OA lesion in the remaining, intact cartilage surface. One of the biological insights that can be derived from this spatial remodelling process is that the chondrocytes are able to respond in a generalised and coordinated fashion to distant focal OA. The spatial characteristics of this process are tremendously different from the cellular aggregations typical for OA lesions, suggesting differences in the underlying mechanisms. Here we summarise the available information on the spatial organisation of chondrocytes and its potential roles in cartilage functioning. The spatial organisation could be used to diagnose early OA onset before manifest OA results in tissue destruction and clinical symptoms. With further development, this concept may become clinically suitable for the diagnosis of preclinical OA.

  18. Evaluation of the effects of different treatments for the elbow joint using joint proprioception and surface electromyography.

    PubMed

    Huang, Qiuchen; Wang, Kuei-Yuan; Yu, Lili; Zhou, Yue; Gu, Rui; Cui, Yao; Hu, Chunying; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2015-12-01

    [Purpose] The purpose of this study was to examine the immediate effects of strength training and neuromuscular joint facilitation (NJF) distal resistance training on muscle strength and proprioception. [Subjects] The subjects were 15 young healthy people (29.3±4.1 y, 166.8±7.1 cm, 62.4 ± 11.6 ky). [Methods] Two isometric contraction techniques were applied on the elbow joint: elbow joint flexion muscle strength training (MST) and the elbow joint flexion pattern of NJF. Muscle strength (measured by surface electromyography [sEMG]) and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in error in elbow flexion angle repetition represented the improvement resulting from NJF. sEMG of the biceps brachii showed significant increases in the maximum discharge and average discharge after the intervention. [Conclusion] This result suggests that elbow joint proprioception and muscle strength can be improved by NJF together with proximal resistance training.

  19. Community Shifts in the Surface Microbiomes of the Coral Porites astreoides with Unusual Lesions

    PubMed Central

    Meyer, Julie L.; Paul, Valerie J.; Teplitski, Max

    2014-01-01

    Apical lesions on Porites astreoides were characterized by the appearance of a thin yellow band, which was preceded by bleaching of the coral tissues and followed by a completely denuded coral skeleton, which often harbored secondary macroalgal colonizers. These characteristics have not been previously described in Porites and do not match common Caribbean coral diseases. The lesions were observed only in warmer months and at shallow depths on the fore reef in Belize. Analysis of the microbial community composition based on the V4 hypervariable region of 16S ribosomal RNA genes revealed that the surface microbiomes associated with nonsymptomatic corals were dominated by the members of the genus Endozoicomonas, consistent with other studies. Comparison of the microbiomes of nonsymptomatic and lesioned coral colonies sampled in July and September revealed two distinct groups, inconsistently related to the disease state of the coral, but showing some temporal signal. The loss of Endozoicomonas was characteristic of lesioned corals, which also harbored potential opportunistic pathogens such as Alternaria, Stenotrophomonas, and Achromobacter. The presence of lesions in P. astreoides coincided with a decrease in the relative abundance of Endozoicomonas, rather than the appearance of specific pathogenic taxa. PMID:24937478

  20. High Contrast Reflectance Imaging of Simulated Lesions on Tooth Occlusal Surfaces at Near-IR Wavelengths

    PubMed Central

    Fried, William A.; Fried, Daniel; Chan, Kenneth H.; Darling, Cynthia L.

    2015-01-01

    Introduction In vivo and in vitro studies have shown that high contrast images of tooth demineralization can be acquired in the near-infrared (near-IR) without the interference of stain. The purpose of this study is to compare the lesion contrast in reflectance at near-IR wavelengths coincident with high water absorption with those in the visible, the near-IR at 1,300 nm and with fluorescence measurements for early lesions in occlusal surfaces. Methods Twenty-four human molars were used in this in vitro study. Teeth were painted with an acid-resistant varnish, leaving a 4 × 4 mm window in the occlusal surface of each tooth exposed for demineralization. Artificial lesions were produced in the exposed windows after 1- and 2-day exposure to a demineralizing solution at pH 4.5. Lesions were imaged using near-IR reflectance at three wavelengths, 1,300, 1,460, and 1,600 nm using a high definition InGaAs camera. Visible light reflectance, and fluorescence with 405 nm excitation and detection at wavelengths greater than 500 nm were also used to acquire images for comparison. Crossed polarizers were used for reflectance measurements to reduce interference from specular reflectance. Results The contrast of both the 1- and 2-day lesions were significantly higher (P < 0.05) for near-IR reflectance imaging at 1,460 and 1,600 nm than it was for near-IR reflectance imaging at 1,300 nm, visible reflectance imaging, and fluorescence. Conclusion The markedly higher contrast at 1,460 and 1,600 nm wavelengths, coincident with higher water absorption, suggest that these wavelengths are better suited than 1,300 nm for imaging early/shallow demineralization on tooth surfaces. PMID:23857066

  1. Surface layer erosion of natural caries lesions with phosphoric and hydrochloric acid gels in preparation for resin infiltration.

    PubMed

    Meyer-Lueckel, H; Paris, S; Kielbassa, A M

    2007-01-01

    The infiltration of proximal enamel lesions with low-viscosity light curing resins could be a viable approach to stop lesion progression. However, penetration of sealant might be hampered by the comparatively highly mineralized surface layers of natural lesions. Therefore, the aim of this study was to compare the efficacy of three different etching gels in removing the surface layer in various etching times. Extracted human molars and premolars showing proximal white spot lesions were cut across the demineralized areas. Ninety-six lesions expected from visual examination to be confined to the outer enamel (C1) were selected. The cut surface and half of each lesion were varnished, thus serving as control. Subsequently, the lesions were etched with either phosphoric (37%) or hydrochloric (5 or 15%) acid gel for 30-120 s (n = 8/group). Specimens were examined using confocal microscopy and transversal microradiography. Surface layer reduction was significantly increased in lesions etched with 15% HCl gel for 90 and 120 s compared to those etched with H(3)PO(4) gel for 30-120 s (p < 0.05). No significant differences regarding the depths of erosion in the lesions compared to sound enamel could be observed (p > 0.05). An effective reduction in the surface layer of natural enamel caries can be achieved by etching with 15% hydrochloric acid gel for 90-120 s.

  2. [Systematization of the articular surfaces of the carpometacarpal joints (author's transl)].

    PubMed

    el Bacha, A; Maillot, C

    1977-01-01

    A study, done on 100 hands, of the systematization of the articular surfaces of the carpometacarpal joints, clearly delineates the variability of circumference, dimesions, and relief of the articular facets. An attempt to draw general conclusions from this morphological study, in terms of arthrokinetics, leads to an understanding of the nature of the joints and the movements that are performed at this site.

  3. A STUDY ON HIGH STRENGTH BOLTED JOINT WITH METAL-SPRAYED CONTACT SURFACES

    NASA Astrophysics Data System (ADS)

    Minami, Kuniaki; Saito, Masamichi; Yokoyama, Hideki; Sugimoto, Ichiro; Nojima, Takao; Masunaga, Toshihiko; Nagasaki, Eiji

    Slip coefficient of high-strength bolt friction joints is well known to depend on the condition of contact surfaces. The coefficient is determined as 0.4 in the Specifications for Highway Bridges and the Design Standards for Railway Structures and Commentary (Steel Structures) in Japan, in the condition of roughened contact surfaces with mill scale removed or painted contact surfaces with inorganic zinc rich paint. However, the slip coefficient with metal-sprayed surfaces is not clear. For the joints with metalsprayed surfaces, hot-dip galvanized bolts are applied and such bolts are tightened by turn-of-nut method. However, it is unclear how much axial force is induced into the bolts in the joints with metal-sprayed surfaces. In order to examine slip coefficient of the bolted joints with metal-sprayed contact surfaces slip tests of high strength bolted joints were carried out. On the basis of above examinations, the slip coefficient with metal-sprayed surfaces is proposed in this paper. To clarify the induced axial force of the bolts, bolt-tightening tests were carried out. Considering bolt diameter, bolt length, induced axial forces and their relaxation, nut rotation angles are proposed in relation to different bolt size.

  4. Surface Modifications for Improved Wear Performance in Artificial Joints: A Review

    NASA Astrophysics Data System (ADS)

    Sullivan, Stacey J. L.; Topoleski, L. D. Timmie

    2015-11-01

    Artificial joint replacement is one of the most successful treatments for arthritis. Excellent wear and corrosion resistance, together with high strength and fracture toughness, are fundamental requirements for implant materials. Wear and/or corrosion of the materials used in artificial joints may lead to implant failure. Therefore, hard and wear-resistant materials, like cobalt-chromium-molybdenum and ceramic, are currently used as bearing surfaces. However, even using such hard materials, wear and/or corrosion related failure of artificial joints remains a central concern. One primary goal in orthopedic biomaterials research is to create more wear-resistant surfaces. Different technologies have been used to create new surfaces, or to modify existing surfaces, to prevent wear. It is the intent of this overview first to provide a summary of materials currently used as bearing surfaces in artificial joints, their functions, and their contributions to device longevity. Then, we will discuss advancements in modifying those bearing surfaces to produce more wear-resistant artificial joints.

  5. Laser Surface Pre-treatment of Aluminium for Hybrid Joints with Glass Fibre Reinforced Thermoplastics

    NASA Astrophysics Data System (ADS)

    Heckert, André; Zaeh, Michael F.

    Lightweight construction is a major trend in the automotive industry. Theconnection of fibre reinforced plastics with aluminium is consequently seen as promising prospect. In this regard, thermal joining can be applied for bonding of such hybrid joints. But in order to create a load bearing metal plastic joint, the surface of the metal has to be pre-treated. Recent research has shown that with laser surface pre-treatment high joint strengths are obtained. Yet there are a variety of laser sources and manufacturable surface topographies with structure sizes ranging from macroscopic to nanoscopic profiles. Within this work,macroscopic, microscopic and nanoscopic laser processed structures are created on aluminium and consequently joined to glass fibre reinforced thermoplastics of different fibre length and fibre content. High shear tensile strengths of up to 42 N/mm2 were obtained depending on the allocated material and the surface pre-treatment.

  6. Acute spontaneous atraumatic bilateral anterior dislocation of the shoulder joint with Hill-Sachs lesions: first reported case and review of literature.

    PubMed

    Manoharan, Gopikanthan; Singh, Rohit; Ahmed, Bessam; Kathuria, Vinod

    2014-01-01

    The anatomy of the shoulder joint comprises a relatively large humeral head with a shallow glenoid cavity allowing a remarkable range of motion at the expense of inherent instability. Despite anterior shoulder dislocations being the most common type encountered, bilateral dislocations are rare and almost always posterior. The aetiology is usually direct or indirect trauma related to sports, seizures, electric shock or electroconvulsive therapy. We present the first reported case of atraumatic bilateral acute anterior shoulder dislocations with associated Hill-Sachs lesions in a young, fit and well patient with no comorbidities. MRI illustrated the Hill-Sachs lesions with superior labral tear from anterior to posterior, and confirmed the acute nature of the injury by demonstrating the bone marrow oedema. The patient was treated surgically with arthroscopic anterior stabilisation. At 6 months following surgery, the patient has a pain free full range of movement of both shoulders with no further dislocations and has returned to work.

  7. Acute spontaneous atraumatic bilateral anterior dislocation of the shoulder joint with Hill-Sachs lesions: first reported case and review of literature

    PubMed Central

    Manoharan, Gopikanthan; Singh, Rohit; Ahmed, Bessam; Kathuria, Vinod

    2014-01-01

    The anatomy of the shoulder joint comprises a relatively large humeral head with a shallow glenoid cavity allowing a remarkable range of motion at the expense of inherent instability. Despite anterior shoulder dislocations being the most common type encountered, bilateral dislocations are rare and almost always posterior. The aetiology is usually direct or indirect trauma related to sports, seizures, electric shock or electroconvulsive therapy. We present the first reported case of atraumatic bilateral acute anterior shoulder dislocations with associated Hill-Sachs lesions in a young, fit and well patient with no comorbidities. MRI illustrated the Hill-Sachs lesions with superior labral tear from anterior to posterior, and confirmed the acute nature of the injury by demonstrating the bone marrow oedema. The patient was treated surgically with arthroscopic anterior stabilisation. At 6 months following surgery, the patient has a pain free full range of movement of both shoulders with no further dislocations and has returned to work. PMID:24895390

  8. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-arresting path shall be plane to within a maximum deviation of one-half the maximum clearance specified in § 18.31(a)(6). All metal surfaces forming a flame-arresting path shall be finished during...

  9. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-arresting path shall be plane to within a maximum deviation of one-half the maximum clearance specified in § 18.31(a)(6). All metal surfaces forming a flame-arresting path shall be finished during...

  10. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-arresting path shall be plane to within a maximum deviation of one-half the maximum clearance specified in § 18.31(a)(6). All metal surfaces forming a flame-arresting path shall be finished during...

  11. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-arresting path shall be plane to within a maximum deviation of one-half the maximum clearance specified in § 18.31(a)(6). All metal surfaces forming a flame-arresting path shall be finished during...

  12. Modulation of joint moments and work in the goat hindlimb with locomotor speed and surface grade

    PubMed Central

    Arnold, Allison S.; Lee, David V.; Biewener, Andrew A.

    2013-01-01

    SUMMARY Goats and other quadrupeds must modulate the work output of their muscles to accommodate the changing mechanical demands associated with locomotion in their natural environments. This study examined which hindlimb joint moments goats use to generate and absorb mechanical energy on level and sloped surfaces over a range of locomotor speeds. Ground reaction forces and the three-dimensional locations of joint markers were recorded as goats walked, trotted and galloped over 0, +15 and −15 deg sloped surfaces. Net joint moments, powers and work were estimated at the goats' hip, knee, ankle and metatarsophalangeal joints throughout the stance phase via inverse dynamics calculations. Differences in locomotor speed on the level, inclined and declined surfaces were characterized and accounted for by fitting regression equations to the joint moment, power and work data plotted versus non-dimensionalized speed. During level locomotion, the net work generated by moments at each of the hindlimb joints was small (less than 0.1 J kg−1 body mass) and did not vary substantially with gait or locomotor speed. During uphill running, by contrast, mechanical energy was generated at the hip, knee and ankle, and the net work at each of these joints increased dramatically with speed (P<0.05). The greatest increases in positive joint work occurred at the hip and ankle. During downhill running, mechanical energy was decreased in two main ways: goats generated larger knee extension moments in the first half of stance, absorbing energy as the knee flexed, and goats generated smaller ankle extension moments in the second half of stance, delivering less energy. The goats' hip extension moment in mid-stance was also diminished, contributing to the decrease in energy. These analyses offer new insight into quadrupedal locomotion, clarifying how the moments generated by hindlimb muscles modulate mechanical energy at different locomotor speeds and grades, as needed to accommodate the

  13. Joint variability of global runoff and global sea surface temperatures

    USGS Publications Warehouse

    McCabe, G.J.; Wolock, D.M.

    2008-01-01

    Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the analysis period. The annual runoff time series data are combined with gridded annual sea surface temperature data, and the combined dataset is subjected to a principal components analysis (PCA) to identify the primary modes of variability. The first three components from the PCA explain 29% of the total variability in the combined runoff/SST dataset. The first component explains 15% of the total variance and primarily represents long-term trends in the data. The long-term trends in SSTs are evident as warming in all of the oceans. The associated long-term trends in runoff suggest increasing flows for parts of North America, South America, Eurasia, and Australia; decreasing runoff is most notable in western Africa. The second principal component explains 9% of the total variance and reflects variability of the El Ni??o-Southern Oscillation (ENSO) and its associated influence on global annual runoff patterns. The third component explains 5% of the total variance and indicates a response of global annual runoff to variability in North Aflantic SSTs. The association between runoff and North Atlantic SSTs may explain an apparent steplike change in runoff that occurred around 1970 for a number of continental regions.

  14. Novel Lesions of Bones and Joints Associated with Chikungunya Virus Infection in Two Mouse Models of Disease: New Insights into Disease Pathogenesis

    PubMed Central

    Goupil, Brad A.; McNulty, Margaret A.; Martin, Matthew J.; McCracken, Michael K.; Christofferson, Rebecca C.; Mores, Christopher N.

    2016-01-01

    Chikungunya virus is an arbovirus spread predominantly by Aedes aegypti and Ae. albopictus mosquitoes, and causes debilitating arthralgia and arthritis. While these are common manifestations during acute infection and it has been suggested they can recur in patients chronically, gaps in knowledge regarding the pathogenesis still exist. Two established mouse models were utilized (adult IRF 3/7 -/- -/- and wild-type C57BL/6J mice) to evaluate disease manifestations in bones and joints at various timepoints. Novel lesions in C57BL/6J mice consisted of periostitis (91%) and foci of cartilage of necrosis (50% of mice at 21 DPI). Additionally, at 21 DPI, 50% and 75% of mice exhibited periosteal bone proliferation affecting the metatarsal bones, apparent via histology and μCT, respectively. μCT analysis did not reveal any alterations in trabecular bone volume measurements in C57BL/6J mice. Novel lesions demonstrated in IRF 3/7 -/- -/- mice at 5 DPI included focal regions of cartilage necrosis (20%), periosteal necrosis (66%), and multifocal ischemic bone marrow necrosis (100%). Contralateral feet in 100% of mice of both strains had similar, though milder lesions. Additionally, comparison of control IRF 3/7 -/- -/- and wild-type C57BL/6J mice demonstrated differences in cortical bone. These experiments demonstrate novel manifestations of disease similar to those occurring in humans, adding insight into disease pathogenesis, and representing new potential targets for therapeutic interventions. Additionally, results demonstrate the utility of μCT in studies of bone and joint pathology and illustrate differences in bone dynamics between mouse strains. PMID:27182740

  15. Novel Lesions of Bones and Joints Associated with Chikungunya Virus Infection in Two Mouse Models of Disease: New Insights into Disease Pathogenesis.

    PubMed

    Goupil, Brad A; McNulty, Margaret A; Martin, Matthew J; McCracken, Michael K; Christofferson, Rebecca C; Mores, Christopher N

    2016-01-01

    Chikungunya virus is an arbovirus spread predominantly by Aedes aegypti and Ae. albopictus mosquitoes, and causes debilitating arthralgia and arthritis. While these are common manifestations during acute infection and it has been suggested they can recur in patients chronically, gaps in knowledge regarding the pathogenesis still exist. Two established mouse models were utilized (adult IRF 3/7 -/- -/- and wild-type C57BL/6J mice) to evaluate disease manifestations in bones and joints at various timepoints. Novel lesions in C57BL/6J mice consisted of periostitis (91%) and foci of cartilage of necrosis (50% of mice at 21 DPI). Additionally, at 21 DPI, 50% and 75% of mice exhibited periosteal bone proliferation affecting the metatarsal bones, apparent via histology and μCT, respectively. μCT analysis did not reveal any alterations in trabecular bone volume measurements in C57BL/6J mice. Novel lesions demonstrated in IRF 3/7 -/- -/- mice at 5 DPI included focal regions of cartilage necrosis (20%), periosteal necrosis (66%), and multifocal ischemic bone marrow necrosis (100%). Contralateral feet in 100% of mice of both strains had similar, though milder lesions. Additionally, comparison of control IRF 3/7 -/- -/- and wild-type C57BL/6J mice demonstrated differences in cortical bone. These experiments demonstrate novel manifestations of disease similar to those occurring in humans, adding insight into disease pathogenesis, and representing new potential targets for therapeutic interventions. Additionally, results demonstrate the utility of μCT in studies of bone and joint pathology and illustrate differences in bone dynamics between mouse strains.

  16. Development of High Temperature Dissimilar Joint Technology for Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Bowman, Cheryl L.; Gabb, Timothy P.

    2009-01-01

    NASA is developing fission surface power (FSP) system technology as a potential option for use on the surface of the moon or Mars. The goal is to design a robust system that takes full advantage of existing materials data bases. One of the key components of the power conversion system is the hot-side Heat Exchanger (HX). One possible design for this heat exchanger requires a joint of the dissimilar metals 316L stainless steel and Inconel 718, which must sustain extended operation at high temperatures. This study compares two joining techniques, brazing and diffusion bonding, in the context of forming the requisite stainless steel to superalloy joint. The microstructures produced by brazing and diffusion bonding, the effect of brazing cycle on the mechanical tensile properties of the alloys, and the strength of several brazed joints will be discussed.

  17. Influence of stains on lesion contrast in the pits and fissures of tooth occlusal surfaces from 800-1600-nm

    NASA Astrophysics Data System (ADS)

    Almaz, Elias C.; Simon, Jacob C.; Fried, Daniel; Darling, Cynthia L.

    2016-02-01

    For over one hundred years, x-rays have served as a cornerstone of dentistry. Dental radiographic imaging technologies have constantly improved, however, detecting occlusal lesions remains as one of the greatest challenges due to the low sensitivity of radiographs and the overlap of enamel. Once detected, occlusal lesions have penetrated far into the dentin, necessitating invasive restorative treatment. The adoption of near-infrared (NIR) systems in dentistry introduces the potential for early detection of occlusal lesions. Commercially available NIR systems for intra-oral applications currently operate near 800-nm; however, extrinsic stains may interfere with the detection of demineralization of the underlying enamel surface. Higher wavelengths such as 1300-nm render stains nearly transparent and enhances the contrast of sound enamel to demineralized enamel. This novel finding promotes minimally invasive dentistry and allows oral health professionals the ability to detect, image, track, and monitor early lesions without repeated exposure to ionizing radiation nor invasive treatment.

  18. Neural network committees for finger joint angle estimation from surface EMG signals

    PubMed Central

    Shrirao, Nikhil A; Reddy, Narender P; Kosuri, Durga R

    2009-01-01

    Background In virtual reality (VR) systems, the user's finger and hand positions are sensed and used to control the virtual environments. Direct biocontrol of VR environments using surface electromyography (SEMG) signals may be more synergistic and unconstraining to the user. The purpose of the present investigation was to develop a technique to predict the finger joint angle from the surface EMG measurements of the extensor muscle using neural network models. Methodology SEMG together with the actual joint angle measurements were obtained while the subject was performing flexion-extension rotation of the index finger at three speeds. Several neural networks were trained to predict the joint angle from the parameters extracted from the SEMG signals. The best networks were selected to form six committees. The neural network committees were evaluated using data from new subjects. Results There was hysteresis in the measured SMEG signals during the flexion-extension cycle. However, neural network committees were able to predict the joint angle with reasonable accuracy. RMS errors ranged from 0.085 ± 0.036 for fast speed finger-extension to 0.147 ± 0.026 for slow speed finger extension, and from 0.098 ± 0.023 for the fast speed finger flexion to 0.163 ± 0.054 for slow speed finger flexion. Conclusion Although hysteresis was observed in the measured SEMG signals, the committees of neural networks were able to predict the finger joint angle from SEMG signals. PMID:19154615

  19. The surface lamina of the articular cartilage of human zygapophyseal joints.

    PubMed

    Giles, L G

    1992-07-01

    Literature referring to the conflicting results of investigations into the possible existence and composition of the lamina splendens is reviewed. Two hundred micrometer thick histological sections from 80 human cadaveric lower lumbar zygapophyseal joint articular cartilages were examined by ordinary light and darkfield microscopy. The findings illustrate what appears to be an acellular surface lamina on the opposing cartilaginous surfaces. No speculation is made regarding the possible physiological significance of the lamina based on this anatomical study. PMID:1609968

  20. Evolution of Topographic Stress Perturbations Near the Surface of the Earth and Application to Sheeting Joints

    NASA Astrophysics Data System (ADS)

    Martel, S. J.

    2014-12-01

    Topography perturbs the near-surface stress fields caused by gravity and by regional horizontal stresses. Two-dimensional analytical solutions for elastic stresses in uniform, isotropic rock allow the effects of gravity and a uniform regional horizontal stress P to be distinguished beneath isolated bell-shaped ridges and valleys. The topographic stress perturbations vary depending on the shape of the topography. Gravity, by itself, causes surface-perpendicular and surface-parallel compressive stresses beneath the crest of a bell-shaped ridge. Regional compression contributes a surface-parallel compression atop broad gentle bell-shaped ridges with steepest slopes less than 45°, but a surface-parallel tension atop narrower ridges with steeper slopes. If P is an order of magnitude less compressive than rg|b|, where r is rock density, g is gravitational acceleration, and b is the topographic relief, then effects of gravity dominate effects of the regional compression near the topographic surface. Conversely, if P is an order of magnitude more compressive than rg|b|, then effects of regional compression dominate the effects of gravity, and tensile stresses can develop normal to the surface beneath gentle convex bell-shaped ridges and the convex portions of bell-shaped valleys. The latter conditions promote the widespread development of sheeting joints. The locations of topographic inflection points help define where sheeting joints can develop at a particular time. As erosion progresses and the shape of the topographic surface changes, sheeting joints can form in new areas and be left as relict structures in others. The distribution of sheeting joints thus reflects the dynamic response of geologic systems that evolve through time.

  1. Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of joints

    PubMed Central

    KUMAR, P.; OKA, M.; TOGUCHIDA, J.; KOBAYASHI, M.; UCHIDA, E.; NAKAMURA, T.; TANAKA, K.

    2001-01-01

    The uppermost superficial surface layer of articular cartilage, the ‘lamina splendens’ which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at −10 °C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 μm in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed. PMID:11554503

  2. Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of joints.

    PubMed

    Kumar, P; Oka, M; Toguchida, J; Kobayashi, M; Uchida, E; Nakamura, T; Tanaka, K

    2001-09-01

    The uppermost superficial surface layer of articular cartilage, the 'lamina splendens' which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at -10 degrees C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 microm in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed. PMID:11554503

  3. Characterization of Anisotropy of Joint Surface Roughness and Aperture by Variogram Approach Based on Digital Image Processing Technique

    NASA Astrophysics Data System (ADS)

    Chen, S. J.; Zhu, W. C.; Yu, Q. L.; Liu, X. G.

    2016-03-01

    The mechanical and hydraulic anisotropy of rock joints are strongly dependent on the surface roughness and aperture. To date, accurate quantification of the anisotropic characteristics of joint surfaces remains a key issue. For this purpose, the digital image processing (DIP) technique was used to retrieve the joint surface topography, and a variogram function was used to characterize the anisotropy of the joint surface roughness and estimate the joint aperture. A new index, SR V , related to both the sill and the range of the variogram is proposed to describe the anisotropy of the joint surface roughness, and a new aperture index, b, is derived to quantify the joint aperture. These newly proposed indexes, SR V and b, were validated by characterizing three artificial triangular joint surfaces, then the values of both SR V and b were calculated along 42 directions on an artificial joint surface. The range of SR V was between 0.058622 and 0.331283, while that of b was from 0.270433 to 0.397715 mm. The results show that the newly proposed indexes SR V and b are effective for quantifying the anisotropic roughness and aperture of joint surfaces, respectively. In addition, based on the hypothesis that there exists a smooth upper wall for the artificial joint, a relationship between the indexes SR V and b was obtained based on the data analysis. It indicates that the trends of the indexes SR V and b tend to coincide, although some of their individual values differ. In this respect, the hydraulic aperture of rock joints is related to not only surface roughness but also the distribution of asperities on the surface. In addition, this method can also be used to characterize the roughness of real rock joints when the joint surface is treated by dying with ink before taking digital photos. This study provides a new method for properly quantifying the directional variability of joint surface roughness and estimating the mechanical and hydraulic properties of rock joints based

  4. The joint use of the tangential electric field and surface Laplacian in EEG classification.

    PubMed

    Carvalhaes, C G; de Barros, J Acacio; Perreau-Guimaraes, M; Suppes, P

    2014-01-01

    We investigate the joint use of the tangential electric field (EF) and the surface Laplacian (SL) derivation as a method to improve the classification of EEG signals. We considered five classification tasks to test the validity of such approach. In all five tasks, the joint use of the components of the EF and the SL outperformed the scalar potential. The smallest effect occurred in the classification of a mental task, wherein the average classification rate was improved by 0.5 standard deviations. The largest effect was obtained in the classification of visual stimuli and corresponded to an improvement of 2.1 standard deviations.

  5. Serial removal of caries lesions from tooth occlusal surfaces using near-IR image-guided IR laser ablation

    PubMed Central

    Chan, Kenneth H.; Tom, Henry; Darling, Cynthia L.; Fried, Daniel

    2015-01-01

    Previous studies have established that caries lesions can be imaged with high contrast without the interference of stains at near-IR wavelengths greater than 1300-nm. It has been demonstrated that computer controlled laser scanning systems utilizing IR lasers operating at high pulse repetition rates can be used for serial imaging and selective removal of caries lesions. In this study, we report our progress towards the development of algorithms for generating rasterized ablation maps from near-IR reflectance images for the removal of natural lesions from tooth occlusal surfaces. An InGaAs camera and a filtered tungsten-halogen lamp producing near-IR light in the range of 1500–1700-nm were used to collect crosspolarization reflectance images of tooth occlusal surfaces. A CO2 laser operating at a wavelength of 9.3- μm with a pulse duration of 10–15-μs was used for image-guided ablation. PMID:25914499

  6. Serial removal of caries lesions from tooth occlusal surfaces using near-IR image-guided IR laser ablation

    NASA Astrophysics Data System (ADS)

    Chan, Kenneth H.; Tom, Henry; Darling, Cynthia L.; Fried, Daniel

    2015-02-01

    Previous studies have established that caries lesions can be imaged with high contrast without the interference of stains at near-IR wavelengths greater than 1300-nm. It has been demonstrated that computer controlled laser scanning systems utilizing IR lasers operating at high pulse repetition rates can be used for serial imaging and selective removal of caries lesions. In this study, we report our progress towards the development of algorithms for generating rasterized ablation maps from near-IR reflectance images for the removal of natural lesions from tooth occlusal surfaces. An InGaAs camera and a filtered tungsten-halogen lamp producing near-IR light in the range of 1500-1700-nm were used to collect crosspolarization reflectance images of tooth occlusal surfaces. A CO2 laser operating at a wavelength of 9.3- μm with a pulse duration of 10-15-μs was used for image-guided ablation.

  7. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    NASA Astrophysics Data System (ADS)

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-01

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm. The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs data sets indicate that the results of these types of joint inversions must be interpreted carefully.

  8. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    DOE PAGES

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks ofmore » both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.« less

  9. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    SciTech Connect

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.

  10. Joint inversion of high-frequency surface waves with fundamental and higher modes

    USGS Publications Warehouse

    Luo, Y.; Xia, J.; Liu, J.; Liu, Q.; Xu, S.

    2007-01-01

    Joint inversion of multimode surface waves for estimating the shear (S)-wave velocity has received much attention in recent years. In this paper, we first analyze sensitivity of phase velocities of multimodes of surface waves for a six-layer earth model, and then we invert surface-wave dispersion curves of the theoretical model and a real-world example. Sensitivity analysis shows that fundamental mode data are more sensitive to the S-wave velocities of shallow layers and are concentrated on a very narrow frequency band, while higher mode data are more sensitive to the parameters of relatively deeper layers and are distributed over a wider frequency band. These properties provide a foundation of using a multimode joint inversion to define S-wave velocities. Inversion results of both synthetic data and a real-world example demonstrate that joint inversion with the damped least-square method and the singular-value decomposition technique to invert high-frequency surface waves with fundamental and higher mode data simultaneously can effectively reduce the ambiguity and improve the accuracy of S-wave velocities. ?? 2007.

  11. Looking into the Near Surface with More Data and Multiple Joint Imaging Technologies

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2015-12-01

    While exploration geophysicists are making tremendous efforts to image the deep subsurface for hydrocarbon resources, the complex near surface structures often impose significant challenges. Unlike the subsurface, the near surface structures vary from region to region. Thus, it is difficult to develop any benchmark model that represents common issues worldwide. During past 20 years, near surface imaging technologies have been advanced from refraction traveltime analysis and inversion to waveform inversion. Immediate benefit is to resolve any complex velocity structure associated with low velocity hidden layers if such waveform inversion is properly handled. However, inverting seismic waveform often suffers from cycle-skipping due to poor starting model or missing of low frequency data. Jointly inverting traveltime, waveform envelope and waveform data seems stabilizing the solutions. With more data utilized for the near surface imaging, we are also able to infer anisotropic parameters, attenuation factors, density, and both Vp and Vs. Since the cross-gradient approach was introduced in 2005, the simultaneous inversion of multiple types of geophysical data has also been applied in the near surface imaging. That includes joint seismic, gravity and EM inversion for mapping seismic velocity, density, and resistivity into a near surface structure with consistent geology. I demonstrate the changes of the near surface structural images due to the progress of the imaging technology development and the transition to much more data included with five real data examples.

  12. Primary diffuse leptomeningeal gliomatosis: unusual MRI with non-enhancing nodular lesions on the cerebellar surface and spinal leptomeningeal enhancement

    PubMed Central

    Kastenbauer, S; Danek, A; Klein, W; Yousry, T; Bise, K; Reifenberger, G; Pfister, H

    2000-01-01

    A 28 year old man presented with a 1 month history of symptoms of intracranial hypertension. Examination showed bilateral papilloedema and meningeal signs. Magnetic resonance imaging showed nodular lesions on the cerebellar and pontine surface and thickening of the thoracic spinal leptomeninges. Throughout the course of the disease, contrast enhancement was detected in the spinal leptomeninges but not intracranially. Primary diffuse leptomeningeal gliomatosis (PDLG) was diagnosed by biopsy and later confirmed on necropsy. The present case is remarkable for the nodular superficial cerebellar lesions and the absence of intracranial contrast enhancement of the leptomeninges.

 PMID:10945815

  13. Diminishing friction of joint surfaces as initiating factor for destabilising permafrost rocks?

    NASA Astrophysics Data System (ADS)

    Funk, Daniel; Krautblatter, Michael

    2010-05-01

    Degrading alpine permafrost due to changing climate conditions causes instabilities in steep rock slopes. Due to a lack in process understanding, the hazard is still difficult to asses in terms of its timing, location, magnitude and frequency. Current research is focused on ice within joints which is considered to be the key-factor. Monitoring of permafrost-induced rock failure comprises monitoring of temperature and moisture in rock-joints. The effect of low temperatures on the strength of intact rock and its mechanical relevance for shear strength has not been considered yet. But this effect is signifcant since compressive and tensile strength is reduced by up to 50% and more when rock thaws (Mellor, 1973). We hypotheisze, that the thawing of permafrost in rocks reduces the shear strength of joints by facilitating the shearing/damaging of asperities due to the drop of the compressive/tensile strength of rock. We think, that decreasing surface friction, a neglected factor in stability analysis, is crucial for the onset of destabilisation of permafrost rocks. A potential rock slide within the permafrost zone in the Wetterstein Mountains (Zugspitze, Germany) is the basis for the data we use for the empirical joint model of Barton (1973) to estimate the peak shear strength of the shear plane. Parameters are the JRC (joint roughness coefficient), the JCS (joint compressive strength) and the residual friction angle (φr). The surface roughness is measured in the field with a profile gauge to create 2D-profiles of joint surfaces. Samples of rock were taken to the laboratory to measure compressive strength using a high-impact Schmidt-Hammer under air-dry, saturated and frozen conditions on weathered and unweathered surfaces. Plugs where cut out of the rock and sand blasted for shear tests under frozen and unfrozen conditions. Peak shear strength of frozen and unfrozen rocks will be calculated using Barton's model. First results show a mean decrease of compressive

  14. Joint Geophysical Imaging of the Utah Area Using Seismic Body Waves, Surface Waves and Gravity Data

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Maceira, M.; Toksoz, M. N.; Burlacu, R.; Yang, Y.

    2009-12-01

    We present a joint geophysical imaging method that makes use of seismic body wave arrival times, surface wave dispersion measurements, and gravity data to determine three-dimensional (3D) Vp and Vs models. An empirical relationship mapping densities to Vp and Vs for earth materials is used to link them together. The joint inversion method takes advantage of strengths of individual data sets and is able to better constrain the velocity models from shallower to greater depths. Combining three different data sets to jointly invert for the velocity structure is equivalent to a multiple-objective optimization problem. Because it is unlikely that the different “objectives” (data types) would be optimized by the same parameter choices, some trade-off between the objectives is needed. The optimum weighting scheme for different data types is based on relative uncertainties of individual observations and their sensitivities to model parameters. We will apply this joint inversion method to determine 3D Vp and Vs models of the Utah area. The seismic body wave arrival times are assembled from waveform data recorded by the University of Utah Seismograph Stations (UUSS) regional network for the past 7 years. The surface wave dispersion measurements are obtained from the ambient noise tomography study by the University of Colorado group using EarthScope/USArray stations. The gravity data for the Utah area is extracted from the North American Gravity Database managed by the University of Texas at El Paso. The preliminary study using the seismic body wave arrival times indicates strong low velocity anomalies in middle crust beneath some known geothermal sites in Utah. The joint inversion is expected to produce a reasonably well-constrained velocity structure of the Utah area, which is helpful for characterizing and exploring existing and potential geothermal reservoirs.

  15. Effect of Surface Preparation on CLAM/CLAM Hot Isostatic Pressing diffusion bonding joints

    NASA Astrophysics Data System (ADS)

    Li, C.; Huang, Q.; Zhang, P.

    2009-04-01

    Surface preparation is essential for the Hot Isostatic Pressing (HIP) diffusion bonding of RAFM steels. Hot Isostatic Pressing (HIP) diffusion bonding experiments on China Low Activation Martensitic (CLAM) steel was performed to study the effect of surface preparation. A few approaches such as hand lapping, dry-milling and grinding etc., were used to prepare the faying surfaces of the HIP joints. Different sealing techniques were used as well. The HIP parameters were 150 MPa/3 h/1150 °C. After post HIP heat treatment (PHHT), the tensile and Charpy impact tests were carried out. The results showed that hand lapping was not suitable to prepare the faying surfaces of HIP diffusion bonding specimens although the surface roughness by hand lapping was very low.

  16. Clinicopathologic Correlation of White, Non scrapable Oral Mucosal Surface Lesions: A Study of 100 Cases

    PubMed Central

    Raghunath, Vandana; Karpe, Tanveer; Akifuddin, Syed; Imran, Shahid; Dhurjati, Venkata Naga Nalini; Aleem, Mohammed Ahtesham; Khatoon, Farheen

    2016-01-01

    Introduction White, non scrapable lesions are commonly seen in the oral cavity. Based on their history and clinical appearance, most of these lesions can be easily diagnosed, but sometimes diagnosis may go wrong. In order to arrive to a confirmative diagnosis, histopathological assessment is needed in many cases, if not all. Aims 1) To find out the prevalence of clinically diagnosed oral white, non scrapable lesions. 2) To find out the prevalence of histopathologically diagnosed oral white, non scrapable lesions. 3) To correlate the clinical and histopathological diagnosis in the above lesions. Materials and Methods A total of 100 cases of oral white, non scrapable lesions were included in the study. Based on their history and clinical presentation, clinical provisional diagnosis was made. Then biopsy was done and confirmatory histopathological diagnosis was given and both were correlated. In order to correlate clinical and histopathological diagnosis Discrepancy Index (DI) was calculated for all the cases. Results Based on clinical diagnosis, there were 59 cases (59%) of leukoplakia, 29 cases (29%) of lichen planus and six cases (6%) of lichenoid reaction; whereas, based on histopathological diagnosis, there were 66 cases (66%) of leukoplakia epithelial hyperplasia and hyperkeratosis (leukoplakia) and 30 cases (30%) of lichen planus. Seventy eight clinically diagnosed cases (78%) correlated with the histopathological diagnosis and 22 cases (22%) did not correlate. The total discrepancy index was 22%. Conclusion A clinician needs to be aware of oral white, non scrapable lesions. Due to the overlapping of many clinical features in some of these lesions and also due to their malignant potential, a histopathological confirmative diagnosis is recommended. PMID:27042583

  17. Joint analysis of refractions with surface waves: An inverse solution to the refraction-traveltime problem

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Xia, J.; Steeples, D.; Park, C.B.

    2006-01-01

    We describe a possible solution to the inverse refraction-traveltime problem (IRTP) that reduces the range of possible solutions (nonuniqueness). This approach uses a reference model, derived from surface-wave shear-wave velocity estimates, as a constraint. The application of the joint analysis of refractions with surface waves (JARS) method provided a more realistic solution than the conventional refraction/tomography methods, which did not benefit from a reference model derived from real data. This confirmed our conclusion that the proposed method is an advancement in the IRTP analysis. The unique basic principles of the JARS method might be applicable to other inverse geophysical problems. ?? 2006 Society of Exploration Geophysicists.

  18. Design, fabrication and test of graphite/polyimide composite joints and attachments. [spacecraft control surfaces

    NASA Technical Reports Server (NTRS)

    Cushman, J. B.; Mccleskey, S. F.; Ward, S. H.

    1982-01-01

    The design, analysis, and testing performed to develop four types of graphite/polyimide (Gr/PI) bonded and bolted composite joints for lightly loaded control surfaces on advanced space transportation systems that operate at temperatures up to 561 K (550 F) are summarized. Material properties and small specimen tests were conducted to establish design data and to evaluate specific design details. Static discriminator tests were conducted on preliminary designs to verify structural adequacy. Scaled up specimens of the final joint designs, representative of production size requirements, were subjected to a series of static and fatigue tests to evaluate joint strength. Effects of environmental conditioning were determined by testing aged (125 hours at 589 K (600 F)) and thermal cycled (116 K to 589 K (-250 F to 600 F), 125 times) specimens. It is concluded Gr/PI joints can be designed and fabricated to carry the specified loads. Test results also indicate a possible resin loss or degradation of laminates after exposure to 589 K (600 F) for 125 hours.

  19. The surface discharge and breakdown characteristics of HTS DC cable and stop joint box

    NASA Astrophysics Data System (ADS)

    Kim, W. J.; Kim, H. J.; Cho, J. W.; Kim, S. H.

    2014-09-01

    A high temperature superconducting (HTS) DC cable system consists of a HTS cable and cable joint. The HTS DC cable should be electrically connected in joint boxes because of the unit length of HTS cable is limited to several-hundred meters. In particular, the stop joint box (SJB) must be developed for a compact cooling system. Polypropylene laminated paper (PPLP) and epoxy maybe used as insulating materials for HTS DC cable and SJB. To develop a HTS DC cable, it is necessary to develop the cryogenic insulation technology, materials and the joint methods. In this paper, we will mainly discuss on the DC and impulse characteristics of epoxy and PPLP in liquid nitrogen (LN2). The surface discharge characteristics of epoxy included fillers, PPLP and epoxy with PPLP composite (epoxy + PPLP) were measured under 0.4 MPa. Also, the PPLP-insulated mini-model cable was fabricated and then DC, impulse and DC polarity reversal breakdown strength of mini-model cable under 0.4 MPa were investigated.

  20. Joint sulcal detection on cortical surfaces with graphical models and boosted priors.

    PubMed

    Shi, Yonggang; Tu, Zhuowen; Reiss, Allan L; Dutton, Rebecca A; Lee, Agatha D; Galaburda, Albert M; Dinov, Ivo; Thompson, Paul M; Toga, Arthur W

    2009-03-01

    In this paper, we propose an automated approach for the joint detection of major sulci on cortical surfaces. By representing sulci as nodes in a graphical model, we incorporate Markovian relations between sulci and formulate their detection as a maximum a posteriori (MAP) estimation problem over the joint space of major sulci. To make the inference tractable, a sample space with a finite number of candidate curves is automatically generated at each node based on the Hamilton-Jacobi skeleton of sulcal regions. Using the AdaBoost algorithm, we learn both individual and pairwise shape priors of sulcal curves from training data, which are then used to define potential functions in the graphical model based on the connection between AdaBoost and logistic regression. Finally belief propagation is used to perform the MAP inference and select the joint detection results from the sample spaces of candidate curves. In our experiments, we quantitatively validate our algorithm with manually traced curves and demonstrate the automatically detected curves can capture the main body of sulci very accurately. A comparison with independently detected results is also conducted to illustrate the advantage of the joint detection approach. PMID:19244008

  1. Evaluation of near-surface stress distributions in dissimilar welded joint by scanning acoustic microscopy.

    PubMed

    Kwak, Dong Ryul; Yoshida, Sanichiro; Sasaki, Tomohiro; Todd, Judith A; Park, Ik Keun

    2016-04-01

    This paper presents the results from a set of experiments designed to ultrasonically measure the near surface stresses distributed within a dissimilar metal welded plate. A scanning acoustic microscope (SAM), with a tone-burst ultrasonic wave frequency of 200 MHz, was used for the measurement of near surface stresses in the dissimilar welded plate between 304 stainless steel and low carbon steel. For quantitative data acquisition such as leaky surface acoustic wave (leaky SAW) velocity measurement, a point focus acoustic lens of frequency 200 MHz was used and the leaky SAW velocities within the specimen were precisely measured. The distributions of the surface acoustic wave velocities change according to the near-surface stresses within the joint. A three dimensional (3D) finite element simulation was carried out to predict numerically the stress distributions and compare with the experimental results. The experiment and FE simulation results for the dissimilar welded plate showed good agreement. This research demonstrates that a combination of FE simulation and ultrasonic stress measurements using SAW velocity distributions appear promising for determining welding residual stresses in dissimilar material joints.

  2. Structural tests and development of a laminar flow control wing surface composite chordwise joint

    NASA Technical Reports Server (NTRS)

    Lineberger, L. B.

    1984-01-01

    The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. The Lockheed-Georgia Company accomplished under NAS1-16235 Laminar-Flow-Control (LFC) Wing Panel Structural Design and Development (WSSD); design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joint was demonstrated by fabricating and testing complex, concept selection specimens. The Lockheed-Georgia Company accomplishments, Development of LFC Wind Surface Composite Structures (WSCS), are documented. Tests were conducted on two CV2 panels to verify the static tension and fatigue strength of LFC wing surface chordwise joints.

  3. Embrittlement of surface mount solder joints by hot solder-dipped, gold-plated leads

    SciTech Connect

    Vianco, P.T.

    1993-07-01

    The detachment of beam-leaded transistors from several surface mount circuit boards following modest thermal cycling was examined. Microstructural analysis of the package leads and bonding pads from the failed units indicated that gold embrittlement was responsible for a loss of solder joint mechanical integrity that caused detachment of transistors from the circuit boards. An analysis of the hot dipping process used to remove gold from the leads prior to assembly demonstrated that the gold, although dissolved from the lead, remained in the nearby solder and was subsequently retained in the coating formed on the lead upon withdrawal from the bath. This scenario allowed gold to enter the circuit board solder joints. It was hypothesized, and later confirmed by experimental trials, that increasing the number of dips prevented gold from entering the solder coatings.

  4. Joint body and surface wave tomography applied to the Toba caldera complex (Indonesia)

    NASA Astrophysics Data System (ADS)

    Jaxybulatov, Kairly; Koulakov, Ivan; Shapiro, Nikolai

    2016-04-01

    We developed a new algorithm for a joint body and surface wave tomography. The algorithm is a modification of the existing LOTOS code (Koulakov, 2009) developed for local earthquake tomography. The input data for the new method are travel times of P and S waves and dispersion curves of Rayleigh and Love waves. The main idea is that the two data types have complementary sensitivities. The body-wave data have good resolution at depth, where we have enough crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution. The surface wave dispersion curves can be retrieved from the correlations of the ambient seismic noise and in this case the sampled path distribution does not depend on the earthquake sources. The contributions of the two data types to the inversion are controlled by the weighting of the respective equations. One of the clearest cases where such approach may be useful are volcanic systems in subduction zones with their complex magmatic feeding systems that have deep roots in the mantle and intermediate magma chambers in the crust. In these areas, the joint inversion of different types of data helps us to build a comprehensive understanding of the entire system. We apply our algorithm to data collected in the region surrounding the Toba caldera complex (north Sumatra, Indonesia) during two temporary seismic experiments (IRIS, PASSCAL, 1995, GFZ, LAKE TOBA, 2008). We invert 6644 P and 5240 S wave arrivals and ~500 group velocity dispersion curves of Rayleigh and Love waves. We present a series of synthetic tests and real data inversions which show that joint inversion approach gives more reliable results than the separate inversion of two data types. Koulakov, I., LOTOS code for local earthquake tomographic inversion. Benchmarks for testing tomographic algorithms, Bull. seism. Soc. Am., 99(1), 194-214, 2009, doi:10.1785/0120080013

  5. Prospective evaluation of skin surface electropotentials in Japanese patients with suspicious breast lesions.

    PubMed

    Fukuda, M; Shimizu, K; Okamoto, N; Arimura, T; Ohta, T; Yamaguchi, S; Faupel, M L

    1996-10-01

    The biofield breast examination (BBE) is a new, noninvasive and cost-effective method for diagnosing breast lesions currently undergoing multicenter evaluation in the USA and Europe. The test analyzes subtle differences in electrical potential caused by dysregulated epithelial proliferation. This report summarizes a prospective evaluation of BBE in a population of 101 patients with suspicious breast lesions scheduled either for open surgical biopsy or fine needle aspiration biopsy. Of the 101 patients included in the study, 49 were found to have a breast malignancy and 52 were found to have a benign breast lesion. BBE correctly identified 44 of 49 biopsy-proven cancers (sensitivity=90%) and correctly indicated no cancer in 31 of 52 biopsy-proven benign cases (specificity=60%). Sensitivity increased to 95% for cancers less than 2.5 cm in size. These results indicate that BBE may be an effective adjunctive test to help to resolve abnormalities discovered by physical examination or other screening methods.

  6. [Elevated gastric lesions].

    PubMed

    de Careaga, B; Villagómez, G; Pabón, J; Calderón, O; Elío, D; Pérez, J; Martínez, M; Patiño, F; Ponce, R; Lora, J

    1986-01-01

    Elevated gastric lesions, represent an important group among gastric pathology. To establish its incidence in our experience, we studied the endoscopic reports of two important hospitals in La Paz city: Instituto de Gastroenterología Boliviano Japonés and Hospital Obrero No. 1. In order to make a good endoscopic diagnosis among different elevated lesions we use some parameters like: location, shape, size, diameter, surface of the lesion and surrounding mucosa and characteristics of the falls. 10.472 endoscopic reports were reviewed, 497 elevated gastric lesions were found, 475 corresponded to mucosal lesions (352 benign lesions and 123 malignant lesions), 11 to submucosal and 11 extragastric lesions.

  7. Effect of Plasma Surface Finish on Wettability and Mechanical Properties of SAC305 Solder Joints

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung-Ho; Koike, Junichi; Yoon, Jeong-Won; Yoo, Sehoon

    2016-09-01

    The wetting behavior, interfacial reactions, and mechanical reliability of Sn-Ag-Cu solder on a plasma-coated printed circuit board (PCB) substrate were evaluated under multiple heat-treatments. Conventional organic solderability preservative (OSP) finished PCBs were used as a reference. The plasma process created a dense and highly cross-linked polymer coating on the Cu substrates. The plasma finished samples had higher wetting forces and shorter zero-cross times than those with OSP surface finish. The OSP sample was degraded after sequential multiple heat treatments and reflow processes, whereas the solderability of the plasma finished sample was retained after multiple heat treatments. After the soldering process, similar microstructures were observed at the interfaces of the two solder joints, where the development of intermetallic compounds was observed. From ball shear tests, it was found that the shear force for the plasma substrate was consistently higher than that for the OSP substrate. Deterioration of the OSP surface finish was observed after multiple heat treatments. Overall, the plasma surface finish was superior to the conventional OSP finish with respect to wettability and joint reliability, indicating that it is a suitable material for the fabrication of complex electronic devices.

  8. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    SciTech Connect

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-30

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying material requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  9. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    NASA Astrophysics Data System (ADS)

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-01

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying material requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  10. The surface geometry of inherited joint and fracture trace patterns resulting from active and passive deformation

    NASA Technical Reports Server (NTRS)

    Podwysocki, M. H.; Gold, D. P.

    1974-01-01

    Hypothetical models are considered for detecting subsurface structure from the fracture or joint pattern, which may be influenced by the structure and propagated to the surface. Various patterns of an initially orthogonal fracture grid are modeled according to active and passive deformation mechanisms. In the active periclinal structure with a vertical axis, fracture frequency increased both over the dome and basin, and remained constant with decreasing depth to the structure. For passive periclinal features such as a reef or sand body, fracture frequency is determined by the arc of curvature and showed a reduction over the reefmound and increased over the basin.

  11. Deterioration mechanisms of joint prosthesis materials. Several solutions by ion implantation surface treatments.

    PubMed

    Rieu, J; Pichat, A; Rabbe, L M; Chabrol, C; Robelet, M

    1990-07-01

    Materials for orthopaedic implants can fail for several combined reasons: corrosion, fatigue and wear for metals, wear and creep for polymers, fracture for ceramics. Some typical cases are analysed and it is demonstrated that ion implantation improves metals and polymers used for joint prosthesis. Implantations of nitrogen, oxygen and argon ions modify the structure of a 2-500 nm thick layer in the materials. The results of friction tests on the couple metal-polymer are correlated with the surface properties. PMID:2397260

  12. Near-IR imaging of interproximal lesions from occlusal surfaces and the influence of stains and plaque

    NASA Astrophysics Data System (ADS)

    Fried, Daniel; Bühler, Christopher M.; Ngaotheppitak, Patara; Darling, Cynthia L.

    2006-02-01

    Dental enamel manifests high transparency in the near-IR (NIR). Our previous work demonstrated that NIR light at 1310-nm is ideally suited for the transillumination of interproximal dental caries (dental decay in between teeth) and that it can also be used to image decay in the pits and fissures of the occlusal (biting) surfaces of posterior teeth where most new dental decay occurs. Early occlusal lesions cannot be detected by x-rays during the early stages of lesion development due to the overlapping topography of the crown of the tooth. Stains and non-calcified plaque are not visible in the NIR enabling better discrimination of demineralized areas. We also demonstrate that interproximal lesions can be imaged from the occlusal surface (from above). Moreover, multiple illumination and detector angles can be exploited for optimal contrast between caries and sound tissue. These measurements suggest that NIR imaging offers significant advantages over the conventional visual, tactile and radiographic caries detection methods and other optical caries detection and imaging techniques.

  13. Verification of the effect of surface preparation on Hot Isostatic Pressing diffusion bonding joints of CLAM steel

    NASA Astrophysics Data System (ADS)

    Zhao, Yanyun; Li, Chunjing; Huang, Bo; Liu, Shaojun; Huang, Qunying

    2014-12-01

    Hot Isostatic Pressing (HIP) diffusion bonding with CLAM steel is the primary candidate fabrication technique for the first wall (FW) of DFLL-TBM. Surface state is one of the key factors for the joints quality. The effect of surface state prepared with grinder and miller on HIP diffusion bonding joints of CLAM steel was investigated. HIP diffusion bonding was performed at 140 MPa and 1373 K within 3 h. The mechanical properties of the joints were investigated with instrumented Charpy V-notch impact tests and the microstructures of the joints were analyzed with scanning electron microscopy (SEM). The results showed that the milled samples with fine surface roughness were more suitable for CLAM steel HIP diffusion bonding.

  14. Effects of surface preparation on the long-term durability of adhesively bonded composite joints

    NASA Astrophysics Data System (ADS)

    Bardis, Jason Dante

    The long-term durability of adhesively bonded composite joints is critical to modern aircraft structures, which are increasingly adopting bonding as an alternative option to mechanical fastening. The effects of the surface preparation of the adherends are critical, affecting initial strength, long-term durability, fracture toughness, and failure modes of bonded joints. In this study, several potential factors are evaluated, with focus on the following: (1) Effects of possible chemical contamination from release fabrics, release films, and peel plies during adherend cure. (2) Chemical and mechanical effects of abrasion on the fracture toughness and failure mode. (3) Characterization of paste and film adhesives. There are several standard test methods used to evaluate specimen fracture, but the majority concentrate on bonded metals and interlaminar composite fracture. Testing concentrated on mode I tests; a custom double cantilever beam specimen was devised and utilized, and two forms of a wedge crack test (traveling and static) were also used. Additionally, single lap shear tests were run to contrast the mode I tests. Non-destructive testing included X-ray photography of crack fronts, energy dispersive spectroscopy and X-ray photoelectron spectroscopy surface chemistry analyses, and scanning electron microscope imaging of prepared surfaces. All mode I test methods tended to be in agreement in the ranking of different surface preparation methods. Test results revealed that release agents deposited on adherend surfaces during their cure cycle prevented proper adhesion. While mechanical abrasion did improve their fracture toughness and lower their contamination greatly, the test values did not reach the levels of samples that were not contaminated before bonding, and the interfacial modes of failure did not always change to desirable modes.

  15. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    SciTech Connect

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G; Joshi, C P; Falkson, C; Schreiner, L John

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  16. Crustal structure of North Dakota from joint inversion of surface wave dispersion and teleseismic P-wave reciever functions

    NASA Astrophysics Data System (ADS)

    Walsh, Braden Michael

    Studying and determining crustal structure of the Earth is important for understanding the interior of the Earth. Using methods like receiver functions and surface wave dispersion allows the determination of differences in structure and composition through the crust. Jointly inverting receiver functions and surface wave dispersion reduces the error and over-interpretation of the crustal structure estimation. Receiver functions and surface wave dispersion invert well together because receiver functions are very sensitive to velocity contrasts and vertical travel times, and surface wave dispersion is sensitive to average velocity and insensitive to sharp velocity contrasts. By jointly inverting receiver functions and surface wave dispersion, shear wave velocity profiles can be created to determine the properties of the crustal structure and velocity contrasts. With the use of IRIS Transportable Array stations data throughout the United States, this thesis takes a closer look at the crustal structure of North Dakota through the joint inversion of surface wave dispersion and teleseismic P-wave receiver functions. The receiver functions in North Dakota show shallow sediment effects that affect the joint inversion process. In western North Dakota the Williston basin and in eastern North Dakota the Red River Valley cause ringing effects in the receiver functions. The shallow sediments in North Dakota control and overpower the rest of the crustal signal in the receiver functions, and thus affect the ability of determining the crustal shear wave velocity structure of North Dakota through the joint inversion of receiver functions and surface wave dispersion, thus the use of background geology is necessary.

  17. Surface errors without semantic impairment in acquired dyslexia: a voxel-based lesion-symptom mapping study.

    PubMed

    Binder, Jeffrey R; Pillay, Sara B; Humphries, Colin J; Gross, William L; Graves, William W; Book, Diane S

    2016-05-01

    Patients with surface dyslexia have disproportionate difficulty pronouncing irregularly spelled words (e.g. pint), suggesting impaired use of lexical-semantic information to mediate phonological retrieval. Patients with this deficit also make characteristic 'regularization' errors, in which an irregularly spelled word is mispronounced by incorrect application of regular spelling-sound correspondences (e.g. reading plaid as 'played'), indicating over-reliance on sublexical grapheme-phoneme correspondences. We examined the neuroanatomical correlates of this specific error type in 45 patients with left hemisphere chronic stroke. Voxel-based lesion-symptom mapping showed a strong positive relationship between the rate of regularization errors and damage to the posterior half of the left middle temporal gyrus. Semantic deficits on tests of single-word comprehension were generally mild, and these deficits were not correlated with the rate of regularization errors. Furthermore, the deep occipital-temporal white matter locus associated with these mild semantic deficits was distinct from the lesion site associated with regularization errors. Thus, in contrast to patients with surface dyslexia and semantic impairment from anterior temporal lobe degeneration, surface errors in our patients were not related to a semantic deficit. We propose that these patients have an inability to link intact semantic representations with phonological representations. The data provide novel evidence for a post-semantic mechanism mediating the production of surface errors, and suggest that the posterior middle temporal gyrus may compute an intermediate representation linking semantics with phonology. PMID:26966139

  18. Surface errors without semantic impairment in acquired dyslexia: a voxel-based lesion-symptom mapping study.

    PubMed

    Binder, Jeffrey R; Pillay, Sara B; Humphries, Colin J; Gross, William L; Graves, William W; Book, Diane S

    2016-05-01

    Patients with surface dyslexia have disproportionate difficulty pronouncing irregularly spelled words (e.g. pint), suggesting impaired use of lexical-semantic information to mediate phonological retrieval. Patients with this deficit also make characteristic 'regularization' errors, in which an irregularly spelled word is mispronounced by incorrect application of regular spelling-sound correspondences (e.g. reading plaid as 'played'), indicating over-reliance on sublexical grapheme-phoneme correspondences. We examined the neuroanatomical correlates of this specific error type in 45 patients with left hemisphere chronic stroke. Voxel-based lesion-symptom mapping showed a strong positive relationship between the rate of regularization errors and damage to the posterior half of the left middle temporal gyrus. Semantic deficits on tests of single-word comprehension were generally mild, and these deficits were not correlated with the rate of regularization errors. Furthermore, the deep occipital-temporal white matter locus associated with these mild semantic deficits was distinct from the lesion site associated with regularization errors. Thus, in contrast to patients with surface dyslexia and semantic impairment from anterior temporal lobe degeneration, surface errors in our patients were not related to a semantic deficit. We propose that these patients have an inability to link intact semantic representations with phonological representations. The data provide novel evidence for a post-semantic mechanism mediating the production of surface errors, and suggest that the posterior middle temporal gyrus may compute an intermediate representation linking semantics with phonology.

  19. Cell-based approaches to joint surface repair: a research perspective

    PubMed Central

    Roelofs, A.J.; Rocke, J.P.J.; De Bari, C.

    2013-01-01

    Summary Repair of lesions of the articular cartilage lining the joints remains a major clinical challenge. Surgical interventions include osteochondral autograft transfer and microfracture. They can provide some relief of symptoms to patients, but generally fail to durably repair the cartilage. Autologous chondrocyte implantation has thus far shown the most promise for the durable repair of cartilage, with long-term follow-up studies indicating improved structural and functional outcomes. However, disadvantages of this technique include the need for additional surgery, availability of sufficient chondrocytes for implantation, and maintenance of their phenotype during culture-expansion. Mesenchymal stem cells offer an attractive alternative cell-source for cartilage repair, due to their ease of isolation and amenability to ex vivo expansion while retaining stem cell properties. Preclinical and clinical studies have demonstrated the potential of mesenchymal stem cells to promote articular cartilage repair, but have also highlighted several key challenges. Most notably, the quality and durability of the repair tissue, its resistance to endochondral ossification, and its effective integration with the surrounding host tissue. In addition, challenges exist related to the heterogeneity of mesenchymal stem cell preparations and their quality-control, as well as optimising the delivery method. Finally, as our knowledge of the cellular and molecular mechanisms underlying articular cartilage repair increases, promising studies are emerging employing bioactive scaffolds or therapeutics that elicit an effective tissue repair response through activation and mobilisation of endogenous stem and progenitor cells. PMID:23598176

  20. Ultrasonic detection technology based on joint robot on composite component with complex surface

    SciTech Connect

    Hao, Juan; Xu, Chunguang; Zhang, Lan

    2014-02-18

    Some components have complex surface, such as the airplane wing and the shell of a pressure vessel etc. The quality of these components determines the reliability and safety of related equipment. Ultrasonic nondestructive detection is one of the main methods used for testing material defects at present. In order to improve the testing precision, the acoustic axis of the ultrasonic transducer should be consistent with the normal direction of the measured points. When we use joint robots, automatic ultrasonic scan along the component surface normal direction can be realized by motion trajectory planning and coordinate transformation etc. In order to express the defects accurately and truly, the robot position and the signal of the ultrasonic transducer should be synchronized.

  1. Joint effects of illumination geometry and object shape in the perception of surface reflectance

    PubMed Central

    Olkkonen, Maria; Brainard, David H

    2011-01-01

    Surface properties provide useful information for identifying objects and interacting with them. Effective utilization of this information, however, requires that the perception of object surface properties be relatively constant across changes in illumination and changes in object shape. Such constancy has been studied separately for changes in these factors. Here we ask whether the separate study of the illumination and shape effects is sufficient, by testing whether joint effects of illumination and shape changes can be predicted from the individual effects in a straightforward manner. We found large interactions between illumination and object shape in their effects on perceived glossiness. In addition, analysis of luminance histogram statistics could not account for the interactions. PMID:23145259

  2. Lithological and Surface Geometry Joint Inversions Using Multi-Objective Global Optimization Methods

    NASA Astrophysics Data System (ADS)

    Lelièvre, Peter; Bijani, Rodrigo; Farquharson, Colin

    2016-04-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based minimum-structure geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy may be to consider two fundamentally different types of inversions: lithological and surface geometry inversions. A major advantage of these two inversion approaches is that joint inversion of multiple types of geophysical data is greatly simplified. In a lithological inversion, the subsurface is discretized into a mesh and each cell contains a particular rock type. A lithological model must be translated to a physical property model before geophysical data simulation. Each lithology may map to discrete property values or there may be some a priori probability density function associated with the mapping. Through this mapping, lithological inverse problems limit the parameter domain and consequently reduce the non-uniqueness from that presented by standard mesh-based inversions that allow physical property values on continuous ranges. Furthermore, joint inversion is greatly simplified because no additional mathematical coupling measure is required in the objective function to link multiple physical property models. In a surface geometry inversion, the model comprises wireframe surfaces representing contacts between rock units. This parameterization is then fully consistent with Earth models built by geologists, which in 3D typically comprise wireframe contact surfaces of tessellated triangles. As for the lithological case, the physical properties of the units lying between the contact

  3. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-01

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying materia1 requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  4. Adhesive-Bonded Composite Joint Analysis with Delaminated Surface Ply Using Strain-Energy Release Rate

    NASA Technical Reports Server (NTRS)

    Chadegani, Alireza; Yang, Chihdar; Smeltzer, Stanley S. III

    2012-01-01

    This paper presents an analytical model to determine the strain energy release rate due to an interlaminar crack of the surface ply in adhesively bonded composite joints subjected to axial tension. Single-lap shear-joint standard test specimen geometry with thick bondline is followed for model development. The field equations are formulated by using the first-order shear-deformation theory in laminated plates together with kinematics relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. The system of second-order differential equations is solved to using the symbolic computation tool Maple 9.52 to provide displacements fields. The equivalent forces at the tip of the prescribed interlaminar crack are obtained based on interlaminar stress distributions. The strain energy release rate of the crack is then determined by using the crack closure method. Finite element analyses using the J integral as well as the crack closure method are performed to verify the developed analytical model. It has been shown that the results using the analytical method correlate well with the results from the finite element analyses. An attempt is made to predict the failure loads of the joints based on limited test data from the literature. The effectiveness of the inclusion of bondline thickness is justified when compared with the results obtained from the previous model in which a thin bondline and uniform adhesive stresses through the bondline thickness are assumed.

  5. LIDAR-based outcrop characterisation - joint classification, surface and block size distribution

    NASA Astrophysics Data System (ADS)

    Tanner, David C.; Dietrich, Patrick; Krawczyk, Charlotte M.

    2013-04-01

    Outcrops, in the first instance, only offer at best a 2-2.5D view of the available geological information, such as joints and fractures. In order to study geodynamic processes, it is necessary to calculate true values of, for example, fracture densities and block dimensions. We show how LIDAR-generated point-cloud data of outcrops can be used to delineate such geological surfaces. Our methods do not require the point-set to be meshed; instead we work with the original point cloud, thus avoiding meshing errors. In a first step we decompose the point-cloud into tiny volumes; in each volume we calculate the best fitting plane. An expert can then decide which of the planes are important (in an interactive density pole diagram) and classify them. Actual block surfaces are identified by applying a clustering algorithm to the mini-planes. Subsequently, we calculate the size of these surfaces. Finally we estimate the block size distribution within the outcrop by projecting the block surfaces into the rock volume. To assess the reproducibility of our results we show to which extent they depend on various parameters, such as the resolution of the LIDAR scan and algorithm parameters. In theory the results can be calculated at the site of measurement to ensure the LIDAR scan resolution is sufficient and if necessary rerun the scan with different parameters. We demonstrate our methods with LIDAR data that we produced in a sandstone quarry in Germany. The part of the outcrop which we measured with the LIDAR was out-of-reach for measurements with a geological compass, but our results correlate well with compass measurements from a different outcrop in the same quarry. Three main surfaces could be delineated from the point cloud: the bedding, and two major joint types. The three fabrics are almost orthogonal. Our statistical results suggest that blocks with a volume of several hundred liters can be expected regularly within the quarry. The results can be directly used to

  6. Processing of surface EMG through pattern recognition techniques aimed at classifying shoulder joint movements.

    PubMed

    Rivela, Diletta; Scannella, Alessia; Pavan, Esteban E; Frigo, Carlo A; Belluco, Paolo; Gini, Giuseppina

    2015-01-01

    Artificial arms for shoulder disarticulation need a high number of degrees of freedom to be controlled. In order to control a prosthetic shoulder joint, an intention detection system based on surface electromyography (sEMG) pattern recognition methods was proposed and experimentally investigated. Signals from eight trunk muscles that are generally preserved after shoulder disarticulation were recorded from a group of eight normal subjects in nine shoulder positions. After data segmentation, four different features were extracted (sample entropy, cepstral coefficients of the 4th order, root mean square and waveform length) and classified by means of linear discriminant analysis. The classification accuracy was 92.1% and this performance reached 97.9% after reducing the positions considered to five classes. To reduce the computational cost, the two channels with the least discriminating information were neglected yielding to a classification accuracy diminished by just 4.08%. PMID:26736704

  7. Long-term hip simulator testing of the artificial hip joint bearing surface grafted with biocompatible phospholipid polymer.

    PubMed

    Moro, Toru; Takatori, Yoshio; Kyomoto, Masayuki; Ishihara, Kazuhiko; Hashimoto, Masami; Ito, Hideya; Tanaka, Takeyuki; Oshima, Hirofumi; Tanaka, Shigeyuki; Kawaguchi, Hiroshi

    2014-03-01

    To prevent periprosthetic osteolysis and subsequent aseptic loosening of artificial hip joints, we recently developed a novel acetabular highly cross-linked polyethylene (CLPE) liner with graft polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) on its surface. We investigated the wear resistance of the poly(MPC) (PMPC)-grafted CLPE liner during 20 million cycles in a hip joint simulator. We extended the simulator test of one liner to 70 million cycles to investigate the long-term durability of the grafting. Gravimetric, surface, and wear particle analyses revealed that PMPC grafting onto the CLPE liner surface markedly decreased the production of wear particles and showed that the effect of PMPC grafting was maintained through 70 million cycles. We believe that PMPC grafting can significantly improve the wear resistance of artificial hip joints. PMID:24249706

  8. Articular surface approximation in equivalent spatial parallel mechanism models of the human knee joint: an experiment-based assessment.

    PubMed

    Ottoboni, A; Parenti-Castelli, V; Sancisi, N; Belvedere, C; Leardini, A

    2010-01-01

    In-depth comprehension of human joint function requires complex mathematical models, which are particularly necessary in applications of prosthesis design and surgical planning. Kinematic models of the knee joint, based on one-degree-of-freedom equivalent mechanisms, have been proposed to replicate the passive relative motion between the femur and tibia, i.e., the joint motion in virtually unloaded conditions. In the mechanisms analysed in the present work, some fibres within the anterior and posterior cruciate and medial collateral ligaments were taken as isometric during passive motion, and articulating surfaces as rigid. The shapes of these surfaces were described with increasing anatomical accuracy, i.e. from planar to spherical and general geometry, which consequently led to models with increasing complexity. Quantitative comparison of the results obtained from three models, featuring an increasingly accurate approximation of the articulating surfaces, was performed by using experimental measurements of joint motion and anatomical structure geometries of four lower-limb specimens. Corresponding computer simulations of joint motion were obtained from the different models. The results revealed a good replication of the original experimental motion by all models, although the simulations also showed that a limit exists beyond which description of the knee passive motion does not benefit considerably from further approximation of the articular surfaces.

  9. The articular disc surface in different functional conditions of the human temporo-mandibular joint.

    PubMed

    Marchetti, C; Bernasconi, G; Reguzzoni, M; Farina, A

    1997-07-01

    The peripheral discal tissue and the surface covering layer have been studied in normal and in variously damaged human temporo-mandibular joint discs. In the normal disc the tissue consisted of dense bundles of fibers and rare fibrocytes. The surface of the disc was covered by a regular basophilic and electron-dense layer. These morphological characteristics persisted also in some pathological discs in which fibrous derangements had already occurred in the deep parts. In very deformed and damaged discs associated with serious functional anomalies, the superficial discal tissue consisted of rare fibers dispersed in a loose ground substance and of an increased number of cells. The superficial coating was formed by an irregular dense lamina and aggregates of various materials containing cellular debris, vesicles, filaments and amorphous components. These deposits are probably due to degeneration processes of discal tissue. This investigation suggests that the superficial discal tissue and the covering layer are together involved in maintaining the functional properties of the articular surfaces. Their structural modification in severe functional anomalies leads to failure in the maintenance of nonadherence conditions and to deterioration of the functional defect.

  10. Comparison of regression models for estimation of isometric wrist joint torques using surface electromyography

    PubMed Central

    2011-01-01

    Background Several regression models have been proposed for estimation of isometric joint torque using surface electromyography (SEMG) signals. Common issues related to torque estimation models are degradation of model accuracy with passage of time, electrode displacement, and alteration of limb posture. This work compares the performance of the most commonly used regression models under these circumstances, in order to assist researchers with identifying the most appropriate model for a specific biomedical application. Methods Eleven healthy volunteers participated in this study. A custom-built rig, equipped with a torque sensor, was used to measure isometric torque as each volunteer flexed and extended his wrist. SEMG signals from eight forearm muscles, in addition to wrist joint torque data were gathered during the experiment. Additional data were gathered one hour and twenty-four hours following the completion of the first data gathering session, for the purpose of evaluating the effects of passage of time and electrode displacement on accuracy of models. Acquired SEMG signals were filtered, rectified, normalized and then fed to models for training. Results It was shown that mean adjusted coefficient of determination (Ra2) values decrease between 20%-35% for different models after one hour while altering arm posture decreased mean Ra2 values between 64% to 74% for different models. Conclusions Model estimation accuracy drops significantly with passage of time, electrode displacement, and alteration of limb posture. Therefore model retraining is crucial for preserving estimation accuracy. Data resampling can significantly reduce model training time without losing estimation accuracy. Among the models compared, ordinary least squares linear regression model (OLS) was shown to have high isometric torque estimation accuracy combined with very short training times. PMID:21943179

  11. Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

    USGS Publications Warehouse

    Carlson, D.

    2010-01-01

    Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77??E and N37??E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8??, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  12. Joint spatiotemporal variability of global sea surface temperatures and global Palmer drought severity index values

    USGS Publications Warehouse

    Apipattanavis, S.; McCabe, G.J.; Rajagopalan, B.; Gangopadhyay, S.

    2009-01-01

    Dominant modes of individual and joint variability in global sea surface temperatures (SST) and global Palmer drought severity index (PDSI) values for the twentieth century are identified through a multivariate frequency domain singular value decomposition. This analysis indicates that a secular trend and variability related to the El Niño–Southern Oscillation (ENSO) are the dominant modes of variance shared among the global datasets. For the SST data the secular trend corresponds to a positive trend in Indian Ocean and South Atlantic SSTs, and a negative trend in North Pacific and North Atlantic SSTs. The ENSO reconstruction shows a strong signal in the tropical Pacific, North Pacific, and Indian Ocean regions. For the PDSI data, the secular trend reconstruction shows high amplitudes over central Africa including the Sahel, whereas the regions with strong ENSO amplitudes in PDSI are the southwestern and northwestern United States, South Africa, northeastern Brazil, central Africa, the Indian subcontinent, and Australia. An additional significant frequency, multidecadal variability, is identified for the Northern Hemisphere. This multidecadal frequency appears to be related to the Atlantic multidecadal oscillation (AMO). The multidecadal frequency is statistically significant in the Northern Hemisphere SST data, but is statistically nonsignificant in the PDSI data.

  13. Surface electromyographic assessment of patients with long lasting temporomandibular joint disorder pain.

    PubMed

    Tartaglia, Gianluca M; Lodetti, Gianluigi; Paiva, Guiovaldo; De Felicio, Claudia Maria; Sforza, Chiarella

    2011-08-01

    The normalized electromyographic characteristics of masticatory muscles in patients with temporomandibular joint disorders (TMD) and healthy controls were compared. Thirty TMD patients (15 men, 15 women, mean age 23 years) with long lasting pain (more than 6 months), and 20 control subjects matched for sex and age were examined. All patients had arthrogenous TMD according to the Research Diagnostic Criteria for TMD (RDC/TMD). Surface electromyography of masseter and temporal muscles was performed during maximum teeth clenching either on cotton rolls or in intercuspal position. Standardized EMG indices and the median power frequency were obtained, and compared between the two groups and sexes using ANOVAs. During clenching, the TMD patients had larger asymmetry in their temporalis muscles, larger temporalis activity relative to masseter, and reduced mean power frequencies than the control subjects (p<0.05, ANOVA). In both groups, the mean power frequencies of the temporalis muscles were larger than those of the masseter muscles (p<0.001). No sex related differences, and no sex × group interactions were found. In conclusion, young adult patients with long lasting TMD have an increased and more asymmetric standardized activity of their temporalis anterior muscle, and reduced mean power frequencies, relative to healthy controls.

  14. [Benign lymphoepithelial lesion of the salivary glands].

    PubMed

    Dusek, J; Cerný, L; Wiedermann, B

    1977-05-01

    A series of eight observations serves for demonstrating the clinico-pathological picture of the benign lymphoepithelial lesion of salivary glands. The glandular lesion was associated with joint symptoms, one of the female patients developed malignant lymphoma.

  15. 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.

  16. Clinical evaluation of demineralization and remineralization of intact root surface lesions in the clinic by a quantitative light-induced fluorescence system.

    PubMed

    Durmusoglu, Oykü; Tağtekin, Dilek Arslantunali; Yanikoğlu, Funda

    2012-03-01

    Detection of demineralization of root surface caries is an important issue since preventive approaches prolong tooth life. Quantitative light-induced fluorescence (QLF) has been shown to be useful for the laboratory assessment of demineralization of root surfaces. The aim of this study was to determine the demineralization and remineralization of root surface intact and cavitated caries lesions using a QLF system as a nondestructive in vivo method. Noncavitated and demineralized root surface lesions were detected and scored using the QLF system. Oral hygiene education was given and periodontal cleaning was completed before the remineralization treatment. After obtaining baseline QLF data, the patients were informed about the remineralization treatment. Fluoride varnish was applied to the carious lesions at the baseline visit, and the patients were then reviewed after 1, 2, 3 and 4 weeks, with QLF assessment and fluoride varnish application repeated at each review. Repeated-measures ANOVA (α = 0.05) showed significant differences between ΔQ values at each visit (p < 0.001); ΔQ showed marked decreases at all the cut-off values (15, 20, 25, 30). The changes in ΔQ were not affected by the cut-off value. The ΔQ values of QLF showed differences at all visits. The QLF system was able to detect early root surface caries lesions in vivo. Bifluoride 12 varnish improved mineral levels as shown by the QLF system. The treatment response to chemicals of intact noncavitated root surface carious lesions could be followed nondestructively in the clinic using QLF to quantify remineralization at recall visits. Teeth with root surface caries can be kept by controlling their remineralization.

  17. Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2005-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials (HazMats) or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) A void duplication of effort in actions required to reduce or eliminate HazMats through joint center cooperation and technology sharing. This project will identify, evaluate and approve alternative surface preparation technologies for use at NASA and Air Force Space Command (AFSPC) installations. Materials and processes will be evaluated with the goal of selecting those processes that will improve corrosion protection at critical systems, facilitate easier maintenance activity, extend maintenance cycles, eliminate flight hardware contamination and reduce the amount of hazardous waste generated. This Joint Test Protocol (JTP) contains the critical requirements and tests necessary to qualify alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel Applications. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of NASA and Air Force Space Command (AFSPC) participants. The Field Test Plan (FTP), entitled Joint Test Protocol for Validation of Alternative Low Emission Surface Preparation/Depainting Technologies for Structural Steel, prepared by ITB, defines the field evaluation and testing requirements for validating alternative surface preparation/depainting technologies and supplements the JTP.

  18. Joint Test Report for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2007-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the NASA Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) Avoid duplication of effort in actions required to reduce or eliminate hazardous materials through joint center cooperation and technology sharing. The objective of this project was to qualify candidate alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel applications at NASA facilities. This project compares the surface preparation/depainting performance of the proposed alternatives to existing surface preparation/depainting systems or standards. This Joint Test Report (JTR) contains the results of testing as per the outlines of the Joint Test Protocol (JTP), Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, and the Field Test Plan (FTP), Field Evaluations Test Plan for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, for critical requirements and tests necessary to qualify alternatives for coating removal systems. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of government and industry participants. This JTR documents the results of the testing as well as any test modifications made during the execution of the project. This JTR is made available as a reference for future pollution prevention endeavors by other NASA Centers, the Department of Defense and commercial users to minimize duplication of effort. The current coating removal processes

  19. Incidence of cartilaginous and ligamentous lesions of the radio-carpal and distal radio-ulnar joint in an elderly population.

    PubMed

    Fortems, Y; De Smet, L; Dauwe, D; Stoffelen, D; Deneffe, G; Fabry, G

    1994-10-01

    51 wrists of 30 embalmed cadavers have been used to perform an anatomical and radiological study relating cartilaginous and ligamentous lesions of the wrist with sex, age, ulnar variance (UV) and the state of the triangular fibrocartilage complex (TFCC) in an elderly population (mean 76.6 years). Two-thirds of all wrists (66%) showed cartilaginous lesions, mainly on the lunate (22, or 44%). The TFCC was perforated in 23 wrists (46%), and most were central degenerative perforations. Correlations were found between ulnar variance and TFCC thickness (P < 0.05) and ulnar variance and TFCC perforations (P < 0.05). A significant relation was observed between age and proximal row intercarpal ligamentous ruptures (P < 0.05) and between age and ulnar variance (P < 0.05). No statistical correlation was seen between ulnar variance and cartilaginous lesions on the lunate (P < 0.05) in this slightly ulnar negative population (mean-0.37 mm). PMID:7822912

  20. Uptake of fluoride by human surface enamel from ammonium bifluoride and consequent reduction in the penetration in vitro by caries-like lesions.

    PubMed

    Tyler, J E; Poole, D F

    1984-01-01

    In-vitro fluoride uptake by mid-coronal, premolar enamel surfaces from topically-applied solutions of NH4HF2 was determined using a multi-electrode system for fluoride and calcium analyses. In tooth surfaces dehydrated with 100 per cent ethanol before the topical application of 1 per cent aqueous NH4HF2, there was a 2-3-fold increase in fluoride concentration up to a depth of 50 microns and fluoride enhancement to a total depth of 100 microns into the enamel. Caries-like lesions were induced in vitro in both treated and untreated enamel by the use of acidified, 6 per cent hydroxymethyl-cellulose gel containing 0.04 per cent hydroxyapatite at pH 4.5. After 120 days exposure, the mean depth of lesion penetration in the controls was 149 (+/- 34) microns. No lesions occurred in half the treated specimens; in specimens with lesions, the mean depth of penetration was 19 (+/- 3) microns. Thus, NH4HF2 was a potent inhibitor of caries-like lesion formation in vitro.

  1. Surface substance loss of subsurface bovine enamel lesions after different steps of the resinous infiltration technique: a 3D topography analysis.

    PubMed

    Yang, Fan; Mueller, Jan; Kielbassa, Andrej M

    2012-07-01

    Surface substance loss of subsurface enamel lesions before (baseline/demineralization) and after each step of the infiltration technique was evaluated by means of a three-dimensional focus variation. Eighty enamel specimens were prepared and partially varnished (control). Non-varnished areas were demineralized (pH 4.95; 28 days), and etched with phosphoric acid gel (20%; 5 s). Specimens were randomly assigned to eight groups (n = 10), and were infiltrated using four resinous materials. In subgroups 1, polymerization and finishing with abrasive polishing strips followed. In subgroups 2, excess material was removed before polymerization (E1/E2-Excite, Vivadent; F1/F2-Fortify, Bisco; G1/G2-Glaze & Bond, DMG; I1/I2-Icon, DMG). Topometrical evaluation revealed a negligible substance loss of demineralized enamel. After etching, mean (±SD) differences of height decreased uniformly (-6.6 ± 2.0 μm; p = 0.089; ANOVA). For infiltrated lesions, DH of subgroups 1 was comparable to the etched lesions, with a significant increase (compared to etched lesions) in subgroups 2 (1.1 ± 0.1 μm; p < 0.001; t test). Within the limitations of this study, it is concluded that etching of initial subsurface lesions will result in significant surface substance loss; removal of excess material before light-curing should simplify the infiltration procedure, and this will avoid any abrasion resulting from polishing procedures. PMID:21678019

  2. Formation mechanisms and near-surface stress orientations derived from fractographic markings on exfoliation joints in the Alps

    NASA Astrophysics Data System (ADS)

    Ziegler, M.; Loew, S.; Bahat, D.

    2013-12-01

    Granitic bedrock of the upper Aar valley (Grimsel area, Swiss Alps) contains four distinct exfoliation joint generations, which formed during different stages of the Pleistocene and occur in an Alpine landscape between inner trough valley bottoms and high mountain crests. Exfoliation joints of this investigation likely formed during the Middle Pleistocene (0.7-0.4 Ma; batch 1) and Upper Pleistocene to Holocene (<0.1 Ma; batch 2), subparallel to distinct glacial valley (palaeo-)topography. Mapping revealed that exfoliation joints of these batches exhibit prominent fracture surface morphologies. The bulk of exfoliation joints of batches 1 and 2 show common, characteristic fractographic features: (1) noncircular, radial plumose structures, (2) arrest marks on parent fracture planes and fringe cracks, and (3) gradually-developing fringe zones of en échelon type (Figure 1). We interpret smooth transitions from plumose structures on the parent plane to en échelon fringe cracks, combined with non-systematic stepping senses of fringe cracks, as local stress field variations (vs. temporal variations) in the vicinity of pre-existing joints and faults. Multiple arrest marks reveal that exfoliation joints in the Grimsel area formed incrementally and, together with absence of hackle fringes, suggest stable fracture conditions. Furthermore, we put special emphasis on surveying the orientations of plumose structure axes. We assume that plumose structure axes formed parallel to the maximum principal (far-field) compressive stress (σ1). This enables us to infer near-surface stress orientations within Alpine slopes. We found a correlation between the orientations of plumose structure axes and slope aspects for batches 1 and 2. Primarily low pitch angles (<~30°) of plumose structure axes suggest persistently subhorizontal to slightly inclined σ1 orientations, i.e. the orientation of σ1 changes together with change in slope aspect. We attribute this surface-near variability of

  3. A simplified evaluation system of surface-related lung lesions of pigs for official meat inspection under industrial slaughter conditions in Germany

    PubMed Central

    2014-01-01

    Background European and national administrative legislation require objective evaluation systems for organ lesions at pig slaughter. These results can be used as basis for herd health improvement programs by farmers and their consulting veterinarians. Various studies have shown that the current evaluation and recording of lesions by authorized meat inspectors are not reliable and produce significant inter-rater disagreement especially for lung lesions in pigs. The objectives of this study were to increase the usability of official meat inspection data by a developed and validated scheme and to analyze potential improvements in the reliability of the proposed system under industrialized slaughter conditions. Results A simplified evaluation scheme for surface-related lung lesions was developed based on morphometric evaluations of unaffected lungs with quantitative relationships of each lobe to the whole lung (“Rule of Tens”). Furthermore, a theoretical as well as a hands-on training program for meat inspectors was developed and applied. Based on 5,183 lungs, the authors established a baseline of the inter-rater reliability of current routine assessments of lung lesions as documented by meat inspectors compared with the assessments of an independent veterinarian using the developed simplified evaluation scheme. Most frequent inter-rater disagreements greater than 75% were found for moderate pneumonia. Sources of the deviations most frequently included misinterpretations of technical artifacts, which were erroneously assessed by the meat inspectors as pneumonic lung lesions. Results of the post-training investigation based on 4,646 lungs showed a significantly improved reliability of lung lesion evaluation and the inter-rater agreement increased in all respects. Especially the disagreement of recording moderate cases of pneumonia decreased in total to 15% deviations from reference. Conclusions The presented simplified lung evaluation scheme showed its capability to

  4. Joint Inversion of Receiver Function, Surface Wave Dispersion and ZH Ratio for Crustal Structure Based on Tikhonov Regularization

    NASA Astrophysics Data System (ADS)

    Yao, H.; Zhang, P.

    2015-12-01

    We proposed a joint iterative inversion method using receiver function, surface wave dispersion and ZH ratio data to better resolve 1-D crustal shear and compressional wave speed structure simultaneously. We implement a three-stage inversion strategy, which can take advantages of each dataset due to their complementary sensitivities to crust structures, to obtain structure information step by step using iterative linearized inversion approaches based on Tikhonov regularization of model parameters. We firstly invert surface wave dispersion and ZH ratio data to get 1-D shear velocity model, then incorporate P-wave receiver function data to obtain a much finer shear velocity model considering its high sensitivity to discontinuities. For the first two steps, the compressional velocity and density parameters are obtained from the shear velocity model using some empirical relationship. Finally, three datasets are further used to jointly invert for the compressional velocity structure based on the obtained shear velocity model. Synthetic tests show the superiority of joint inversion against separate inversion using only one or two datasets. They also demonstrate that the three-stage inversion strategy can make better use of different datasets to implement inversion physically and resolve finer crustal structure with more accuracy.

  5. Joint inversion of Multi-frequency Electromagnetic Induction and Seismic Refraction Data For Improved Near Surface Characterization

    NASA Astrophysics Data System (ADS)

    Elwaseif, M.

    2015-12-01

    We present a joint inversion routine between multi-frequency Electromagnetic (EM) induction and seismic refraction data that is based on using both cross-gradients and disconnect constraints. The joint inverse problem was solved using an iterative nonlinear least-squares formulation. Following each iteration, the cross gradient constraint enforces structural similarities between the EM and seismic models, whereas the disconnect constraint enforces sharp boundaries between different strata within the EM model. The locations of boundaries within the EM model are assumed to be consistent with the locations of user-defined velocity contours in the seismic model. We tested our method on a challenging synthetic EM and seismic model scenario that contains water-bearing zones as well as positively and negatively correlated model parameter values. In addition, we applied our method to GEM-2 and seismic refraction field data sets acquired along a 28-m-long profile in Laramie (WY), and we precisely recorded the locations where ground surface resistivity and velocity likely changes along that line. Unlike the results of separate EM and seismic inversions and the results of joint inversion based only on a cross-gradient constraint, our method was able to detect the water-bearing zones. In addition, it better captured ground surface changes in the field data set.

  6. A specific mechanomodulatory role for p38 MAPK in embryonic joint articular surface cell MEK-ERK pathway regulation.

    PubMed

    Lewthwaite, Jo C; Bastow, Edward R; Lamb, Katherine J; Blenis, John; Wheeler-Jones, Caroline P D; Pitsillides, Andrew A

    2006-04-21

    Mechanisms regulating cell behavior and extracellular matrix composition in response to mechanical stimuli remain unresolved. Our previous studies have established that the MEK-ERK cascade plays a specific role in the mechano-dependent joint formation process by promoting the assembly of pericellular matrices reliant upon hyaluronan (HA) for their integrity. Here we demonstrate: (i) novel cross-talk between p38 MAPK and MEK-ERK signaling pathways that is specific for mechanical stimuli and (ii) a role for p38 MAPK in facilitating HA production by cells derived from the articular surface of embryonic chick tibiotarsal joints. We find that p38 MAPK blockade restricts pericellular assembly of HA-rich matrices and reduces basal as well as mechanical strain-induced release of HA. p38 MAPK blockers potentiated early strain-induced increases but restricted sustained increases in MEK/ERK phosphorylation at later times; c-Fos hyperphosphorylation at threonine 325 was found to parallel this p38 MAPK-mediated modulation of ERK activation. In contrast, p38 MAPK inhibitors had no detectable effect on the ERK activation induced by fibroblast growth factor 2 or pervanadate, a phosphatase inhibitor, and MEK inhibitors did not influence p38 MAPK phosphorylation, confirming both the specificity and unidirectionality of p38 MAPK-ERK cross-talk. Immunochemical and immunoblotting studies revealed constitutive p38 MAPK activation in cells at, or derived from, developing articular joint surfaces. Unlike the MEK-ERK pathway, however, p38 MAPK was not further stimulated by mechanical stimulation in vitro. Thus, p38 MAPK specifically facilitates ERK activation and downstream signaling in response to mechanical stimuli. These results suggest that constitutively active p38 MAPK serves an essential, permissive role in mechanically induced changes in ERK activation and in the accumulation of HA-rich extracellular matrices that serve a key role in joint development.

  7. Native Chondrocyte Viability during Cartilage Lesion Progression

    PubMed Central

    Ganguly, Kumkum; McRury, Ian D.; Goodwin, Peter M.; Morgan, Roy E.; Augé, Wayne K.

    2010-01-01

    Objective: Early surgical intervention for articular cartilage disease is desirable before full-thickness lesions develop. As early intervention treatments are designed, native chondrocyte viability at the treatment site before intervention becomes an important parameter to consider. The purpose of this study is to evaluate native chondrocyte viability in a series of specimens demonstrating the progression of articular cartilage lesions to determine if the chondrocyte viability profile changes during the evolution of articular cartilage disease to the level of surface fibrillation. Design: Osteochondral specimens demonstrating various degrees of articular cartilage damage were obtained from patients undergoing knee total joint replacement. Three groups were created within a patient harvest based on visual and tactile cues commonly encountered during surgical intervention: group 1, visually and tactilely intact surfaces; group 2, visually intact, tactilely soft surfaces; and group 3, surface fibrillation. Confocal laser microscopy was performed following live/dead cell viability staining. Results: Groups 1 to 3 demonstrated viable chondrocytes in all specimens, even within the fibrillated portions of articular cartilage, with little to no evidence of dead chondrocytes. Chondrocyte viability profile in articular cartilage does not appear to change as disease lesion progresses from normal to surface fibrillation. Conclusions: Fibrillated partial-thickness articular cartilage lesions are a good therapeutic target for early intervention. These lesions retain a high profile of viable chondrocytes and are readily diagnosed by visual and tactile cues during surgery. Early intervention should be based on matrix failure rather than on more aggressive procedures that further corrupt the matrix and contribute to chondrocyte necrosis of contiguous untargeted cartilage. PMID:26069561

  8. A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity.

    PubMed

    Shimamoto, Akira; Yamashita, Keitaro; Inoue, Hirofumi; Yang, Sung-Mo; Iwata, Masahiro; Ike, Natsuko

    2013-04-01

    Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α. The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: R Quota, which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.

  9. An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

    SciTech Connect

    Vianco, P.T.

    1998-10-15

    A overview has been presented on the topic of alternative surface finishes for package I/Os and circuit board features. Aspects of processability and solder joint reliability were described for the following coatings: baseline hot-dipped, plated, and plated-and-fused 100Sn and Sn-Pb coatings; Ni/Au; Pd, Ni/Pd, and Ni/Pd/Au finishes; and the recently marketed immersion Ag coatings. The Ni/Au coatings appear to provide the all-around best option in terms of solderability protection and wire bondability. Nickel/Pal ftishes offer a slightly reduced level of performance in these areas that is most likely due to variable Pd surface conditions. It is necessmy to minimize dissolved Au or Pd contents in the solder material to prevent solder joint embrittlement. Ancillary aspects that included thickness measurement techniques; the importance of finish compatibility with conformal coatings and conductive adhesives; and the need for alternative finishes for the processing of non-Pb bearing solders were discussed.

  10. Design and validation of surface-marker clusters for the quantification of joint rotations in general movements in early infancy.

    PubMed

    Berthouze, Luc; Mayston, Margaret

    2011-04-01

    Lack of complexity in general movements in early infancy is an important marker of potential motor disorders of neurological origin, such as cerebral palsy. Quantitative approaches to characterising this complexity are hampered by experimental difficulties in recording from infants in their first few months of life. The aim of this study was to design and validate bespoke surface-marker clusters to facilitate data acquisition and enable full quantification of joint rotations. The clusters were validated by recording the controlled movements of a soft-body dummy doll simultaneously with an optical (Qualisys) and inertial (XSens) motion capture system. The angles estimated from the optical system were compared with those measured by the inertial system. We demonstrate that the surface-marker based approach compares well with the use of an inertial system to obtain "direct" readings of the rotations whilst alleviating the issues associated with the use of an optical motion capture system. We briefly report use of this technique in 1-5 month old infants. By enabling full quantification of joint rotation, use of the custom made markers could pave the way for early diagnosis of movement disorders. PMID:21288525

  11. The distal radioulnar joint. Anatomic and functional considerations.

    PubMed

    Kauer, J M

    1992-02-01

    The distal radioulnar joint is functionally coupled with the proximal radioulnar joint, thus forming a mechanism for the longitudinal rotation of the hand. Distal radioulnar mobility is derived from the geometry of the joint, joint surfaces, and radioulnar connections. There is a structural and functional separation between the distal radioulnar and carpal joints, giving the possibility of pronation and supination in every position of the hand to the forearm. As for the stability of the joints involved, the ulnar articular disk plays an essential role. Being part of both distal radioulnar and carpal joints, the disk has very specific morphologic features that not only are individualized to the function of both joints but also stabilize the joints in their independent movements. Developmental data give the strong impression of an architectural scheme, of which the distal radioulnar joint is only a part. Traumatic lesions at the distal radioulnar joint and disturbances in normal distal radioulnar alignment have to be viewed, therefore, in a wider context. PMID:1735231

  12. Surface modifications of nylon/carbon fiber composite for improving joint adhesion

    SciTech Connect

    Wu, R.; Liao, S.L.; Tong, T.S.; Young, J.T.

    1996-12-31

    Various methods were used to modify the nylon/carbon fiber composite surfaces, including grit blasting, flame and plasma pretreatments. The surfaces of nylon composites after pretreatments were characterized by contact angle measurements, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). XPS results show that several functional groups were formed after plasma and flame pretreatments. The scanning electron microscope (SEM) photographs suggest that the blasting pretreatment increased the surface roughness of nylon composites. All these surface pretreatments dramatically increased the lap shear strength if proper operation conditions were used. The reasons for the increase of lap shear strength were explained.

  13. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks.

    PubMed

    Ghaly, Michael; Du, Yong; Links, Jonathan M; Frey, Eric C

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect's fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were computed

  14. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks.

    PubMed

    Ghaly, Michael; Du, Yong; Links, Jonathan M; Frey, Eric C

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect's fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were computed

  15. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks

    NASA Astrophysics Data System (ADS)

    Ghaly, Michael; Du, Yong; Links, Jonathan M.; Frey, Eric C.

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect’s fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were

  16. Improvement of the T-peel Strength of Polypropylene Adhesion Joints by Surface Photografting Pre-Treatment with Methyl Methacrylate

    NASA Astrophysics Data System (ADS)

    Balart, R.; Sánchez-Nácher, L.; Balart, J.; Fombuena, V.; España, J. M.

    2010-06-01

    Although polypropylene is one of the most used polymers at industrial level due to good balanced properties, it presents some restrictions in applications that require good adhesion properties as well as coating and painting. These restrictions are related to its non polar nature which leads to low wetting properties. So that, in most cases, it is necessary a previous surface pre-treatment in order to improve adhesion properties. These surface treatments could be physical or chemical. Among the wide variety of physical processes, plasma technologies are useful from both technical and environmental points of view. If we take into account economic considerations, chemical processes are interesting due to low cost equipment and procedures. In particular, we have used photografting of methyl methacrylate (MMA) monomer on polypropylene substrates with UV radiation and initiators. This process is useful to promote chemical modification of polypropylene surface by grafting MMA monomers into polypropylene polymer chains. Due to polarity of some groups in MMA monomers, it is possible to increase surface wettability thus promoting a remarkable increase in adhesion properties of polypropylene. In this work, changes in wettability of polypropylene surfaces in terms of the exposure time to UV radiation in presence of MMA monomers and initiators has been investigated. Furthermore, chemical changes have been characterized by FTIR analysis and mechanical performance of adhesion joints has been evaluated by T-peel tests.

  17. Validity and reproducibility of a laser fluorescence system for detecting the activity of white-spot lesions on free smooth surfaces in vivo.

    PubMed

    Pinelli, Camila; Campos Serra, Mônica; de Castro Monteiro Loffredo, Leonor

    2002-01-01

    The aim of the study was to determine the reproducibility and validity of DIAGNOdent in detecting active and arrested caries lesions on free smooth surfaces. Volunteers were selected from state schools of Piracicaba, São Paulo, Brazil. Overall, 220 lesions were clinically examined. Two specially trained ('calibrated') examiners performed both clinical and laser evaluations independently, and after a 1-week interval, the examinations were repeated. The intra-examiner agreement for the laser evaluation was substantial (kappa(ex1) = 0.79, kappa(ex2) = 0.71). There was almost perfect agreement between the two examiners for the clinical examination (kappa(ex1) = 0.95, kappa(ex2) = 0.85). The inter-examiner agreement showed substantial reproducibility (kappa = 0.77) for the laser examination and almost perfect agreement (kappa = 0.85) for the clinical evaluation. The validation criterion was the clinical examination of white spots, recorded as active or arrested. The sensitivity was 0.72 and the specificity was 0.73, which indicates that the DIAGNOdent was a good auxiliary method for detecting incipient caries lesions on free smooth surfaces. The utilization of both methods can improve the efficacy of caries diagnosis.

  18. Conformational Insights into the Lesion and Sequence Effects for Arylamine-Induced Translesion DNA Synthesis: 19F NMR, Surface Plasmon Resonance, and Primer Kinetic Studies

    PubMed Central

    2015-01-01

    Adduct-induced DNA damage can affect transcription efficiency and DNA replication and repair. We previously investigated the effects of the 3′-next flanking base (G*CT vs G*CA; G*, FABP, N-(2′-deoxyguanosin-8-yl)-4′-fluoro-4-aminobiphenyl; FAF, N-(2′-deoxyguanosin-8-yl)-7-fluoro-2-aminofluorene) on the conformation of arylamine-DNA lesions in relation to E. coli nucleotide excision repair (JainV., HiltonB., LinB., PatnaikS., LiangF., DarianE., ZouY., MackerellA. D.Jr., and ChoB. P. (2013) Nucleic Acids Res., 41, 869−88023180767). Here, we report the differential effects of the same pair of sequences on DNA replication in vitro by the polymerases exofree Klenow fragment (Kf-exo–) and Dpo4. We obtained dynamic 19F NMR spectra for two 19-mer modified templates during primer elongation: G*CA [d(5′-CTTACCATCG*CAACCATTC-3′)] and G*CT [d(5′-CTTACCATCG*CTACCATTC-3′)]. We found that lesion stacking is favored in the G*CT sequence compared to the G*CA counterpart. Surface plasmon resonance binding results showed consistently weaker affinities for the modified DNA with the binding strength in the order of FABP > FAF and G*CA > G*CT. Primer extension was stalled at (n) and near (n – 1 and n + 1) the lesion site, and the extent of blockage and the extension rates across the lesion were influenced by not only the DNA sequences but also the nature of the adduct’s chemical structure (FAF vs FABP) and the polymerase employed (Kf-exo– vs Dpo4). Steady-state kinetics analysis with Kf-exo– revealed the most dramatic sequence and lesion effects at the lesion (n) and postinsertion (n + 1) sites, respectively. Taken together, these results provide insights into the important role of lesion-induced conformational heterogeneity in modulating translesion DNA synthesis. PMID:24915610

  19. TU-C-12A-12: Differentiating Bone Lesions and Degenerative Joint Disease in NaF PET/CT Scans Using Machine Learning

    SciTech Connect

    Perk, T; Bradshaw, T; Muzahir, S; Jeraj, R; Meyer, E

    2014-06-15

    Purpose: [F-18]NaF PET can be used to image bone metastases; however, tracer uptake in degenerative joint disease (DJD) often appears similar to metastases. This study aims to develop and compare different machine learning algorithms to automatically identify regions of [F-18]NaF scans that correspond to DJD. Methods: 10 metastatic prostate cancer patients received whole body [F-18]NaF PET/CT scans prior to treatment. Image segmentation resulted in 852 ROIs, 69 of which were identified by a nuclear medicine physician as DJD. For all ROIs, various PET and CT textural features were computed. ROIs were divided into training and testing sets used to train eight different machine learning classifiers. Classifiers were evaluated based on receiver operating characteristics area under the curve (AUC), sensitivity, specificity, and positive predictive value (PPV). We also assessed the added value of including CT features in addition to PET features for training classifiers. Results: The training set consisted of 37 DJD ROIs with 475 non-DJD ROIs, and the testing set consisted of 32 DJD ROIs with 308 non-DJD ROIs. Of all classifiers, generalized linear models (GLM), decision forests (DF), and support vector machines (SVM) had the best performance. AUCs of GLM (0.929), DF (0.921), and SVM (0.889) were significantly higher than the other models (p<0.001). GLM and DF, overall, had the best sensitivity, specificity, and PPV, and gave a significantly better performance (p<0.01) than all other models. PET/CT GLM classifiers had higher AUC than just PET or just CT. GLMs built using PET/CT information had superior or comparable sensitivities, specificities and PPVs to just PET or just CT. Conclusion: Machine learning algorithms trained with PET/CT features were able to identify some cases of DJD. GLM outperformed the other classification algorithms. Using PET and CT information together was shown to be superior to using PET or CT features alone. Research supported by the Prostate

  20. Analyzing the effects of temperature on soot formation with a joint volume-surface-hydrogen model

    SciTech Connect

    Blanquart, G.; Pitsch, H.

    2009-08-15

    The intent of the current work is to present and further validate a new tri-variate model for the formation of soot particles, to apply this model in analyzing the effects of temperature on the formation and growth of soot, and to compare the findings with the present understanding derived from numerous experimental studies. In this novel model, a particle is represented as a fractal shaped aggregate and is described by three independent quantities: the volume, the surface area, and the number of hydrogenated sites (or active sites) on the surface. The introduction of this third variable allows for a better description of the surface reactivity at high temperatures. This approach is extended by a model for the total carbon-to-hydrogen (C/H) ratio of the particle. The model is validated first in high temperature premixed ethylene flames, premixed benzene flames, an acetylene counterflow diffusion flame, and toluene pyrolysis in shock-tubes. Then, the soot volume fraction is computed for a series of atmospheric laminar ethylene premixed flames with varying flame temperatures. The soot model is shown to reproduce the well known bell-shaped temperature dependence of soot volume fraction, which was found in many experiments. It is observed that nucleation is the largest contributor to soot volume fraction at low temperatures while growth by surface reactions is more important at higher temperatures. The surface reactivity and the volumetric carbon-to-hydrogen ratio (C/H) are also computed as a function of temperature. The surface reactivity is found to depend not only on the temperature but also on the particle size and the residence time in the flame. Finally, as observed experimentally, the C/H ratio is found to be essentially constant and close to unity for low temperature flames and increases with residence time in high temperature flames. (author)

  1. Asymptomatic rectal mucosal lesions and hepatitis B surface antigen at sites of sexual contact in homosexual men with persistent hepatitis B virus infection.

    PubMed

    Reiner, N E; Judson, F N; Bond, W W; Francis, D P; Petersen, N J

    1982-02-01

    To ascertain why active and passive oral-anal and genital anal intercourse correlate strongly with hepatitis B virus (HBV) infection in homosexual men, we studied 22 men with HBV infection for the presence of hepatitis B surface antigen (HBsAg) in gingival and anorectal mucosa, feces, and semen. Thirteen of 22 (59%) patients had asymptomatic rectal mucosal lesions consisting of punctate bleeding points. Seventy-seven percent of swabbed specimens from lesions, 62% from feces, 59% from rectal mucosa, and 50% from anal canal mucosa contained HBsAg. Sera diluted serially and tested for HBsAg by radioimmunoassay showed that men with serum titers of 105 or greater were more likely to have HBsAg in specimens from lesions (p = 0.034), feces (p = 0.032), and normal mucosa (p = 0.001) than men with titers under 10 5. Asymptomatic rectal bleeding is frequent in homosexual men with persistent HBV infection. Rectal mucosa, feces, and anal canal mucosa become contaminated with HBsAg, creating a setting for de facto parenteral transmission when there is contact with oral or urethral mucosa. PMID:7059064

  2. Mass spectrometry imaging of levofloxacin distribution in TB-infected pulmonary lesions by MALDI-MSI and continuous liquid microjunction surface sampling

    PubMed Central

    Prideaux, Brendan; ElNaggar, Mariam S.; Zimmerman, Matthew; Wiseman, Justin M.; Li, Xiaohua; Dartois, Véronique

    2015-01-01

    A multi-modal mass spectrometry imaging (MSI) and profiling approach has been applied to assess the partitioning of the anti-TB fluoroquinolone levofloxacin into pulmonary lesions. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) and a commercial liquid microjunction surface sampling technology (LMJ-SSP), or flowprobe, have been used to both spatially profile and image drug distributions in lung tissue sections from TB-infected rabbits following oral administration of a single human-equivalent dose. Levofloxacin levels were highest at 6 h post-dose in normal lung, cellular granuloma, and necrotic caseum compartments. The drug accumulated in the cellular granuloma regions with lower amounts partitioning into central caseous compartments. Flowprobe imaging at 630 μm (limited by the probe tip diameter) enabled visualization of drug distribution into lesion compartments, including limited differentiation of relative drug abundance in cellular versus caseous regions of the lesions. MALDI-MSI analysis at 75 μm provided more detailed drug distribution, which clearly accumulated in the cellular region immediately surrounding the central caseum core. Imaging and profiling data acquired by flowprobe and MALDI-MSI were validated by quantitative LC/MS/MS analysis of lung and granuloma homogenates taken from the same animals. The results of the investigation show flowprobe imaging and sampling as a rapid and sensitive alternative to MALDI-MSI for profiling drug distributions into tissues when spatial resolution of data below the threshold of the probe diameter is not required. PMID:26185484

  3. Spine and sacroiliac joints on magnetic resonance imaging in patients with early axial spondyloarthritis: prevalence of lesions and association with clinical and disease activity indices from the Italian group of the SPACE study.

    PubMed

    Lorenzin, M; Ortolan, A; Frallonardo, P; Vio, S; Lacognata, C; Oliviero, F; Punzi, L; Ramonda, R

    2016-01-01

    Our aim was to determine the prevalence of spine and sacroiliac joint (SIJ) lesions on magnetic resonance imaging (MRI) in patients with early axial spondyloarthritis (axSpA) and their correlation with disease activity indices. Sixty patients with low back pain (LBP) (≥3 months, ≤2 years, onset ≤45 years), attending the SpA-clinic of the Unità Operativa Complessa Reumatologia of Padova [SpondyloArthritis-Caught-Early (SPACE) study], were studied following a protocol including physical examination, questionnaires, laboratory tests, X-rays and spine and SIJ MRI. Positive spine and SIJ MRI and X-rays images were scored independently by 2 readers using the SPARCC method, modified Stoke ankylosing spondylitis spine score and New York criteria. The axial pain and localization of MRI-lesions were referred to 4 sites: cervical/thoracic/lumbar spine and SIJ. All patients were classified into three groups: patients with signs of radiographic sacroiliitis (r-axSpA), patients without signs of r-axSpA but with signs of sacroiliitis on MRI (nr-axSpA MRI SIJ+), patients without signs of sacroiliitis on MRI and X-rays (nr-axSpA MRI SIJ-). The median age at LBP onset was 29.05±8.38 years; 51.6% of patients showed bone marrow edema (BME) in spine-MRI and 56.7% of patients in SIJ-MRI. Signs of enthesitis were found in 55% of patients in the thoracic district. Of the 55% of patients with BME on spine-MRI, 15% presented presented a negative SIJMRI. There was a significant difference between these cohorts with regard to the prevalence of radiographic sacroiliitis, active sacroiliitis on MRI and SPARCC SIJ score. The site of pain correlated statistically with BME lesions in thoracic and buttock districts. Since positive spine-MRI images were observed in absence of sacroiliitis, we can hypothesize that this finding could have a diagnostic significance in axSpA suspected axSpA. PMID:27608795

  4. The reliability of surface electromyography to assess quadriceps fatigue during multi joint tasks in healthy and painful knees.

    PubMed

    Callaghan, Michael J; McCarthy, Christopher J; Oldham, Jacqueline A

    2009-02-01

    This study's aim was to determine the between days reliability of surface EMG recordings from the superficial quadriceps during a multi joint sub-maximal fatiguing protocol. Three subject groups (healthy n=29; patellofemoral pain syndrome n=74; knee osteoarthritis n=55) performed the task at 60 maximum voluntary isometric contraction on three separate days. Spectral and amplitude EMG parameters were recorded from vastus medialis oblique, vastus lateralis and rectus femoris and were analysed for between days reliability using intraclass correlation coefficient (ICC((2,1))), the standard errors of measure and smallest detectable differences. For frequency results, initial and final frequency values had 'good' or 'excellent' reliability in all groups for all muscles. ICCs for median frequency slopes for vastus medialis oblique, vastus lateralis, and rectus femoris respectively, in the osteoarthritis group were 0.04, 0.55, and 0.72; in the patellofemoral pain group were 0.41, 0.17, and 0.33; in the healthy group were 0.68, 0.64, and 0.31. The standard errors of measurement and smallest detectable differences for all groups and for all muscles were unacceptably high. For amplitude results, ICC root mean squared initial and final values were 'good' to 'excellent' for all groups and all muscles, albeit with high measurement error. The ICCs for root mean squared slopes in all tests were 'poor' with extremely high measurement error. The poor between days reliability and high measurement error suggests that surface EMG should not be adopted to assess fatigue during multi joint sub-maximal isometric quadriceps testing.

  5. The Interplay of Surface Mount Solder Joint Quality and Reliability of Low Volume SMAs

    NASA Technical Reports Server (NTRS)

    Ghaffarian, R.

    1997-01-01

    Spacecraft electronics including those used at the Jet Propulsion Laboratory (JPL), demand production of highly reliable assemblies. JPL has recently completed an extensive study, funded by NASA's code Q, of the interplay between manufacturing defects and reliability of ball grid array (BGA) and surface mount electronic components.

  6. Effects of isoflurane, fentanyl, or thiopental anesthesia on regional cerebral blood flow and brain surface PO2 in the presence of a focal lesion in rabbits.

    PubMed

    Murr, R; Schürer, L; Berger, S; Enzenbach, R; Peter, K; Baethmann, A

    1993-11-01

    These studies were conducted to determine the effect of anesthetic drugs on tissue perfusion and O2 supply in the brain with focal cerebral edema. Using an open cranium preparation, we studied the effects of isoflurane (I; 1 minimum alveolar anesthetic concentration), of fentanyl (F; 0.5-1 microgram.kg-1 x min-1), or of thiopental (T; 32.5 mg.kg-1 x h-1) on regional cerebral blood flow (rCBF) and regional brain tissue PO2 in albino rabbits (n = 6 per group) with a focal brain lesion (cold injury). The doses of anesthetics were sufficient to suppress nociception. rCBF (H2 clearance) and tissue PO2 (multiwire surface electrode) were studied adjacent to and distant from the lesion. Cerebral hyperemia developed immediately after trauma in all groups, although the flow increase did not attain statistical significance. rCBF was subsequently reduced by about 25% in the vicinity of the lesion. Distant from the trauma, a continuing hyperemia (+30%) was later observed in animals with isoflurane, whereas rCBF was decreased then by 10%-20% in animals with fentanyl, or was unchanged with thiopental. Brain tissue PO2 was increased with isoflurane in areas distant from the lesion, but decreased with fentanyl. However, with thiopental, the PO2 level had already been lowered before trauma with a subsequent tendency toward normalization. The heterogeneity of the tissue PO2 in fentanyl anesthesia, as well as the increased frequency of hypoxic PO2 values with thiopental, might have resulted from microcirculatory disturbances. Thus, although isoflurane seemed to facilitate hyperemia with an increased O2 supply to the brain, fentanyl tended to induce the opposite response. Although these properties suggest the potential to manipulate perfusion and O2 supply in cerebral ischemia or hyperemia after head injury, the effects of such measures on intracranial pressure, neurologic status, and outcome have yet to be proven.

  7. 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 ...

  8. Joint Inversion of Phase and Amplitude Data of Surface Waves for North American Upper Mantle

    NASA Astrophysics Data System (ADS)

    Hamada, K.; Yoshizawa, K.

    2015-12-01

    For the reconstruction of the laterally heterogeneous upper-mantle structure using surface waves, we generally use phase delay information of seismograms, which represents the average phase velocity perturbation along a ray path, while the amplitude information has been rarely used in the velocity mapping. Amplitude anomalies of surface waves contain a variety of information such as anelastic attenuation, elastic focusing/defocusing, geometrical spreading, and receiver effects. The effects of elastic focusing/defocusing are dependent on the second derivative of phase velocity across the ray path, and thus, are sensitive to shorter-wavelength structure than the conventional phase data. Therefore, suitably-corrected amplitude data of surface waves can be useful for improving the lateral resolution of phase velocity models. In this study, we collect a large-number of inter-station phase velocity and amplitude ratio data for fundamental-mode surface waves with a non-linear waveform fitting between two stations of USArray. The measured inter-station phase velocity and amplitude ratios are then inverted simultaneously for phase velocity maps and local amplification factor at receiver locations in North America. The synthetic experiments suggest that, while the phase velocity maps derived from phase data only reflect large-scale tectonic features, those from phase and amplitude data tend to exhibit better recovery of the strength of velocity perturbations, which emphasizes local-scale tectonic features with larger lateral velocity gradients; e.g., slow anomalies in Snake River Plain and Rio Grande Rift, where significant local amplification due to elastic focusing are observed. Also, the spatial distribution of receiver amplification factor shows a clear correlation with the velocity structure. Our results indicate that inter-station amplitude-ratio data can be of help in reconstructing shorter-wavelength structures of the upper mantle.

  9. A sequential data assimilation approach for the joint reconstruction of mantle convection and surface tectonics

    NASA Astrophysics Data System (ADS)

    Bocher, M.; Coltice, N.; Fournier, A.; Tackley, P. J.

    2016-01-01

    With the progress of mantle convection modelling over the last decade, it now becomes possible to solve for the dynamics of the interior flow and the surface tectonics to first order. We show here that tectonic data (like surface kinematics and seafloor age distribution) and mantle convection models with plate-like behaviour can in principle be combined to reconstruct mantle convection. We present a sequential data assimilation method, based on suboptimal schemes derived from the Kalman filter, where surface velocities and seafloor age maps are not used as boundary conditions for the flow, but as data to assimilate. Two stages (a forecast followed by an analysis) are repeated sequentially to take into account data observed at different times. Whenever observations are available, an analysis infers the most probable state of the mantle at this time, considering a prior guess (supplied by the forecast) and the new observations at hand, using the classical best linear unbiased estimate. Between two observation times, the evolution of the mantle is governed by the forward model of mantle convection. This method is applied to synthetic 2-D spherical annulus mantle cases to evaluate its efficiency. We compare the reference evolutions to the estimations obtained by data assimilation. Two parameters control the behaviour of the scheme: the time between two analyses, and the amplitude of noise in the synthetic observations. Our technique proves to be efficient in retrieving temperature field evolutions provided the time between two analyses is ≲10 Myr. If the amplitude of the a priori error on the observations is large (30 per cent), our method provides a better estimate of surface tectonics than the observations, taking advantage of the information within the physics of convection.

  10. Drop Reliability of Epoxy-contained Sn-58 wt.%Bi Solder Joint with ENIG and ENEPIG Surface Finish Under Temperature and Humidity Test

    NASA Astrophysics Data System (ADS)

    Myung, Woo-Ram; Kim, Yongil; Kim, Kyung-Yeol; Jung, Seung-Boo

    2016-07-01

    The influence of two kinds of surface finish, namely electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG), on the interfacial reactions and drop reliability of epoxy-enhanced Sn-58 wt.%Bi solder has been investigated after temperature-humidity storage tests. The chemical composition and morphology of intermetallic compounds (IMCs) were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electron probe microanalysis. Also, the mechanical reliability of solder joints was evaluated using board-level drop tests. The Sn-Bi epoxy solder/ENEPIG joint exhibited higher IMC growth rate than the Sn-Bi epoxy solder/ENIG joint. After 500 h at 85°C/85% RH storage condition, new IMCs were formed on the Ni3Sn4 layer in samples with both surface finishes. The results of board-level drop tests showed that the number of drops was higher for the ENIG than the ENEPIG surface finish. Solder joint fracture occurred along the interface between the solder and IMC layer for the ENIG surface finish. However, with the ENEPIG surface finish, the crack propagated between the IMCs.

  11. Heat-resistant organic molecular layer as a joint interface for metal reduction on plastics surfaces

    NASA Astrophysics Data System (ADS)

    Sang, Jing; Aisawa, Sumio; Hirahara, Hidetoshi; Kudo, Takahiro; Mori, Kunio

    2016-04-01

    Heat-resistant organic molecular layers have been fabricated by triazine-based silane coupling agent for metal reduction on plastic surfaces using adsorption method. These molecular layers were used as an interfacial layer between polyamide (PA6) and metal solution to reduce Ag+ ion to Ag0. The interfacial behaviors of triazine molecular layer at the interfaces between PA6 and Ag solution were investigated using quartz crystal microbalance (QCM). The kinetics of molecular adsorption on PA6 was investigated by using triazine-based silane coupling agent solutions at different pH and concentration. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and local nano thermal analysis were employed to characterize the surfaces and interfaces. The nano thermal analysis results show that molecular layers of triazine-based silane coupling agent greatly improved heat resistance of PA6 resin from 170 °C up to 230 °C. This research developed an in-depth insight for molecular behaviors of triazine-based silane coupling agent at the PA6 and Ag solution interfaces and should be of significant value for interfacial research between plastics and metal solution in plating industry.

  12. Simultaneous measurement of human joint force, surface electromyograms, and functional MRI-measured brain activation.

    PubMed

    Liu, J Z; Dai, T H; Elster, T H; Sahgal, V; Brown, R W; Yue, G H

    2000-08-15

    Functional magnetic resonance imaging (fMRI) has been increasingly used in studying human brain function given its non-invasive feature and good spatial resolution. However, difficulties in acquiring data from peripheral (e.g. information from muscle) during fMRI studies of motor function hinder interpretation of fMRI data and designing more sophisticated investigations. Here we describe a system that was designed to concurrently measure handgrip force, surface electromyograms (EMG) of finger flexor and extensor muscles, and fMRI of human brain. The system included a pressure transducer built in a hydraulic environment, a heavily shielded EMG recording element, and a visual feedback structure for online monitoring of force and/or EMG signal, by the subject positioned in the scanner during an fMRI experiment. System evaluation and subsequent fMRI motor function studies have indicated that by using this system, high quality force and EMG signals can be recorded without sacrificing the quality of the fMRI data. PMID:10967361

  13. The Crust and Upper Mantle Structure of Northeastern Iran from Joint Waveform Tomography Imaging of Body and Surface Waves

    NASA Astrophysics Data System (ADS)

    Baker, B.; Roecker, S. W.; Priestley, K. F.; Tatar, M.

    2012-12-01

    The deformation resulting from the Arabian-Eurasian collision at the longitude of Iran is concentrated in the Zagros, Alborz and Kopeh Dagh Mountains. The Zagros and Alborz Mountains have been the focus of a number of studies but little is known about the structure of NE Iran and the Kopeh Dagh. The Kopeh Dagh form a linear intracontinental fold-and-thrust belt trending NW-SE between the stable Turkmenistan platform and Central Iran, and mark the northern limit to deformation in NE Iran. To the south of the Kopeh Dagh lie a series of elongated mountain ranges: the Binalud, which is a structural and geological eastward continuation of the Alborz, the Siah Kuh near Sabzevar and the Kuh-e-Sorkh near Kashmar. Between August 2006 and February 2008 we operated 17 broadband seismographs along a profile from Sarakhs, near the northeastern political border of Iran with Turkmenistan, across the Kopeh Dagh Mountains, to Yazd in Central Iran. We apply a combination of the teleseismic body wave waveform tomography technique of Roecker et al (2010) with an extension of this technique to surface waves (Roecker et al, 2011) to analyze this data to determine the elastic wavespeed structure of this area. The joint inversion of these different types of waves affords similar types of advantages that are common to combined surface wave dispersion/receiver function inversions in compensating for intrinsic weaknesses in horizontal and vertical resolution capabilities. We compare results recovered from a several different inverse methods, starting with simple gradient techniques to the more sophisticated pseudo-Hessian or L-BFGS approach, and find that the latter are generally more robust. Modelling of receiver functions and surface wave dispersion prior to the analysis is shown to be an efficacious way to generate starting models for this analysis.

  14. Vascular Lesions.

    PubMed

    Jahnke, Marla N

    2016-08-01

    Vascular lesions in childhood are comprised of vascular tumors and vascular malformations. Vascular tumors encompass neoplasms of the vascular system, of which infantile hemangiomas (IHs) are the most common. Vascular malformations, on the other hand, consist of lesions due to anomalous development of the vascular system, including the capillary, venous, arterial, and lymphatic systems. Capillary malformations represent the most frequent type of vascular malformation. IHs and vascular malformations tend to follow relatively predictable growth patterns in that IHs grow then involute during early childhood, whereas vascular malformations tend to exhibit little change. Both vascular tumors and vascular malformations can demonstrate a wide range of severity and potential associated complications necessitating specialist intervention when appropriate. Evaluation and treatment of the most common types of vascular lesions are discussed in this article. [Pediatr Ann. 2016;45(8):e299-e305.]. PMID:27517358

  15. Seismic Tomography of the Continental United States from a Joint Inversion of Surface Waves and Body Waves

    NASA Astrophysics Data System (ADS)

    Golos, E. M.; Yao, H.; Zhang, H.; Fang, H.; Burdick, S.; Schaeffer, A. J.; Vernon, F.; Lebedev, S.; van der Hilst, R. D.

    2015-12-01

    We present a model of seismic velocity anomalies for the entire continental United States—coast to coast, surface to lower mantle—using a joint body wave-surface wave inversion. This technique (Zhang et al., 2014), performed on a global adaptively-spaced grid, exploits the good vertical resolution at shallow depths of surface wave data, and the sampling of the deep mantle by teleseismic body (P and S) waves. The resultant model has better resolution at all depths than either method alone, enabling evaluation of interactions between lithospheric and mantle processes. We utilize the depth-dependence of surface wave sensitivity kernels to express surface wave phase velocity data directly in terms of spatial velocity structure (Fang et al., 2015). The data used are Rayleigh wave phase velocities from earthquakes and ambient noise (Schaeffer and Lebedev, 2013; Ekström, 2014) and S phase travel times from USArray, measured at the Array National Facility (ANF). We include a suite of synthetic tests to verify the performance of the inversion and compare it to results from traditional tomographic methods. We also use P arrivals and the influence of Vp on Rayleigh wave propagation speed to generate a preliminary model of Vp variations, independent from but consistent with the Vs model. Our model corroborates the well-established pattern of slow anomalies in the western US, especially in the Basin and Range and Rio Grande Rift regions. New details emerge in the eastern US, thanks to increasing data from the region. A distinction is observed between widespread fast lithospheric anomalies, associated with stable cratonic material, and deeper fast features, associated with the remnants of the Farallon Plate. It has been proposed that these fragments, near the mantle transition zones, still affect mantle dynamics (Forte et al., 2007), so better resolution of these anomalies is an important advancement. In addition, slower velocities are observed beneath the Appalachians and

  16. Hemiarthroplasty of the shoulder joint using a custom-designed high-density nano-hydroxyapatite/polyamide prosthesis with a polyvinyl alcohol hydrogel humeral head surface in rabbits.

    PubMed

    Guo, Yongwen; Guo, Jun; Bai, Ding; Wang, Hang; Zheng, Xiaohui; Guo, Weihua; Tian, Weidong

    2014-07-01

    In this study, a novel custom-designed high-density nano-hydroxyapatite/polyamide (n-HA/PA) prosthesis with a polyvinyl alcohol (PVA) hydrogel humeral head surface was employed to repair the shoulder joint head for hemiarthroplasty in rabbits. The prosthesis was fabricated using three-dimensional computed tomography and computer-aided design and computer-aided manufacturing systems for perfect fitting. Sixteen New Zealand white rabbits underwent humeral head excision, and received the composite prostheses for hemiarthroplasty. The implant sites were free from suppuration and necrosis at all periods. The X-ray results showed that there was a clear space between the prosthesis head and the glenoid surface, and the joint capsules and surfaces of the glenoid and PVA were well preserved without any damage during the whole inspection period. A high density of bone was observed around the firmware part of the prosthesis. Histological results revealed that significant osteogenesis was surrounding the firmware part, and the joint space was clear and the cartilage of the upper joint surface was basically intact. There was no visible absorption of the joint surfaces even after 3 months of continuous functional motions. The maximum tensile strength between the prosthesis and host bone reached 2.63 MPa at the 12th week postimplantation. In conclusion, the customized prosthesis by combination of PVA and high-density n-HA/PA has excellent biocompatibility and biological fixation, and offers a promising substitute for both the cartilage and the bone of the humeral head in a rabbit model as level V evidence.

  17. Hemiarthroplasty of the shoulder joint using a custom-designed high-density nano-hydroxyapatite/polyamide prosthesis with a polyvinyl alcohol hydrogel humeral head surface in rabbits.

    PubMed

    Guo, Yongwen; Guo, Jun; Bai, Ding; Wang, Hang; Zheng, Xiaohui; Guo, Weihua; Tian, Weidong

    2014-07-01

    In this study, a novel custom-designed high-density nano-hydroxyapatite/polyamide (n-HA/PA) prosthesis with a polyvinyl alcohol (PVA) hydrogel humeral head surface was employed to repair the shoulder joint head for hemiarthroplasty in rabbits. The prosthesis was fabricated using three-dimensional computed tomography and computer-aided design and computer-aided manufacturing systems for perfect fitting. Sixteen New Zealand white rabbits underwent humeral head excision, and received the composite prostheses for hemiarthroplasty. The implant sites were free from suppuration and necrosis at all periods. The X-ray results showed that there was a clear space between the prosthesis head and the glenoid surface, and the joint capsules and surfaces of the glenoid and PVA were well preserved without any damage during the whole inspection period. A high density of bone was observed around the firmware part of the prosthesis. Histological results revealed that significant osteogenesis was surrounding the firmware part, and the joint space was clear and the cartilage of the upper joint surface was basically intact. There was no visible absorption of the joint surfaces even after 3 months of continuous functional motions. The maximum tensile strength between the prosthesis and host bone reached 2.63 MPa at the 12th week postimplantation. In conclusion, the customized prosthesis by combination of PVA and high-density n-HA/PA has excellent biocompatibility and biological fixation, and offers a promising substitute for both the cartilage and the bone of the humeral head in a rabbit model as level V evidence. PMID:24404998

  18. Quantitative elastography of skin and skin lesion using phase-sensitive OCT (PhS-OCT) and surface wave method

    NASA Astrophysics Data System (ADS)

    Li, Chunhui; Guan, Guangying; Huang, Zhihong; Wang, Ruikang

    2012-01-01

    This paper presents the combination of phase sensitive optical coherence tomography (PhS-OCT) imaging system and surface wave method to achieve quantitative evaluation and elastography of the mechanical properties of in vivo human skin. PhS-OCT measures the surface acoustic waves (SAWs) generated by impulse stimulation from a home-made shaker, and provide the B-frame images for the sample. The surface wave phase velocity dispersion curves were calculated, from which the elasticity of different skin layers were determined. The combination of phase velocities from adjacent two locations generates a quantitative elastography of sample. The experimental results agree well with theoretical expectations and may offer potential use in clinical situations.

  19. Diamond-like carbon coatings enhance the hardness and resilience of bearing surfaces for use in joint arthroplasty.

    PubMed

    Roy, M E; Whiteside, L A; Xu, J; Katerberg, B J

    2010-04-01

    The purpose of this study was to evaluate the potential of a hard diamond-like carbon (DLC) coating to enhance the hardness and resilience of a bearing surface in joint replacement. The greater hardness of a magnesium-stabilized zirconium (Mg-PSZ) substrate was expected to provide a harder coating-substrate composite microhardness than the cobalt-chromium alloy (CoCr) also used in arthroplasty. Three femoral heads of each type (CoCr, Mg-PSZ, DLC-CoCr and DLC-Mg-PSZ) were examined. Baseline (non-coated) and composite coating/substrate hardness was measured by Vickers microhardness tests, while nanoindentation tests measured the hardness and elastic modulus of the DLC coating independent of the Mg-PSZ and CoCr substrates. Non-coated Mg-PSZ heads were considerably harder than non-coated CoCr heads, while DLC coating greatly increased the microhardness of the CoCr and Mg-PSZ substrates. On the nanoscale the non-coated heads were much harder than on the microscale, with CoCr exhibiting twice as much plastic deformation as Mg-PSZ. The mechanical properties of the DLC coatings were not significantly different for both the CoCr and Mg-PSZ substrates, producing similar moduli of resilience and plastic resistance ratios. DLC coatings greatly increased hardness on both the micro and nano levels and significantly improved resilience and resistance to plastic deformation compared with non-coated heads. Because Mg-PSZ allows less plastic deformation than CoCr and provides a greater composite microhardness, DLC-Mg-PSZ will likely be more durable for use as a bearing surface in vivo.

  20. Aquifer characterisation using Surface NMR jointly with other geophysical techniques at the Nauen/Berlin test site

    NASA Astrophysics Data System (ADS)

    Yaramanci, Ugur; Lange, Gerhard; Hertrich, Marian

    2002-05-01

    The quite new technique of Surface Nuclear Magnetic Resonance (SNMR) has been extensively tested on the test site Nauen near Berlin to yield the geometry, water content and hydraulic conductivity of the aquifer. The test site is composed of an unconfined aquifer consisting of Quaternary sands with glacial till beneath. It is a very favourable site for assessing the suitability and performance of joint geophysical methods for groundwater exploration. Complementary measurements to SNMR were conducted with Ground Penetrating Radar (GPR), 1D-complex resistivity soundings, i.e. Spectral Induced Polarisation (SIP), 2D-geoelectrics and refraction seismics. Laboratory measurements of porosities, grain size distributions and Nuclear Magnetic Resonance (NMR) decay times were carried out on core samples, and hydraulic conductivities were also derived in order to control and interpret the results of field measurements. The SNMR method allowed the detection of the aquifer beyond any doubt and the determination of the approximate aquifer geometry. The aquifer water content found by SNMR fits very well with the independent measurements on core samples. Hydraulic conductivities derived from decay times are well in range with those from laboratory measurements. GPR allowed a very reliable determination of the aquifer geometry. This information, incorporated into inversion of geoelectric data, led to an improved determination of aquifer electrical resistivity. The estimation of water content by GPR and geoelectrics, even under the favourable conditions in Nauen, is by far not as reliable as that by SNMR. Obtaining information about hydraulic conductivity is possible only with SNMR. Thus, in combination with other geophysical methods, SNMR allows a much more detailed and reliable assessment of aquifers than what was possible with other surface geophysical methods before. In fact, it is, by far, the only method that allows direct detection of water and reliable estimations about water

  1. Cutaneous human papillomavirus types detected on the surface of male external genital lesions: A case series within the HPV Infection in Men Study

    PubMed Central

    Pierce Campbell, Christine M.; Messina, Jane L.; Stoler, Mark H.; Jukic, Drazen M.; Tommasino, Massimo; Gheit, Tarik; Rollison, Dana E.; Sichero, Laura; Sirak, Bradley A.; Ingles, Donna J.; Abrahamsen, Martha; Lu, Beibei; Villa, Luisa L.; Lazcano-Ponce, Eduardo; Giuliano, Anna R.

    2013-01-01

    Background Cutaneous human papillomaviruses (HPVs) may be associated with cutaneous epithelial lesions and non-melanoma skin cancers. No study has systematically evaluated the presence of genus beta [β]-HPV in male genital skin or external genital lesions (EGLs). Objectives To examine cutaneous β-HPV types detected on the surface of EGLs in men and describe their presence prior to EGL development. Study design A retrospective case series was conducted among 69 men with pathologically confirmed EGLs (n=72) who participated in the HPV Infection in Men Study. Archived exfoliated cells collected from the surface of each EGL and normal genital skin specimens 6–12 months preceding EGL development were tested for β-HPV DNA using a type-specific multiplex genotyping assay. Results β-HPV DNA was detected on 61.1% of all EGLs, with types 38 (16.7%), 5 (15.3%), and 12 (12.5%) most commonly identified. HPV prevalence differed across pathological diagnoses, with the largest number of β-HPV types detected on condylomas. Most β-HPV types were detected on normal genital skin prior to EGL development, though the prevalence was lower on EGLs compared to preceding normal genital skin. Conclusions EGLs and the normal genital skin of men harbor a large number of β-HPV types; however, it appears that β-HPVs are unrelated to EGL development in men. Despite evidence to support a causal role in skin carcinogenesis at UVR-exposed sites, cutaneous HPV appears unlikely to cause disease at the UVR-unexposed genitals. PMID:24210970

  2. Double-letter processing in surface dyslexia and dysgraphia following a left temporal lesion: A multimodal neuroimaging study.

    PubMed

    Tomasino, Barbara; Marin, Dario; Maieron, Marta; D'Agostini, Serena; Fabbro, Franco; Skrap, Miran; Luzzatti, Claudio

    2015-12-01

    Neuropsychological data about acquired impairments in reading and writing provide a strong basis for the theoretical framework of the dual-route models. The present study explored the functional neuroanatomy of the reading and spelling processing system. We describe the reading and writing performance of patient CF, an Italian native speaker who developed an extremely selective reading and spelling deficit (his spontaneous speech, oral comprehension, repetition and oral picture naming were almost unimpaired) in processing double letters associated with surface dyslexia and dysgraphia, following a tumor in the left temporal lobe. In particular, the majority of CF's errors in spelling were phonologically plausible substitutions, errors concerning letter numerosity of consonants, and syllabic phoneme-to-grapheme conversion (PGC) errors. A similar pattern of impairment also emerged in his reading behavior, with a majority of lexical stress errors (the only possible type of surface reading errors in the Italian language, due the extreme regularity of print-to-sound correspondence). CF's neuropsychological profile was combined with structural neuroimaging data, fiber tracking, and functional maps and compared to that of healthy control participants. We related CF's deficit to a dissociation between impaired ventral/lexical route (as evidenced by a fractional anisotropy - FA decrease along the inferior fronto-occipital fasciculus - IFOF) and relatively preserved dorsal/phonological route (as evidenced by a rather full integrity of the superior longitudinal fasciculus - SLF). In terms of functional processing, the lexical-semantic ventral route network was more activated in controls than in CF, while the network supporting the dorsal route was shared by CF and the control participants. Our results are discussed within the theoretical framework of dual-route models of reading and spelling, emphasize the importance of the IFOF both in lexical reading and spelling, and offer

  3. Double-letter processing in surface dyslexia and dysgraphia following a left temporal lesion: A multimodal neuroimaging study.

    PubMed

    Tomasino, Barbara; Marin, Dario; Maieron, Marta; D'Agostini, Serena; Fabbro, Franco; Skrap, Miran; Luzzatti, Claudio

    2015-12-01

    Neuropsychological data about acquired impairments in reading and writing provide a strong basis for the theoretical framework of the dual-route models. The present study explored the functional neuroanatomy of the reading and spelling processing system. We describe the reading and writing performance of patient CF, an Italian native speaker who developed an extremely selective reading and spelling deficit (his spontaneous speech, oral comprehension, repetition and oral picture naming were almost unimpaired) in processing double letters associated with surface dyslexia and dysgraphia, following a tumor in the left temporal lobe. In particular, the majority of CF's errors in spelling were phonologically plausible substitutions, errors concerning letter numerosity of consonants, and syllabic phoneme-to-grapheme conversion (PGC) errors. A similar pattern of impairment also emerged in his reading behavior, with a majority of lexical stress errors (the only possible type of surface reading errors in the Italian language, due the extreme regularity of print-to-sound correspondence). CF's neuropsychological profile was combined with structural neuroimaging data, fiber tracking, and functional maps and compared to that of healthy control participants. We related CF's deficit to a dissociation between impaired ventral/lexical route (as evidenced by a fractional anisotropy - FA decrease along the inferior fronto-occipital fasciculus - IFOF) and relatively preserved dorsal/phonological route (as evidenced by a rather full integrity of the superior longitudinal fasciculus - SLF). In terms of functional processing, the lexical-semantic ventral route network was more activated in controls than in CF, while the network supporting the dorsal route was shared by CF and the control participants. Our results are discussed within the theoretical framework of dual-route models of reading and spelling, emphasize the importance of the IFOF both in lexical reading and spelling, and offer

  4. Stress-induced cervical lesions.

    PubMed

    Braem, M; Lambrechts, P; Vanherle, G

    1992-05-01

    The increasing occurrence of dental lesions at the cervical surfaces requires more knowledge of the causes of the process. Acidic and abrasive mechanisms have clearly been documented as causes but the stress theory by Lee and Eakle is still controversial. This report describes several incidences of possible stress-induced lesions according to the characteristics described by Lee and Eakle. The occurrences of subgingival lesions lend credence to the stress-induction theory by exclusion of other superimposing etiologic factors. With the current concepts, a perceptive approach to the treatment of cervical lesions can be executed. PMID:1527763

  5. A new algorithm for three-dimensional joint inversion of body wave and surface wave data and its application to the Southern California plate boundary region

    NASA Astrophysics Data System (ADS)

    Fang, Hongjian; Zhang, Haijiang; Yao, Huajian; Allam, Amir; Zigone, Dimitri; Ben-Zion, Yehuda; Thurber, Clifford; van der Hilst, Robert D.

    2016-05-01

    We introduce a new algorithm for joint inversion of body wave and surface wave data to get better 3-D P wave (Vp) and S wave (Vs) velocity models by taking advantage of the complementary strengths of each data set. Our joint inversion algorithm uses a one-step inversion of surface wave traveltime measurements at different periods for 3-D Vs and Vp models without constructing the intermediate phase or group velocity maps. This allows a more straightforward modeling of surface wave traveltime data with the body wave arrival times. We take into consideration the sensitivity of surface wave data with respect to Vp in addition to its large sensitivity to Vs, which means both models are constrained by two different data types. The method is applied to determine 3-D crustal Vp and Vs models using body wave and Rayleigh wave data in the Southern California plate boundary region, which has previously been studied with both double-difference tomography method using body wave arrival times and ambient noise tomography method with Rayleigh and Love wave group velocity dispersion measurements. Our approach creates self-consistent and unique models with no prominent gaps, with Rayleigh wave data resolving shallow and large-scale features and body wave data constraining relatively deeper structures where their ray coverage is good. The velocity model from the joint inversion is consistent with local geological structures and produces better fits to observed seismic waveforms than the current Southern California Earthquake Center (SCEC) model.

  6. Elastohydrodynamic lubrication analysis of a functionally graded layered bearing surface, with particular reference to 'cushion form bearings' for artificial knee joints.

    PubMed

    Virdee, S S; Wang, F C; Xu, H; Jin, Z M

    2003-01-01

    Elastohydrodynamic lubrication of a functionally graded layered (FGL) bearing surface, whose elastic modulus increases with depth from the bearing surface, was investigated in this study. The finite difference method was employed to solve the Reynolds equation, simultaneously with the elasticity equation of the bearing surface, under circular point contacts. The finite element method was adopted to solve the elasticity equation for the FGL bearing surface. The displacement coefficients thus obtained were used to calculate the elastic deformation of the bearing surface, required for the elastohydrodynamic lubrication analysis. Good agreement of the predicted film thickness and pressure distribution was obtained, between the present method and a previous study for a single layered bearing surface with a uniform elastic modulus. The general numerical methodology was then applied to an FGL bearing surface with both linear and exponential variations in elastic modulus, with particular reference to the 'cushion form bearing' for artificial knee joints. The predicted film thickness and pressure distribution were shown to be quite close to those obtained for a single layer under typical operating conditions representative of artificial knee joints, provided that the elastic modulus of the single layer was chosen to be the average elastic modulus of the graded layer.

  7. Response surface models to predict potato tuber infection by Fusarium sambucinum from duration of wetness and temperature, and dry rot lesion expansion from storage time and temperature.

    PubMed

    Lui, L H; Kushalappa, A C

    2002-06-01

    Dry rot (Fusarium sambucinum) of potatoes causes significant yield loss in storage and may also produce mycotoxins. Disease dynamics of dry rot development in potato tubers after harvest was studied and modeled. Potato tubers were surface sterilized, wounded, inoculated with a spore suspension of F. sambucinum and incubated in mist chambers placed in growth chambers at 4, 8, 12, 16 or 20 degrees C. After 0, 3, 6, 12, 24 and 48 h of incubation five tubers from each treatment were removed, dried and stored at 16 degrees C and 95% RH for 15 days. Inoculated tubers were also maintained in mist chambers for 24 h at 16 degrees C for the establishment of initial infections, dried, and stored at 4, 8, 12, or 16 degrees C for up to 90 days at 95% RH. At 15 days intervals, tubers were sliced, diameters and depths of diseased area measured, and data transformed to proportion of maximum volume diseased (PVD). The amount of infection was least at the lowest temperature tested and at the end of a 3-h wet period, but infection increased with an increase in wetness duration and temperature. At a storage temperature of 16 degrees C, lesions expanded rapidly reaching maxima in about 45 days of storage. A cubic regression model to predict infection potential from incubation temperature and duration of wetness explained 94.2% of the variation in PVD. A cubic regression model to predict lesion expansion potential as a function of storage temperature and duration explained 99.7% of the variation in PVD. These models could be used to manage potato dry rot, after validation under commercial conditions.

  8. Shape, Loading, and Motion in the Bioengineering Design, Fabrication, and Testing of Personalized Synovial Joints

    PubMed Central

    Williams, Gregory M.; Chan, Elaine F.; Temple-Wong, Michele M.; Bae, Won C.; Masuda, Koichi; Bugbee, William D.; Sah, Robert L.

    2009-01-01

    With continued development and improvement of tissue engineering therapies for small articular lesions, increased attention is being focused on the challenge of engineering partial or whole synovial joints. Joint-scale constructs could have applications in the treatment of large areas of articular damage or in biological arthroplasty of severely degenerate joints. This review considers the roles of shape, loading and motion in synovial joint mechanobiology and their incorporation into the design, fabrication, and testing of engineered partial or whole joints. Incidence of degeneration, degree of impairment, and efficacy of current treatments are critical factors in choosing a target for joint bioengineering. The form and function of native joints may guide the design of engineered joint-scale constructs with respect to size, shape, and maturity. Fabrication challenges for joint-scale engineering include controlling chemo-mechano-biological microenvironments to promote the development and growth of multiple tissues with integrated interfaces or lubricated surfaces into anatomical shapes, and joint-scale bioreactors which nurture and stimulate the tissue with loading and motion. Finally, evaluation of load-bearing and tribological properties can range from tissue to joint scale and can focus on biological structure at present or after adaptation. PMID:19815214

  9. Assessment of the influence of surface finishing and weld joints on the corrosion/oxidation behaviour of stainless steels in lead bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Martín-Muñoz, F. J.; Soler-Crespo, L.; Gómez-Briceño, D.

    2011-09-01

    The objective of this paper is to gain some insight into the influence of the surface finishing in the oxidation/corrosion behaviour of 316L and T91 steels in lead bismuth eutectic (LBE). Specimens of both materials with different surface states were prepared (as-received, grinded, grinded and polished, and electrolitically polished) and oxidation tests were carried out at 775 and 825 K from 100 to 2000 h for two different oxygen concentrations and for H 2/H 2O molar ratios of 3 and 0.03. The general conclusion for these tests is that the effect of surface finishing on the corrosion/protection processes is not significant under the tested conditions. In addition the behaviour of weld joints, T91-T91 Tungsten Inert Gas (TIG) and T91-316L have been also studied under similar conditions. The conclusions are that, whereas T91-T91 welded joint shows the same corrosion properties as the parent materials for the conditions tested, AISI 316L-T91 welded joint, present an important dissolution over seam area that it associated to the electrode 309S used for the fabrication process.

  10. The Bennett lesion of the shoulder.

    PubMed

    De Maeseneer, M; Jaovisidha, S; Jacobson, J A; Tam, W; Schils, J P; Sartoris, D J; Fronek, J; Resnick, D

    1998-01-01

    In this article we review the imaging features and significance of the Bennett lesion of the shoulder. Standard radiographic, computed arthrotomographic, and MR findings in three baseball pitchers diagnosed with Bennett lesions of the shoulder are discussed. A crescent-shaped region of mineralization at the posteroinferior aspect of the glenoid rim, consistent with a Bennett lesion, arises at the insertion of the posterior joint capsule. The diagnosis of this lesion, typically in baseball pitchers, should raise suspicion for associated labral and rotator cuff abnormalities.

  11. 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

  12. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

    PubMed Central

    Anasane, Nayana; Ahirrao, Yogesh; Chitnis, Deepa; Meshram, Suresh

    2013-01-01

    Background: Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. Materials and Methods: A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Results: Transverse strength values for all repaired groups were significantly lower than those for the control group (P < 0.001) (88.77 MPa), with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa) which was significantly superior to the other joint surface contours (P < 0.001). Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin (P < 0.001). Conclusion: Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins. PMID:23946739

  13. Upper mantle structure beneath the Galápagos Archipelago from joint inversion of body and surface waves (Invited)

    NASA Astrophysics Data System (ADS)

    Villagomez, D. R.; Toomey, D. R.; Hooft, E. E.; Solomon, S. C.

    2010-12-01

    We conducted a joint tomographic study of teleseismic body-wave delay times and Rayleigh-wave phase velocities to constrain the seismic structure of the upper mantle beneath the Galápagos Archipelago. Data are from 10 broadband stations deployed over a period of 3 years and one station of the Global Seismographic Network. The seismic network spanned an area of 200 by 300 km2, and the station spacing was 50-70 km. We measured 1783 P wave delay times and 1000 S wave delay times from 110 teleseismic events, and we used 12 maps of lateral variation of Rayleigh-wave phase velocity at periods from 20 s to 125 s obtained by us earlier. We invert simultaneously the delay times and phase velocities for three-dimensional variations in P and S wave velocity VP and VS, and we allow for variable weighting of body and surface wave data and coupling of P and S wave structures. The inversion solutions contain low-velocity anomalies that extend from the surface to the maximum depth of resolution (~300 km). We interpret the low-velocity volume at depths greater than ~100 km to be the locus of an upwelling mantle plume. Between 300 and 100 km depth the low-velocity anomaly is nearly cylindrical with a radius of ~75 km, and the VS anomaly reaches a magnitude of -2%. We attribute this reduction to a combination of higher-than-normal temperature and partial melt. The low-velocity anomaly tilts northward as it shoals; at 300 km depth it is centered ~75 km to the south of Isabela, whereas at 100 km depth it is centered beneath that island. We propose that the northward tilt of the plume as it rises is due to background mantle flow toward the Galápagos Spreading Center. At the top of the low-velocity volume is a rapid increase in VS, which we term the high-velocity lid. We attribute the base of this lid, which is at varying depth across the archipelago and is deepest (~100 km) beneath the southern end of Isabela, to a compositional change produced by the depletion and dehydration

  14. A joint data assimilation system (Tan-Tracker) to simultaneously estimate surface CO2 fluxes and 3-D atmospheric CO2 concentrations from observations

    NASA Astrophysics Data System (ADS)

    Tian, X.; Xie, Z.; Liu, Y.; Cai, Z.; Fu, Y.; Zhang, H.; Feng, L.

    2013-09-01

    To quantitatively estimate CO2 surface fluxes (CFs) from atmospheric observations, a joint data assimilation system ("Tan-Tracker") is developed by incorporating a joint data assimilation framework into the GEOS-Chem atmospheric transport model. In Tan-Tracker, we choose an identity operator as the CF dynamical model to describe the CFs' evolution, which constitutes an augmented dynamical model together with the GEOS-Chem atmospheric transport model. In this case, the large-scale vector made up of CFs and CO2 concentrations is taken as the prognostic variable for the augmented dynamical model. And thus both CO2 concentrations and CFs are jointly assimilated by using the atmospheric observations (e.g., the in-situ observations or satellite measurements). In contrast, in the traditional joint data assimilation frameworks, CFs are usually treated as the model parameters and form a state-parameter augmented vector jointly with CO2 concentrations. The absence of a CF dynamical model will certainly result in a large waste of observed information since any useful information for CFs' improvement achieved by the current data assimilation procedure could not be used in the next assimilation cycle. Observing system simulation experiments (OSSEs) are carefully designed to evaluate the Tan-Tracker system in comparison to its simplified version (referred to as TT-S) with only CFs taken as the prognostic variables. It is found that our Tan-Tracker system is capable of outperforming TT-S with higher assimilation precision for both CO2 concentrations and CO2 fluxes, mainly due to the simultaneous assimilation of CO2 concentrations and CFs in our Tan-Tracker data assimilation system.

  15. Joint assimilation of Aquarius-derived sea surface salinity and AVHRR-derived sea surface temperature in an ocean general circulation model using SEEK filter: Implication for mixed layer depth and barrier layer thickness

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhisek; Sharma, Rashmi; Kumar, Raj; Basu, Sujit

    2015-10-01

    Sea surface salinity (SSS) from Aquarius mission and sea surface temperature (SST) from Advanced Very High Resolution Radiometer (AVHRR) for the years 2012-2014 are assimilated into the global Massachusetts Institute of Technology General Circulation Model (MITGCM). Investigation of the impact of assimilation of these two data sets on simulated mixed layer depth (MLD) and barrier layer thickness (BLT) forms the core of our study. The method of assimilation is the Singular Evolutive Extended Kalman (SEEK) filter. Several assimilation runs are performed. Single-parameter assimilation, as well as joint assimilation, is conducted. To begin with, the model simulated SST and SSS are compared with independent Argo observations of these two parameters. Use of latitudinally varying error variances, which is a novel feature of our study, gives rise to the significant improvement in the simulation of SSS and SST. The best result occurs when joint assimilation is performed. Afterward, simulated MLD and BLT are compared with the same parameters derived from Argo observations forming an independent validation data set. Comparisons are performed both in temporal and spatial domains. Significant positive impact of assimilation is found in all the cases studied, and joint assimilation is found to outperform single-parameter assimilation in each of the cases considered. It is found that simulations of MLD and BLT improve up to 24% and 29%, respectively, when a joint assimilation of SSS and SST is carried out.

  16. Novel lesion detection aids.

    PubMed

    Neuhaus, K W; Longbottom, C; Ellwood, R; Lussi, A

    2009-01-01

    Several non-invasive and novel aids for the detection of (and in some cases monitoring of) caries lesions have been introduced in the field of 'caries diagnostics' over the last 15 years. This chapter focusses on those available to dentists at the time of writing; continuing research is bound to lead to further developments in the coming years. Laser fluorescence is based on measurements of back-scattered fluorescence of a 655-nm light source. It enhances occlusal and (potentially) approximal lesion detection and enables semi-quantitative caries monitoring. Systematic reviews have identified false-positive results as a limitation. Quantitative light-induced fluorescence is another sensitive method to quantitatively detect and measure mineral loss both in enamel and some dentine lesions; again, the trade-offs with lower specificity when compared with clinical visual detection must be considered. Subtraction radiography is based on the principle of digitally superimposing two radiographs with exactly the same projection geometry. This method is applicable for approximal surfaces and occlusal caries involving dentine but is not yet widely available. Electrical caries measurements gather either site-specific or surface-specific information of teeth and tooth structure. Fixed-frequency devices perform best for occlusal dentine caries but the method has also shown promise for lesions in enamel and other tooth surfaces with multi-frequency approaches. All methods require further research and further validation in well-designed clinical trials. In the future, they could have useful applications in clinical practice as part of a personalized, comprehensive caries management system. PMID:19494675

  17. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data for Three-Dimensional Seismic Velocity Structure Around SAFOD

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Thurber, C. H.; Maceira, M.; Roux, P.

    2013-12-01

    The crust around the San Andreas Fault Observatory at depth (SAFOD) has been the subject of many geophysical studies aimed at characterizing in detail the fault zone structure and elucidating the lithologies and physical properties of the surrounding rocks. Seismic methods in particular have revealed the complex two-dimensional (2D) and three-dimensional (3D) structure of the crustal volume around SAFOD and the strong velocity reduction in the fault damage zone. In this study we conduct a joint inversion using body-wave arrival times and surface-wave dispersion data to image the P-and S-wave velocity structure of the upper crust surrounding SAFOD. The two data types have complementary strengths - the body-wave data have good resolution at depth, albeit only where there are crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution and are not dependent on the earthquake source distribution because they are derived from ambient noise. The body-wave data are from local earthquakes and explosions, comprising the dataset analyzed by Zhang et al. (2009). The surface-wave data are for Love waves from ambient noise correlations, and are from Roux et al. (2011). The joint inversion code is based on the regional-scale version of the double-difference (DD) tomography algorithm tomoDD. The surface-wave inversion code that is integrated into the joint inversion algorithm is from Maceira and Ammon (2009). The propagator matrix solver in the algorithm DISPER80 (Saito, 1988) is used for the forward calculation of dispersion curves from layered velocity models. We examined how the structural models vary as we vary the relative weighting of the fit to the two data sets and in comparison to the previous separate inversion results. The joint inversion with the 'optimal' weighting shows more clearly the U-shaped local structure from the Buzzard Canyon Fault on the west side of SAF to the Gold Hill Fault on the east side.

  18. A joint NOAA/USGS study to evaluate satellite assessment of land surface features and climatic variables

    USGS Publications Warehouse

    Gallo, K.P.; Tarpley, J.D.; Howard, S.M.; Moore, D.G.

    1987-01-01

    Data collection and preliminary analyses have begun for a study that will evaluate the usefulness of satellite data for assessment of land surface features and climatic variables. The objective of the study is to determine what relationships exist between routinely available ground-based climatic and land surface information and satellite-obtained land surface information. The overall goal is to contribute to the increasingly important understanding of land surface climatology.

  19. Effect of adhesive thickness and surface treatment on shear strength on single lap joint Al/CFRP using adhesive of epoxy/Al fine powder

    NASA Astrophysics Data System (ADS)

    Diharjo, Kuncoro; Anwar, Miftahul; Tarigan, Roy Aries P.; Rivai, Ahmad

    2016-02-01

    The objective of this study is to investigate the effect of adhesive thickness and surface treatment on the shear strength and failure type characteristic of single lap joint (SLJ) CFRP/Al using adhesive epoxy/Al-fine-powder. The CFRP was produced by using hand layup method for 30% of woven roving carbon fiber (w/w) and the resin used was bisphenolic. The adhesive was prepared using 12.5% of aluminum fine powder (w/w) in the epoxy adhesive. The powder was mixed by using a mixing machine at 60 rpm for 6 minutes, and then it was used to join the Al plate-2024 and CFRP. The start time to pressure for the joint process was 20 minutes after the application of adhesive on the both of adherends. The variables in this research are adhesive thickness (i.e. 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm and 1 mm) and surface treatment of adherends (i.e. acetone, chromate sulphuric acid, caustic etch and tucker's reagent). Before shear testing, all specimens were post-cured at 100 °C for 15 minutes. The result shows that the SLJ has the highest shear strength for 0.4 mm of adhesive thickness. When the adhesive thickness is more than 0.4 mm (0.6-1 mm), the shear strength decreases significantly. It might be caused by the property change of adhesive from ductile to brittle. The acetone surface treatment produces the best bonding between the adhesive and adherends (CFRP and Al-plate 2024), and the highest shear strength is 9.31 MPa. The surface treatment give the humidification effect of adherend surfaces by adhesive. The failure characteristic shows that the mixed failure of light-fiber-tear-failure and cohesive-failure are occurred on the high shear strength of SLJ, and the low shear strength commonly has the adhesive-failure type.

  20. 3-D structure of the Rio Grande Rift from 1-D constrained joint inversion of receiver functions and surface wave dispersion

    NASA Astrophysics Data System (ADS)

    Sosa, Anibal; Thompson, Lennox; Velasco, Aaron A.; Romero, Rodrigo; Herrmann, Robert B.

    2014-09-01

    The Southern terminus of the Rio Grande Rift region has been poorly defined in the geologic record, with few seismic studies that provide information on the deeper Rift structure. In consequence, important questions related to tectonic and lithospheric activity of the Rio Grande Rift remain unresolved. To address some of these geological questions, we collect and analyze seismic data from 147 EarthScope Transportable Array (USArray) and other seismic stations in the region, to develop a 3-D crust and upper mantle velocity model. We apply a constrained optimization approach for joint inversion of surface wave and receiver functions using seismic S wave velocities as a model parameter. In particular, we compute receiver functions stacks based on ray parameter, and invert them jointly with collected surface wave group velocity dispersion observations. The inversions estimate 1-D seismic S-wave velocity profiles to 300 km depth, which are then interpolated to a 3-D velocity model using a Bayesian kriging scheme. Our 3-D models show a thin lower velocity crust anomaly along the southeastern Rio Grande Rift, a persistent low velocity anomaly underneath the Colorado Plateau and Basin and Range province, and another one at depth beneath the Jemez lineament, and the southern RGR.

  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. Evaluation of a bisphosphonate enriched ultra-high molecular weight polyethylene for enhanced total joint replacement bearing surface functionality

    NASA Astrophysics Data System (ADS)

    Wright-Walker, Cassandra Jane

    Each year in the United States there is an increasing trend of patients receiving total joint replacement (TJR) procedures. Approximately a half million total knee replacements (TKRs) are performed annually in the United States with increasing prevalence attributed to baby-boomers, obesity, older, and younger patients. This trend is also seen for total hip replacements (THRs) as well. The use of ultra high molecular weight polyethylene (UHMWPE) inserts in TJRs results in wear particle-induced osteolysis, which is the predominant cause for prosthesis failure and revision surgery. Sub-micron size particle generation is inevitable despite the numerous efforts in improving this bearing material. Work by others has shown that the use of oral and intravenous systemic bisphosphonates (BP) can significantly minimize periprosthetic osteolysis. However, the systemic delivery and the high solubility of BPs results in a predominant portion of the drug being excreted via the kidney without reaching its target, bone. This doctoral research project is focused on the development and evaluation of a novel method to administer BPs locally using the inherent wear of UHMWPE for possible use as an anti-osteolysis treatment. For new materials to be considered, they must be mechanically and tribologically comparable to the current gold standard, UHMWPE. In order to evaluate this material, mechanical, drug elution and tribological experiments were performed to allow assessment of material properties. Tensile tests showed comparable yield stress and pin-on-disk testing showed comparable wear to standard virgin UHMWPE. Further, drug elution tests have shown that BP was released from the enriched material both in static and dynamic conditions. Additionally, an aggressive 2 million cycle total knee simulator experiment has shown statistically similar wear results for the two materials. Overall, this research has provided the groundwork for further characterization and development of a new

  3. Antibacterial Surface Design of Titanium-Based Biomaterials for Enhanced Bacteria-Killing and Cell-Assisting Functions Against Periprosthetic Joint Infection.

    PubMed

    Wang, Jiaxing; Li, Jinhua; Qian, Shi; Guo, Geyong; Wang, Qiaojie; Tang, Jin; Shen, Hao; Liu, Xuanyong; Zhang, Xianlong; Chu, Paul K

    2016-05-01

    Periprosthetic joint infection (PJI) is one of the formidable and recalcitrant complications after orthopedic surgery, and inhibiting biofilm formation on the implant surface is considered crucial to prophylaxis of PJI. However, it has recently been demonstrated that free-floating biofilm-like aggregates in the local body fluid and bacterial colonization on the implant and peri-implant tissues can coexist and are involved in the pathogenesis of PJI. An effective surface with both contact-killing and release-killing antimicrobial capabilities can potentially abate these concerns and minimize PJI caused by adherent/planktonic bacteria. Herein, Ag nanoparticles (NPs) are embedded in titania (TiO2) nanotubes by anodic oxidation and plasma immersion ion implantation (PIII) to form a contact-killing surface. Vancomycin is then incorporated into the nanotubes by vacuum extraction and lyophilization to produce the release-killing effect. A novel clinical PJI model system involving both in vitro and in vivo use of methicillin-resistant Staphylococcus aureus (MRSA) ST239 is established to systematically evaluate the antibacterial properties of the hybrid surface against planktonic and sessile bacteria. The vancomycin-loaded and Ag-implanted TiO2 nanotubular surface exhibits excellent antimicrobial and antibiofilm effects against planktonic/adherent bacteria without appreciable silver ion release. The fibroblasts/bacteria cocultures reveal that the surface can help fibroblasts to combat bacteria. We first utilize the nanoarchitecture of implant surface as a bridge between the inorganic bactericide (Ag NPs) and organic antibacterial agent (vancomycin) to achieve total victory in the battle of PJI. The combination of contact-killing and release-killing together with cell-assisting function also provides a novel and effective strategy to mitigate bacterial infection and biofilm formation on biomaterials and has large potential in orthopedic applications. PMID:27054673

  4. 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.

  5. [Management of the meniscal lesion].

    PubMed

    Baillon, B; Cermak, K; Vancabeke, M

    2011-01-01

    About 1,5 million arthroscopies are each year performed in the world, 50 % for meniscal affections. The menisci participate in the femoro-tibial load transmission and in the joint shock absorption; they contribute to the knee stability and play a role in the joint lubrication. The menisci are therefore important structures, and, in the case of a lesion, surgical abstention or repair should be favoured. When a meniscectomy has to be performed, it should be economical, preserving the meniscal wall. Meniscectomy is contra-indicated in the child and in the case of knee osteoarthrosis. Meniscal healing is compromised if the knee is unstable. If after total meniscectomy a patient presents symptomatic early osteoarthrosis, without marked loss of alignment, meniscal allografting is a therapeutic option, especially at the lateral compartment.

  6. Joint inversion of multi-configuration electromagnetic induction measurements to estimate soil wetting patterns during surface drip irrigation

    NASA Astrophysics Data System (ADS)

    Jadoon, Khan Z.; Moghadas, Davood; Jadoon, Aurangzeb; Missimer, Thomas M.; McCabe, Matthew

    2014-05-01

    In arid and semi-arid regions, development of precise information on the soil wetting pattern is important to optimize drip irrigation system design for sustainable agricultural water management. Usually mathematical models are commonly used to describe infiltration from a point source to design and manage drip irrigation systems. The extent to which water migrates laterally and vertically away from the drip emitter depends on many factors, including dripper discharge rate, the frequency of water application, duration of drip emission, the soil hydraulic characteristics, initial conditions, evaporation, root water uptake and root distribution patterns. However, several simplified assumptions in the mathematical models affect their utility to provide useful design information. In this respect, non-invasive geophysical methods, i.e., low frequency electromagnetic induction (EMI) systems are becoming powerful tools to map spatial and temporal soil moisture patterns due to fast measurement capability and sensitivity to soil water content and salinity. In this research, a new electromagnetic system, the CMD mini-Explorer, is used for soil characterization to measure the wetting patterns of drip irrigation systems using joint inversion of multi-configuration EMI measurements. Six transects of EMI measurements were carried out in a farm where Acacia trees are irrigated with brackish water using a drip irrigation system. EMI reference data (ground-truths) were calculated using vertical soil electrical conductivity recorded in different trenches along one of the measurement transects. Reference data is used for calibration to minimize the instrumental shifts which often occur in EMI data. Global and local optimization algorithms are used sequentially, to minimize the misfit between the measured and modeled apparent electrical conductivity (δa) to reconstruct the vertical electrical conductivity profile. The electromagnetic forward model based on full solution of Maxwell

  7. Simulation of spiculated breast lesions

    NASA Astrophysics Data System (ADS)

    Elangovan, Premkumar; Alrehily, Faisal; Pinto, R. Ferrari; Rashidnasab, Alaleh; Dance, David R.; Young, Kenneth C.; Wells, Kevin

    2016-03-01

    Virtual clinical trials are a promising new approach increasingly used for the evaluation and comparison of breast imaging modalities. A key component in such an assessment paradigm is the use of simulated pathology, in particular, simulation of lesions. Breast mass lesions can be generally classified into two categories based on their appearance; nonspiculated masses and spiculated masses. In our previous work, we have successfully simulated non-spiculated masses using a fractal growth process known as diffusion limited aggregation. In this new work, we have extended the DLA model to simulate spiculated lesions by using features extracted from patient DBT images containing spiculated lesions. The features extracted included spicule length, width, curvature and distribution. This information was used to simulate realistic looking spicules which were attached to the surface of a DLA mass to produce a spiculated mass. A batch of simulated spiculated masses was inserted into normal patient images and presented to an experienced radiologist for review. The study yielded promising results with the radiologist rating 60% of simulated lesions in 2D and 50% of simulated lesions in DBT as realistic.

  8. Earth surface deformation in the North China Plain detected by joint analysis of GRACE and GPS data.

    PubMed

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C K; Li, Zhao

    2014-10-22

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1-4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1-2 mm/year and a correlation of 85.0%-98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements.

  9. Earth surface deformation in the North China Plain detected by joint analysis of GRACE and GPS data.

    PubMed

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C K; Li, Zhao

    2014-01-01

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1-4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1-2 mm/year and a correlation of 85.0%-98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements. PMID:25340454

  10. Earth Surface Deformation in the North China Plain Detected by Joint Analysis of GRACE and GPS Data

    PubMed Central

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C.K.; Li, Zhao

    2014-01-01

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1–4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1–2 mm/year and a correlation of 85.0%–98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements. PMID:25340454

  11. Pinning across the metatarsophalangeal joint for hammertoe correction: where are we aiming and what is the damage to the metatarsal articular surface?

    PubMed

    Galli, Melissa M; Brigido, Stephen A; Protzman, Nicole M

    2014-01-01

    Kirschner wire (K-wire) fixation across the metatarsophalangeal joint (MTPJ) is commonly used in hammertoe repair surgery. The purpose of the present study was twofold: (1) to determine where the K-wire penetrates the metatarsal articular surface to achieve a rectus digit; and (2) to quantify the percentage of cartilage disruption to better understand the consequences of K-wire transfixation of the MTPJ. Arthrodesis was conducted on the second, third, and fourth proximal interphalangeal joints of 10 below-the-knee cadaver specimens, using a 1.6-mm K-wire. Digital alignment was confirmed with simulated weightbearing intraoperatively and radiographically. The K-wire was removed, and the MTPJ was dissected until the metatarsal head was fully exposed. The penetration point was plotted on a quadrant system with deviation noted from the epicenter. Center was defined as the point equidistant from the medial-to-lateral and superior-to-inferior edges on the distal surface of the metatarsal head, excluding the plantar condyles. Statistically significantly deviations were found in the K-wire placement from the center (35.9% ± 17.5%, p < .001), medial-to-lateral width (22.2% ± 19.2%, p < .001), and dorsal-to-plantar height (15.8% ± 25.0%, p = .002). Relative to the center, the K-wire was superior in 22 (79%), inferior in 6 (21%), medial in 22 (79%), and lateral in 6 (21%) of the cadaveric MTPJs. The mean percentage of disruption of the articular cartilage was 1.8% ± .4% and was similar for the second, third, and fourth MTPJs (p = .13) and for the left and right feet (p = .75). This information could be used to guide surgeons when they transfixate the MTPJ during hammertoe correction and might contribute to preservation of the articular cartilage.

  12. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion for Three-Dimensional Seismic Structure Around SAFOD

    NASA Astrophysics Data System (ADS)

    Zhang, Haijiang; Maceira, Monica; Roux, Philippe; Thurber, Clifford

    2014-11-01

    We incorporate body-wave arrival time and surface-wave dispersion data into a joint inversion for three-dimensional P-wave and S-wave velocity structure of the crust surrounding the site of the San Andreas Fault Observatory at Depth. The contributions of the two data types to the inversion are controlled by the relative weighting of the respective equations. We find that the trade-off between fitting the two data types, controlled by the weighting, defines a clear optimal solution. Varying the weighting away from the optimal point leads to sharp increases in misfit for one data type with only modest reduction in misfit for the other data type. All the acceptable solutions yield structures with similar primary features, but the smaller-scale features change substantially. When there is a lower relative weight on the surface-wave data, it appears that the solution over-fits the body-wave data, leading to a relatively rough V s model, whereas for the optimal weighting, we obtain a relatively smooth model that is able to fit both the body-wave and surface-wave observations adequately.

  13. Study on weld bead surface profile and angular distortion in 6 mm thick butt weld joints of SS304 using fiber laser

    NASA Astrophysics Data System (ADS)

    Bhargava, P.; Paul, C. P.; Mundra, G.; Premsingh, C. H.; Mishra, S. K.; Nagpure, D.; Kumar, Atul; Kukreja, L. M.

    2014-02-01

    We deployed a 2 kW continuous wave fiber laser integrated with the 5-axis workstation to understand the effect of various processing parameters (laser power, welding speed, beam spot size and chamfer at welded edges) on depth of penetration, angular distortion and welded bead surface profile during autogenous laser welding of 6 mm thick austenitic stainless steel type 304 plates. Full penetration with reduced weld bead surface undulation (<100 µm) and least angular distortion (<0.8°) was achieved for butt joints having chamfered edges of 0.8 mm. The microscopic studies revealed grossly defect-free fusion zone with a few porosities at isolated locations. The microstructure at the fusion zone was largely austenitic with few ferrites and the direction of growth was epitaxial towards the fusion line. The measured values of microhardness at base material and fusion zone were 208±4 HV0.1 and 235±10 HV0.1 respectively. The tensile testing of laser welded samples indicated the ultimate strength >605 MPa and these samples could be bent for an angle >170° without noticeable crack during bend test. The study opened the avenues for the deployment of fiber laser welding technology for applications demanding critical values of surface weld bead profile and distortion.

  14. Estimation of Yield and Height-of-Burst for Near-Surface Explosions from Joint Inversion of Air-Blast and Seismic Data

    NASA Astrophysics Data System (ADS)

    Rodgers, A.; Xu, H.; Templeton, D. C.; Ramirez, A. L.; Chipman, V.; Ford, S. R.; Chambers, D. H.

    2011-12-01

    Near-surface explosions generate air-blast overpressure and seismic ground motions. It is well known that air-blast and seismic amplitudes depend on explosive yield and range. However for explosions near the ground surface the excitation of air-blast overpressure in the atmosphere and seismic motions depends strongly on the height-of-burst (HOB) for above ground or depth-of-burial (DOB, negative HOB) for buried explosions. We report an algorithm for estimating yield and HOB from near-surface explosions by joint inversion of air-blast overpressure and seismic ground motion amplitudes. The HUMBLE REDWOOD series of chemical explosions conducted at Kirtland AFB were explicitly designed to investigate the effect of HOB on air-blast and seismic motions. Analysis of these data indicates that scaled-range and HOB effects separate and provide calibration data for signal behavior with yield, range and HOB. Variation of air-blast measurements with scaled range for above ground explosions is reasonably well fit by reported models. Dependence with scaled HOB is determined with residuals from above ground air-blast models fit to a parameterized curve. Resampling of the data allows estimates of model errors for both scaled range and scaled HOB and is also used to propagate model errors in the inversion. Similar analysis is performed for the dependence of seismic amplitudes with scaled range and scaled HOB. The inversion of air-blast and seismic amplitudes for yield and HOB uses either a grid search or Markov Chain Monte Carlo (MCMC) approach. The algorithm runs very quickly in either case because the forward calculations are algebraic and very efficient for this two-dimensional model space. We show that inversion results obtained with only one data type (air-blast or seismic) are strongly non-unique and often have large bias. However, joint inversion of air-blast and seismic data breaks the trade-offs between yield and HOB and leads to more accurate estimates. We find that

  15. Osteoarthrosis of the Antebrachiocarpal Joint of 7 Riding Horses

    PubMed Central

    Magnusson, L-E; Ekman, S

    2001-01-01

    Osteoarthrosis (OA) of the antebrachiocarpal joint from 7 riding horses is described. The horses were old mares and developed severe OA, with ankylosis in some of the joints. The lesions were bilateral, and the owners noticed the lameness in a late event. The cause of severe OA in these mares is not clear. The fact that OA was bilateral indicates that a single traumatic injury is unlikely as an etiologic factor. Considering the severe joint lesions it took long time before the horse-owners noticed the lameness. It is discussed if the threshold of pain is higher in the antebrachiocarpal joint compared with the middle carpal joint. PMID:11957370

  16. Monitoring Hurricanes with a Dense Seismic Array: Joint Inversion of Seismic and Barometric Data for Surface-Pressure Source

    NASA Astrophysics Data System (ADS)

    Valentine, A. P.; Al-Attar, D.; Trampert, J.; Woodhouse, J. H.

    2014-12-01

    Tropical cyclones (hurricanes and typhoons) are mostly atmospheric phenomena but they also generate significant ground motions in the solid earth when they become strong. If a dense seismological array exists along the path of a hurricane, we can learn about some processes near the hurricane eye through seismic data. In this study, we report our analysis of Hurricane Arthur which passed near Earthscope's Transportable Array (TA), a network of seismometers located at the time along the east coast of the US. Hurricane Arthur mostly traveled along the eastern coast of the US from July 1 to July 5, 2014; however, it made landfall for a short time on the coast of North Carolina at 0315 UTC on July 4. The next few hours provided us with a short span of seismic and barometric data associated with the center of Hurricane Arthur. Our basic approach to analyze this data is the same as in a previous study we conducted of Hurricane Isaac (2012), where we analyzed the seismic amplitude-distance data and the pressure amplitude-distance data for each 6-hour location of the hurricane. Here, we performed a joint inversion of the seismic and barometric data while Hurricane Arthur was nearest the coast. Barometer data provides the information on pressure source, which is the source of seismic-wave excitation and seismic data provides the resultant wavefields. We confine our analysis to frequencies below 0.02 Hz because in higher frequency bands ocean waves created the dominant seismic waves. In a similar manner to our previous study on Hurricane Isaac, we invert for the pressure correlation length. The results were consistent with what was seen for Hurricane Isaac in that we observed a signal generated by Hurricane Arthur's eyewall. After landfall, there is a peak at about 70-80km from the center of the hurricane in both the seismic and the barometric data. We also found that the correlation length changes with distance from the hurricane center and also has a peak around 70-80km.

  17. Examination of Surface Residuals Obtained During Re-Lubrication of the International Space Station (ISS) Solar Alpha Rotary Joint (SARJ)

    NASA Technical Reports Server (NTRS)

    Martinez, J. E.; Golden, J. L.

    2012-01-01

    The starboard SARJ mechanism on the ISS suffered a premature lubrication failure, resulting in widespread loss of the nitride case layer on its 10.3 meter circumference, 15-5PH steel race ring [1, 2]. To restore functionality, vacuum-stable grease was applied on-orbit, first to the port SARJ mechanism to save it from the damage suffered by the starboard mechanism. After 3 years of greased operation, telemetry indicated that the port mechanism required relubrication, so part of that process included sampling each of the three race ring surfaces to evaluate any wear debris recovered and the state of the originally applied grease. Extensive microscopic examination was conducted, which directed subsequent microanalysis of particulate. Since the SARJ mechanism operates in the vacuum of space, a sampling method and tool had to be developed for use by astronauts while working in the extravehicular mobility unit (EMU). The sampling tool developed was a cotton terry-cloth mitt for the EMU glove, with samples taken by swiping each of the three port SARJ race-ring surfaces. The sample mitts for each surface were folded inward after sampling to preserve sample integrity, for return and ground analysis. The sample mitt for what is termed the outer canted surface of the SARJ race-ring is shown in Figure 1. Figure 1 also demonstrates how increasing levels of magnification were used to survey the contamination removed in sampling, specifically looking for signs of wear debris or other features which could be further evaluated using Scanning Electron Microscopy (SEM) methods. The most surprising overall result at this point in the analysis was the relatively small amounts of grease recovered during sampling. It is clear that the mechanism was not operating with surplus lubricant. Obviously, evidence of molybdenum disulfide (MoS2), a major component in the grease applied, was prevalent in the analysis conducted. But a small amount of mechanism wear debris was observed. Figure 2

  18. Modelling of the mechanical behavior of a polyurethane finger interphalangeal joint endoprosthesis after surface modification by ion implantation

    NASA Astrophysics Data System (ADS)

    Beliaev, A.; Svistkov, A.; Iziumov, R.; Osorgina, I.; Kondyurin, A.; Bilek, M.; McKenzie, D.

    2016-04-01

    Production of biocompatible implants made of polyurethane treated with plasma is very perspective. During plasma treatment the surface of polyurethane acquires unique physic-chemical properties. However such treatment may change the mechanical properties of polyurethane which may adversely affect the deformation behaviour of the real implant. Therefore careful study of the mechanical properties of the plasma-modified polyurethane is needed. In this paper, experimental observations of the elastic characteristics of plasma treated polyurethane and modelling of the deformation behaviour of polyurethane bio-implants are reported.

  19. Time-dependent model of creep on the Hayward fault from joint inversion of 18 years of InSAR and surface creep data

    NASA Astrophysics Data System (ADS)

    Shirzaei, M.; Bürgmann, R.

    2013-04-01

    Spatial and temporal variations of aseismic fault creep influence the size and timing of large earthquakes along partially coupled faults. To solve for a time-dependent model of creep on the Hayward fault, we invert 18 years of surface deformation data (1992-2010), obtained by interferometric processing of 52 and 50 SAR images acquired by the ERS1/2 and Envisat satellites, respectively, and surface creep data obtained at 19 alinement and 4 creepmeter stations. For multi-temporal analysis of the SAR data we developed a method for identifying stable pixels using wavelet multi-resolution analysis. We also implement a variety of wavelet-based filters for reducing the effects of environmental artifacts. Using a reweighted least squares approach, we inverted the interferometric data to generate a time series of surface deformation over the San Francisco Bay Area with a precision of better than a few millimeters. To jointly invert the InSAR displacement time series and the surface creep data for a time-dependent model of fault creep, we use a robust inversion approach combined with a Kalman filter. The time-dependent model constrains a zone of high slip deficit that may represent the locked rupture asperity of past and future M≈7 earthquakes. We identify several additional temporal variations in creep rate along the Hayward fault, the most important one being a zone of accelerating slip just northwest of the major locked zone. We estimate that a slip-rate deficit equivalent to Mw 6.3-6.8 has accumulated on the fault, since the last event in 1868.

  20. Surface marker cluster translation, rotation, scaling and deformation: Their contribution to soft tissue artefact and impact on knee joint kinematics.

    PubMed

    Benoit, D L; Damsgaard, M; Andersen, M S

    2015-07-16

    When recording human movement with stereophotogrammetry, skin deformation and displacement (soft tissue artefact; STA) inhibits surface markers' ability to validly represent the movement of the underlying bone. To resolve this issue, the components of marker motions which contribute to STA must be understood. The purpose of this study is to describe and quantify which components of this marker motion (cluster translation, rotation, scaling and deformation) contribute to STA during the stance phase of walking, a cutting manoeuvre, and one-legged hops. In vivo bone pin-based tibio-femoral kinematics of six healthy subjects were used to study skin marker-based STA. To quantify how total cluster translation, rotation, scaling and deformation contribute to STA, a resizable and deformable cluster model was constructed. STA was found to be greater in the thigh than the shank during all three movements. We found that the non-rigid (i.e. scaling and deformation) movements contribute very little to the overall amount of error, rendering surface marker optimisation methods aimed at minimising this component superfluous. The results of the current study indicate that procedures designed to account for cluster translation and rotation during human movement are required to correctly represent the motion of body segments, however reducing marker cluster scaling and deformation will have little effect on STA. PMID:25935684

  1. Fabrication of dense α-alumina layer on Ti-6Al-4V alloy hybrid for bearing surfaces of artificial hip joint.

    PubMed

    Khanna, Rohit; Kokubo, Tadashi; Matsushita, Tomiharu; Takadama, Hiroaki

    2016-12-01

    Recent advances in hip replacements are focused towards producing reliable bearing surfaces to enhance their longevity. In this perspective, progressive attempts have been made to improve the wear resistance of polyethylene to eliminate osteolysis and mechanical reliability of brittle alumina ceramics, but in vain. It is proposed that both high wear resistance and mechanical reliability can be retained if a thin layer of dense alumina is formed onto high toughness Ti-6Al-4V alloy. For this purpose, we devised a unique methodology in which a layer of Al metal was deposited onto the Ti alloy substrate by cold spraying (CS), followed by a heat treatment to form Al3Ti reaction layer at their interface to improve adhesion and subsequent micro-arc oxidation (MAO) treatment to transform Al to alumina layer. An optimal MAO treatment of cold sprayed Al formed an adherent and dense α-alumina layer with high Vickers hardness matching with that of sintered alumina used as a femoral head. Structure-phase-property relationships in dense α-alumina layer have been revealed and discussed in the light of our research findings. The designed alumina/Ti alloy hybrid might be a potential candidate for reliable bearing surfaces of artificial hip joint. PMID:27612821

  2. Benign breast lesions: Ultrasound

    PubMed Central

    Masciadri, N.; Ferranti, C.

    2011-01-01

    Benign breast diseases constitute a heterogeneous group of lesions arising in the mammary epithelium or in other mammary tissues, and they may also be linked to vascular, inflammatory or traumatic pathologies. Most lesions found in women consulting a physician are benign. Ultrasound (US) diagnostic criteria indicating a benign lesion are described as well as US findings in the most frequent benign breast lesions. PMID:23396888

  3. Crustal and upper-mantle structure of the southeastern Tibetan Plateau from joint analysis of surface wave dispersion and receiver functions

    NASA Astrophysics Data System (ADS)

    Li, Mengkui; Zhang, Shuangxi; Wang, Fang; Wu, Tengfei; Qin, Weibing

    2016-03-01

    Researches on the southeastern Tibetan Plateau provide important insights into the tectonic evolution of the Tibetan Plateau. In this study, we have constructed a high-resolution 3D shear-wave velocity model through joint inversion of receiver functions and surface wave dispersion data. The crustal thickness and Poisson's ratio models are first determined by H-k stacking of receiver functions. The crustal thickness changes from 30 km in the south to 62 km in the north, presenting strong lateral variations. The fundamental mode of Rayleigh wave dispersion data spanning periods from 8 to 65 s were then jointly used to constraint the absolute shear-wave velocity. The shear-wave velocity structure shows lateral variations. There are low velocity zones distributed in the crust and upper mantle. Two continuously distributed low velocity zones are clearly presented in the middle-to-lower crust, which extend from north toward southeast and southwest, respectively, joining together in southern Yunnan. In this study, we deduced the migration model of soft materials in middle-to-lower crust in southeastern Tibetan Plateau, which explains that the resistance from Sichuan Basin separates the flowing materials from Tibetan Plateau into southeast and northwest branches. They flow along the west margin of Sichuan Basin and then extrude out from northeastern and southeastern Tibetan Plateau respectively. The southeast branch is blocked and cannot flow in the entire crust. It is limited in a certain range of depths and channels. The two low velocity zones in this study possibly present two flow channels of the middle-to-lower crustal materials extruded from the Tibetan Plateau.

  4. Temporomandibular Joint, Closed

    MedlinePlus

    ... Oral Health > The Temporomandibular Joint, Closed The Temporomandibular Joint, Closed Main Content Title: The Temporomandibular Joint, Closed Description: The temporomandibular joint connects the lower ...

  5. Generalized Degenerative Joint Disease in Osteoprotegerin (Opg) Null Mutant Mice.

    PubMed

    Bolon, B; Grisanti, M; Villasenor, K; Morony, S; Feige, U; Simonet, W S

    2015-09-01

    Bone structure is modulated by the interaction between receptor activator of nuclear factor-κB (RANK) and RANK ligand (RANKL). Osteoprotegerin (OPG), a decoy receptor for RANKL, modifies osteoclast-mediated bone resorption directly and spares articular cartilage indirectly in rodents with immune-mediated arthritis by preventing subchondral bone destruction. The OPG/RANKL balance also seems to be critical in maintaining joint integrity in osteoarthritis, a condition featuring articular bone and cartilage damage in the absence of profound inflammation. The current study explored the role of OPG in sparing articular cartilage by evaluating joint lesions in adult C57BL/6J mice lacking osteoprotegerin (Opg (-) (/-)). At 3, 5, 7, 9, and 12 months of age, both sexes of Opg (-) (/-) mice developed severe degenerative joint disease (DJD) characterized by progressive loss of cartilage matrix and eventually articular cartilage. Lesions developed earlier and more severely in Opg (-) (/-) mice relative to age-matched, wild-type (Opg (+) (/+)), or heterozygous (Opg (+) (/-)) littermates (P ≤ .05). The femorotibial joint was affected bilaterally at 3 months, while other key weight-bearing diarthrodial joints (eg, coxofemoral, scapulohumeral, humeroradioulnar) were affected later and unilaterally. Cortical bone in subchondral plates and long bone diaphyses of Opg (-) (/-) mice but not Opg (+/+) or Opg (+) (/-) animals was osteoporotic by 3 months of age (P ≤ .05); the extent of porosity was less than the degree of DJD. Closure of the physes in long bones (P ≤ .05) and cartilage retention in the femoral primary spongiosa (P ≤ .05) affected chiefly Opg (-) (/-) mice. These data suggest that OPG plays an essential direct role in maintaining cartilage integrity in the articular surfaces and physes.

  6. Pathology of articular cartilage and synovial membrane from elbow joints with and without degenerative joint disease in domestic cats.

    PubMed

    Freire, M; Meuten, D; Lascelles, D

    2014-09-01

    The elbow joint is one of the feline appendicular joints most commonly and severely affected by degenerative joint disease. The macroscopic and histopathological lesions of the elbow joints of 30 adult cats were evaluated immediately after euthanasia. Macroscopic evidence of degenerative joint disease was found in 22 of 30 cats (39 elbow joints) (73.33% cats; 65% elbow joints), and macroscopic cartilage erosion ranged from mild fibrillation to complete ulceration of the hyaline cartilage with exposure of the subchondral bone. Distribution of the lesions in the cartilage indicated the presence of medial compartment joint disease (most severe lesions located in the medial coronoid process of the ulna and medial humeral epicondyle). Synovitis scores were mild overall and correlated only weakly with macroscopic cartilage damage. Intra-articular osteochondral fragments either free or attached to the synovium were found in 10 joints. Macroscopic or histologic evidence of a fragmented coronoid process was not found even in those cases with intra-articular osteochondral fragments. Lesions observed in these animals are most consistent with synovial osteochondromatosis secondary to degenerative joint disease. The pathogenesis for the medial compartmentalization of these lesions has not been established, but a fragmented medial coronoid process or osteochondritis dissecans does not appear to play a role.

  7. A miniature specimen mechanical testing technique scaled to articulating surface of polyethylene components for total joint arthroplasty.

    PubMed

    Kurtz, S M; Jewett, C W; Foulds, J R; Edidin, A A

    1999-01-01

    The small punch test was developed to investigate the mechanical behavior of polyethylene using miniature specimens (< 14 mg) measuring 0.5 mm in thickness and 6.4 mm in diameter. The objective of this study was to demonstrate the feasibility and reproducibility of the small punch test when applied to clinically relevant polyethylenes. Mechanical behavior was characterized during 66 tests performed on GUR4150HP and GUR4120 specimens following alternate sterilization methods and 4 weeks of accelerated aging at 80 degrees C. The small punch test was found to be highly reproducible with regard to characterizing the ductility, ultimate strength, and fracture resistance of sterilized and aged polyethylene. In the future, the small punch test can be used to directly measure mechanical properties near the articulating surface of retrieved components.

  8. Joint detection of anatomical points on surface meshes and color images for visual registration of 3D dental models

    NASA Astrophysics Data System (ADS)

    Destrez, Raphaël.; Albouy-Kissi, Benjamin; Treuillet, Sylvie; Lucas, Yves

    2015-04-01

    Computer aided planning for orthodontic treatment requires knowing occlusion of separately scanned dental casts. A visual guided registration is conducted starting by extracting corresponding features in both photographs and 3D scans. To achieve this, dental neck and occlusion surface are firstly extracted by image segmentation and 3D curvature analysis. Then, an iterative registration process is conducted during which feature positions are refined, guided by previously found anatomic edges. The occlusal edge image detection is improved by an original algorithm which follows Canny's poorly detected edges using a priori knowledge of tooth shapes. Finally, the influence of feature extraction and position optimization is evaluated in terms of the quality of the induced registration. Best combination of feature detection and optimization leads to a positioning average error of 1.10 mm and 2.03°.

  9. Boundary lubricating ability of synovial fluid in degenerative joint disease.

    PubMed

    Davis, W H; Lee, S L; Sokoloff, L

    1978-01-01

    The boundary lubricating ability of eleven synovial fluids was measured in a miniaturized latex--glass test system. The specimens were obtained at necropsy from knees in which the degree of degenerative joint disease varied from none to very severe. The lubricating ability of the fluid was independent of the viscosity over a wide range of shear rates. It was not diminished even in advanced lesions. In two additional fluids, the mucin clot was poor; the lubricating ability of one of these was compromised. Thus, although degenerative joint disease, during its quiescent stages, is not associated with defective synovial lubrication, the possibility that transient defects might lead to cartilage wear during life has not been excluded. The measurements are believed to be valid indicators of boundary lubricating ability under physiological conditions despite the fact that the test surfaces were not cartilaginous and the loading was relatively low (up to 47 pounds per square inch).

  10. Example based lesion segmentation

    NASA Astrophysics Data System (ADS)

    Roy, Snehashis; He, Qing; Carass, Aaron; Jog, Amod; Cuzzocreo, Jennifer L.; Reich, Daniel S.; Prince, Jerry; Pham, Dzung

    2014-03-01

    Automatic and accurate detection of white matter lesions is a significant step toward understanding the progression of many diseases, like Alzheimer's disease or multiple sclerosis. Multi-modal MR images are often used to segment T2 white matter lesions that can represent regions of demyelination or ischemia. Some automated lesion segmentation methods describe the lesion intensities using generative models, and then classify the lesions with some combination of heuristics and cost minimization. In contrast, we propose a patch-based method, in which lesions are found using examples from an atlas containing multi-modal MR images and corresponding manual delineations of lesions. Patches from subject MR images are matched to patches from the atlas and lesion memberships are found based on patch similarity weights. We experiment on 43 subjects with MS, whose scans show various levels of lesion-load. We demonstrate significant improvement in Dice coefficient and total lesion volume compared to a state of the art model-based lesion segmentation method, indicating more accurate delineation of lesions.

  11. Example Based Lesion Segmentation

    PubMed Central

    Roy, Snehashis; He, Qing; Carass, Aaron; Jog, Amod; Cuzzocreo, Jennifer L.; Reich, Daniel S.; Prince, Jerry; Pham, Dzung

    2016-01-01

    Automatic and accurate detection of white matter lesions is a significant step toward understanding the progression of many diseases, like Alzheimer’s disease or multiple sclerosis. Multi-modal MR images are often used to segment T2 white matter lesions that can represent regions of demyelination or ischemia. Some automated lesion segmentation methods describe the lesion intensities using generative models, and then classify the lesions with some combination of heuristics and cost minimization. In contrast, we propose a patch-based method, in which lesions are found using examples from an atlas containing multi-modal MR images and corresponding manual delineations of lesions. Patches from subject MR images are matched to patches from the atlas and lesion memberships are found based on patch similarity weights. We experiment on 43 subjects with MS, whose scans show various levels of lesion-load. We demonstrate significant improvement in Dice coefficient and total lesion volume compared to a state of the art model-based lesion segmentation method, indicating more accurate delineation of lesions.

  12. Arthroscopic fixation of cell free polymer-based cartilage implants with a bioinspired polymer surface on the hip joint: a cadaveric pilot study.

    PubMed

    Lahner, Matthias; Duif, Christian; Ficklscherer, Andreas; Kaps, Christian; Kalwa, Lukas; Seidl, Tobias

    2014-01-01

    This study investigates the adhesion capacity of a polyglycolic acid- (PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10 mm × 15 mm full-thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds (P = 0.03752, P = 0.03078, P = 0.00512, P = 0.00512). PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation.

  13. Arthroscopic Fixation of Cell Free Polymer-Based Cartilage Implants with a Bioinspired Polymer Surface on the Hip Joint: A Cadaveric Pilot Study

    PubMed Central

    Lahner, Matthias; Duif, Christian; Ficklscherer, Andreas; Kaps, Christian; Kalwa, Lukas; Seidl, Tobias

    2014-01-01

    This study investigates the adhesion capacity of a polyglycolic acid- (PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10 mm × 15 mm full-thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds (P = 0.03752, P = 0.03078, P = 0.00512, P = 0.00512). PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation. PMID:25247185

  14. A joint data assimilation system (Tan-Tracker) to simultaneously estimate surface CO2 fluxes and 3-D atmospheric CO2 concentrations from observations

    NASA Astrophysics Data System (ADS)

    Tian, X.; Xie, Z.; Liu, Y.; Cai, Z.; Fu, Y.; Zhang, H.; Feng, L.

    2014-12-01

    We have developed a novel framework ("Tan-Tracker") for assimilating observations of atmospheric CO2 concentrations, based on the POD-based (proper orthogonal decomposition) ensemble four-dimensional variational data assimilation method (PODEn4DVar). The high flexibility and the high computational efficiency of the PODEn4DVar approach allow us to include both the atmospheric CO2 concentrations and the surface CO2 fluxes as part of the large state vector to be simultaneously estimated from assimilation of atmospheric CO2 observations. Compared to most modern top-down flux inversion approaches, where only surface fluxes are considered as control variables, one major advantage of our joint data assimilation system is that, in principle, no assumption on perfect transport models is needed. In addition, the possibility for Tan-Tracker to use a complete dynamic model to consistently describe the time evolution of CO2 surface fluxes (CFs) and the atmospheric CO2 concentrations represents a better use of observation information for recycling the analyses at each assimilation step in order to improve the forecasts for the following assimilations. An experimental Tan-Tracker system has been built based on a complete augmented dynamical model, where (1) the surface atmosphere CO2 exchanges are prescribed by using a persistent forecasting model for the scaling factors of the first-guess net CO2 surface fluxes and (2) the atmospheric CO2 transport is simulated by using the GEOS-Chem three-dimensional global chemistry transport model. Observing system simulation experiments (OSSEs) for assimilating synthetic in situ observations of surface CO2 concentrations are carefully designed to evaluate the effectiveness of the Tan-Tracker system. In particular, detailed comparisons are made with its simplified version (referred to as TT-S) with only CFs taken as the prognostic variables. It is found that our Tan-Tracker system is capable of outperforming TT-S with higher assimilation

  15. JOINT ANALYSIS OF NEAR-INFRARED PROPERTIES AND SURFACE BRIGHTNESS FLUCTUATIONS OF LARGE MAGELLANIC CLOUD STAR CLUSTERS

    SciTech Connect

    Raimondo, G.

    2009-08-01

    Surface brightness fluctuations (SBFs) have been proved to be a very powerful technique to determine the distance and characterize the stellar content in extragalactic systems. Nevertheless, before facing the problem of stellar content in distant galaxies, we need to calibrate the method onto nearby well known systems. In this paper we analyze the properties at the J and K{sub s} bands of a sample of 19 star clusters in the Large Magellanic Cloud, for which accurate near-infrared (NIR) resolved star photometry and integrated photometry are available. For the same sample, we derive the SBF measurements in the J and K{sub s} bands. We use the multipurpose stellar population code SPoT (Stellar POpulations Tools) to simulate the color-magnitude diagram, stellar counts, integrated magnitudes, colors, and SBFs of each cluster. The present procedure allows us to estimate the age and metallicity of the clusters in a consistent way, and provides a new calibration of the empirical s-parameter. We take advantage of the high sensitivity of NIR SBFs to thermally pulsing asymptotic (TP-AGB) stars to test different mass-loss rates affecting the evolution of such stars. We argue that NIR-SBFs can contribute to the disentangling of the observable properties of TP-AGB stars, especially in galaxies, where a large number of these stars are present.

  16. [Biomechanics of the knee joint].

    PubMed

    Witzel, U

    1993-01-01

    The capsular and ligamentous structures as control system of a healthy knee-joint supported by the muscular system are responsible for the rolling and gliding motion of the femoral condyles on the tibial plateau. Both the condyles and the tibial plateau have individually developed but to each other adjusted shapes and fine structures thereby. These structures consist of hyaline cartilage at their three-dimensional surfaces and of closely packed fibrils (lamina splendens) as the final gliding zone for tensile load. The orientation of the collagenous fibres can be made visible by split lines. The chondral surfaces are indirectly in contact to each other and orthogonally stressed at the particular point of contact. The indirect contact of the cartilaginous surfaces happens under interposition of the menisci. The meniscus serves to reduce and equalize the surface pressure by its own projected surface on the one hand and by maintaining of a hydraulic pressure of the synovial fluid on the other hand. Deviations of the condylar position as a result on ligamentous instabilities or ruptures with a following occurring loss of congruence, meniscal lesions or traumatic ruptures lead to a rapid discharge of the synovial fluid under load. The result is a hydraulic head loss with direct contact of the chondral surfaces under stress leading to arthrotic deformations. Severe arthrotic deformations or very much every meniscectomy produce intraarticular lumped loads resulting in a hyper-physiologic chondral pressure and malnutrition thereby. Further on there develop subchondral stress concentrations (caused by the lumped loads) leading to osseous damages, too. MR-pictures can make visible these damages. Chondromalacia, fissure or even chondrolysis are arthroscopically detectable sometimes. As after-effects of deficient knee ligaments occur pathological deviations of the femoral condyles and resulting destructions of the articular surfaces under stress enormously intensified by

  17. Moho Depth and Shear Velocity Structure in Northwest India and West Tibet from the Joint Inversion of Receiver Function and Surface Waves

    NASA Astrophysics Data System (ADS)

    Gilligan, A.; Priestley, K. F.; Roecker, S. W.; Levin, V. L.; Rai, S. S.

    2014-12-01

    The Tibetan Plateau is a key locality in understanding large-scale continental dynamics. A large number of investigations have examined the structure and processes in eastern Tibet, however western Tibet remains relatively understudied. The limited number of previous studies in this region indicate that the western part of the Tibetan Plateau is not a simple extension of the eastern part, despite the lack of surface features indicating differences between these two regions. In particular, wavespeeds higher than those in eastern Tibet have been observed in the upper mantle by a number of investigators. We present new, high resolution, shear velocity models for Northwest India and West Tibet from the joint inversion of P receiver functions and fundamental mode Rayleigh wave group velocities recorded at seismic stations in four arrays in this region. The areas covered by these arrays include the Karakoram and Altan-Taygh faults, major terrane boundaries in West Tibet and the Himalayas. The arrays used include broadband data collected by the West Tibet Array, a US-China deployment on the western side of the Tibetan Plateau between 2007-2011, and a French experiment in 2001. We construct group velocity tomographic maps throughout Central and Southern Asia from surface wave data between periods of 5-70s. The inclusion of Rayleigh wave dispersion measurements from ambient noise cross-correlations between stations in the West Tibet Array allow a local node spacing as fine as 0.25 degrees, meaning it is possible to resolve features as small as 1 degree at short periods in that region. These group velocity maps appears to confirm observations that group velocities at 60 and 70s group velocities are higher in West Tibet than they are in East Tibet. We use the shear wave velocity models obtained from the joint inversion to obtain estimates of Moho depth in Northwest India and West Tibet. The Moho is deep throughout Tibet in this region, increasing northwards and flattening out

  18. 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.

  19. Joint Commission

    MedlinePlus

    ... Sunday 1:00 CST, November 6, 2016 Workplace Violence Prevention Resources The Joint Commission has launched “Workplace Violence Prevention Resources,” an online resource center dedicated to ...

  20. Joint Problems

    MedlinePlus

    ... ankles and toes. Other types of arthritis include gout or pseudogout. Sometimes, there is a mechanical problem ... for more information on osteoarthritis, rheumatoid arthritis and gout. How Common are Joint Problems? Osteoarthritis, which affects ...

  1. OSTEOCHONDRAL AUTOLOGOUS TRANSPLANTATION FOR TREATING CHONDRAL LESIONS IN THE PATELLA

    PubMed Central

    Cohen, Moises; Amaro, Joicemar Tarouco; Fernandes, Ricardo de Souza Campos; Arliani, Gustavo Gonçalves; Astur, Diego da Costa; Kaleka, Camila Cohen; Skaf, Abdalla

    2015-01-01

    Objective: The primary aim of this study was to assess the clinical and functional evolution of patients with total-thickness symptomatic cartilaginous injury of the patellar joint surface, treated by means of osteochondral autologous transplantation. Methods: This prospective study was conducted from June 2008 to March 2011 and involved 17 patients. The specific questionnaires of Lysholm, Kujala and Fulkerson were completed preoperatively and one year postoperatively in order to assess the affected knee, and SF-36 was used to assess these patients’ general quality of life. The nonparametric paired Wilcoxon test was used for statistical analysis on the pre and postoperative questionnaires. The data were analyzed using the SPSS for Windows software, version 16.0, and a significance level of 5% was used. Results: The Lysholm preoperative and postoperative average scores were 54.59 and 75.76 points (p < 0.05). The Fulkerson pre and postoperative average scores were 52.53 and 78.41 points (p < 0.05). Conclusions: We believe that autologous osteochondral transplantation is a good treatment method for total-thickness symptomatic chondral lesions of the joint surface of the patella. PMID:27042645

  2. Influence of joint topology on the formation of brazed joints

    NASA Astrophysics Data System (ADS)

    Sekulic, Dusan P.; Zellmer, Benjamin P.; Nigro, Nicholas

    2001-09-01

    This paper discusses the influence of joint topology on the formation of brazed joints. For the purposes of this study, the joint topology is defined by dimensionless parameters that characterize: (i) the geometry of the mating surfaces (shape and configuration), (ii) the gap between bonded parts (clearance and tolerances), (iii) the joint orientation in the gravity field and (iv) the volume of the joint. The influence of these parameters is presented for several joints with a topology that is typically found in the manufacture of compact heat exchangers. The results were obtained by employing a method that is based on a variational principle and minimization of the potential energy of the molten aluminium liquid metal just prior to the onset of solidification. The method, which was verified by comparison with experimental data obtained from controlled atmosphere brazing of aluminium alloys, is discussed in an accompanying paper.

  3. Effects of holmium:YAG laser on equine articular cartilage and subchondral bone adjacent to traumatic lesions

    NASA Astrophysics Data System (ADS)

    Collier, Michael A.; Haugland, L. Mark; Bellamy, Janine; Johnson, Lanny L.; Rohrer, Michael D.; Walls, Robert C.; Bartels, Kenneth E.

    1994-09-01

    The effects of Ho:YAG laser energy on articular cartilage and subchondral bone adjacent to traumatically created cartilage lesions in a continuous weight-bearing model were investigated. The 2.1 micrometers wavelength was delivered in hand-controlled contact and near-contact hard tissue arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal and intercarpal joints of four adult horses. One-hundred twenty traumatic lesions were created on three weight-bearing articular surfaces with a knife, curette, or a motorized burr. Depths of the lesions were partial and full thickness. Configurations of the lesions were lacerations, scrapes, and craters. Left limbs were used as controls. Right limb lesions were treated with various intensities of laser energy. Animals were sacrificed at intervals of 1, 3, and 8 weeks. Gross microscopic anatomy was documented, and tissue sections were subjected to blind review by a pathologist. Mankin grading for cellularity and proteoglycan content was used to qualitatively evaluate cartilage response. Cartilage adjacent to all lesions exposed to laser energy had better cellularity and proteoglycan content than corresponding controls by Mankin grading.

  4. Examination of the suitability of alpha-tocopherol as a stabilizer for ultra-high molecular weight polyethylene used for articulating surfaces in joint endoprostheses.

    PubMed

    Wolf, C; Krivec, T; Blassnig, J; Lederer, K; Schneider, W

    2002-02-01

    The lifetime of articulating surfaces in joint endoprostheses made of ultra-high molecular weight polyethylene (UHMW-PE), especially of UHMW-PE-cups of hip-endoprostheses, is usually limited to 10-15 years due to material failure as a result of oxidation of the UHMW-PE in vivo. In this study the suitability of the natural antioxidant alpha-tocopherol (vitamin E) as a stabilizer for UHMW-PE in these applications was investigated. Specimens with 0.1%, 0.2%, 0.4% and 0.8% w/w alpha-tocopherol as well as unstabilized samples were sintered and sterilized with gamma-rays at 25 kGy in accordance with standard processing methods of cups for total hip-endoprostheses. These specimens were aged in pure oxygen at 70 degrees C and 5 bar as well as in aqueous H2O2 at 50 degrees C. The degree of oxidation was observed by means of FTIR-spectroscopy, DSC analysis and mechanical testing. The FTIR-measurements showed that alpha-tocopherol can prolong the lifetime of UHMW-PE in an oxidative environment by a factor of more than 2.5. In the mechanical tests no embrittlement could be observed with the stabilized samples. A comparison with the standard antioxidant system Irganox 1010/Irgafos 168 (Ciba-Geigy, Switzerland) was carried out and revealed that alpha-tocopherol can even exceed the stabilization effect of this widely-used antioxidant system.

  5. Analysis of minor fractures associated with joints and faulted joints

    NASA Astrophysics Data System (ADS)

    Cruikshank, Kenneth M.; Zhao, Guozhu; Johnson, Arvid M.

    the simplest is a veer, where the end of one joint segment turns gradually toward a nearby joint segment. The veer is a result of a nearby, shear-stress-free face such as a joint surface. Our greatest difficulty has been explaining long overlap of parallel joint segments, that is, the lack of veer. The only plausible explanation we know is suggested by the research of Cottrell and Rice, that high compression parallel to the joint segments will tend to prevent the joints from turning toward one another. The most interesting and puzzling fractures are stepped joints and associated echelon cracks, in which the slight misalignment of the stepped joints suggests mild left-lateral shear, while the strong misalignment of echelon cracks that continue the traces of the stepped joints suggests strong right-lateral shear. The stepped joints are thought to reflect local left-lateral shearing that acted over an area of several thousand square metres, whereas the stepped echelon cracks reflect local interaction between the tips of nearby joints propagating in different directions.

  6. 21 CFR 884.2990 - Breast lesion documentation system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breast lesion documentation system. 884.2990... Devices § 884.2990 Breast lesion documentation system. (a) Identification. A breast lesion documentation system is a device for use in producing a surface map of the breast as an aid to document palpable...

  7. 21 CFR 884.2990 - Breast lesion documentation system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breast lesion documentation system. 884.2990... Devices § 884.2990 Breast lesion documentation system. (a) Identification. A breast lesion documentation system is a device for use in producing a surface map of the breast as an aid to document palpable...

  8. 21 CFR 884.2990 - Breast lesion documentation system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breast lesion documentation system. 884.2990... Devices § 884.2990 Breast lesion documentation system. (a) Identification. A breast lesion documentation system is a device for use in producing a surface map of the breast as an aid to document palpable...

  9. 21 CFR 884.2990 - Breast lesion documentation system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breast lesion documentation system. 884.2990... Devices § 884.2990 Breast lesion documentation system. (a) Identification. A breast lesion documentation system is a device for use in producing a surface map of the breast as an aid to document palpable...

  10. 21 CFR 884.2990 - Breast lesion documentation system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breast lesion documentation system. 884.2990... Devices § 884.2990 Breast lesion documentation system. (a) Identification. A breast lesion documentation system is a device for use in producing a surface map of the breast as an aid to document palpable...

  11. Giant intraosseous cyst-like lesions in rheumatoid arthritis report of a case.

    PubMed

    Lohse, Anne; Carbillet, Jean-Pierre; Onimus, Michel; Stevenel, Françoise; Toussirot, Eric; Wendling, Daniel

    2003-02-01

    The term "intraosseous synovial cyst" is used to designate both the epiphyseal cyst-like lesions seen in patients with rheumatoid arthritis (RA) and mucoid cysts, which occur in a different setting. We report the case of a patient in whom a 4-cm cyst-like lesion developed in the left tibia 18 years after onset of RA and 6 years after osmic acid synovectomy of the left knee. Positive contrast arthrography and magnetic resonance imaging visualized a communication between the lesion and the joint space. Preexisting bone and joint lesions and increased intraarticular pressure play a major role in the genesis of cyst-like lesions in RA. In our patient, the osmic acid synovectomy may have contributed to the development of the lesion. "Synovial cyst" is a misnomer for these giant lesions, which are geodes rather than cysts. Despite their low incidence, these lesions deserve attention because they raise diagnostic and therapeutic problems.

  12. Ghost cell lesions

    PubMed Central

    Rajesh, E.; Jimson, Sudha; Masthan, K. M. K.; Balachander, N.

    2015-01-01

    Ghost cells have been a controversy for a long time. Ghost cell is a swollen/enlarged epithelial cell with eosnophilic cytoplasm, but without a nucleus. In routine H and E staining these cells give a shadowy appearance. Hence these cells are also called as shadow cells or translucent cells. The appearance of these cells varies from lesion to lesion involving odontogenic and nonodontogenic lesions. This article review about the origin, nature and significance of ghost cells in different neoplasms. PMID:26015694

  13. Surface modification with dopamine and heparin/poly-L-lysine nanoparticles provides a favorable release behavior for the healing of vascular stent lesions.

    PubMed

    Liu, Tao; Zeng, Zheng; Liu, Yang; Wang, Jian; Maitz, Manfred F; Wang, Yuan; Liu, Shihui; Chen, Junying; Huang, Nan

    2014-06-11

    Surface biofunctional modification of coronary artery stents to prevent thrombosis and restenosis formation, as well as accelerate endothelialization, has become a new hot spot. However, bioactive coatings on implants are not yet sufficiently developed for long-term activity, as they quickly lose efficiency in vivo and finally fail. On the basis of a novel time-ordered concept of biofunctionality for vascular stents, heparin/poly l-lysine nanoparticle (NP) was developed and immobilized on a polydopamine-coated titanium surface, with the aim of regulating and maintaining the intravascular biological response within the normal range after biomaterial implantation. An in vitro dynamic release model was established to mimic the blood flow condition in vivo with three phases: (1) An early phase (1-7 days) with release of predominantly anticoagulant and anti-inflammatory substances and to a minor degree antiproliferative effects against smooth muscle cells (SMCs); (2) this is followed by a phase (7-14 days) of supported endothelial cell (ECs) proliferation and suppressed SMC proliferation with persisting high antithrombogenicity and anti-inflammatory properties of the surface. (3) Finally, a stable stage (14-28 days) with adequate biomolecules on the surface that maintain hemocompatibility and anti inflammation as well as inhibit SMCs proliferation and promote ECs growth. In vivo animal tests further confirmed that the NP-modified surface provides a favorable release behavior to apply a stage-adjusted remedy. We suggested that these observations provide important guidance and potential means for reasonable and suitable platform construction on a stent surface. PMID:24731022

  14. Elastic Wavespeed Images of Northern Chile Subduction Zone from the Joint Inversion of Body and Surface Waves: Structure of the Andean Forearc and the Double Seismic Zone

    NASA Astrophysics Data System (ADS)

    Comte, D.; Carrizo, D.; Roecker, S. W.; Peyrat, S.; Arriaza, R.; Chi, R. K.; Baeza, S.

    2015-12-01

    Partly in anticipation of an imminent megathrust earthquake, a significant amount of seismic data has been collected over the past several years in northern Chile by local deployments of seismometers. In this study we generate elastic wavespeed images of the crust and upper mantle using a combination of body wave arrival times and surface wave dispersion curves. The body wave data set consists of 130000 P and 108000 S wave arrival times generated by 12000 earthquakes recorded locally over a period of 25 years by networks comprising about 360 stations. The surface wave data set consists of Rayleigh wave dispersion curves determined from ambient noise recorded by 60 broad band stations from three different networks over a period of three years. Transit time biases due to an uneven distribution of noise were estimated using a technique based on that of Yao and van der Hilst (2009) and found to be as high as 5% for some station pairs. We jointly invert the body and surface wave observations to both improve the overall resolution of the crustal images and reduce the trade-off between shallow and deep structures in the images of the subducted slab. Of particular interest in these images are three regions of anomalous Vp/Vs: (1) An extensive zone of low Vp/Vs (1.68) correlates with trench-parallel magmatic belts emplaced in the upper continental crust. In the region of the coast and continental slope, low Vp/Vs corresponds to batholithic structures in the Jurassic-Cretaceous magmatic arc. Between the central depression and Domeyko Cordillera, low Vp/Vs correlates with the distribution of magmatic arcs of Paleocene-Oligocene and Eocene-Oligocene age. Low Vp/Vs also correlates with the location of the Mejillones Peninsula. (2) A region of high Vp/Vs occurs in what is most likely the serpentinized wedge of the subduction zone. (3) An additional zone of low Vp/Vs is located in the middle of the double seismic zone at depths of 90-110 km. This region may exist all along the

  15. Osteoma of temporomandibular joint: a rarity.

    PubMed

    Misra, Neeta; Srivastava, Saurabh; Bodade, Pankaj R; Rastogi, Vikalp

    2013-09-06

    Osteoma is a benign tumour consisting of mature bone tissue. It is an uncommon lesion that occurs in the bones of the craniofacial complex. Only a few cases involving the temporomandibular joint have been reported. An osteoma of the left temporomandibular joint causing limited mouth opening in a 22-year-old man with CT findings revealing the unusual possibility in differential diagnosis of trismus.

  16. Osteoma of temporomandibular joint: a rarity

    PubMed Central

    Misra, Neeta; Srivastava, Saurabh; Bodade, Pankaj R; Rastogi, Vikalp

    2013-01-01

    Osteoma is a benign tumour consisting of mature bone tissue. It is an uncommon lesion that occurs in the bones of the craniofacial complex. Only a few cases involving the temporomandibular joint have been reported. An osteoma of the left temporomandibular joint causing limited mouth opening in a 22-year-old man with CT findings revealing the unusual possibility in differential diagnosis of trismus. PMID:24014334

  17. Preinvasive lesions

    Cancer.gov

    This definition is for allocation of lesions with preinvasive/borderline properties. It is currently aimed at newly identified neoplasms, which may be similar to those described in humans. In mouse pathology, many adenomas may be preinvasive/borderline lesions. However, their inclusion in the preinvasive category can be justified only upon development of better diagnostic criteria.

  18. Examination of the suitability of alpha-tocopherol as a stabilizer for ultra-high molecular weight polyethylene used for articulating surfaces in joint endoprostheses.

    PubMed

    Wolf, C; Krivec, T; Blassnig, J; Lederer, K; Schneider, W

    2002-02-01

    The lifetime of articulating surfaces in joint endoprostheses made of ultra-high molecular weight polyethylene (UHMW-PE), especially of UHMW-PE-cups of hip-endoprostheses, is usually limited to 10-15 years due to material failure as a result of oxidation of the UHMW-PE in vivo. In this study the suitability of the natural antioxidant alpha-tocopherol (vitamin E) as a stabilizer for UHMW-PE in these applications was investigated. Specimens with 0.1%, 0.2%, 0.4% and 0.8% w/w alpha-tocopherol as well as unstabilized samples were sintered and sterilized with gamma-rays at 25 kGy in accordance with standard processing methods of cups for total hip-endoprostheses. These specimens were aged in pure oxygen at 70 degrees C and 5 bar as well as in aqueous H2O2 at 50 degrees C. The degree of oxidation was observed by means of FTIR-spectroscopy, DSC analysis and mechanical testing. The FTIR-measurements showed that alpha-tocopherol can prolong the lifetime of UHMW-PE in an oxidative environment by a factor of more than 2.5. In the mechanical tests no embrittlement could be observed with the stabilized samples. A comparison with the standard antioxidant system Irganox 1010/Irgafos 168 (Ciba-Geigy, Switzerland) was carried out and revealed that alpha-tocopherol can even exceed the stabilization effect of this widely-used antioxidant system. PMID:15348641

  19. Imaging Pediatric Vascular Lesions

    PubMed Central

    Nguyen, Tuyet A.; Krakowski, Andrew C.; Naheedy, John H.; Kruk, Peter G.

    2015-01-01

    Vascular anomalies are commonly encountered in pediatric and dermatology practices. Most of these lesions are benign and easy to diagnose based on history and clinical exam alone. However, in some cases the diagnosis may not be clear. This may be of particular concern given that vascular anomalies may occasionally be associated with an underlying syndrome, congenital disease, or serious, life-threatening condition. Defining the type of vascular lesion early and correctly is particularly important to determine the optimal approach to management and treatment of each patient. The care of pediatric patients often requires collaboration from a multitude of specialties including pediatrics, dermatology, plastic surgery, radiology, ophthalmology, and neurology. Although early characterization of vascular lesions is important, consensus guidelines regarding the evaluation and imaging of vascular anomalies does not exist to date. Here, the authors provide an overview of pediatric vascular lesions, current classification systems for characterizing these lesions, the various imaging modalities available, and recommendations for appropriate imaging evaluation. PMID:26705446

  20. Extragastric Dieulafoy's lesion

    PubMed Central

    Gauci, James; Galea, Samuel; Galea, Joseph; Schembri, Mark

    2014-01-01

    A 74-year-old man on warfarin for aortic valve replacement presented with recurrent episodes of melaena. An initial oesophagogastroduodenoscopy (OGD) was normal, as were red cell scanning and colonoscopy. It was a third OGD that revealed the cause of the melaena—a vascular lesion in the duodenum, at the junction between D1 and D2. An extragastric Dieulafoy's lesion was diagnosed, and the lesion was injected with epinephrine and tattooed. Over the following months, episodes of bleeding recurred despite further attempts at injection. Percutaneous radiologically assisted embolisation of the gastroduodenal artery, and eventually duodenotomy and oversuturing of the lesion were performed to no avail. The patient has undergone over 10 endoscopies, and has received over 70 units of packed red cells to date, since his initial presentation 6 years ago. Attempts to stop the bleeding permanently have been difficult, highlighting the complexity of managing such a lesion. PMID:25216921

  1. Bdellovibrio bacteriovorus HD100 guards against Pseudomonas tolaasii brown-blotch lesions on the surface of post-harvest Agaricus bisporus supermarket mushrooms

    PubMed Central

    2014-01-01

    Background Pseudomonas tolaasii is a problematic pathogen of cultured mushrooms, forming dark brown ‘blotches’ on mushroom surfaces and causing spoilage during crop growth and post-harvest . Treating P. tolaasii infection is difficult, as other, commensal bacterial species such as Pseudomonas putida are necessary for mushroom growth, so treatments must be relatively specific. Results We have found that P. tolaasii is susceptible to predation in vitro by the δ-proteobacterium Bdellovibrio bacteriovorus. This effect also occurred in funga, where B. bacteriovorus was administered to post-harvest mushroom caps before and after administration of the P. tolaasii pathogen. A significant, visible improvement in blotch appearance, after incubation, was observed on administration of Bdellovibrio. A significant reduction in viable P. tolaasii cell numbers, recovered from the mushroom tissue, was detected. This was accompanied by a more marked reduction in blotch severity on Bdellovibrio administration. We found that there was in some cases an accompanying overgrowth of presumed-commensal, non-Pseudomonas bacteria on post-harvest mushroom caps after Bdellovibrio-treatment. These bacteria were identified (by 16SrRNA gene sequencing) as Enterobacter species, which were seemingly resistant to predation. We visualised predatory interactions occuring between B. bacteriovorus and P. tolaasii on the post-harvest mushroom cap surface by Scanning Electron Microscopy, seeing predatory invasion of P. tolaasii by B. bacteriovorus in funga. This anti-P. tolaasii effect worked well in post-harvest supermarket mushrooms, thus Bdellovibrio was not affected by any pre-treatment of mushrooms for commercial/consumer purposes. Conclusions The soil-dwelling B. bacteriovorus HD100 preys upon and kills P. tolaasii, on mushroom surfaces, and could therefore be applied to prevent spoilage in post-harvest situations where mushrooms are stored and packaged for sale. PMID:24946855

  2. 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.

  3. Approach alternatives for treatment of osteochondral lesions of the talus.

    PubMed

    Navid, David O; Myerson, Mark S

    2002-09-01

    Osteochondral lesions of the talus are common injuries, especially in the athletic population. Although multiple etiologies exist, lateral lesions have a higher incidence of association with a specific traumatic event. It has been postulated that lateral lesions are produced when the anterolateral aspect of the talar dome impacts the fibula on application of an inversion or dorsiflexion stress to the ankle [2]. There is general agreement that surgery should be performed only in symptomatic cases, as osteochondral lesions of the talar dome show little tendency to progression and do not seem to lead to osteoarthritis [10,42]. Appropriate preoperative imaging is extremely important. Standard radiographs of the ankle supplemented with lateral plantar flexion and dorsiflexion views and CT or Mr imaging can be helpful in evaluating the size, depth, and exact location of the lesion. This information is essential in planning the appropriate surgical procedure. Although many stage I and II lesions respond well to conservative therapy and a period of immobilization, some higher-grade lesions (stage III and IV) eventually require surgical intervention. Most lesions can be approached arthroscopically. Many arthroscopic procedures have been shown to be successful, including debridement with abrasion chondroplasty, subchondral drilling, and microfracture [18-20]. But certain larger or refractory lesions may require an open approach to the ankle joint to restore the articular cartilage. Most lateral lesions have an anterior location and are easily accessible through a standard anterolateral approach. Most medial lesions are located on the posterior talar dome, and a medial malleolar osteotomy is usually required. Osteotomies, in particular of the medial malleolus, should be approached carefully. The possible complications of nonunion and malunion can lead to progressive arthritis of the ankle joint.

  4. Multifocal vascular lesions.

    PubMed

    Levin, Laura E; Lauren, Christine T

    2016-03-01

    Multifocal vascular lesions are important to recognize and appropriately diagnose. Generally first noticed on the skin, multifocal vascular lesions may have systemic involvement. Distinguishing among the different types of multifocal vascular lesions is often based on clinical features; however, radiological imaging and/or biopsy are frequently needed to identify distinct features and guide treatment. Knowledge of the systemic associations that can occur with different vascular anomalies may reduce life-threatening complications, such as coagulopathy, bleeding, cardiac compromise, and neurologic sequelae. This review provides a synopsis of the epidemiology, pathogenesis, presentation, workup, and treatment of several well-recognized multifocal vascular tumors and malformations. PMID:27607324

  5. Oral Lesions in Neonates

    PubMed Central

    Rao, Roopa S; Majumdar, Barnali; Jafer, Mohammed; Maralingannavar, Mahesh; Sukumaran, Anil

    2016-01-01

    ABSTRACT Oral lesions in neonates represent a wide range of diseases often creating apprehension and anxiety among parents. Early examination and prompt diagnosis can aid in prudent management and serve as baseline against the future course of the disease. The present review aims to enlist and describe the diagnostic features of commonly encountered oral lesions in neonates. How to cite this article: Patil S, Rao RS, Majumdar B, Jafer M, Maralingannavar M, Sukumaran A. Oral Lesions in Neonates. Int J Clin Pediatr Dent 2016;9(2):131-138. PMID:27365934

  6. Retinal lesions in septicemia.

    PubMed

    Neudorfer, M; Barnea, Y; Geyer, O; Siegman-Igra, Y

    1993-12-15

    We explored the association between septicemia and specific retinal lesions in a prospective controlled study. Hemorrhages, cotton-wool spots, or Roth's spots were found in 24 of 101 septicemic patients (24%), compared to four of 99 age- and gender-matched control patients (4%) (P = .0002). There was no significant association between types of organisms or focus of infection and the presence of specific lesions. Histologic examination of affected eyes disclosed cytoid bodies in the nerve fiber layer without inflammation. A definite association between septicemia and retinal lesions was found and indicates the need for routine ophthalmoscopy in septicemic patients. PMID:8250076

  7. Synovial Lipomatosis of the Glenohumeral Joint

    PubMed Central

    Safran, Ori

    2016-01-01

    Synovial lipomatosis (also known as lipoma arborescens) is a rare and benign lesion affecting synovium-lined cavities. It is characterized by hyperplasia of mature fat tissue in the subsynovial layer. Although the most commonly affected site is the knee joint, rarely additional locations such as tendon sheath and other joints are involved. We present a case of synovial lipomatosis of the glenohumeral joint in a 44-year-old man. The clinical data radiological studies and histopathologic results are described, as well as a review of the current literature. PMID:27563476

  8. Synovial Lipomatosis of the Glenohumeral Joint.

    PubMed

    Beyth, Shaul; Safran, Ori

    2016-01-01

    Synovial lipomatosis (also known as lipoma arborescens) is a rare and benign lesion affecting synovium-lined cavities. It is characterized by hyperplasia of mature fat tissue in the subsynovial layer. Although the most commonly affected site is the knee joint, rarely additional locations such as tendon sheath and other joints are involved. We present a case of synovial lipomatosis of the glenohumeral joint in a 44-year-old man. The clinical data radiological studies and histopathologic results are described, as well as a review of the current literature.

  9. Imaging caries lesions and lesion progression with polarization-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Fried, Daniel; Xie, John; Shafi, Sahar; Featherstone, John D. B.; Breunig, Thomas; Le, Charles Q.

    2002-06-01

    New diagnostic tools are needed for the characterization of dental caries in the early stages of development. If carious lesions are detected early enough, they can be arrested without the need for surgical intervention. The objective of this study was to demonstrate that polarization sensitive optical coherence tomography (PS-OCT) can be used for the imaging of early caries lesions and for the monitoring of lesion progression over time. High-resolution polarization resolved images were acquired of natural caries lesions and simulated caries lesions of varying severity created over time periods of 1 to 14 days. Linearly polarized light was incident on the tooth samples and the reflected intensity in both orthogonal polarizations was measured. PS-OCT was invaluable for removing the confounding influence of surface reflections and native birefringence and for resolving the surface structure of caries lesions. This study demonstrated that PS-OCT is well suited for the resolution of interproximal and occlusal caries, early root caries, and secondary caries around composite fillings. Longitudinal measurements of lesion progression established a strong correlation (p<0.001) between the reflected light from the lesion area and the square root of time indicating that PS-OCT is well suited for monitoring changes in enamel mineralization over time.

  10. Uncertainty of knee joint muscle activity during knee joint torque exertion: the significance of controlling adjacent joint torque.

    PubMed

    Nozaki, Daichi; Nakazawa, Kimitaka; Akai, Masami

    2005-09-01

    In the single-joint torque exertion task, which has been widely used to control muscle activity, only the relevant joint torque is specified. However, the neglect of the neighboring joint could make the procedure unreliable, considering our previous result that even monoarticular muscle activity level is indefinite without specifying the adjacent joint torque. Here we examined the amount of hip joint torque generated with knee joint torque and its influence on the activity of the knee joint muscles. Twelve healthy subjects were requested to exert various levels of isometric knee joint torque. The knee and hip joint torques were obtained by using a custom-made device. Because no information about hip joint torque was provided to the subjects, the hip joint torque measured here was a secondary one associated with the task. The amount of hip joint torque varied among subjects, indicating that they adopted various strategies to achieve the task. In some subjects, there was a considerable internal variability in the hip joint torque. Such variability was not negligible, because the knee joint muscle activity level with respect to the knee joint torque, as quantified by surface electromyography (EMG), changed significantly when the subjects were requested to change the strategy. This change occurred in a very systematic manner: in the case of the knee extension, as the hip flexion torque was larger, the activity of mono- and biarticular knee extensors decreased and increased, respectively. These results indicate that the conventional single knee joint torque exertion has the drawback that the intersubject and/or intertrial variability is inevitable in the relative contribution among mono- and biarticular muscles because of the uncertainty of the hip joint torque. We discuss that the viewpoint that both joint torques need to be considered will bring insights into various controversial problems such as the shape of the EMG-force relationship, neural factors that help

  11. Arthroscopic optical coherence tomography provides detailed information on articular cartilage lesions in horses.

    PubMed

    te Moller, N C R; Brommer, H; Liukkonen, J; Virén, T; Timonen, M; Puhakka, P H; Jurvelin, J S; van Weeren, P R; Töyräs, J

    2013-09-01

    Arthroscopy enables direct inspection of the articular surface, but provides no information on deeper cartilage layers. Optical coherence tomography (OCT), based on measurement of reflection and backscattering of light, is a diagnostic technique used in cardiovascular surgery and ophthalmology. It provides cross-sectional images at resolutions comparable to that of low-power microscopy. The aim of this study was to determine if OCT is feasible for advanced clinical assessment of lesions in equine articular cartilage during diagnostic arthroscopy. Diagnostic arthroscopy of 36 metacarpophalangeal joints was carried out ex vivo. Of these, 18 joints with varying degrees of cartilage damage were selected, wherein OCT arthroscopy was conducted using an OCT catheter (diameter 0.9 mm) inserted through standard instrument portals. Five sites of interest, occasionally supplemented with other locations where defects were encountered, were arthroscopically graded according to the International Cartilage Repair Society (ICRS) classification system. The same sites were evaluated qualitatively (ICRS classification and morphological description of the lesions) and quantitatively (measurement of cartilage thickness) on OCT images. OCT provided high resolution images of cartilage enabling determination of cartilage thickness. Comparing ICRS grades determined by both arthroscopy and OCT revealed poor agreement. Furthermore, OCT visualised a spectrum of lesions, including cavitation, fibrillation, superficial and deep clefts, erosion, ulceration and fragmentation. In addition, with OCT the arthroscopically inaccessible area between the dorsal MC3 and P1 was reachable in some cases. Arthroscopically-guided OCT provided more detailed and quantitative information on the morphology of articular cartilage lesions than conventional arthroscopy. OCT could therefore improve the diagnostic value of arthroscopy in equine orthopaedic surgery. PMID:23810744

  12. Skin lesion of blastomycosis

    MedlinePlus

    ... in: Africa Canada Central and southeastern United States India Israel Saudi Arabia A person gets infected by ... is diagnosed by identifying the fungus in a culture taken from a skin lesion. This usually requires ...

  13. Acute nontraumatic liver lesions.

    PubMed

    Caremani, Marcello; Tacconi, Danilo; Lapini, Laura

    2013-11-26

    The principal conditions requiring emergency/urgent intervention in patients with nontraumatic liver lesions are hemorrhage (with or without tumor rupture), rupture of hydatid cysts (with or without infection), complications arising from liver abscesses or congenital liver cysts, rupture related to peliosis hepatis, and in rare cases spontaneous hemorrhage. This article examines each of these conditions, its appearance on ultrasound (the first-line imaging method of choice for assessing any urgent nontraumatic liver lesion) and indications for additional imaging studies.

  14. [Osteoarticular lesions from parachuting].

    PubMed

    Orso, C A; Valbonesi, L; Calabrese, B F; D'Onofrio, S

    1990-01-01

    Based on personal experience gained in a parachuting centre (Pescara Aero-club) from 1975 up to 1988, the authors report their evaluation on chronic and acute osteoarticular lesions. The review of the cases was not based on the incidence of the lesions nor on their characteristics, normally found in common traumatology, but it was related to the dynamics of the trauma during the landing and to painful syndromes following a prolonged parachuting activity.

  15. [Injuries of the acromioclavicular joint].

    PubMed

    Meeder, P J; Dannöhl, C

    1988-07-01

    The injuries of the acromio-clavicular joint require a differentiated diagnosis and treatment. The classification of the acromio-clavicular dislocations from grade I to grade III according to Tossy is proved. The diagnosis of a complete acromio-clavicular dislocation (Tossy III) is an indication for a surgical repair. Many and different methods are reported in the literature. 178 patients with a fresh acromio-clavicular dislocation (Typ Tossy II and III) were treated at the BG-Unfallklinik Tübingen from 1970 to 1987 by suturing the ligaments, inserting pins across the joint and tension wire bending. In old cases with Tossy III dislocation of the acromio-clavicular joint an oblique osteotomy combined with the reduction of the clavicle is recommended as a method of choice. The results of these procedures and there possible intra- and postoperative complications are reported. The incision along the clavicle quite often gives scar problems. Therefore the advantages of an arched incision across the acromio-clavicular joint is pointed out. Because of there biomechanical relationship fractures in the lateral third of the clavicle are similar to dislocations of the acromio-clavicular joint. The classification of these fractures according to Jäger, Buschle and Breitner allows a differentiated management of these lesions.

  16. Anatomy and histology of the sacroiliac joints.

    PubMed

    Egund, Niels; Jurik, Anne Grethe

    2014-07-01

    The anatomy of joints provides an important basis for understanding the nature and imaging of pathologic lesions and their imaging appearance. This applies especially to the sacroiliac (SI) joints, which play a major role in the diagnosis of spondyloarthritis. They are composed of two different joint portions, a cartilage-covered portion ventrally and a ligamentous portion dorsally, and thus rather complex anatomically. Knowledge of anatomy and the corresponding normal imaging findings are important in the imaging diagnosis of sacroiliitis, especially by MR imaging. A certain distinction between the two joint portions by MR imaging is only obtainable by axial slice orientation. Together with a perpendicular coronal slice orientation, it provides adequate anatomical information and thereby a possibility for detecting the anatomical site of disease-specific characteristics and normal variants simulating disease. This overview describes current knowledge about the normal macroscopic and microscopic anatomy of the SI joints.

  17. Costovertebral and costotransverse joint involvement in rheumatoid arthritis.

    PubMed Central

    Cohen, M J; Ezekiel, J; Persellin, R H

    1978-01-01

    Lesions of the costovertebral (CV) and costotransverse (CT) joints are distinctly unusual in rheumatoid arthritis. The patient presented had dramatic changes in these joints with destruction, ankylosis, and bony overgrowth. This led to a moderate respiratory impairment and a distinctive radiological presentation. Images PMID:718281

  18. Pyrothermal treatment of welded joints

    SciTech Connect

    Serikov, S.V.; Idiyatullin, R.S.; Myakushkin, S.N.; Yaufman, V.V.

    1992-03-01

    The results of investigation of the structure and distribution of residual stresses in welded joints in pipes after heat treatment, which includes heating of the surface being treated due to combustion of plates formed from a thermite-type material of pyrotechnic composition, placed around the perimeter of the welded joint, and also an assessment of the level of residual stresses prior to and after pyrotechnic treatment demonstrated the promising nature of the proposed method. 5 refs., 5 figs.

  19. [Diagnostic temporo-mandibular arthroscopy. Principle lesions, apropos of 50 case reports].

    PubMed

    Chossegros, C; Cheynet, F; Blanc, J L; Gola, R; Lachard, J

    1991-01-01

    Diagnostic arthroscopy is reserved to patients who suffer from internal temporo-mandibular joint derangements resisting to conservative treatments. This technique allows an acute diagnostic approach to the intra-articular lesions of the superior compartment.

  20. Meniscal Ramp Lesions

    PubMed Central

    Chahla, Jorge; Dean, Chase S.; Moatshe, Gilbert; Mitchell, Justin J.; Cram, Tyler R.; Yacuzzi, Carlos; LaPrade, Robert F.

    2016-01-01

    Meniscal ramp lesions are more frequently associated with anterior cruciate ligament (ACL) injuries than previously recognized. Some authors suggest that this entity results from disruption of the meniscotibial ligaments of the posterior horn of the medial meniscus, whereas others support the idea that it is created by a tear of the peripheral attachment of the posterior horn of the medial meniscus. Magnetic resonance imaging (MRI) scans have been reported to have a low sensitivity, and consequently, ramp lesions often go undiagnosed. Therefore, to rule out a ramp lesion, an arthroscopic evaluation with probing of the posterior horn of the medial meniscus should be performed. Several treatment options have been reported, including nonsurgical management, inside-out meniscal repair, or all-inside meniscal repair. In cases of isolated ramp lesions, a standard meniscal repair rehabilitation protocol should be followed. However, when a concomitant ACL reconstruction (ACLR) is performed, the rehabilitation should follow the designated ACLR postoperative protocol. The purpose of this article was to review the current literature regarding meniscal ramp lesions and summarize the pertinent anatomy, biomechanics, diagnostic strategies, recommended treatment options, and postoperative protocol. PMID:27504467

  1. Monitoring pigmented skin lesions

    NASA Astrophysics Data System (ADS)

    Wallace, Vincent P.; Bamber, Jeffery C.; Ott, Robert J.; Crawford, Diane C.; Mortimer, Peter S.

    2002-06-01

    The rising incidence of skin cancer has led to an increase in the number of patients with skin lesions that require diagnosis, mostly using subjective visual examination. Successful treatment depends on early diagnosis. Unfortunately diagnostic accuracy, even by experts, can be as low as 56%; therefore, an accurate, objective diagnostic aid is greatly needed. Reflectance characteristics of pigmented skin lesions were documented to evaluate their diagnostic potential. Reflectance spectra in the wavelength range 320-1100nm were obtained from 260 lesions. Differences between spectra from benign and malignant lesions were utilized by extracting features with the best discriminating power. Discrimination was evaluated using two techniques: multivariate statistical analysis and artificial neural networks, using histology as the standard. Each technique was tested in a blind study and assessed in terms of its ability to diagnose new cases and compared to the clinical diagnosis. The artificial neural network achieved the best diagnostic performance for discriminating between malignant melanoma and benign nevi, having a sensitivity of 100% and a specificity of 65%. Utilization of visible and infrared techniques for monitoring skin lesions has lead to improvements in diagnostic accuracy. We conclude that these techniques are worthy of further development and evaluation in clinical practice as a screening tool.

  2. Prosthetic elbow joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1994-01-01

    An artificial, manually positionable elbow joint for use in an upper extremity, above-elbow, prosthetic is described. The prosthesis provides a locking feature that is easily controlled by the wearer. The instant elbow joint is very strong and durable enough to withstand the repeated heavy loadings encountered by a wearer who works in an industrial, construction, farming, or similar environment. The elbow joint of the present invention comprises a turntable, a frame, a forearm, and a locking assembly. The frame generally includes a housing for the locking assembly and two protruding ears. The forearm includes an elongated beam having a cup-shaped cylindrical member at one end and a locking wheel having a plurality of holes along a circular arc on its other end with a central bore for pivotal attachment to the protruding ears of the frame. The locking assembly includes a collar having a central opening with a plurality of internal grooves, a plurality of internal cam members each having a chamfered surface at one end and a V-shaped slot at its other end; an elongated locking pin having a crown wheel with cam surfaces and locking lugs secured thereto; two coiled compression springs; and a flexible filament attached to one end of the elongated locking pin and extending from the locking assembly for extending and retracting the locking pin into the holes in the locking wheel to permit selective adjustment of the forearm relative to the frame. In use, the turntable is affixed to the upper arm part of the prosthetic in the conventional manner, and the cup-shaped cylindrical member on one end of the forearm is affixed to the forearm piece of the prosthetic in the conventional manner. The elbow joint is easily adjusted and locked between maximum flex and extended positions.

  3. [The temporo-mandibular joint in pathologic conditions: rheumatoid arthritis and seronegative spondyloarthritis].

    PubMed

    Scutellari, P N; Orzincolo, C; Ceruti, S

    1993-10-01

    Pain and dysfunction of the temporomandibular joint (TMJ) are major clinical problems, especially in arthritides and allied conditions. In the last 10 years, such new imaging methods as arthrography, CT and MRI have been developed, but many problems are still to be solved. This study was aimed at reporting the radiographic patterns of lesions in TMJ rheumatoid arthritis and seronegative spondyloarthropathies and at investigating the role of conventional radiology in the assessment of these disorders. Digital hypocycloidal tomography of the TMJ was performed on 44 patients affected with rheumatoid arthritis, on 2 with Sjögren's syndrome, 2 with ankylosing spondylitis, 4 with psoriatic arthritis and 1 with Reiter's syndrome. CT, with sagittal and coronal scans, was performed only on 9 patients (18 joints) whose clinical and radiographic findings were particularly severe. The radiographic features of the lesions--i.e., erosions, osteophytes, subchondral bone sclerosis and condylar-glenoid fossa remodelling--cannot be distinguished from one another and from the so-called allied conditions; nevertheless, in rheumatoid arthritis abnormalities are usually bilateral and symmetric, whereas in seronegative arthropathies joint involvement is usually unilateral. In the first stage of the disease, these lesions are better demonstrated by CT than by tomography, thanks to better contrast and spatial resolution of the former, especially on the lateral and medial aspects of the joint. The most common findings were: erosions (68.2%), osteophytes (31.8%), subchondral bone sclerosis (28.6%) and condylar-glenoid fossa remodelling (9.1%). In the clinical practice sagittal multidirectional tomography remains today the method of choice because it can demonstrate several areas on the condylar surface, with finer anatomical detailing, and it can solve most diagnostic problems in TMJ disorders. Thus, CT is recommended only in the patients whose diagnosis remains questionable with the above

  4. A study of lubrication, processing conditions, and material combinations that affect the wear of micro-textured-carbide coated cobalt-chromium-molybdenum alloy surfaces used for artificial joints implants

    NASA Astrophysics Data System (ADS)

    Ettienne-Modeste, Geriel A.

    Total joint replacement remains one of the most successful treatments for arthritis. The most common materials used for artificial joints are metals (e.g., cobalt-chrome alloys or titanium alloys), which articulate against ultra-high molecular weight polyethylene. Wear related failures of artificial joints may be reduced with the use of novel micro-textured carbide surfaces. The micro-textured carbide surfaces were deposited on a CoCrMo alloy using microwave plasma-assisted chemical vapor deposition. Wear tests were conducted to determine wear mechanisms and properties of the micro-textured surfaces. The research presented in this thesis addresses: (1) rheolgoical behavior of bovine calf serum with and without antibacterial agents to determine whether they can be used as appropriate models for synovial fluid, (2) the wear behavior of the micro-textured CoCrMo surface system, and (3) the mechanical and material properties of the micro-textured CoCrMo alloy surface relevant to wear performance. The rheological studies showed that the apparent viscosity of bovine calf serum increased with an increase in concentration before and after the serum was used for wear testing. The wear analysis showed that the processing conditions (2hr deposition vs. 4hr deposition times) affected the wear properties. The 2hr carbide-on-carbide lubricated in 50% BCS produced the lowest wear factor and rate for the five wear couple systems containing the carbide disk or plate material. Greater wear was produced in serum without penicillin/streptomycin (P/S) compared to the serum containing P/S. A greater carbide coating thickness 10 (micrometers) was produced during the 4hr deposition time than for the 2hr deposition (˜3mum). The nano-hardness value was higher than the micro-hardness for both the 4hr and 2hr carbide surfaces. The micro-hardness results of the worn carbide surfaces showed that an increase in BCS concentration from 0% to 100% increased the micro-hardness (HV) for carbide

  5. Intraventricular mass lesions

    SciTech Connect

    Morrison, G.; Sobel, D.F.; Kelley, W.M.; Norman, D.

    1984-11-01

    Determining the precise etiology of an intraventricular mass can be a difficult diagnostic problem. CT and angiographic findings were reviewed in a series of 73 patients who had intraventricular masses. The histologic diagnosis can be suggested preoperatively by an analysis of the frequency of lesions occurring at a given ventricular location, lesion density before and after administration of contrast material, age, and sex of the patient, morphologic appearance of the mass, and presence or absence of hydrocephalus. Angiography is useful when meningioma, choroid plexus papilloma and carcinoma, or arteriovenous malformation are considered.

  6. An in Vitro Evaluation of Remineralization Potential of Novamin® on Artificial Enamel Sub-Surface Lesions Around Orthodontic Brackets Using Energy Dispersive X-Ray Analysis (EDX)

    PubMed Central

    Padmanabhan, Sridevi; Chitharanjan, Arun B

    2014-01-01

    Objective: To evaluate and compare the Ca/P ratio of enamel samples around the orthodontic brackets for time periods of 0, 2 and 10 days in two groups (control group and study group). Materials and Methods: Forty extracted teeth were randomly divided into control group and study group. All samples were demineralized and incubated in artificial saliva at 37°C for a period of 10 days after demineralization. During this phase the enamel samples in the study group were treated with remineralizing paste (NuproNusolution containing Novamin®-Dentsply) for 10 days. At the end of the incubation period, Ca/P ratios were analyzed for both the groupsby EDX analysis. Data obtained was subjected to statistical analysis using student t-test for paired samples and Student t- test for individual samples (p ≤ 0.05). Results: It was found that the mean Ca/P ratio was significantly lower for the control group as compared to the study group (p-value < 0.05) after 10 d of incubation. Conclusion: Novamin® containing remineralization toothpaste showed significant remineralizing potential in inhibition of artificial enamel sub-surface lesion around bracket after 10 days of remineralization phase. EDX element analysis was found to be an efficient method to quantify the changes in mineral content of a sample during in vitro caries studies. PMID:25584326

  7. Magnetic resonance imaging of liver lesions: exceptions and atypical lesions.

    PubMed

    van den Bos, Indra C; Hussain, Shahid M; de Man, Robert A; Zondervan, Pieter E; Ijzermans, Jan N M; Preda, A; Krestin, Gabriel P

    2008-01-01

    On state-of-the-art magnetic resonance imaging, most lesions can be detected and characterized with confidence according to well-known criteria. However, atypical characteristics in some common lesions and the incidental encounter with rare lesions may pose diagnostic difficulties. In this article, six challenging hepatic lesions will be discussed and evaluated on the most important magnetic resonance imaging sequences, with histological correlation when available. In addition, the background information concerning these lesions will be described based on the most recent available literature. By reading this article, the reader will be able to (1) categorize the lesion in solid and fluid-containing lesions, based on the T2 signal intensity; and (2) define the benign or malignant nature of the lesion, in relation to the signal intensity and dynamic enhancement pattern, despite the presence of atypical characteristics of some lesions. PMID:18436109

  8. Thermal Protection System with Staggered Joints

    NASA Technical Reports Server (NTRS)

    Simon, Xavier D. (Inventor); Robinson, Michael J. (Inventor); Andrews, Thomas L. (Inventor)

    2014-01-01

    The thermal protection system disclosed herein is suitable for use with a spacecraft such as a reentry module or vehicle, where the spacecraft has a convex surface to be protected. An embodiment of the thermal protection system includes a plurality of heat resistant panels, each having an outer surface configured for exposure to atmosphere, an inner surface opposite the outer surface and configured for attachment to the convex surface of the spacecraft, and a joint edge defined between the outer surface and the inner surface. The joint edges of adjacent ones of the heat resistant panels are configured to mate with each other to form staggered joints that run between the peak of the convex surface and the base section of the convex surface.

  9. High-strength braze joints between copper and steel

    NASA Technical Reports Server (NTRS)

    Kuhn, R. F.

    1967-01-01

    High-strength braze joints between copper and steel are produced by plating the faying surface of the copper with a layer of gold. This reduces porosity in the braze area and strengthens the resultant joint.

  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. Joint Instability and Osteoarthritis

    PubMed Central

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA. PMID:25741184

  12. 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

  13. [Managing focal incidental renal lesions].

    PubMed

    Nicolau, C; Paño, B; Sebastià, C

    2016-01-01

    Incidental renal lesions are relatively common in daily radiological practice. It is important to know the different diagnostic possibilities for incidentally detected lesions, depending on whether they are cystic or solid. The management of cystic lesions is guided by the Bosniak classification. In solid lesions, the goal is to differentiate between renal cancer and benign tumors such as fat-poor angiomyolipoma and oncocytoma. Radiologists need to know the recommendations for the management of these lesions and the usefulness of the different imaging techniques and interventional procedures in function of the characteristics of the incidental lesion and the patient's life expectancy.

  14. 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.

  15. 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.

  16. Calculation of tubular joints as compound shells

    NASA Astrophysics Data System (ADS)

    Golovanov, A. I.

    A scheme for joining isoparametric finite shell elements with a bend in the middle surface is described. A solution is presented for the problem of the stress-strain state of a T-joint loaded by internal pressure. A refined scheme is proposed for calculating structures of this kind with allowance for the stiffness of the welded joint.

  17. Altered pain and thermal sensation in subjects with isolated parietal and insular cortical lesions

    PubMed Central

    Veldhuijzen, D.S.; Greenspan, J.D; Kim, J.H.; Lenz, F.A.

    2009-01-01

    Studies of sensory function following cortical lesions have often included lesions which multiple cortical, white matter, and thalamic structures. We now test the hypothesis that lesions anatomically constrained to particular insular and parietal structures and their subjacent white matter are associated with different patterns of sensory loss. Sensory loss was measured by quantitative sensory testing (QST), and evaluated statistically with respect to normal values. All seven subjects with insular and/or parietal lesions demonstrated thermal hypoesthesia, although the etiology of the lesions was heterogeneous. Cold and heat hypoalgesia were only found in the subject with the most extensive parietal and insular lesion, which occurred in utero. Cold allodynia occurred clinically and by thresholds in two subjects with isolated ischemic lesions of the posterior insular/ retroinsular cortex, and by thresholds in two subjects with a lesion of parietal cortex with little or no insular involvement. Central pain occurred in the two subjects with clinical allodynia secondary to isolated lesions of the posterior insular/retroinsular cortex, which spared the anterior and posterior parietal cortex. These results suggest that nonpainful cold and heat sensations are jointly mediated by parietal and insular cortical structures so that lesions anywhere in this system may diminish sensitivity. In contrast, thermal pain is more robust requiring larger cortical lesions of these same structures to produce hypoalgesia. In addition, cold allodynia can result from restricted lesions that also produce thermal hypoesthesia, but not from all such lesions. PMID:19939715

  18. Histopathological findings, phenotyping of inflammatory cells, and expression of markers of nitritative injury in joint tissue samples from calves after vaccination and intraarticular challenge with Mycoplasma bovis strain 1067

    PubMed Central

    2014-01-01

    Background The pathogenesis of caseonecrotic lesions developing in lungs and joints of calves infected with Mycoplasma bovis is not clear and attempts to prevent M. bovis-induced disease by vaccines have been largely unsuccessful. In this investigation, joint samples from 4 calves, i.e. 2 vaccinated and 2 non-vaccinated, of a vaccination experiment with intraarticular challenge were examined. The aim was to characterize the histopathological findings, the phenotypes of inflammatory cells, the expression of class II major histocompatibility complex (MHC class II) molecules, and the expression of markers for nitritative stress, i.e. inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), in synovial membrane samples from these calves. Furthermore, the samples were examined for M. bovis antigens including variable surface protein (Vsp) antigens and M. bovis organisms by cultivation techniques. Results The inoculated joints of all 4 calves had caseonecrotic and inflammatory lesions. Necrotic foci were demarcated by phagocytic cells, i.e. macrophages and neutrophilic granulocytes, and by T and B lymphocytes. The presence of M. bovis antigens in necrotic tissue lesions was associated with expression of iNOS and NT by macrophages. Only single macrophages demarcating the necrotic foci were positive for MHC class II. Microbiological results revealed that M. bovis had spread to approximately 27% of the non-inoculated joints. Differences in extent or severity between the lesions in samples from vaccinated and non-vaccinated animals were not seen. Conclusions The results suggest that nitritative injury, as in pneumonic lung tissue of M. bovis-infected calves, is involved in the development of caseonecrotic joint lesions. Only single macrophages were positive for MHC class II indicating down-regulation of antigen-presenting mechanisms possibly caused by local production of iNOS and NO by infiltrating macrophages. PMID:25162202

  19. Condylomatous lesions of the upper aerodigestive tract.

    PubMed

    Nash, M; Lucente, F E; Srinivasan, K; Gould, W J

    1987-12-01

    Condyloma acuminatum is one of four types of common human verrucous lesions that are of viral etiology. Also known as "moist wart," condyloma acuminatum is most often seen on the mucosal surfaces of the anogenital area. However, occurrences in the mucosal lined areas of the head and neck region are quite rare. Since 1901, 30 cases of condylomatous lesions have been reported in the upper aerodigestive tract, occurring mainly in the various regions of the oral cavity. Eighteen of the cases were confirmed by histopathologic documentation, while the remainder were anecdotal. We have recently encountered six new cases of condyloma acuminatum, verified by histologic examination. One occurred on the tongue, another in the tonsillar fossa, one in the hypopharynx and three on the vocal cords. We present these cases and review the previously reported cases. In addition, we will discuss the differential diagnosis of these lesions, and their importance to the practicing otolaryngologist.

  20. Evaluation of two transport aircraft and several ground test vehicle friction measurements obtained for various runway surface types and conditions. A summary of test results from joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1990-01-01

    Tests with specially instrumented NASA Boeing 737 and 727 aircraft together with several different ground friction measuring devices were conducted for a variety of runway surface types and conditions. These tests are part of joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program aimed at obtaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow and ice-covered runway conditions is discussed as well as ground vehicle friction data obtained under similar runway conditions. For a given contaminated runway surface condition, the correlation between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, type and amount of surface contaminant, and ambient temperature are discussed. The effect of surface type on wet friction levels is also evaluated from comparative data collected on grooved and ungrooved concrete and asphalt surfaces.

  1. Strength evaluation of socket joints

    NASA Technical Reports Server (NTRS)

    Rash, Larry C.

    1994-01-01

    This report documents the development of a set of equations that can be used to provide a relatively simple solution for identifying the strength of socket joints and for most cases avoid the need of more lengthy analyses. The analytical approach was verified by comparison of the contact load distributions to results obtained from a finite element analysis. The contacting surfaces for the specific joint in this analysis are in the shape of frustrums of a cone and are representative of the tapered surfaces in the socket-type joints used to join segments of model support systems for wind tunnels. The results are in the form of equations that can be used to determine the contact loads and stresses in the joint from the given geometry and externally applied loads. Equations were determined to define the bending moments and stresses along the length of the joints based on strength and materials principles. The results have also been programmed for a personal computer and a copy of the program is included.

  2. [Temporo-mandibular joint. Morpho-functional considerations].

    PubMed

    Scutariu, M D; Indrei, Anca

    2004-01-01

    The temporo-mandibular joint is distinguished from most other synovial joints of the body by two features: 1. the two jointed components carry teeth whose position and occlusion introduce a very strong influence on the movements of the temporo-mandibular joint and 2. its articular surfaces are not covered by hyaline cartilage, but by a dense, fibrous tissue. This paper describes the parts of the temporo-mandibular joint: the articular surfaces (the condylar process of the mandible and the glenoid part of the temporal bone), the fibrocartilaginous disc which is interposed between the mandibular and the temporal surface, the fibrous capsule of the temporo-mandibular joint and the ligaments of this joint. All these parts present a very strong adaptation at the important functions of the temporo-mandibular joint.

  3. Dissociative Binding of Carboxylic Acid Ligand on Nanoceria Surface in Aqueous Solution: A Joint in Situ Spectroscopic Characterization and First-Principles Study

    SciTech Connect

    Lu, Zhou; Karakoti, Ajay S.; Velarde Ruiz Esparza, Luis A.; Wang, Weina; Yang, Ping; Thevuthasan, Suntharampillai; Wang, Hongfei

    2013-11-21

    Carboxylic acid is a common ligand anchoring group to functionalize nanoparticle surfaces. Its binding structures and mechanisms as a function of the oxidation states of metal oxide nanoparticle surfaces are not well characterized experimentally. We present an in situ sum frequency generation vibrational spectroscopy (SFG-VS) study on the binding of deuterated acetic acid on ceria nanoparticles in the aqueous solution. In the SFG experiment, ceria nanoparticles were deposited on the flat surface of a CaF2 hemisphere in contact with acetic acid solutions. While the ceria nanoparticle deprotonated the acetic acid, the CaF2 surface could not. Thus, the binding of the deprotonated acetic acid on ceria can be selectively probed. SFG spectra revealed that the binding modes of the carboxylate group depend on the oxidation states of the ceria surfaces. SFG polarization analysis suggested that the bidentate chelating and bridging binding modes co-exist on the reduced ceria surfaces, while the oxidized ceria surfaces are dominated by the bidentate bridging mode. The direct spectroscopic evidence helps to clarify the binding structures and mechanisms on the ceria nanoparticles. Furthermore, the middle-infrared (IR) transparent CaF2 and its chemical inertness make CaF2 and similar substrate materials good candidates for direct SFG-VS measurement of nanoparticle surface reactions and binding chem-istry.

  4. Posterior shoulder pain in throwing athletes with a Bennett lesion: factors that influence throwing pain.

    PubMed

    Nakagawa, Shigeto; Yoneda, Minoru; Hayashida, Kenji; Mizuno, Naoko; Yamada, Shinichi

    2006-01-01

    A Bennett lesion is a bony spur at the posterior glenoid that is often seen in baseball players and usually asymptomatic. However, it sometimes becomes painful, but the mechanism of throwing pain is still unknown. The purposes of this study were to identify clinical characteristics associated with the Bennett lesion causing shoulder pain (painful Bennett lesion) and to try to predict which type of Bennett lesion might become painful. Several clinical factors in 51 consecutive baseball players who underwent arthroscopic surgery were investigated. Of these baseball players, 24 had a bony spur: 13 were diagnosed as having a painful Bennett lesion and 11 were diagnosed as having an asymptomatic Bennett lesion, according to our previously reported criteria. The other 27 players did not have a bony spur. Posterior joint laxity, no deficit of internal rotation, and an avulsed fragment on computed tomography scan were determined to be the characteristic clinical features in the shoulders with a painful Bennett lesion.

  5. [Leishmania infantum induced bone lesions in a dog].

    PubMed

    Wallborn, Felix; Söffler, Charlotte; Winkels, Philipp; Hess, Marcus; Engelhardt, Peter

    2016-08-17

    A 3-year-old Labrador Retriever originating from Spain was presented with a left-sided hind limb lameness for several months. The orthopedic examination revealed a pain response when palpating the left tarsal joint. Radiographic and computed tomographic studies showed polyostotic, aggressive osteolytic bone lesions with mild erosive arthritis. The diagnosis of canine leishmaniasis was confirmed by bone biopsy and the detection of the pathogen by PCR. Three weeks after initiation of therapy with allopurinol, the dog presented no signs of lameness. Eight months after start of therapy, radiographic examination revealed moderate regression of the osteolytic bone lesions. PMID:27304984

  6. Synovial joints: from development to homeostasis.

    PubMed

    Longobardi, Lara; Li, Tieshi; Tagliafierro, Lidia; Temple, Joseph D; Willcockson, Helen H; Ye, Ping; Esposito, Alessandra; Xu, Fuhua; Spagnoli, Anna

    2015-02-01

    Synovial joint morphogenesis occurs through the condensation of mesenchymal cells into a non-cartilaginous region known as the interzone and the specification of progenitor cells that commit to the articular fate. Although several signaling molecules are expressed by the interzone, the mechanism is poorly understood. For treatments of cartilage injuries, it is critical to discover the presence of joint progenitor cells in adult tissues and their expression gene pattern. Potential stem cell niches have been found in different joint regions, such as the surface zone of articular cartilage, synovium, and groove of Ranvier. Inherited joint malformations as well as joint-degenerating conditions are often associated with other skeletal defects and may be seen as the failure of morphogenic factors to establish the correct microenvironment in cartilage and bone. Therefore, exploring how joints form can help us understand how cartilage and bone are damaged and develop drugs to reactivate this developing mechanism.

  7. Synovial Joints: from Development to Homeostasis

    PubMed Central

    Li, Tieshi; Tagliafierro, Lidia; Temple, Joseph D.; Willcockson, Helen H.; Ye, Ping; Esposito, Alessandra; Xu, Fuhua; Spagnoli, Anna

    2015-01-01

    Synovial joint morphogenesis occurs through the condensation of mesenchymal cells into a non-cartilaginous region known as interzone, and the specification of progenitor cells that commit to the articular fate. Although several signaling molecules are expressed by the interzone, the mechanism is poorly understood. For treatments of cartilage injuries, it is critical to discover the presence of joint progenitor cells in adult tissues and their expression gene pattern. Potential stem cells niches have been found in different joint regions, such as the surface zone of articular cartilage, synovium and groove of Ranvier. Inherited joint malformation as well as joint degenerating conditions are often associated with other skeletal defects, and may be seen as the failure of morphogenic factors to establish the correct microenvironment in cartilage and bone. Therefore, exploring how joints form can help us understand how cartilage and bone are damaged and to develop drugs to reactivate this developing mechanism. PMID:25431159

  8. Cystic Lesions of the Mediastinum.

    PubMed

    Vargas, Daniel; Suby-Long, Thomas; Restrepo, Carlos S

    2016-06-01

    Cystic lesions are commonly seen in the mediastinum, and they may arise from virtually any organ. The vast majority of these lesions are benign and result in no symptoms. When large, cysts may produce symptoms related to compression of adjacent structures. The most common mediastinal cysts are pericardial and foregut duplication cysts. Both computed tomography and magnetic resonance are routinely used to evaluate these lesions. Although computed tomography offers superior spatial resolution, magnetic resonance is useful in differentiating cysts that contain proteinaceous material from solid lesions. Occasionally, cysts arise from solid lesions, such as thymoma or teratoma. Although cysts are alike in appearance, location helps narrowing the differential diagnoses.

  9. Lesion mimic mutants

    PubMed Central

    Moeder, Wolfgang

    2008-01-01

    Over the last decade a substantial number of lesion mimic mutants (LMM) have been isolated and a growing number of the genes have been cloned. It is now becoming clear that these mutants are valuable tools to dissect various aspects of programmed cell death (PCD) and pathogen resistance pathways in plants. Together with other forward genetics approaches LMMs shed light on the PCD machinery in plant cells and revealed important roles for sphingolipids, Ca2+ and chloroplast-derived porphyrin-metabolites during cell death development. PMID:19513227

  10. Low-Thermal-Stress Structural Joints For Dissimilar Materials

    NASA Technical Reports Server (NTRS)

    Matza, Edward C.

    1990-01-01

    Structural joint developed for attachment of hypersonic control surface to aircraft wing structure. Transmits large torque loads from composite control surface and torque tube to wing structure through metallic attachment lug and collar. Torque load transmitted from tube to collar by series of radially oriented cleats. Bearing surfaces of cleats plane passing through center-line of torque tube. Such joints accommodate differential thermal growth between parts of dissimilar materials. Potential for application to high-temperature structural joints associated with hypervelocity vehicles.

  11. Joint surface reconstruction and 4D deformation estimation from sparse data and prior knowledge for marker-less Respiratory motion tracking

    SciTech Connect

    Berkels, Benjamin; Rumpf, Martin; Bauer, Sebastian; Ettl, Svenja; Arold, Oliver; Hornegger, Joachim

    2013-09-15

    Purpose: The intraprocedural tracking of respiratory motion has the potential to substantially improve image-guided diagnosis and interventions. The authors have developed a sparse-to-dense registration approach that is capable of recovering the patient's external 3D body surface and estimating a 4D (3D + time) surface motion field from sparse sampling data and patient-specific prior shape knowledge.Methods: The system utilizes an emerging marker-less and laser-based active triangulation (AT) sensor that delivers sparse but highly accurate 3D measurements in real-time. These sparse position measurements are registered with a dense reference surface extracted from planning data. Thereby a dense displacement field is recovered, which describes the spatio-temporal 4D deformation of the complete patient body surface, depending on the type and state of respiration. It yields both a reconstruction of the instantaneous patient shape and a high-dimensional respiratory surrogate for respiratory motion tracking. The method is validated on a 4D CT respiration phantom and evaluated on both real data from an AT prototype and synthetic data sampled from dense surface scans acquired with a structured-light scanner.Results: In the experiments, the authors estimated surface motion fields with the proposed algorithm on 256 datasets from 16 subjects and in different respiration states, achieving a mean surface reconstruction accuracy of ±0.23 mm with respect to ground truth data—down from a mean initial surface mismatch of 5.66 mm. The 95th percentile of the local residual mesh-to-mesh distance after registration did not exceed 1.17 mm for any subject. On average, the total runtime of our proof of concept CPU implementation is 2.3 s per frame, outperforming related work substantially.Conclusions: In external beam radiation therapy, the approach holds potential for patient monitoring during treatment using the reconstructed surface, and for motion-compensated dose delivery using

  12. Denervation of the wrist joint.

    PubMed

    Buck-Gramcko, D

    1977-01-01

    A collective review was made of the results of denervation of the wrist joint for painful restrictiorn of motion done in 313 patients and follow-up studies on 195 (average 4.1 years, ranging from 9 months to 14 years). Complete denervation was done in only 30, partial denervation in the others being done after testing with local anesthetic blocks. Sixty-nine of the patients retained a moble wrist without pain or with slight pain with heavy work. No evidence of Charcot-like joints was seen. Poorest results followed when the operation was done for sequelae of intra-articular fracture of the radius, fracture dislocations, unstable ligamentous support, joint surface destruction, or for those required to do heavy manual labor. Arthrodesis was done secondarily in nine patients. PMID:839055

  13. The Planar Shape of Rock Joints

    NASA Astrophysics Data System (ADS)

    Zhang, Lianyang; Einstein, Herbert H.

    2010-02-01

    Knowing the planar shape of discontinuities is important when characterizing discontinuities in a rock mass. However, the real discontinuity shape is rarely known, since the rock mass is usually inaccessible in three dimensions. Information on discontinuity shape is limited and often open to more than one interpretation. This paper discusses the planar shape of rock joints, the most common discontinuities in rock. First, a brief literature review about the shape of joints is presented, including some information on joint-surface morphology, inferences from observed trace lengths on different sampling planes, information based on experimental studies, and joint shapes assumed by different researchers. This review shows that joints not affected by adjacent geological structures such as bedding boundaries or pre-existing fractures tend to be elliptical (or approximately circular but rarely). Joints affected by or intersecting such geological structures tend to be rectangular. Then, using the general stereological relationship between trace length distributions and joint size distributions developed by Zhang et al. (Geotechnique 52(6):419-433, 2002) for elliptical joints, the effect of sampling plane orientation on trace lengths is investigated. This study explains why the average trace lengths of non-equidimensional (elliptical or similar polygonal) joints on two sampling planes can be about equal and thus the conclusion that rock joints are equidimensional (circular) drawn from the fact that the average trace lengths on two sampling planes are approximately equal can be wrong. Finally, methods for characterizing the shape and size of joints (elliptical or rectangular) from trace length data are recommended, and the appropriateness of using elliptical joint shapes to represent polygonal, especially rectangular, joints is discussed.

  14. Optical Assessment of Caries Lesion Structure and Activity

    NASA Astrophysics Data System (ADS)

    Lee, Robert Chulsung

    New, more sophisticated diagnostic tools are needed for the detection and characterization of caries lesions in the early stages of development. It is not sufficient to simply detect caries lesions, methods are needed to assess the activity of the lesion and determine if chemical or surgical intervention is needed. Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface lesion structure and measure the thickness of the highly mineralized surface zone. Other studies have demonstrated that the rate of dehydration can be correlated with the lesion activity and that the rate can be measured using optical methods. The main objective of this work was to test the hypothesis that optical methods can be used to assess lesion activity on tooth coronal and root surfaces. Simulated caries models were used to develop and validate an algorithm for detecting and measuring the highly mineralized surface layer using PS-OCT. This work confirmed that the algorithm was capable of estimating the thickness of the highly mineralized surface layer with high accuracy. Near-infrared (NIR) reflectance and thermal imaging methods were used to assess activity of caries lesions by measuring the state of lesion hydration. NIR reflectance imaging performed the best for artificial enamel and natural coronal caries lesion samples, particularly at wavelengths coincident with the water absorption band at 1460-nm. However, thermal imaging performed the best for artificial dentin and natural root caries lesion samples. These novel optical methods outperformed the conventional methods (ICDAS II) in accurately assessing lesion activity of natural coronal and root caries lesions. Infrared-based imaging methods have shown potential for in-vivo applications to objectively assess caries lesion activity in a single examination. It is likely that if future clinical trials are a success, this novel imaging

  15. Butt Joint Tool Commissioning

    SciTech Connect

    Martovetsky, N N

    2007-12-06

    ITER Central Solenoid uses butt joints for connecting the pancakes in the CS module. The principles of the butt joining of the CICC were developed by the JAPT during CSMC project. The difference between the CSMC butt joint and the CS butt joint is that the CS butt joint is an in-line joint, while the CSMC is a double joint through a hairpin jumper. The CS butt joint has to carry the hoop load. The straight length of the joint is only 320 mm, and the vacuum chamber around the joint has to have a split in the clamp shell. These requirements are challenging. Fig.1 presents a CSMC joint, and Fig.2 shows a CS butt joint. The butt joint procedure was verified and demonstrated. The tool is capable of achieving all specified parameters. The vacuum in the end was a little higher than the target, which is not critical and readily correctable. We consider, tentatively that the procedure is established. Unexpectedly, we discover significant temperature nonuniformity in the joint cross section, which is not formally a violation of the specs, but is a point of concern. All testing parameters are recorded for QA purposes. We plan to modify the butt joining tool to improve its convenience of operation and provide all features necessary for production of butt joints by qualified personnel.

  16. Pressure suit joint analyzer

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.; Webbon, B. W. (Inventor)

    1982-01-01

    A measurement system for simultaneously measuring torque and angular flexure in a pressure suit joint is described. One end of a joint under test is held rigid. A torque transducer is pivotably supported on the other movable end of a joint. A potentiometer is attached to the transducer by an arm. The wiper shaft of the potentiometer is gripped by a reference arm that rotates the wiper shaft the same angle as the flexure of joint. A signal is generated by the potentiometer which is representative of the joint flexure. A compensation circuit converts the output of the transducer to a signal representative of joint torque.

  17. Photoacoustic characterization of radiofrequency ablation lesions

    NASA Astrophysics Data System (ADS)

    Bouchard, Richard; Dana, Nicholas; Di Biase, Luigi; Natale, Andrea; Emelianov, Stanislav

    2012-02-01

    Radiofrequency ablation (RFA) procedures are used to destroy abnormal electrical pathways in the heart that can cause cardiac arrhythmias. Current methods relying on fluoroscopy, echocardiography and electrical conduction mapping are unable to accurately assess ablation lesion size. In an effort to better visualize RFA lesions, photoacoustic (PA) and ultrasonic (US) imaging were utilized to obtain co-registered images of ablated porcine cardiac tissue. The left ventricular free wall of fresh (i.e., never frozen) porcine hearts was harvested within 24 hours of the animals' sacrifice. A THERMOCOOLR Ablation System (Biosense Webster, Inc.) operating at 40 W for 30-60 s was used to induce lesions through the endocardial and epicardial walls of the cardiac samples. Following lesion creation, the ablated tissue samples were placed in 25 °C saline to allow for multi-wavelength PA imaging. Samples were imaged with a VevoR 2100 ultrasound system (VisualSonics, Inc.) using a modified 20-MHz array that could provide laser irradiation to the sample from a pulsed tunable laser (Newport Corp.) to allow for co-registered photoacoustic-ultrasound (PAUS) imaging. PA imaging was conducted from 750-1064 nm, with a surface fluence of approximately 15 mJ/cm2 maintained during imaging. In this preliminary study with PA imaging, the ablated region could be well visualized on the surface of the sample, with contrasts of 6-10 dB achieved at 750 nm. Although imaging penetration depth is a concern, PA imaging shows promise in being able to reliably visualize RF ablation lesions.

  18. [Magnetic resonance imaging in the diagnosis of knee joint sarcomas].

    PubMed

    Shubkin, V N; Gunicheva, N V; Akhadov, T A; Puzhitskiĭ, L B; Keshishian, R A

    2007-01-01

    The purpose of the investigation was to study the potentialities of magnetic resonance imaging (MRI) in the diagnosis of knee joint sarcomas. The paper presents the results of examining 13 patients of different age, shows the potentialities of the technique in the identification of knee joint sarcomas, and describes the MRI semiotics of sarcomas in both the routine study and that using contrast enhancement in lesions of bone and soft tissue elements in the presence of regional metastases.

  19. Decomposing Large Inverse Problems with an Augmented Lagrangian Approach: Application to Joint Inversion of Body-Wave Travel Times and Surface-Wave Dispersion Measurements

    NASA Astrophysics Data System (ADS)

    Reiter, D. T.; Rodi, W. L.

    2015-12-01

    Constructing 3D Earth models through the joint inversion of large geophysical data sets presents numerous theoretical and practical challenges, especially when diverse types of data and model parameters are involved. Among the challenges are the computational complexity associated with large data and model vectors and the need to unify differing model parameterizations, forward modeling methods and regularization schemes within a common inversion framework. The challenges can be addressed in part by decomposing the inverse problem into smaller, simpler inverse problems that can be solved separately, providing one knows how to merge the separate inversion results into an optimal solution of the full problem. We have formulated an approach to the decomposition of large inverse problems based on the augmented Lagrangian technique from optimization theory. As commonly done, we define a solution to the full inverse problem as the Earth model minimizing an objective function motivated, for example, by a Bayesian inference formulation. Our decomposition approach recasts the minimization problem equivalently as the minimization of component objective functions, corresponding to specified data subsets, subject to the constraints that the minimizing models be equal. A standard optimization algorithm solves the resulting constrained minimization problems by alternating between the separate solution of the component problems and the updating of Lagrange multipliers that serve to steer the individual solution models toward a common model solving the full problem. We are applying our inversion method to the reconstruction of the·crust and upper-mantle seismic velocity structure across Eurasia.· Data for the inversion comprise a large set of P and S body-wave travel times·and fundamental and first-higher mode Rayleigh-wave group velocities.

  20. Thalamic Lesions: A Radiological Review

    PubMed Central

    Renard, Dimitri; Campello, Chantal; Bouly, Stephane; Le Floch, Anne; Thouvenot, Eric; Waconge, Anne; Taieb, Guillaume

    2014-01-01

    Background. Thalamic lesions are seen in a multitude of disorders including vascular diseases, metabolic disorders, inflammatory diseases, trauma, tumours, and infections. In some diseases, thalamic involvement is typical and sometimes isolated, while in other diseases thalamic lesions are observed only occasionally (often in the presence of other typical extrathalamic lesions). Summary. In this review, we will mainly discuss the MRI characteristics of thalamic lesions. Identification of the origin of the thalamic lesion depends on the exact localisation inside the thalamus, the presence of extrathalamic lesions, the signal changes on different MRI sequences, the evolution of the radiological abnormalities over time, the history and clinical state of the patient, and other radiological and nonradiological examinations. PMID:25100900

  1. An Evaluation of Nonsuppurative Joint Disease in Slaughter Pigs

    PubMed Central

    Johnston, Kathleen M.; Doige, Cecil E.; Osborne, A. Dudley

    1987-01-01

    Fifty-two joints from pigs with nonsuppurative joint disease from a local abattoir were examined grossly, histologically, and microbiologically in order to establish macroscopic differences between degenerative arthropathy and arthritis due to an infectious organism. The joints were grouped grossly according to the type and severity of lesions of the synovial membrane and cartilage, and microscopically according to the severity of synovial membrane lesions. Osteochondrosis and Erysipelothrix rhusiopathiae were the most common causes of nonsuppurative joint disease in the joints examined. The major macroscopic differences between these two arthropathies were in the nature and severity of the synovial and cartilaginous lesions and involvement of the lymph node draining the diseased joint. Typically, in osteochondrosis, the changes are feathery hypertrophy of villi, focal full-thickness cartilage buckles, ulcers or flaps, and no change in the draining lymph node, whereas in Erysipelothrix- caused arthritis, the villous hypertrophy is severe and polypoid in nature, there is diffuse erosion of articular cartilage, and the draining lymph node is consistently hypertrophic and often cystic. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10.Figure 11. PMID:17422755

  2. 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 ...

  3. 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 ...

  4. 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.

  5. Hip joint replacement

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002975.htm Hip joint replacement To use the sharing features on this page, please enable JavaScript. Hip joint replacement is surgery to replace all or part ...

  6. Joint remote sensing of aerosol optical properties and surface reflectance by sun-photometer and satellite in the urban area of Beijing, China

    NASA Astrophysics Data System (ADS)

    Mao, Jietai; Zhang, Junhua

    2003-04-01

    Aerosol optical depth in the urban area of Beijing has been measured by multi-wavelength sun-photometer during a one-year period from Apr. 1999 to Mar. 2000. Using the aerosol optical depth as the atmospheric correction parameter, the reflectance of the urban surface and the mean aerosol type have been retrieved by the apparent reflectance of the visible channel of the Visible and Infrared Spin Scan Radiometer (VISSR) onboard the Japanese Geostationary Meteorology Satellite.

  7. Pigmented Lesion of Buccal Mucosa

    PubMed Central

    Bajpai, Manas; Kumar, Malay; Kumar, Manish; Agarwal, Deshant

    2014-01-01

    Pigmented lesions are commonly found in the mouth. Such lesions represent a variety of clinical entities, ranging from physiologic changes to manifestation of systemic illness and malignant neoplasm. Diagnosis of such lesions requires a proper case history, extraoral and intraoral examination, and, in some cases, biopsy, aspiration cytology, and laboratory investigations. Here we present a case of purple lesion on the buccal mucosa of a 34-year-old male patient which was provisionally diagnosed as mucocele but on the basis of histopathological picture it was finally diagnosed as angiofibroma, and we also discuss the clinical and histopathological differential diagnosis. PMID:25161669

  8. [Total temporomandibular joint prostheses].

    PubMed

    Zwetyenga, N; Amroun, S; Wajszczak, B-L; Moris, V

    2016-09-01

    The temporomandibular joint (TMJ) is probably the most complex human joint. As in all joints, its prosthetic replacement may be indicated in selected cases. Significant advances have been made in the design of TMJ prostheses during the last three decades and the indications have been clarified. The aim of our work was to make an update on the current total TMJ total joint replacement. Indications, contraindications, prosthetic components, advantages, disadvantages, reasons for failure or reoperation, virtual planning and surgical protocol have been exposed.

  9. Crustal structure of the eastern Borborema Province, NE Brazil, from the joint inversion of receiver functions and surface wave dispersion: Implications for plateau uplift

    NASA Astrophysics Data System (ADS)

    Luz, Rosana M. N.; Julià, Jordi; Nascimento, Aderson F.

    2015-05-01

    We investigate the crustal structure of the Borborema Province of NE Brazil by developing 44 S wave velocity-depth profiles from the joint inversion of receiver functions and fundamental mode, Rayleigh wave group velocities. The Borborema Province is located in the northeasternmost corner of the South American continent and represents a portion of a larger Neoproterozoic mobile belt that formed during the Brasiliano-Pan African orogeny. Extensional processes in the Mesozoic—eventually leading to the separation of Africa and South America—left a number of aborted rift basins in the continental interiors, and episodes of diffuse intraplate volcanism and uplift marked the evolution of the Province after continental breakup. Our velocity-depth profiles reveal the existence of two crustal types in the Province: (i) the thin crustal type, which consists of 30-32.5 km thick crust, with an upper layer of 3.4-3.6 km/s overlying a lower layer of 3.7-3.8 km/s and (ii) the thick crustal type, which consists of a 35-37.5 km thick crust, with velocities between 3.5 and 3.9 km/s down to ˜30 km depth and a gradational increase in velocity (VS≥4.0 km/s) down to upper mantle depths. The crustal types correlate well with topography, with the thick crustal type being mainly found in the high-standing southern Borborema Plateau and the thin crustal type being mostly found in the low-lying Sertaneja depression and coastal cuestas. Interestingly, the thin crustal type is also observed under the elevated topography of the northern Plateau. We argue that the thick crustal type is rheologically strong and not necessarily related to postbreakup mantle processes, as it is commonly believed. We propose that extensional processes in the Mesozoic stretched portions of the Brasiliano crust and formed the thin crustal type that is now observed in the regions of low-lying topography, leaving the rheologically strong thick crust of the southern Plateau at higher elevations. The crust making

  10. Feedback at the Working Surface: A Joint X-ray and Low-Frequency Radio Spectral Study of the Cocoon Shock in Cygnus A

    NASA Astrophysics Data System (ADS)

    Wise, Michael W.; Rafferty, D. A.; McKean, J. P.

    2013-04-01

    We report on preliminary results from a joint spectral analysis of the cocoon shock region in Cygnus A using deep archival Chandra data and new low-frequency radio data from LOFAR. Being both bright in X-rays and the most powerful radio source in the local universe, the FRII radio galaxy Cygnus A represents an ideal opportunity to study the interaction between the jets produced by the central AGN and the surrounding intracluster medium (ICM) in which that AGN is embedded. Using the entire 235 ksec archival Chandra exposure, we have performed a spatially resolved, X-ray spectral analysis of the ICM in Cygnus A. By combining the resulting X-ray images and temperature maps with spectral index maps between 30-80 MHz and 120-180 MHz calculated from a recent, deep LOFAR observation, we can resolve the X-ray and radio emitting plasmas in any given region on spatial scales of 3-4 kpc over the central 100 kpc. We clearly resolve the cocoon shock surrounding Cygnus A and determine the Mach number of the shock as a function of position angle. Temperature jumps associated with this shock are detected over a large fraction of the total shock circumference. Significant non-thermal emission is also detected in the regions surrounding the SE and NW leading edges of the shock near the hotspots. In this talk, we will present a detailed analysis of the energetics of this interface region between the radio plasma inside the cocoon shock and the X-ray emitting gas outside the shock. Inside the shock, we will present constraints on the emission mechanisms in the jet, counter-jet, and hotspots based on the combined radio and X-ray spectra. Using maps of the spectral age derived from the LOFAR data and independent age estimates based on various cavity features seen in the X-ray image, we will present a picture of the evolution of the shock region in Cygnus A over the past 50 Myr. Finally, we will discuss the implications these observations have for AGN feedback models as well as the

  11. 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…

  12. 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

  13. Comparison of SPECT/CT and MRI in Diagnosing Symptomatic Lesions in Ankle and Foot Pain Patients: Diagnostic Performance and Relation to Lesion Type

    PubMed Central

    Ha, Seunggyun; Hong, Sung Hwan; Paeng, Jin Chul; Lee, Dong Yeon; Cheon, Gi Jeong; Arya, Amitabh; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    Purpose The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. Materials and Methods Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests. Results In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P < 0.001), and its area under curve on ROC analysis was 0.787. In the analysis of each lesion type, the specificity of SPECT/CT was poor in joint lesions compared with other lesion types and MRI (P < 0.001, respectively). MRI exhibited lower specificity than SPECT/CT in bone lesions (P = 0.004) and ligament/tendon lesions (P < 0.001). Conclusions SPECT/CT has MRI-comparable diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity. PMID:25668182

  14. RSRM Nozzle-to-Case Joint J-leg Development

    NASA Technical Reports Server (NTRS)

    Albrechtsen, Kevin U.; Eddy, Norman F.; Ewing, Mark E.; McGuire, John R.

    2003-01-01

    Since the beginning of the Space Shuttle Reusable Solid Rocket Motor (RSRM) program, nozzle-to-case joint polysulfide adhesive gas paths have occurred on several flight motors. These gas paths have allowed hot motor gases to reach the wiper O-ring. Even though these motors continue to fly safely with this condition, a desire was to reduce such occurrences. The RSRM currently uses a J-leg joint configuration on case field joints and igniter inner and outer joints. The J-leg joint configuration has been successfully demonstrated on numerous RSRM flight and static test motors, eliminating hot gas intrusion to the critical O-ring seals on these joints. Using the proven technology demonstrated on the case field joints and igniter joints, a nozzle-to-case joint J-leg design was developed for implementation on RSRM flight motors. This configuration provides an interference fit with nozzle fixed housing phenolics at assembly, with a series of pressurization gaps incorporated outboard of the joint mating surface to aid in joint pressurization and to eliminate any circumferential flow in this region. The joint insulation is bonded to the nozzle phenolics using the same pressure sensitive adhesive used in the case field joints and igniter joints. An enhancement to the nozzle-to-case joint J-leg configuration is the implementation of a carbon rope thermal barrier. The thermal barrier is located downstream of the joint bondline and is positioned within the joint in a manner where any hot gas intrusion into the joint passes through the thermal barrier, reducing gas temperatures to a level that would not affect O-rings downstream of the thermal barrier. This paper discusses the processes used in reaching a final nozzle-to-case joint J-leg design, provides structural and thermal results in support of the design, and identifies fabrication techniques and demonstrations used in arriving at the final configuration.

  15. [The focal renal lesions].

    PubMed

    Tuma, Jan

    2013-06-01

    The focal renal lesions are altogether common. Most frequently are found Columna Bertini hypertrophies (so called pseudotumors) and simple renal cysts. The role of sonography in the practice is to distinguish pseudotumors from real renal tumors, and simple renal cysts from complex cysts. The differentiation of complex renal cysts is possible with the help of the CEUS (= contrast enhanced ultrasound) and other imaging modalities such as CT or MRI. In these cases, the CEUS imaging agent has clear advantages over CT and MRI, because it is composed of gas bubbles, which are only slightly smaller than red blood cells and remains exclusively intravascularly while the CT and MRI contrast agents diffuse into the interstitial space without any real perfusion. The real tumors can be differentiated from certain focal non-tumorous changes based on the ultrasound and clinic. The further differentiation of individual kidney tumors and metastases using ultrasound, MRI, CT and CEUS is only partly possible. In all uncertain or unclear cases, therefore, an open or ultrasound-guided biopsy is useful.

  16. Pressure-actuated joint system

    NASA Technical Reports Server (NTRS)

    McGuire, John R. (Inventor)

    2004-01-01

    A pressure vessel is provided that includes first and second case segments mated with one another. First and second annular rubber layers are disposed inboard of the first and second case segments, respectively. The second annular rubber layer has a slot extending from the radial inner surface across a portion of its thickness to define a main body portion and a flexible portion. The flexible portion has an interfacing surface portion abutting against an interfacing surface portion of the first annular rubber layer to follow movement of the first annular rubber layer during operation of the pressure vessel. The slot receives pressurized gas and establishes a pressure-actuated joint between the interfacing surface portions. At least one of the interfacing surface portions has a plurality of enclosed and sealed recesses formed therein.

  17. Joint custody: preliminary impressions.

    PubMed

    Awad, G A

    1983-02-01

    Joint custody is currently a popular and debatable issue. It is felt that some of the controversy is due to the lack of agreement on a definition. Following some examples of the differences in personal and judicial definitions of joint custody, a classification of custody is offered. Four types of custody arrangements are described: Absolute Sole Custody, Sole Custody, Non-Alternating Joint Custody (disputed and undisputed) and Alternating Joint Custody (disputed and undisputed). A critical review of the literature follows. Finally, clinical impressions about the two types of joint custody are discussed. PMID:6839267

  18. Canine elbow dysplasia and primary lesions in German shepherd dogs in France.

    PubMed

    Remy, D; Neuhart, L; Fau, D; Genevois, J P

    2004-05-01

    Five hundred and twenty German shepherd dogs were screened for elbow dysplasia. The following primary lesions were analysed: joint incongruity (JI), fragmented medial coronoid process (FCP), osteochondrosis or osteochondritis of the medial humeral condyle and ununited anconeal process (UAP). Three radiographic views were used for each joint to achieve a definitive diagnosis. The prevalence of elbow dysplasia was 19.4 per cent. The most frequent lesion was JI (16.3 per cent), followed by FCP (11.3 per cent). UAP was diagnosed rarely (1.1 per cent). Combinations of lesions were very frequent (42.2 per cent of the dysplastic elbows). Although these results may be biased due to prescreening of dogs with UAP, it should be highlighted that JI and FCP occur frequently in German shepherd dogs and are probably the most common primary lesions of elbow dysplasia, although they have been under-reported until now. PMID:15163051

  19. Canine elbow dysplasia and primary lesions in German shepherd dogs in France.

    PubMed

    Remy, D; Neuhart, L; Fau, D; Genevois, J P

    2004-05-01

    Five hundred and twenty German shepherd dogs were screened for elbow dysplasia. The following primary lesions were analysed: joint incongruity (JI), fragmented medial coronoid process (FCP), osteochondrosis or osteochondritis of the medial humeral condyle and ununited anconeal process (UAP). Three radiographic views were used for each joint to achieve a definitive diagnosis. The prevalence of elbow dysplasia was 19.4 per cent. The most frequent lesion was JI (16.3 per cent), followed by FCP (11.3 per cent). UAP was diagnosed rarely (1.1 per cent). Combinations of lesions were very frequent (42.2 per cent of the dysplastic elbows). Although these results may be biased due to prescreening of dogs with UAP, it should be highlighted that JI and FCP occur frequently in German shepherd dogs and are probably the most common primary lesions of elbow dysplasia, although they have been under-reported until now.

  20. Noninvasive spectroscopic diagnosis of superficial ocular lesions and corneal infections

    SciTech Connect

    Mourant, J.R.; Bigio, I.J.; Johnson, T.; Shimada, T.; Gritz, D.C.; Storey-Held, K.

    1994-02-01

    The potential of a rapid noninvasive diagnostic system to detect tissue abnormalities on the surface of the eye has been investigated. The optical scatter signal from lesions and normal areas on the conjunctival sclera of the human eye were measured in vivo. It is possible to distinguish nonpigmented pingueculas from other lesions. The ability of the system to detect malignancies could not be tested because none of the measured and biopsied lesions were malignant. Optical scatter and fluorescence spectra of bacterial and fungal suspensions, and corneal irritations were also collected. Both scattering and fluorescence show potential for diagnosing corneal infections.

  1. Inspection of Fusion Joints in Plastic Pipe

    SciTech Connect

    Connie Reichert

    2005-09-01

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost-effective method exists for assessing the quality of fusion joints in the field. Visual examination and pressure testing are current nondestructive approaches, which do not provide any assurance about the long-term pipeline performance. This project developed, demonstrated, and validated an in-situ nondestructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system includes a laser-based image-recognition system that automatically generates and interprets digital images of pipe joints and assigns them a pass/fail rating, which eliminates operator bias in evaluating joint quality. An EWI-patented process, the Weld Zone Inspection Method (WZIM) was developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation, which reveals the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and nonstandard conditions. These welds were subjected to the WZIM and two destructive forms of testing: short-term tensile testing and long-term creep rupture testing. There appears to be a direct correlation between the WZIM and the destructive testing results. Although WZIM appears to be more sensitive than destructive testing can verify, the approach appears valid.

  2. INSPECTION OF FUSION JOINTS IN PLASTIC PIPE

    SciTech Connect

    Alex Savitski; Connie Reichert; John Coffey

    2004-10-29

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost effective method of assessing the quality of fusion joints in the field exists. Visual examination and pressure testing are current non-destructive approaches, which do not provide any assurance about the long-term pipeline performance. This project will develop, demonstrate, and validate an in-situ non-destructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system will include a laser based image-recognition system that will automatically generate and interpret digital images of pipe joints and assign them a pass/fail rating, which eliminates operator bias in evaluating joint quality. A Weld Zone Inspection Method (WZIM) is being developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation and reveal the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and non-standard conditions. These welds were subjected to the WZIM and tensile testing. There appears to be a direct correlation between the WZIM and tensile testing results. Although WZIM appears to be more sensitive than tensile testing can verify, the approach appears valid.

  3. INSPECTION OF FUSION JOINTS IN PLASTIC PIPE

    SciTech Connect

    Alex Savitski; Connie Reichert; John Coffey

    2004-07-13

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost effective method of assessing the quality of fusion joints in the field exists. Visual examination and pressure testing are current non-destructive approaches, which do not provide any assurance about the long-term pipeline performance. This project will develop, demonstrate, and validate an in-situ non-destructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system will include a laser based image-recognition system that will automatically generate and interpret digital images of pipe joints and assign them a pass/fail rating, which eliminates operator bias in evaluating joint quality. A Weld Zone Inspection Method (WZIM) is being developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation and reveal the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and non-standard conditions. These welds were subjected to the WZIM and tensile testing. There appears to be a direct correlation between the WZIM and tensile testing results. Although WZIM appears to be more sensitive than tensile testing can verify, the approach appears valid.

  4. INSPECTION OF FUSION JOINTS IN PLASTIC PIPE

    SciTech Connect

    Alex Savitski; Connie Reichert; John Coffey

    2005-07-13

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost effective method of assessing the quality of fusion joints in the field exists. Visual examination and pressure testing are current non-destructive approaches, which do not provide any assurance about the long-term pipeline performance. This project will develop, demonstrate, and validate an in-situ non-destructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system will include a laser based image-recognition system that will automatically generate and interpret digital images of pipe joints and assign them a pass/fail rating, which eliminates operator bias in evaluating joint quality. A Weld Zone Inspection Method (WZIM) is being developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation and reveal the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and nonstandard conditions. These welds were subjected to the WZIM and tensile testing. There appears to be a direct correlation between the WZIM and tensile testing results. Although WZIM appears to be more sensitive than tensile testing can verify, the approach appears valid.

  5. Cartilage transplantation techniques for talar cartilage lesions.

    PubMed

    Mitchell, Matthew E; Giza, Eric; Sullivan, Martin R

    2009-07-01

    Talar articular cartilage is known to differ significantly from knee cartilage. Even so, recommendations for the treatment of talar cartilage lesions have been based on strategies for the knee. Arthroscopic management of osteochondral lesions of the talus is well documented. Results have been favorable with reparative techniques such as débridement with curettage and débridement with drilling, whether undertaken via early open techniques or more recent arthroscopic procedures. Salvage of failed reparative techniques is controversial. Early efforts to salvage failed débridement focused on osteochondral allografts and autografts that used the knee as a donor site. Results of these restorative techniques have been favorable, but concerns have been raised regarding knee donor site morbidity, the use of malleolar osteotomy, and incomplete restoration of the talar articular surface. More recent restorative techniques developed for the knee have been adapted for the ankle, such as autologous chondrocyte implantation and matrix-induced autologous chondrocyte implantation.

  6. Temporomandibular joint osteoarthrosis and temporomandibular joint hypermobility.

    PubMed

    Dijkstra, P U; de Bont, L G; de Leeuw, R; Stegenga, B; Boering, G

    1993-10-01

    For studying the relationship between condylar hypermobility of the temporomandibular joint (TMJ) and osteoarthrosis (OA), 13 patients with bilateral condylar hypermobility were evaluated clinically and radiographically, 30 years after non-surgical treatment. The evaluation included range of motion, joint and muscle tenderness to palpation, joint sounds and masticatory function. Radiographs of the TMJs were evaluated for the absence or presence of degenerative changes. The hypermobile group (HG) was compared with a control group (CG) (n = 13). The CG was evaluated in the same way as the HG. Statistics included t-tests (to compare ranges of motion in the HG over time and to compare ranges of motion in HG and CG), non-parametric tests (to compare tenderness of muscles and joints, joint sounds, masticatory function and radiographic changes over time in the HG). The tests were also used to compare the same variables between the HG and CG group. The groups' only difference was the presence of radiographic signs of OA. In the HG the number of joints with radiographic degenerative changes increased significantly over time and was significantly higher than the CG. Clinically and functionally, the HG and CG did not differ. Therefore, it is concluded that TMJ hypermobility is a subsidiary factor in the development of TMJ OA. PMID:8118897

  7. Real-time controller for foot-drop correction by using surface electromyography sensor.

    PubMed

    Al Mashhadany, Yousif I; Abd Rahim, Nasrudin

    2013-04-01

    Foot drop is a disease caused mainly by muscle paralysis, which incapacitates the nerves generating the impulses that control feet in a heel strike. The incapacity may stem from lesions that affect the brain, the spinal cord, or peripheral nerves. The foot becomes dorsiflexed, affecting normal walking. A design and analysis of a controller for such legs is the subject of this article. Surface electromyography electrodes are connected to the skin surface of the human muscle and work on the mechanics of human muscle contraction. The design uses real surface electromyography signals for estimation of the joint angles. Various-speed flexions and extensions of the leg were analyzed. The two phases of the design began with surface electromyography of real human leg electromyography signal, which was subsequently filtered, amplified, and normalized to the maximum amplitude. Parameters extracted from the surface electromyography signal were then used to train an artificial neural network for prediction of the joint angle. The artificial neural network design included various-speed identification of the electromyography signal and estimation of the angles of the knee and ankle joints by a recognition process that depended on the parameters of the real surface electromyography signal measured through real movements. The second phase used artificial neural network estimation of the control signal, for calculation of the electromyography signal to be stimulated for the leg muscle to move the ankle joint. Satisfactory simulation (MATLAB/Simulink version 2012a) and implementation results verified the design feasibility.

  8. The cricothyroid joint in elderly Japanese individuals.

    PubMed

    Serikawa, Masamitu; Yamamoto, Masahito; Kawamoto, Ai; Katori, Yukio; Kinoshita, Hideaki; Matsunaga, Satoru; Abe, Shin-Ichi

    2016-06-01

    Using 15 cricothyroid joint (CT joint) specimens obtained from donated cadavers of elderly individuals, we examined the morphologies of the ceratocricoid ligaments as well as the synovial tissue. The ligaments consistently contained abundant elastic fibers: the fibers tended to be straight on the anterior side in contrast to a mesh-like arrangement on the posterior side. Thick and/or long synovial folds were often evident in the CT joint. The synovial tissue usually contained CD68-positive macrophages, but the positive cells were often restricted to certain parts of the tissue. Factor VIII-positive capillaries were present but few in number, and CD3- or IgM-positive lymphocytes were absent in the synovial tissue. Degenerative changes in the joint cartilage, such as roughness or thinning, were often present, but no cartilage defects were evident. Therefore, in contrast to the small, non-weight-bearing joints of the musculoskeletal system, we considered the degeneration of the CT joint to be a specific, silent form of osteoarthritis. For high-pitched phonation and ossification of the laryngeal cartilage, the CT joint in elderly individuals seemed to maintain its anterior gliding and rotation with the aid of elastic fiber-rich tissues compensating for the loss of congruity between the joint cartilage surfaces. PMID:26286109

  9. Sensate Scaffolds Can Reliably Detect Joint Loading

    PubMed Central

    Bliss, C. L.; Szivek, J. A.; Tellis, B. C.; Margolis, D. S.; Schnepp, A. B.; Ruth, J. T.

    2008-01-01

    Treatment of cartilage defects is essential to the prevention of osteoarthritis. Scaffold-based cartilage tissue engineering shows promise as a viable technique to treat focal defects. Added functionality can be achieved by incorporating strain gauges into scaffolds, thereby providing a real-time diagnostic measurement of joint loading. Strain-gauged scaffolds were placed into the medial femoral condyles of 14 adult canine knees and benchtop tested. Loads between 75 and 130 N were applied to the stifle joints at 30°, 50°, and 70° of flexion. Strain-gauged scaffolds were able to reliably assess joint loading at all applied flexion angles and loads. Pressure sensitive films were used to determine joint surface pressures during loading and to assess the effect of scaffold placement on joint pressures. A comparison of peak pressures in control knees and joints with implanted scaffolds, as well as a comparison of pressures before and after scaffold placement, showed that strain-gauged scaffold implantation did not significantly alter joint pressures. Future studies could possibly use strain-gauged scaffolds to clinically establish normal joint loads and to determine loads that are damaging to both healthy and tissue-engineered cartilage. Strain-gauged scaffolds may significantly aid the development of a functional engineered cartilage tissue substitute as well as provide insight into the native environment of cartilage. PMID:16941586

  10. Study of Compatibility of Stainless Steel Weld Joints with Liquid Sodium-Potassium Coolants for Fission Surface Power Reactors for Lunar and Space Applications

    SciTech Connect

    Grossbeck, Martin; Qualls, Louis

    2015-07-31

    To make a manned mission to the surface of the moon or to Mars with any significant residence time, the power requirements will make a nuclear reactor the most feasible source of energy. To prepare for such a mission, NASA has teamed with the DOE to develop Fission Surface Power technology with the goal of developing viable options. The Fission Surface Power System (FSPS) recommended as the initial baseline design includes a liquid metal reactor and primary coolant system that transfers heat to two intermediate liquid metal heat transfer loops. Each intermediate loop transfers heat to two Stirling heat exchangers that each power two Stirling converters. Both the primary and the intermediate loops will use sodium-potassium (NaK) as the liquid metal coolant, and the primary loop will operate at temperatures exceeding 600°C. The alloy selected for the heat exchangers and piping is AISI Type 316L stainless steel. The extensive experience with NaK in breeder reactor programs and with earlier space reactors for unmanned missions lends considerable confidence in using NaK as a coolant in contact with stainless steel alloys. However, the microstructure, chemical segregation, and stress state of a weld leads to the potential for corrosion and cracking. Such failures have been experienced in NaK systems that have operated for times less than the eight year goal for the FSPS. For this reason, it was necessary to evaluate candidate weld techniques and expose welds to high-temperature, flowing NaK in a closed, closely controlled system. The goal of this project was to determine the optimum weld configuration for a NaK system that will withstand service for eight years under FSPS conditions. Since the most difficult weld to make and to evaluate is the tube to tube sheet weld in the intermediate heat exchangers, it was the focus of this research. A pumped loop of flowing NaK was fabricated for exposure of candidate weld specimens at temperatures of 600°C, the expected

  11. Modelling the Shear Behaviour of Rock Joints with Asperity Damage Under Constant Normal Stiffness

    NASA Astrophysics Data System (ADS)

    Indraratna, Buddhima; Thirukumaran, Sivanathan; Brown, E. T.; Zhu, Song-Ping

    2015-01-01

    The shear behaviour of a rough rock joint depends largely on the surface properties of the joint, as well as the boundary conditions applied across the joint interface. This paper proposes a new analytical model to describe the complete shear behaviour of rough joints under constant normal stiffness (CNS) boundary conditions by incorporating the effect of damage to asperities. In particular, the effects of initial normal stress levels and joint surface roughness on the shear behaviour of joints under CNS conditions were studied, and the analytical model was validated through experimental results. Finally, the practical application of the model to a jointed rock slope stability analysis is presented.

  12. Low-Friction Joint for Robot Fingers

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.

    1985-01-01

    Mechanical linkage allows adjacent parts to move relative to each other with low friction and with no chatter, slipping, or backlash. Low-friction joint of two surfaces in rolling contact, held in alinement by taut flexible bands. No sliding friction or "stick-slip" motion: Only rolling-contact and bending friction within bands. Proposed linkage intended for finger joints in mechanical hands for robots and manipulators.

  13. CHARACTERIZATION OF DAMPING IN BOLTED LAP JOINTS

    SciTech Connect

    C. MALONEY; D. PEAIRS; ET AL

    2000-08-01

    The dynamic response of a jointed beam was measured in laboratory experiments. The data were analyzed and the system was mathematically modeled to establish plausible representations of joint damping behavior. Damping is examined in an approximate, local linear framework using log decrement and half power bandwidth approaches. in addition, damping is modeled in a nonlinear framework using a hybrid surface irregularities model that employs a bristles-construct. Experimental and analytical results are presented.

  14. Bone and Joint Infections in Children: Septic Arthritis.

    PubMed

    Agarwal, Anil; Aggarwal, Aditya N

    2016-08-01

    The pathological invasion of a joint and subsequent inflammation is known as septic arthritis. The knee and hip are the most frequently involved joints. Staphylococcus aureus is the most common cause of septic arthritis in children. An acute onset of illness with an inflamed painful joint and restricted movements and inability to use joint (pseudoparalysis) clinically indicates septic arthritis. The diagnosis is difficult in a neonate or young child where refusal to feed, crying, discomfort during change of diaper (if hip is involved) or attempted joint movement may be the only findings. Fever and other systemic signs may also be absent in neonates. Septic arthritis is diagnosed clinically, supported by appropriate radiological and laboratory investigations. The peripheral blood white cell count is frequently raised with a predominance of polymorphonuclear cells. The acute phase reactants such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are often markedly raised. Ultrasonography and MRI are preferred investigations in pediatric septic arthritis. Determination of infecting organism in septic arthritis is the key to the correct antibiotic choice, treatment duration and overall management. Joint aspirate and/or blood culture should be obtained before starting antibiotic treatment. Several effective antibiotic regimes are available for managing septic arthritis in children. Presence of large collections, thick pus, joint loculations and pus evacuating into surrounding soft tissues are main indications for surgical drainage. Joint aspiration can be a practical alternative in case the lesion is diagnosed early, with uncomplicated presentations and superficial joints. PMID:26189923

  15. Bone and Joint Infections in Children: Septic Arthritis.

    PubMed

    Agarwal, Anil; Aggarwal, Aditya N

    2016-08-01

    The pathological invasion of a joint and subsequent inflammation is known as septic arthritis. The knee and hip are the most frequently involved joints. Staphylococcus aureus is the most common cause of septic arthritis in children. An acute onset of illness with an inflamed painful joint and restricted movements and inability to use joint (pseudoparalysis) clinically indicates septic arthritis. The diagnosis is difficult in a neonate or young child where refusal to feed, crying, discomfort during change of diaper (if hip is involved) or attempted joint movement may be the only findings. Fever and other systemic signs may also be absent in neonates. Septic arthritis is diagnosed clinically, supported by appropriate radiological and laboratory investigations. The peripheral blood white cell count is frequently raised with a predominance of polymorphonuclear cells. The acute phase reactants such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are often markedly raised. Ultrasonography and MRI are preferred investigations in pediatric septic arthritis. Determination of infecting organism in septic arthritis is the key to the correct antibiotic choice, treatment duration and overall management. Joint aspirate and/or blood culture should be obtained before starting antibiotic treatment. Several effective antibiotic regimes are available for managing septic arthritis in children. Presence of large collections, thick pus, joint loculations and pus evacuating into surrounding soft tissues are main indications for surgical drainage. Joint aspiration can be a practical alternative in case the lesion is diagnosed early, with uncomplicated presentations and superficial joints.

  16. Perspectives on glenohumeral joint contractures and shoulder dysfunction in children with perinatal brachial plexus palsy.

    PubMed

    Gharbaoui, Idris S; Gogola, Gloria R; Aaron, Dorit H; Kozin, Scott H

    2015-01-01

    Shoulder joint deformities continue to be a challenging aspect of treating upper plexus lesions in children with perinatal brachial plexus palsy (PBPP). It is increasingly recognized that PBPP affects the glenohumeral joint specifically, and that abnormal scapulothoracic movements are a compensatory development. The pathophysiology and assessment of glenohumeral joint contractures, the progression of scapular dyskinesia and skeletal dysplasia, and current shoulder imaging techniques are reviewed. PMID:25835253

  17. PS-OCT of natural pigmented and nonpigmented interproximal caries lesions

    NASA Astrophysics Data System (ADS)

    Ngaotheppitak, Patara; Darling, Cynthia L.; Fried, Daniel

    2005-03-01

    Previous studies have demonstrated that Polarization Sensitive Optical Coherence Tomography (PS-OCT) can be used to image early dental caries. The purpose of this study was to compare the measured reflectivity of natural caries lesions with the mineral loss measured using digital microradiography. An all polarization-maintaining fiber based PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of natural white spot lesions and pigmented lesions on the smooth surfaces of extracted teeth. There was a strong positive correlation between the increase in the integrated reflectivity in the perpendicular polarization axis of the PS-OCT system and the increase in the integrated mineral loss or lesion severity for both white-spot and pigmented lesions, P <0.001. Therefore, PS-OCT is well-suited to assess the severity of natural caries lesions and resolve the internal structure of early caries lesions for the potential assessment of the lesion activity.

  18. Voxelwise Bayesian Lesion Deficit Analysis

    PubMed Central

    Chen, Rong; Hillis, Argye E.; Pawlak, Mikolaj; Herskovits, Edward H

    2008-01-01

    Relating cognitive deficits to the presence of lesions has been an important means of delineating structure-function associations in the human brain. We propose a voxel-based Bayesian method for lesion-deficit analysis, which identifies complex linear or nonlinear associations among brain-lesion locations, and neurological status. We validated this method using a simulated data set, and we applied this algorithm to data obtained from an acute-stroke study to identify associations among voxels with infarct or hypoperfusion, and impaired word reading. We found that a distributed region involving Brodmann areas (BA) 22, 37, 39, and 40 was implicated in word reading. PMID:18328733

  19. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  20. No Carious Cervical Lesions: Abfraction

    PubMed Central

    Shetty, Sumanth M; Shetty, Rashmi G; Mattigatti, Sudha; Managoli, Noopur A; Rairam, Surabhi G; Patil, Ashwini M

    2013-01-01

    Abfraction or Theory of Abfraction is a theory explaining the non-carious cervical lesions (NCCL). It suggests that they are caused by flexural forces, usually from cyclic loading; the enamel, especially at the cementoenamel junction (CEJ), undergoes this pattern of destruction by separating the enamel rods. Clinical aspect importance of these ineart lesions are at most important to be detected for early intervention and treatment modalities as options during the progression of the disease. How to cite this article: Shetty SM, Shetty RG, Mattigatti S, Managoli NA, Rairam SG, Patil AM. No Carious Cervical Lesions: Abfraction. J Int Oral Health 2013; 5(5):142-5. PMID:24324319

  1. Simulating the Structural Response of a Preloaded Bolted Joint

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

    2008-01-01

    The present paper describes the structural analyses performed on a preloaded bolted-joint configuration. The joint modeled was comprised of two L-shaped structures connected together using a single bolt. Each L-shaped structure involved a vertical flat segment (or shell wall) welded to a horizontal segment (or flange). Parametric studies were performed using elasto-plastic, large-deformation nonlinear finite element analyses to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preload, washer-surface-bearing size, edge boundary conditions, joint segment length, and loading history. Joint response is reported in terms of displacements, gap opening, and surface strains. Most of the factors studied were determined to have minimal effect on the bolted-joint response; however, the washer-bearing-surface size affected the response significantly.

  2. Lithosphere-asthenosphere interaction beneath the western United States from the joint inversion of body-wave traveltimes and surface-wave phase velocities

    USGS Publications Warehouse

    Obrebski, M.; Allen, R.M.; Pollitz, F.; Hung, S.-H.

    2011-01-01

    The relation between the complex geological history of the western margin of the North American plate and the processes in the mantle is still not fully documented and understood. Several pre-USArray local seismic studies showed how the characteristics of key geological features such as the Colorado Plateau and the Yellowstone Snake River Plains are linked to their deep mantle structure. Recent body-wave models based on the deployment of the high density, large aperture USArray have provided far more details on the mantle structure while surface-wave tomography (ballistic waves and noise correlations) informs us on the shallow structure. Here we combine constraints from these two data sets to image and study the link between the geology of the western United States, the shallow structure of the Earth and the convective processes in mantle. Our multiphase DNA10-S model provides new constraints on the extent of the Archean lithosphere imaged as a large, deeply rooted fast body that encompasses the stable Great Plains and a large portion of the Northern and Central Rocky Mountains. Widespread slow anomalies are found in the lower crust and upper mantle, suggesting that low-density rocks isostatically sustain part of the high topography of the western United States. The Yellowstone anomaly is imaged as a large slow body rising from the lower mantle, intruding the overlying lithosphere and controlling locally the seismicity and the topography. The large E-W extent of the USArray used in this study allows imaging the 'slab graveyard', a sequence of Farallon fragments aligned with the currently subducting Juan de Fuca Slab, north of the Mendocino Triple Junction. The lithospheric root of the Colorado Plateau has apparently been weakened and partly removed through dripping. The distribution of the slower regions around the Colorado Plateau and other rigid blocks follows closely the trend of Cenozoic volcanic fields and ancient lithospheric sutures, suggesting that the

  3. Multidetector computed tomography of temporomandibular joint: A road less travelled

    PubMed Central

    Pahwa, Shivani; Bhalla, Ashu Seith; Roychaudhary, Ajoy; Bhutia, Ongkila

    2015-01-01

    This article reviews the imaging anatomy of temporomandibular joint (TMJ), describes the technique of multi-detector computed tomography (MDCT) of the TMJ, and describes in detail various osseous pathologic afflictions affecting the joint. Traumatic injuries affecting the mandibular condyle are most common, followed by joint ankylosis as a sequel to arthritis. The congenital anomalies are less frequent, hemifacial microsomia being the most commonly encountered anomaly involving the TMJ. Neoplastic afflictions of TMJ are distinctly uncommon, osteochondroma being one of the most common lesions. MDCT enables comprehensive evaluation of osseous afflictions of TMJ, and is a valuable tool for surgical planning. Sagittal, coronal and 3D reformatted images well depict osseous TMJ lesions, and their relationship to adjacent structures. PMID:25984518

  4. Real-time visualization of joint cavitation.

    PubMed

    Kawchuk, Gregory N; Fryer, Jerome; Jaremko, Jacob L; Zeng, Hongbo; Rowe, Lindsay; Thompson, Richard

    2015-01-01

    Cracking sounds emitted from human synovial joints have been attributed historically to the sudden collapse of a cavitation bubble formed as articular surfaces are separated. Unfortunately, bubble collapse as the source of joint cracking is inconsistent with many physical phenomena that define the joint cracking phenomenon. Here we present direct evidence from real-time magnetic resonance imaging that the mechanism of joint cracking is related to cavity formation rather than bubble collapse. In this study, ten metacarpophalangeal joints were studied by inserting the finger of interest into a flexible tube tightened around a length of cable used to provide long-axis traction. Before and after traction, static 3D T1-weighted magnetic resonance images were acquired. During traction, rapid cine magnetic resonance images were obtained from the joint midline at a rate of 3.2 frames per second until the cracking event occurred. As traction forces increased, real-time cine magnetic resonance imaging demonstrated rapid cavity inception at the time of joint separation and sound production after which the resulting cavity remained visible. Our results offer direct experimental evidence that joint cracking is associated with cavity inception rather than collapse of a pre-existing bubble. These observations are consistent with tribonucleation, a known process where opposing surfaces resist separation until a critical point where they then separate rapidly creating sustained gas cavities. Observed previously in vitro, this is the first in-vivo macroscopic demonstration of tribonucleation and as such, provides a new theoretical framework to investigate health outcomes associated with joint cracking.

  5. Real-Time Visualization of Joint Cavitation

    PubMed Central

    Rowe, Lindsay

    2015-01-01

    Cracking sounds emitted from human synovial joints have been attributed historically to the sudden collapse of a cavitation bubble formed as articular surfaces are separated. Unfortunately, bubble collapse as the source of joint cracking is inconsistent with many physical phenomena that define the joint cracking phenomenon. Here we present direct evidence from real-time magnetic resonance imaging that the mechanism of joint cracking is related to cavity formation rather than bubble collapse. In this study, ten metacarpophalangeal joints were studied by inserting the finger of interest into a flexible tube tightened around a length of cable used to provide long-axis traction. Before and after traction, static 3D T1-weighted magnetic resonance images were acquired. During traction, rapid cine magnetic resonance images were obtained from the joint midline at a rate of 3.2 frames per second until the cracking event occurred. As traction forces increased, real-time cine magnetic resonance imaging demonstrated rapid cavity inception at the time of joint separation and sound production after which the resulting cavity remained visible. Our results offer direct experimental evidence that joint cracking is associated with cavity inception rather than collapse of a pre-existing bubble. These observations are consistent with tribonucleation, a known process where opposing surfaces resist separation until a critical point where they then separate rapidly creating sustained gas cavities. Observed previously in vitro, this is the first in-vivo macroscopic demonstration of tribonucleation and as such, provides a new theoretical framework to investigate health outcomes associated with joint cracking. PMID:25875374

  6. Electrocautery for Precancerous Anal Lesions

    Cancer.gov

    Results from a randomized clinical trial conducted in Amsterdam suggest that electrocautery is better than topical imiquimod or fluorouracil at treating potentially precancerous anal lesions in HIV-positive men who have sex with men.

  7. Gram stain of skin lesion

    MedlinePlus

    ... may be done along with this test. Other studies are often done on a skin sample to determine if cancer is present. Viral skin lesions like herpes simplex are examined by other tests or a viral culture.

  8. [Total temporomandibular joint prostheses].

    PubMed

    Zwetyenga, N; Amroun, S; Wajszczak, B-L; Moris, V

    2016-09-01

    The temporomandibular joint (TMJ) is probably the most complex human joint. As in all joints, its prosthetic replacement may be indicated in selected cases. Significant advances have been made in the design of TMJ prostheses during the last three decades and the indications have been clarified. The aim of our work was to make an update on the current total TMJ total joint replacement. Indications, contraindications, prosthetic components, advantages, disadvantages, reasons for failure or reoperation, virtual planning and surgical protocol have been exposed. PMID:27554487

  9. Asterixis in focal brain lesions.

    PubMed

    Degos, J D; Verroust, J; Bouchareine, A; Serdaru, M; Barbizet, J

    1979-11-01

    Asterixis was observed in 20 cases of focal brain lesions. Metabolic or toxic factors were excluded. An electromyogram study of asterixis was carried out in nine cases to establish the diagnosis. The site of the focal lesion was either parietal or mesencephalic and was always contralateral to the asterixis. "Focal asterixis" could result from a dysfunction of the sensorimotor integration in the parietal lobe and the midbrain.

  10. Benign Pediatric Salivary Gland Lesions.

    PubMed

    Carlson, Eric R; Ord, Robert A

    2016-02-01

    Salivary gland lesions are rare in pediatric patients. In addition, the types of salivary gland tumors are different in their distribution in specific sites in the major and minor salivary glands in children compared with adults. This article reviews benign neoplastic and nonneoplastic salivary gland disorders in pediatric patients to help clinicians to develop an orderly differential diagnosis that will lead to expedient treatment of pediatric patients with salivary gland lesions.

  11. 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.

  12. Micro-structure and frictional characteristics of beetle?s joint

    NASA Astrophysics Data System (ADS)

    Dai, Zhendong; Gorb, Stanislav N.

    2004-01-01

    Geometric and micro-structure design, tribology properties of beetle joints were experimentally studied, which aimed to enlighten ideas for the joint design of MEMS. The observation by using SEM and microscopy suggested that beetle’s joints consist of a concave surface matched with a convex surface. The heads of the beetles, rubbing with flat glass, were tested in fresh and dried statuses and compared with sapphire ball with flat glass. Frictional coefficient of the joint material on glass was significantly lower than that of the sapphire sphere on glass. The material of the joint cuticle for convex surface is rather stiff (the elastic modulus 4.5 Gpa) and smooth. The surface is hydrophobic (the contact angle of distilled water was 88.3°). It is suggested here that the high stiffness of the joint material and hydrophobicity of the joint surface are parts of the mechanism minimizing friction in insect joints.

  13. Endoscopic Management of Dieulafoy's Lesion

    PubMed Central

    Jeon, Hye Kyung

    2015-01-01

    A Dieulafoy's lesion is a vascular abnormality consisting of a large caliber-persistent tortuous submucosal artery. A small mucosal defect with the eruption of this protruding vessel can cause bleeding. In fact, a Dieulafoy's lesion is a relatively rare but potentially life-threatening condition. It accounts for 1% to 2% of cases of acute gastrointestinal bleeding. Although there is no consensus on the treatment of Dieulafoy's lesions; treatment options depend on the mode of presentation, site of the lesion, and available expertise. Endoscopic therapy is usually successful in achieving primary hemostasis, with hemostasis success rates reaching 75% to 100%. Although various therapeutic endoscopic methods are used to control bleeding in Dieulafoy's lesions, the best method for endoscopic intervention is not clear. Combination endoscopic therapy is known to be superior to monotherapy because of a lower rate of recurrent bleeding. In addition, mechanical therapies including hemostatic clipping and endoscopic band ligation are more effective and successful in controlling bleeding than other endoscopic methods. Advances in endoscopic techniques have reduced mortality in patients with Dieulafoy's lesion-from 80% to 8%-and consequently, the need for surgical intervention has been reduced. Currently, surgical intervention is used for cases that fail therapeutic endoscopic or angiographic interventions. PMID:25844338

  14. DNA lesions: A thermodynamic perspective

    SciTech Connect

    Plum, G.E.; Breslauer, K.J.

    1994-12-31

    The studies described in this paper are part of an overall program project entitled {open_quotes}The Chemistry and Biology of Exocyclic DNA Adducts and Oxidative DNA Damage.{close_quotes}. Initially, all the project leaders discuss and agree on biologically interesting lesions to target for study. Then begins the process of developing the chemistry required to synthesize modified nucleosides that either correspond to or model the damage sites of interest. Such modified nucleotides then are incorporated into oligonucleotides that are hybridized to their complements, thereby forming lesion-containing duplex structures. In any given duplex, the identity of the lesion-opposing nucleoside on the complementary strand is systematically altered, thereby allowing us to evaluate the impact on duplex properties of the identity of the base opposite the lesion. For comparative purposes, the undamaged parent Watson-Crick duplex also is synthesized. Such families of DNA duplexes are then sent for independent physiochemical characterizations. Armed with an extensive body of biophysical data, one then searches for correlations between the physiochemical influences of the lesions on duplex properties and the biological consequences of each lesion. At this stage, our approach is highly empirical. Ultimately, we hope that our studies will reveal correlations between physiochemical properties and biological consequences such that we will develop predictive powers and gain insight into the mechanisms of recognition, repair, and mutagenesis.

  15. Diagnosis of Knee Osteochondral Lesions With Ultrasound Imaging.

    PubMed

    Penttilä, Pekko; Liukkonen, Jukka; Joukainen, Antti; Virén, Tuomas; Jurvelin, Jukka S; Töyräs, Juha; Kröger, Heikki

    2015-10-01

    Evaluation of articular cartilage and subchondral bone is essential in the diagnosis of joint diseases and injuries. Interobserver and intraobserver reproducibilities of arthroscopic grading are only poor to moderate. Thus, for quantitative and objective evaluation of cartilage and subchondral bone, ultrasound arthroscopy (UA) has been introduced to clarify this dilemma. Assessment of the clinical feasibility of high-frequency ultrasonography (US) during 6 knee arthroscopies was conducted, and the surgical technique is presented. US imaging was conducted with a flexible 9-MHz US catheter inserted into the joint through conventional portals. US and arthroscopy videos were synchronously recorded, and US parameters for cartilage and subchondral bone characteristics were measured. Arthroscopy and US imaging were combined to perform cartilage grading. UA produced quantitative data on lesion size, as well as cartilage quality, and showed subchondral bone changes. Visualization of an osteochondritis dissecans lesion not detected by conventional arthroscopy and US-guided retrograde drilling were possible with UA. To conclude, UA proved to be clinically feasible and aided in the diagnosis when assessing knee osteochondral lesions. PMID:26697300

  16. Diagnosis of Knee Osteochondral Lesions With Ultrasound Imaging

    PubMed Central

    Penttilä, Pekko; Liukkonen, Jukka; Joukainen, Antti; Virén, Tuomas; Jurvelin, Jukka S.; Töyräs, Juha; Kröger, Heikki

    2015-01-01

    Evaluation of articular cartilage and subchondral bone is essential in the diagnosis of joint diseases and injuries. Interobserver and intraobserver reproducibilities of arthroscopic grading are only poor to moderate. Thus, for quantitative and objective evaluation of cartilage and subchondral bone, ultrasound arthroscopy (UA) has been introduced to clarify this dilemma. Assessment of the clinical feasibility of high-frequency ultrasonography (US) during 6 knee arthroscopies was conducted, and the surgical technique is presented. US imaging was conducted with a flexible 9-MHz US catheter inserted into the joint through conventional portals. US and arthroscopy videos were synchronously recorded, and US parameters for cartilage and subchondral bone characteristics were measured. Arthroscopy and US imaging were combined to perform cartilage grading. UA produced quantitative data on lesion size, as well as cartilage quality, and showed subchondral bone changes. Visualization of an osteochondritis dissecans lesion not detected by conventional arthroscopy and US-guided retrograde drilling were possible with UA. To conclude, UA proved to be clinically feasible and aided in the diagnosis when assessing knee osteochondral lesions. PMID:26697300

  17. Guess-Work and Reasonings on Centennial Evolution of Surface Air Temperature in Russia. Part III: Where is the Joint Between Norms and Hazards from a Bifurcation Analysis Viewpoint?

    NASA Astrophysics Data System (ADS)

    Kolokolov, Yury; Monovskaya, Anna

    2016-06-01

    The paper continues the application of the bifurcation analysis in the research on local climate dynamics based on processing the historically observed data on the daily average land surface air temperature. Since the analyzed data are from instrumental measurements, we are doing the experimental bifurcation analysis. In particular, we focus on the discussion where is the joint between the normal dynamics of local climate systems (norms) and situations with the potential to create damages (hazards)? We illustrate that, perhaps, the criteria for hazards (or violent and unfavorable weather factors) relate mainly to empirical considerations from human opinion, but not to the natural qualitative changes of climate dynamics. To build the bifurcation diagrams, we base on the unconventional conceptual model (HDS-model) which originates from the hysteresis regulator with double synchronization. The HDS-model is characterized by a variable structure with the competition between the amplitude quantization and the time quantization. Then the intermittency between three periodical processes is considered as the typical behavior of local climate systems instead of both chaos and quasi-periodicity in order to excuse the variety of local climate dynamics. From the known specific regularities of the HDS-model dynamics, we try to find a way to decompose the local behaviors into homogeneous units within the time sections with homogeneous dynamics. Here, we present the first results of such decomposition, where the quasi-homogeneous sections (QHS) are determined on the basis of the modified bifurcation diagrams, and the units are reconstructed within the limits connected with the problem of shape defects. Nevertheless, the proposed analysis of the local climate dynamics (QHS-analysis) allows to exhibit how the comparatively modest temperature differences between the mentioned units in an annual scale can step-by-step expand into the great temperature differences of the daily

  18. [Concomitant diseases in primary joint hypermobility syndrome].

    PubMed

    Skoumal, Martin; Haberhauer, Günther; Mayr, Hans

    2004-10-15

    The primary joint hypermobility syndrome (pJH) is an overlap disorder of connective-tissue dysplasias, which incorporates features seen in the Marfan syndromes (MFS), Ehlers-Danlos syndromes (EDS), and osteogenesis imperfecta. Patients with pJH usually present arthralgia, back pain, soft-tissue lesions, recurrent joint dislocation, or subluxation. Extraarticular features may include, e. g., striae cutis, keratoconus, easy bruising, mitral valve prolapse, aortic incompetence, aneurysms, pneumothorax, hernia, urinary incontinence, and pelvic floor prolapse. Due to the high frequency of critical dissection and rupture, the early recognition of rare life-threatening complications such as dilatation of the aortic root and aneurysms is important. Therefore, patients (and their family members) with pJH should also be examined for life-threatening features seen in MFS and EDS. PMID:15490074

  19. Wear analysis of revolute joints with clearance in multibody systems

    NASA Astrophysics Data System (ADS)

    Bai, ZhengFeng; Zhao, Yang; Wang, XingGui

    2013-08-01

    In this work, the prediction of wear for revolute joint with clearance in multibody systems is investigated using a computational methodology. The contact model in clearance joint is established using a new hybrid nonlinear contact force model and the friction effect is considered by using a modified Coulomb friction model. The dynamics model of multibody system with clearance is established using dynamic segmentation modeling method and the computational process for wear analysis of clearance joint in multibody systems is presented. The main computational process for wear analysis of clearance joint includes two steps, which are dynamics analysis and wear analysis. The dynamics simulation of multibody system with revolute clearance joint is carried out and the contact forces are drawn and used to calculate the wear amount of revolute clearance joint based on the Archard's wear model. Finally, a four-bar multibody mechanical system with revolute clearance joint is used as numerical example application to perform the simulation and show the dynamics responses and wear characteristics of multibody systems with revolute clearance joint. The main results of this work indicate that the contact between the joint elements is wider and more frequent in some specific regions and the wear phenomenon is not regular around the joint surface, which causes the clearance size increase non-regularly after clearance joint wear. This work presents an effective method to predict wear of revolute joint with clearance in multibody systems.

  20. ["Floating interphalangeal joint". A case report].

    PubMed

    Aslan, M; Duroux, F; Delattre, O

    2013-02-01

    We report the case of a combination of closed extra-articular phalangeal fractures of the thumb, creating a floating interphalangeal joint. The lesions described were the result of a direct trauma to the thumb during the earthquake in Haiti in January 2010. It was fixed seven days after the trauma using a percutaneous external fixation with a dorsal frame or Martinique's "Ti'fix" - a modification of the Beaubourg fixator. We describe this simple, economical and improved quality method of fixation. Consolidation permitted the removal of the external fixator a month after surgery, followed by early mobilization. We report the functional and aesthetic results at 1-year follow-up.

  1. Infected shoulder joint with loose Suture Anchor in the joint after Bankart’s Repair- A Case Report

    PubMed Central

    Kumar, Mukesh; Thilak, Jai

    2016-01-01

    Introduction: The glenoid labrum is frequently torn in traumatic glenohumeral dislocation; arthroscopic repair is the standard method of treatment. The complications associated with this repair are pulling out of metal suture anchors, chondrolysis and joint infection. The infection of joint after arthroscopy is less than 1%. Staphylococcus is most common organism and rarely followed by Pseudomonas aeruginosa. We report a case of infected shoulder with chondrolysis of the joint and pulled out metal suture anchor lying inside the joint after Bankart’s repair. Case Report: A 22-year-old gentleman came to us with complaints of shoulder joint pain & gross restriction of movements for one year, with history of intermittent fever and treatment in nearby hospital. He also gives past history of recurrent dislocation of shoulder with last episode 18 months back, which was diagnosed as Bankart’s lesion and arthroscopic Bankart’s repair was done 15 months back. He was evaluated at our institute and suspected to have infection of shoulder joint with pulled out metal suture anchor inside the joint. Arthroscopic removal of suture anchor and debridement of shoulder joint was done, Culture was obtained and culture specific antibiotics were given for six weeks, and significant improvement was observed with this line of treatment. At lyear follow up, the patient was able to perform his daily activities with terminal restriction of range of motion. Conclusions: Shoulder joint infection is rare after Bankart’s repair and required a high degree of suspicion. Any foreign materials inside the joint should be taken out & followed with aggressive treatment by debridement, irrigation and culture specific antibiotics. Suppression of joint infection with antibiotics should be avoided specially when there is foreign body inside the joint.

  2. Compound solder joints

    NASA Technical Reports Server (NTRS)

    Batista, R. I.; Simonson, R. B.

    1976-01-01

    Joining technique prevents contamination, may be used to join dissimilar metal tubes, minimizes fluid and gas entrapment, expedites repairs, and can yield joints having leakage rates less than 0.000001 standard cubic cm He/min. Components of joint are solder sleeve, two solder rings, Teflon sleeve, and tubing to be joined.

  3. Truss Slip Joint

    NASA Technical Reports Server (NTRS)

    Thomas, Frank

    1993-01-01

    Truss slip joint has few parts, strong, and assembled and disassembled easily. Designed to carry axial loads as large as 100,000 lb and to accommodate slight initial axial-displacement and angular misalignments. Joint assembled or disassembled by astronaut in space suit or, on Earth, by technician in heavy protective clothing; simple enough to be operable by robot. Modified to accommodate welding.

  4. Wedge Joints for Trusses

    NASA Technical Reports Server (NTRS)

    Wood, Kenneth E.

    1987-01-01

    Structure assembled rapidly with simple hand tools. Proposed locking wedge joints enable rapid assembly of lightweight beams, towers, scaffolds, and other truss-type structures. Lightweight structure assembled from tubular struts joined at nodes by wedge pins fitting into mating slots. Joint assembled rapidly by seating wedge pin in V-shaped slots and deforming end of strut until primary pawl engages it.

  5. Strategies for joint appointments.

    PubMed

    Royle, J; Crooks, D L

    1985-01-01

    The structure and policies governing joint appointments discussed above, are developed primarily through cooperation and collaboration between nursing service and education institutions. The joint appointee participates in the process of negotiation of salary, benefits and role responsibilities and exploration of the implications of the appointment for personal career development. Implementation and maintenance of the appointment requires the collaborative efforts of the joint appointee with both contracting agencies. Factors influencing the functioning of joint appointees have been identified and strategies to facilitate functioning presented. The joint appointee must be independent in thought and action yet adaptable to work within the boundaries of two social systems with differing values and expectations. Nursing management, peers and students can provide the support needed to overcome the frustrations and to achieve the rewards inherent in successful implementation of an exciting and innovative role. PMID:3852805

  6. [Approach to joint effusion].

    PubMed

    Henniger, M; Rehart, S

    2016-09-01

    The fundamental components of the differential diagnostics of joint effusions are the patient history and clinical examination. In the case of unclear findings, arthrosonography can provide information for the distinction between intra-articular and extra-articular pathologies. In atraumatic joint effusions inflammatory parameters in blood are determined in order to differentiate between systemic inflammatory and local inflammatory joint effusions. In the case of normal values further diagnostics are carried out using imaging. With elevated inflammatory parameters the main differential diagnoses are gouty arthritis, autoimmune joint processes and septic arthritis. When in doubt, a joint aspiration and synovial fluid analysis should be performed to rule out septic arthritis or if necessary confirmation of gouty arthritis. PMID:27562127

  7. Testing composite-to-metal tubular lap joints

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.; Slavin, A.M.

    1993-11-01

    Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

  8. Testing composite-to-metal tubular lap joints

    NASA Astrophysics Data System (ADS)

    Guess, T. R.; Reedy, E. D., Jr.; Slavin, A. M.

    Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

  9. Supramolecular synergy in the boundary lubrication of synovial joints

    PubMed Central

    Seror, Jasmine; Zhu, Linyi; Goldberg, Ronit; Day, Anthony J.; Klein, Jacob

    2015-01-01

    Hyaluronan, lubricin and phospholipids, molecules ubiquitous in synovial joints, such as hips and knees, have separately been invoked as the lubricants responsible for the remarkable lubrication of articular cartilage; but alone, these molecules cannot explain the extremely low friction at the high pressures of such joints. We find that surface-anchored hyaluronan molecules complex synergistically with phosphatidylcholine lipids present in joints to form a boundary lubricating layer, which, with coefficient of friction μ≈0.001 at pressures to over 100 atm, has a frictional behaviour resembling that of articular cartilage in the major joints. Our findings point to a scenario where each of the molecules has a different role but must act together with the others: hyaluronan, anchored at the outer surface of articular cartilage by lubricin molecules, complexes with joint phosphatidylcholines to provide the extreme lubrication of synovial joints via the hydration–lubrication mechanism. PMID:25754223

  10. Skin lesions in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz; Jerzemowski, Janusz

    2015-01-01

    Skin lesions, apart from diarrhoeas, fever of unknown origin, and respiratory tract infections belong to the most frequent medical problems in travellers returned from tropical and subtropical destinations, accounting more than 10% of reported cases. Most dermatoses have their clinical onset during travel, although some of them can occur after return. Travel-related dermatological problems can have a wide spectrum of clinical picture, from macular, popular or nodular rash, linear and migratory lesions, to plaques, vesicles, bullae, erosions or ulcers. Skin conditions in returning travellers may be of infectious and non-infectious aetiologies. Infectious lesions may be originally tropical (e.g. dengue, chikungunya, schistosomiasis, leishmaniasis, myiasis, tungiasis, loiasis), although the majority are cosmopolitan (arthropod bites, sunburns, allergic rashes). The evaluation of skin lesions depends on many factors, including immune status of patients, use of medicines, exposure on health hazards (fauna, flora, risky behaviours), as well as the time, duration and location of travel. As the number of travellers to tropical and subtropical destinations has been continuously rising, the number of skin illnesses has also been increasing. This means that specialists in travel medicine need to extend their knowledge of epidemiology, clinical features and diagnosis of travel-related health problems including skin lesions in returning travellers. PMID:26394319

  11. Skin lesions in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz; Jerzemowski, Janusz

    2015-01-01

    Skin lesions, apart from diarrhoeas, fever of unknown origin, and respiratory tract infections belong to the most frequent medical problems in travellers returned from tropical and subtropical destinations, accounting more than 10% of reported cases. Most dermatoses have their clinical onset during travel, although some of them can occur after return. Travel-related dermatological problems can have a wide spectrum of clinical picture, from macular, popular or nodular rash, linear and migratory lesions, to plaques, vesicles, bullae, erosions or ulcers. Skin conditions in returning travellers may be of infectious and non-infectious aetiologies. Infectious lesions may be originally tropical (e.g. dengue, chikungunya, schistosomiasis, leishmaniasis, myiasis, tungiasis, loiasis), although the majority are cosmopolitan (arthropod bites, sunburns, allergic rashes). The evaluation of skin lesions depends on many factors, including immune status of patients, use of medicines, exposure on health hazards (fauna, flora, risky behaviours), as well as the time, duration and location of travel. As the number of travellers to tropical and subtropical destinations has been continuously rising, the number of skin illnesses has also been increasing. This means that specialists in travel medicine need to extend their knowledge of epidemiology, clinical features and diagnosis of travel-related health problems including skin lesions in returning travellers.

  12. Synovial tissue morphology of the cricoarytenoid joint in the elderly: a histological comparison with the cricothyroid joint.

    PubMed

    Katsumura, Sakura; Yamamoto, Masahito; Kitamura, Kei; Kasahara, Masaaki; Katori, Yukio; Abe, Shin-Ichi

    2016-03-01

    We compared the age-related morphology of the cricothyroid (CT) joint with that of the cricoarytenoid (CA) joint using 18 specimens from elderly cadavers in terms of their elastic fiber contents as well as the cells composing the joint capsule and synovial tissues. In contrast to an almost flat-flat interface in the CT joint, the CA joint was similar to a saddle joint. The CA joint capsule was thin and contained few elastic fibers, and in contrast to the CT joint, external fibrous tissues were not exposed to the joint cavity, there being no injury to the CA joint capsule. The lateral and posterior aspects of the CA joint were covered by the lateral and posterior CA muscles, respectively, and the fascia of the latter muscle was sometimes thick with abundant elastic fibers. However, due to possible muscle degeneration, loose connective tissue was often interposed between the fascia and the capsule. The medial and anterior aspects of the CA joint faced loose tissue that was continuous with the laryngeal submucosal tissue. Therefore, in contrast to the CT joint, a definite supporting ligament was usually absent in the CA joint. Synovial folds were always seen in the CA joint, comprising a short triangular mass on the posterior side and long laminar folds on the anterior side. The synovial folds usually contained multiple capillaries and a few CD68-positive macrophages. High congruity of the CA joint surfaces as well as strong muscle support to the arytenoid cartilage appeared to provide the specific synovial morphology. PMID:27051568

  13. Synovial tissue morphology of the cricoarytenoid joint in the elderly: a histological comparison with the cricothyroid joint

    PubMed Central

    Katsumura, Sakura; Kitamura, Kei; Kasahara, Masaaki; Katori, Yukio; Abe, Shin-ichi

    2016-01-01

    We compared the age-related morphology of the cricothyroid (CT) joint with that of the cricoarytenoid (CA) joint using 18 specimens from elderly cadavers in terms of their elastic fiber contents as well as the cells composing the joint capsule and synovial tissues. In contrast to an almost flat-flat interface in the CT joint, the CA joint was similar to a saddle joint. The CA joint capsule was thin and contained few elastic fibers, and in contrast to the CT joint, external fibrous tissues were not exposed to the joint cavity, there being no injury to the CA joint capsule. The lateral and posterior aspects of the CA joint were covered by the lateral and posterior CA muscles, respectively, and the fascia of the latter muscle was sometimes thick with abundant elastic fibers. However, due to possible muscle degeneration, loose connective tissue was often interposed between the fascia and the capsule. The medial and anterior aspects of the CA joint faced loose tissue that was continuous with the laryngeal submucosal tissue. Therefore, in contrast to the CT joint, a definite supporting ligament was usually absent in the CA joint. Synovial folds were always seen in the CA joint, comprising a short triangular mass on the posterior side and long laminar folds on the anterior side. The synovial folds usually contained multiple capillaries and a few CD68-positive macrophages. High congruity of the CA joint surfaces as well as strong muscle support to the arytenoid cartilage appeared to provide the specific synovial morphology. PMID:27051568

  14. Morphological evolution of voids by surface drift diffusion driven by capillary, electromigration, and thermal-stress gradients induced by steady-state heat flow in passivated metallic thin films and flip chip solder joints. I. Theory

    NASA Astrophysics Data System (ADS)

    Ogurtani, Tarik Omer; Akyildiz, Oncu

    2008-07-01

    The morphological evolution of intragranular voids induced by surface drift diffusion under the actions of capillary and electromigration (EM) forces and thermal-stress gradients (TSGs) associated with steady-state heat flow is investigated in passivated metallic thin films and flip chip solder joints via computer simulation using the front-tracking method. In the mesoscopic nonequilibrium thermodynamic formulation of the generalized driving forces for the thermal-stress-induced surface drift diffusion, not only the usual elastic strain energy density contribution but also the elastic dipole tensor interaction (EDTI) between the thermal-stress field and the mobile atomic species (monovacancies) are considered using the concept of elastic interaction energy promoted in unified linear instability analysis (ULISA) [T. O. Ogurtani, Phys. Rev. B 74, 155422 (2006)]. According to extensive computer experiments performed on voids, which are initially cylindrical in shape, two completely different and topographically distinct behaviors are observed during the development of quasistationary state void surface morphologies, even in the presence of strong EM forces. These behaviors strictly depend on whether or not heat flux crowding occurs in the regions between the void surface layer and the sidewalls of the interconnect lines due to proximity effects of the insulating boundaries. In both morphological cases, however, one also observes two well-defined regimes, namely, the EM and TSG dominated regimes in EM versus EDTI parametric space. In the case of the TSG dominated regime, the void center of gravity (centroid) exhibits uniform displacement (drift) velocity proportional and opposite to the induced TSG exactly as predicted by ULISA theory. These domains are bounded by a threshold level curve for the EDTI parameter, above which an extremely sharp crack tip nucleation and propagation occurs in the highly localized minima in the triaxial stress regions (i.e., hot spots

  15. BENIGN BONE TUMORS AND TUMOR-LIKE BONE LESIONS: TREATMENT UPDATE AND NEW TRENDS

    PubMed Central

    Nogueira Drumond, José Marcos

    2015-01-01

    The treatment of benign bone tumors (BBT) and tumor-like bone lesions (TBL) has observed the introduction of new drugs, such as intravenous bisphosphonates, which have ossified bone lesions caused by fibrous dysplasia. Aneurismal bone cyst has been treated with sclerosing agents by percutaneous injection, yielding good results. Adjuvants allow joint salvage, maintenance of movements and function, with low rates of recurrence. Among them, the most used ones are bone cement (PMMA), phenol, nitrogen-based cryotherapy, hydrogen peroxide, ethanol and radiotherapy. New methods of treatment include thermal ablation with radiofrequency and laser, mainly utilized for treating osteoid osteoma. Arthroscopy allows resection of benign intra-joint lesions and assists the surgery of subchondral tumors. A great advance is the utilization of synthetic bone substitutes, which are a mixture of osteoinductive growth factors and osteoconductive ceramics, and have presented comparable results to autogenous bone grafts. There is a recent trend for closed treatments, with percutaneous injection of demineralized bone matrix (DBM) and calcium sulfate. Autogenous cancellous bone graft remains as the gold standard. Vascularized fibula graft, on the other hand, incorporates faster in the treatment of large destructive lesions. Also, allogenic cortical support allows structural augmentation for aggressive tumors. Freeze-dried allografts are used to fill contained defects and as expanders of autografts. Joint endoprosthesis may be used in large destructive lesions of the distal femur, hip and shoulder. PMID:27004184

  16. MISR JOINT_AS Data

    Atmospheric Science Data Center

    2014-07-21

    Joint Aerosol Product (JOINT_AS) The MISR Level 3 Products are global or regional ... field campaigns at daily and monthly time scales. The Joint Aerosol product provides a monthly global statistical summary of MISR ...

  17. Oral Lesions and Lymphoproliferative Disorders

    PubMed Central

    Castellarin, P.; Pozzato, G.; Tirelli, G.; Di Lenarda, R.; Biasotto, M.

    2010-01-01

    Lymphoproliferative disorders are heterogeneous malignancy characterized by the expansion of a lymphoid clone more or less differentiated. At the level of the oral cavity, the lymphoproliferative disorder can occur in various ways, most commonly as lymphoid lesions with extranodal externalization, but sometimes, oral lesions may represent a localization of a disease spread. With regard to the primary localizations of lymphoproliferative disorders, a careful examination of the head and neck, oral, and oropharyngeal area is necessary in order to identify suspicious lesions, and their early detection results in a better prognosis for the patient. Numerous complications have been described and frequently found at oral level, due to pathology or different therapeutic strategies. These complications require precise diagnosis and measures to oral health care. In all this, oral pathologists, as well as dental practitioners, have a central role in the treatment and long-term monitoring of these patients. PMID:20871659

  18. Benign lymphoepithelial lesion and malignancy.

    PubMed

    Hordijk, G J; Meyer, C J

    1981-01-01

    Whereas most patients with benign lymphoepithelial lesion suffer from the involvement of a major salivary gland a number evolve into a clinical form of Sjögren's syndrome or Mikulicz's disease. In a small number development of malignant lymphomas, especially non-Hodgkin's lymphomas, have been described. Therefore, regular follow-up and appropriate histological evaluation of suspected areas in all patients with a benign lymphoepithelial lesion is indicated. Histologically, diagnosis of a non-Hodgkin's lymphoma may be difficult. Demonstration of a cell pattern, monoclonal for cytoplasmic Ig by means of the immunoperoxidase technique may facilitate the diagnosis. In this report we present the history of two cases out of our series with benign lymphoepithelial lesion who developed a non-Hodgkin's lymphoma.

  19. 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.

  20. Laboratory experiments on columnar jointing

    NASA Astrophysics Data System (ADS)

    Goehring, L.; Morris, S. W.

    2003-12-01

    The mechanism causing columnar jointing has remained an enticing mystery since the basalt columns of the Giant's Causeway in N. Ireland were first reported to science in the 17th century. This phenomenon, in which shrinkage cracks form a quasi-hexagonal arrangement, has been shown to produce columns in starch, glass, coal, sandstone, and ice, as well as in a variety of lava flows. This suggests that this pattern-forming process is very general in nature. However, most studies of columnar jointing have been confined to field studies of basalt flows. Following Muller, we have experimented with desiccating corn starch in an effort to understand this pattern from a more general point of view. The diffusion and evaporation of water in starch is thought to be analogous to the diffusion and extraction of heat from a basalt flow. By combining direct sampling and x-ray tomography, fully 3D descriptions of columnar jointing were obtained with starch samples. We have characterized the pattern with several statistical indices, which describe its structure and relative disorder. These methods can resolve the ordering of the colonnade near the free surface. We identified two distinct mechanisms by which the mean column area increases during pattern evolution. We found both a slow, almost power-law increase in column area, as well as episodes of sudden catastrophic jumps in scale. The latter suggests that the column scale is not a simple single-valued function of drying rate, but rather a metastable state subject to hysteresis. Such metastable behaviour might explain a fundamental question about columnar jointing -- why the columns are so regular in the direction of their growth. Moreover, these experiments may help discriminate between the various theoretical models of this pattern forming process. Finally, our results lead to predictions that could be tested by field measurements on basaltic colonnades.

  1. Hydraulic fracturing of jointed formations

    SciTech Connect

    Murphy, H.D.; Fehler, M.C.

    1986-01-01

    Measured by volume, North America's largest hydraulic fracturing operations have been conducted at Fenton Hill, New Mexico to create geothermal energy reservoirs. In the largest operation 21,000 m/sup 3/ of water were injected into jointed granitic rock at a depth of 3.5 km. Microearthquakes induced by this injection were measured with geophones placed in five wells drilled into, or very close, to the reservoir, as well as 11 surface seismometers. The large volume of rock over which the microearthquakes were distributed indicates a mechanism of hydraulic stimulation which is at odds with conventional fracturing theory, which predicts failure along a plane which is perpendicular to the least compressive earth stress. A coupled rock mechanics/fluid flow model provides much of the explanation. Shear slippage along pre-existing joints in the rock is more easily induced than conventional tensile failure, particularly when the difference between minimum and maximum earth stresses is large and the joints are oriented at angles between 30 and 60 degrees to the principal earth stresses, and a low viscosity fluid like water is injected. Shear slippage results in local redistribution of stresses, which allows a branching, or dendritic, stimulation pattern to evolve, in agreement with the patterns of microearthquake locations. These results are qualitatively similar to the controversial process known as ''Kiel'' fracturing, in which sequential injections and shut-ins are repeated to create dendritic fractures for enhanced oil and gas recovery. However, we believe that the explanation is shear slippage of pre-existing joints and stress redistribution, not proppant bridging and fluid blocking as suggested by Kiel. 15 refs., 10 figs.

  2. Renal lesions of nondomestic felids.

    PubMed

    Newkirk, K M; Newman, S J; White, L A; Rohrbach, B W; Ramsay, E C

    2011-05-01

    To comprehensively evaluate the occurrence of renal lesions in a variety of nondomestic felids, necropsy cases from 1978 to 2008 were reviewed from a municipal zoo and a large cat sanctuary for those in which the kidneys were examined histologically. Seventy exotic felids were identified (25 tigers, 18 lions, 6 cougars, 5 leopards, 3 snow leopards, 3 clouded leopards, 3 Canadian lynx, 2 ocelots, 2 bobcats, 2 cheetahs, 1 jaguar), and their histologic renal lesions were evaluated and compared. The most common lesion was tubulointerstitial nephritis (TIN); 36 of 70 (51%) cats were affected to some degree. Lymphocytic interstitial nephritis was the most common lesion in the tigers (9 of 25, 36%) and was rarely seen in other species. Although the renal pelvis was not available for all cats, 28 of 47 (60%) had some degree of lymphocytic pyelitis. There was no significant association between the presence of pyelitis and that of TIN. Only 1 cat had pyelonephritis. Renal papillary necrosis was present in 13 of 70 (19%) cats and was significantly associated with historical nonsteroidal anti-inflammatory drug treatment (odds ratio, 7.1; 95% confidence interval, 1.9 to 26.8). Only 1 cat (lion) had amyloid accumulation, and it was restricted to the corticomedullary junction. Primary glomerular lesions were absent in all cats. Intraepithelial pigment was identified in many of the cats but was not correlated with severity of TIN. Despite several previous reports describing primary glomerular disease or renal amyloidosis in exotic felids, these lesions were rare to absent in this population. PMID:20876911

  3. Destruction of sealant in building envelope joints by birds

    SciTech Connect

    Chin, I.R.; Sass, C.J.

    1998-12-31

    Sealant in joints in the exterior envelope on a building is intended to reduce water entry and air infiltration through the joints and to accommodate movements. Openings in sealant joints can result in water leakage and air infiltration through the joints into the interior of the building. Openings in sealant joints can occur as a result of design, construction, and/or material deficiencies. During the last five years, the authors have been involved in the investigation and repair design of openings in sealant joints, that occurred as a result of the joints having been damaged by birds, and that has resulted in water leakage into the interior of the building. This paper describes four case studies where birds have destroyed the integrity of sealant joints. These case studies have the following common elements which may be considered by designers to mitigate this condition in areas where the potential exists for birds to destroy sealant in buildings and other structures: The presence of birds such as the ring billed gull (Larus Delawarensis) and turkey vulture (Cathartes Aura) in the area of the building; the presence of wide horizontal surfaces and/or wide low sloping surfaces allow the birds to perch in close proximity to the sealant joints; and the use of silicone sealant in the joints between the building substrate sections.

  4. Use of robotics technology to measure friction in animal joints.

    PubMed

    Mabuchi, K; Fujie, H

    1996-04-01

    A new system to measure friction in animal joints has been designed. The system utilizes a robotic arm. Force control of the robotic arm was used to survey the geometry of a sliding surface before the friction of the joint is measured. This enables the precise measurement of friction in joints of complex shape. To test the reliability of the new system we took friction measurements from 10 rabbit stifles. The experimental conditions were: (i) intact joints, (ii) joints after the surfaces were washed. The mean values of the frictional coefficients were 0.008 in the intact joints and 0.015 in the washed joints. These mean values were similar to some previous results obtained from canine hip joints under the same experimental conditions. Furthermore, the standard deviations in this study were smaller than in the previous study. These facts suggest that the new system is reliable. RELEVANCE:--The pathology of osteoarthritis is related to the lubrication mechanisms of joints. In any study of the lubrication mechanisms, an accurate friction measurement is important. In this study we used robotics technology to measure friction in joints.

  5. Can Small Lesions Induce Language Reorganization as Large Lesions Do?

    ERIC Educational Resources Information Center

    Maestu, Fernando; Saldana, Cristobal; Amo, Carlos; Gonzalez-Hidalgo, Mercedes; Fernandez, Alberto; Fernandez, Santiago; Mata, Pedro; Papanicolaou, Andrew; Ortiz, Tomas

    2004-01-01

    Shift of the cortical mechanisms of language from the usually dominant left to the non-dominant right hemisphere has been demonstrated in the presence of large brain lesions. Here, we report a similar phenomenon in a patient with a cavernoma over the anterolateral superior temporal gyrus associated with epilepsy. Language mapping was performed by…

  6. Cutaneous lesions of the nose

    PubMed Central

    2010-01-01

    Skin diseases on the nose are seen in a variety of medical disciplines. Dermatologists, otorhinolaryngologists, general practitioners and general plastic and dermatologic surgeons are regularly consulted regarding cutaneous lesions on the nose. This article is the second part of a review series dealing with cutaneous lesions on the head and face, which are frequently seen in daily practice by a dermatologic surgeon. In this review, we focus on those skin diseases on the nose where surgery or laser therapy is considered a possible treatment option or that can be surgically evaluated. PMID:20525327

  7. Apraxia in deep cerebral lesions.

    PubMed Central

    Agostoni, E; Coletti, A; Orlando, G; Tredici, G

    1983-01-01

    In a series of 50 patients with cerebrovascular lesions (demonstrated with CT scan), seven patients had lesions located in the basal ganglia and/or thalamus. All these seven patients were apractic. Ideomotor apraxia was present in all patients; five also had constructional apraxia, and one had bucco-facial apraxia. None of the patients had utilisation apraxia. These observations indicated that apraxia is not only a "high cerebral (cortical) function", but may depend also on the integrity of subcortical circuits and structures. PMID:6619888

  8. Pediatric Knee Osteochondritis Dissecans Lesions.

    PubMed

    Cruz, Aristides I; Shea, Kevin G; Ganley, Theodore J

    2016-10-01

    Osteochondritis dissecans (OCD) can cause knee pain and dysfunction in children. The etiology of OCD remains unclear; theories on causes include inflammation, ischemia, ossification abnormalities, genetic factors, and repetitive microtrauma. Most OCD lesions in skeletally immature patients will heal with nonoperative treatment. The success of nonoperative treatment decreases once patients reach skeletal maturity. The goals of surgical treatment include maintenance of articular cartilage congruity, rigid fixation of unstable fragments, and repair of osteochondral defects with cells or tissues that can adequately replace lost or deficient cartilage. Unsalvageable OCD lesions can be treated with various surgical techniques. PMID:27637663

  9. 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.

  10. 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.

  11. Arthroscopical and histological study of cartilaginous lesions treated by mosaicplasty

    PubMed Central

    Cirstoiu, CF; Bădilă, AE

    2010-01-01

    Aim. The aim of our study was to assess macro– and microscopically the knee cartilaginous lesions outcome treated by mosaicplasty. Material and method Our study included 32 patients which underwent mosaicplasty for nondegenerative cartilaginous lesions of the knee and a second look arthroscopy. In 21 patients, minibiopsies from the repaired lesion were performed under arthroscopic control (from the cartilaginous region of the transplanted osteocartilaginous grafts and from the spaces between grafts). All repaired lesions were carefully examined during arthroscopy and all harvested minifragments were studied by optical microscopy (staining method – hematoxylin eosin). Results Macroscopically, the articular surface of the repaired cartilaginous lesions was smooth and congruent to the adjacent surfaces. The aspect and resistance to compression of grafted area was similar to those of the normal surrounding cartilage. The transferred cartilage maintained its height, being at the level of the neighboring cartilage. One year postoperatively, the limits of the cartilaginous autografts were still visible. Two years postoperatively, these limits were no longer visible. Microscopically, the region of the former lesion was constituted mainly by viable hyaline cartilage. Fibrous cartilaginous tissue was visualized in the spaces between the grafts. Conclusions The second look arthroscopy showed that after mosaicplasty the repaired articular surface was smooth, leveled, homogenous and congruent to adjacent cartilage. The spaces between grafts are progressively covered by fibrous cartilaginous tissue with a more textured and uneven surface. Mosaicplasty is a biological surgical technique which restores the normal osteocartilaginous architecture of the most part of the grafted area. The transplanted osteocartilaginous cylindrical grafts maintain its viability and mechanical properties. PMID:21254739

  12. Biomechanics of the natural, arthritic, and replaced human ankle joint

    PubMed Central

    2014-01-01

    The human ankle joint complex plays a fundamental role in gait and other activities of daily living. At the same time, it is a very complicated anatomical system but the large literature of experimental and modelling studies has not fully described the coupled joint motion, position and orientation of the joint axis of rotation, stress and strain in the ligaments and their role in guiding and stabilizing joint motion, conformity and congruence of the articular surfaces, patterns of contact at the articular surfaces, patterns of rolling and sliding at the joint surfaces, and muscle lever arm lengths. The present review article addresses these issues as described in the literature, reporting the most recent relevant findings. PMID:24499639

  13. Solitary nodular lesion of tongue- a rare entity.

    PubMed

    Sarada, P; Reddy, C H Sampath; A K, Patil; Kurra, Saritha

    2014-02-01

    The solitary, nodular lesions of the oral mucosa present a diagnostic dilemma to the dentist with their analogous presentation. The lesions that appear on the tongue, a soft muscular organ are distinct and even rarer with varied manifestations. Oral mucosa presents lesions of the tongue in all age groups that may range from a small nodular swelling and ulcer formation in an infant of a few days old to an ulcer or a lesion in a 70-year-old. The reason for the appearance of an ulcer may be trauma to the soft tissues in an infant may be due to the presence of natal teeth to the presence of a sharp tooth in the older individuals. These lesions have to be clinically and histologically correlated for the final outcome of the diagnosis, so that there is no chance of any recurrence. We present a unique case of a solitary nodular lesion on the ventral surface of tongue On a 6 year female, where there was a recurrence after surgical excision and after an unusual therapy of non surgical resolution, no recurrence was observed.

  14. Solitary Nodular Lesion of Tongue- A Rare Entity

    PubMed Central

    Sarada, P.; Reddy, C.H. Sampath; A.K, Patil; Kurra, Saritha

    2014-01-01

    The solitary, nodular lesions of the oral mucosa present a diagnostic dilemma to the dentist with their analogous presentation. The lesions that appear on the tongue, a soft muscular organ are distinct and even rarer with varied manifestations. Oral mucosa presents lesions of the tongue in all age groups that may range from a small nodular swelling and ulcer formation in an infant of a few days old to an ulcer or a lesion in a 70-year-old. The reason for the appearance of an ulcer may be trauma to the soft tissues in an infant may be due to the presence of natal teeth to the presence of a sharp tooth in the older individuals. These lesions have to be clinically and histologically correlated for the final outcome of the diagnosis, so that there is no chance of any recurrence. We present a unique case of a solitary nodular lesion on the ventral surface of tongue On a 6 year female, where there was a recurrence after surgical excision and after an unusual therapy of non surgical resolution, no recurrence was observed. PMID:24701550

  15. Imaging inflammatory acne: lesion detection and tracking

    NASA Astrophysics Data System (ADS)

    Cula, Gabriela O.; Bargo, Paulo R.; Kollias, Nikiforos

    2010-02-01

    It is known that effectiveness of acne treatment increases when the lesions are detected earlier, before they could progress into mature wound-like lesions, which lead to scarring and discoloration. However, little is known about the evolution of acne from early signs until after the lesion heals. In this work we computationally characterize the evolution of inflammatory acne lesions, based on analyzing cross-polarized images that document acne-prone facial skin over time. Taking skin images over time, and being able to follow skin features in these images present serious challenges, due to change in the appearance of skin, difficulty in repositioning the subject, involuntary movement such as breathing. A computational technique for automatic detection of lesions by separating the background normal skin from the acne lesions, based on fitting Gaussian distributions to the intensity histograms, is presented. In order to track and quantify the evolution of lesions, in terms of the degree of progress or regress, we designed a study to capture facial skin images from an acne-prone young individual, followed over the course of 3 different time points. Based on the behavior of the lesions between two consecutive time points, the automatically detected lesions are classified in four categories: new lesions, resolved lesions (i.e. lesions that disappear completely), lesions that are progressing, and lesions that are regressing (i.e. lesions in the process of healing). The classification our methods achieve correlates well with visual inspection of a trained human grader.

  16. Knee joint replacement

    MedlinePlus

    ... is used to attach this part. Repair your muscles and tendons around the new joint and close the surgical cut. The surgery takes about 2 hours. Most artificial knees have both metal and plastic parts. Some ...

  17. Wrist joint assembly

    NASA Technical Reports Server (NTRS)

    Kersten, L.; Johnson, J. D. (Inventor)

    1978-01-01

    A wrist joint assembly is provided for use with a mechanical manipulator arm for finely positioning an end-effector carried by the wrist joint on the terminal end of the manipulator arm. The wrist joint assembly is pivotable about a first axis to produce a yaw motion, a second axis is to produce a pitch motion, and a third axis to produce a roll motion. The wrist joint assembly includes a disk segment affixed to the terminal end of the manipulator arm and a first housing member, a second housing member, and a third housing member. The third housing member and the mechanical end-effector are moved in the yaw, pitch, and roll motion. Drive means are provided for rotating each of the housings about their respective axis which includes a cluster of miniature motors having spur gears carried on the output drive shaft which mesh with a center drive gear affixed on the housing to be rotated.

  18. Improved orthopedic arm joint

    NASA Technical Reports Server (NTRS)

    Dane, D. H.

    1971-01-01

    Joint permits smooth and easy movement of disabled arm and is smaller, lighter and less expensive than previous models. Device is interchangeable and may be used on either arm at the shoulder or at the elbow.

  19. Joint fluid Gram stain

    MedlinePlus

    Gram stain of joint fluid ... result means no bacteria are present on the Gram stain. Normal value ranges may vary slightly among ... Abnormal results mean bacteria were seen on the Gram stain. This may be a sign of a ...

  20. Scaling in Columnar Joints

    NASA Astrophysics Data System (ADS)

    Morris, Stephen

    2007-03-01

    Columnar jointing is a fracture pattern common in igneous rocks in which cracks self-organize into a roughly hexagonal arrangement, leaving behind an ordered colonnade. We report observations of columnar jointing in a laboratory analog system, desiccated corn starch slurries. Using measurements of moisture density, evaporation rates, and fracture advance rates, we suggest an advective-diffusive system is responsible for the rough scaling behavior of columnar joints. This theory explains the order of magnitude difference in scales between jointing in lavas and in starches. We investigated the scaling of average columnar cross-sectional areas in experiments where the evaporation rate was fixed using feedback methods. Our results suggest that the column area at a particular depth is related to both the current conditions, and hysteretically to the geometry of the pattern at previous depths. We argue that there exists a range of stable column scales allowed for any particular evaporation rate.

  1. Hip joint injection

    MedlinePlus

    ... injected so the provider can see where to place the medicine. The steroid medicine is slowly injected into the joint. After the injection, you will remain on the table for another 5 to 10 minutes or so. ...

  2. Temporomandibular Joint Disorder

    MedlinePlus

    ... 2008 Previous Next Related Articles: Temporomandibular Joint Disorder (TMD) Are You Biting Off More Than You Can Chew? Equilibration May Lessen TMD Pain Fender-benders: Source of TMD? First Comes ...

  3. Biotribology of artificial hip joints

    PubMed Central

    Di Puccio, Francesca; Mattei, Lorenza

    2015-01-01

    Hip arthroplasty can be considered one of the major successes of orthopedic surgery, with more than 350000 replacements performed every year in the United States with a constantly increasing rate. The main limitations to the lifespan of these devices are due to tribological aspects, in particular the wear of mating surfaces, which implies a loss of matter and modification of surface geometry. However, wear is a complex phenomenon, also involving lubrication and friction. The present paper deals with the tribological performance of hip implants and is organized in to three main sections. Firstly, the basic elements of tribology are presented, from contact mechanics of ball-in-socket joints to ultra high molecular weight polyethylene wear laws. Some fundamental equations are also reported, with the aim of providing the reader with some simple tools for tribological investigations. In the second section, the focus moves to artificial hip joints, defining materials and geometrical properties and discussing their friction, lubrication and wear characteristics. In particular, the features of different couplings, from metal-on-plastic to metal-on-metal and ceramic-on-ceramic, are discussed as well as the role of the head radius and clearance. How friction, lubrication and wear are interconnected and most of all how they are specific for each loading and kinematic condition is highlighted. Thus, the significant differences in patients and their lifestyles account for the high dispersion of clinical data. Furthermore, such consideration has raised a new discussion on the most suitable in vitro tests for hip implants as simplified gait cycles can be too far from effective implant working conditions. In the third section, the trends of hip implants in the years from 2003 to 2012 provided by the National Joint Registry of England, Wales and Northern Ireland are summarized and commented on in a discussion. PMID:25621213

  4. Nonproliferative and Proliferative Lesions of the Rat and Mouse Female Reproductive System

    PubMed Central

    Dixon, Darlene; Alison, Roger; Bach, Ute; Colman, Karyn; Foley, George L.; Harleman, Johannes H.; Haworth, Richard; Herbert, Ronald; Heuser, Anke; Long, Gerald; Mirsky, Michael; Regan, Karen; Van Esch, Eric; Westwood, F. Russell; Vidal, Justin; Yoshida, Midori

    2014-01-01

    The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the female reproductive tract of laboratory rats and mice, with color photomicrographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous and aging lesions as well as lesions induced by exposure to test materials. There is also a section on normal cyclical changes observed in the ovary, uterus, cervix and vagina to compare normal physiological changes with pathological lesions. A widely accepted and utilized international harmonization of nomenclature for female reproductive tract lesions in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists. PMID:25516636

  5. Nonproliferative and proliferative lesions of the rat and mouse female reproductive system.

    PubMed

    Dixon, Darlene; Alison, Roger; Bach, Ute; Colman, Karyn; Foley, George L; Harleman, Johannes H; Haworth, Richard; Herbert, Ronald; Heuser, Anke; Long, Gerald; Mirsky, Michael; Regan, Karen; Van Esch, Eric; Westwood, F Russell; Vidal, Justin; Yoshida, Midori

    2014-01-01

    The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the female reproductive tract of laboratory rats and mice, with color photomicrographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous and aging lesions as well as lesions induced by exposure to test materials. There is also a section on normal cyclical changes observed in the ovary, uterus, cervix and vagina to compare normal physiological changes with pathological lesions. A widely accepted and utilized international harmonization of nomenclature for female reproductive tract lesions in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.

  6. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Joint clearance. 56.75-10 Section 56.75-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-10 Joint clearance. (a) The clearance between surfaces to be joined shall be...

  7. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Joint clearance. 56.75-10 Section 56.75-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-10 Joint clearance. (a) The clearance between surfaces to be joined shall be...

  8. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Joint clearance. 56.75-10 Section 56.75-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-10 Joint clearance. (a) The clearance between surfaces to be joined shall be...

  9. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Joint clearance. 56.75-10 Section 56.75-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-10 Joint clearance. (a) The clearance between surfaces to be joined shall be...

  10. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Joint clearance. 56.75-10 Section 56.75-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-10 Joint clearance. (a) The clearance between surfaces to be joined shall be...

  11. Cystic Lesions in Autoimmune Pancreatitis.

    PubMed

    Gompertz, Macarena; Morales, Claudia; Aldana, Hernán; Castillo, Jaime; Berger, Zoltán

    2015-01-01

    Autoimmune pancreatitis (AIP) can be chronic or recurrent, but frequently completely reversible after steroid treatment. A cystic lesion in AIP is a rare finding, and it can mimic a pancreatic cystic neoplasm. Difficulties in an exact diagnosis interfere with treatment, and surgery cannot be avoided in some cases. We report the history of a 63-year-old male presenting with jaundice and pruritus. AIP was confirmed by imaging and elevated IgG4 blood levels, and the patient completely recovered after corticosteroid therapy. One year later, he presented with a recurrent episode of AIP with elevated IgG4 levels, accompanied by the appearance of multiple intrapancreatic cystic lesions. All but 1 of these cysts disappeared after steroid treatment, but the remaining cyst in the pancreatic head was even somewhat larger 1 year later. Pancreatoduodenectomy was finally performed. Histology showed the wall of the cystic lesion to be fibrotic; the surrounding pancreatic tissue presented fibrosis, atrophy and lymphoplasmacytic infiltration by IgG4-positive cells, without malignant elements. Our case illustrates the rare possibility that cystic lesions can be part of AIP. These pseudocysts appear in the pancreatic segments involved in the autoimmune disease and can be a consequence of the local inflammation or related to ductal strictures. Steroid treatment should be initiated, after which these cysts can completely disappear with recovery from AIP. Surgical intervention may be necessary in some exceptional cases.

  12. Cystic lesions of the pancreas

    PubMed Central

    Karoumpalis, Ioannis; Christodoulou, Dimitrios K.

    2016-01-01

    Different types of benign or malignant cystic lesions can be observed in the pancreas. Pancreatic cystic lesions are classified under pathology terms into simple retention cysts, pseudocysts and cystic neoplasms. Mucinous cystic neoplasm is a frequent type of cystic neoplasm and has a malignant potential. Serous cystadenoma follows in frequency and is usually benign. Intraductal papillary mucinous neoplasms are the most commonly resected cystic pancreatic neoplasms characterized by dilated segments of the main pancreatic duct and/or side branches, the wall of which is covered by mucus secreting cells. These neoplasms can occupy the pancreatic head or any part of the organ. Solid pseudopapillary tumor is rare, has a low tendency for malignancy, and is usually located in the pancreatic body or tail. Endoscopic ultrasound with the use of fine-needle aspiration and cytology permits discrimination of those lesions. In this review, the main characteristics of those lesions are presented, as well as recommendations regarding their follow up and management according to recent guidelines. PMID:27065727

  13. Devic disease with brainstem lesions.

    PubMed

    Chalumeau-Lemoine, Ludivine; Chretien, Fabrice; Gaëlle Si Larbi, Anne; Brugieres, Pierre; Gray, Françoise; Brun-Buisson, Christian; Creange, Alain

    2006-04-01

    We describe a patient who suffered from an unusually severe form of neuromyelitis optica with a hyperacute time-course evolution requiring mechanical ventilation within 3 days. The patient died after 72 days and autopsy showed major spinal cord, optic nerve, and brainstem necrosis, and multifocal necrotic lesions on the cerebellum and cerebral white matter. PMID:16606774

  14. 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

  15. 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.

  16. 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.

  17. Affinity cytochemistry analysis of mast cells in skin lesions: a possible tool to assess the timing of lesions after death.

    PubMed

    Bonelli, A; Bacci, S; Norelli, G A

    2003-12-01

    The histamine content in vital wounds is known to increase, with a zenith after 3 h, and then decrease until 24 h after wounding. We addressed whether this biochemical alteration has a morphological counterpart. Since the main source of skin histamine are mast cells, the distribution and number of these cells was assessed upon labeling with fluorescent avidin and with antibodies to the mast cell specific enzymes, chymase and tryptase. Analyses were performed on skin from 15 healthy controls (from surgical biopsies), from 15 post-mortem lesions and 75 vital lesions, obtained at autopsy from subjects who had survived from a few seconds to 24 h. The number of mast cells per unit area of section surface increased progressively with survival time, up to a maximum in subjects who survived 1-3 h ( p<0.01), and decreased thereafter becoming less than in the controls if lesions had occurred earlier than 6 h before death ( p<0.01). Samples from post-mortem lesions had significantly fewer mast cells than those of any other groups of samples ( p<0.01). We suggest that in association to other histological and circumstantial evidence the analysis of mast cells by affinity cytochemistry can help to discriminate vital from post-mortem lesions and to estimate survival time after lesions.

  18. SLAP lesions: a treatment algorithm.

    PubMed

    Brockmeyer, Matthias; Tompkins, Marc; Kohn, Dieter M; Lorbach, Olaf

    2016-02-01

    Tears of the superior labrum involving the biceps anchor are a common entity, especially in athletes, and may highly impair shoulder function. If conservative treatment fails, successful arthroscopic repair of symptomatic SLAP lesions has been described in the literature particularly for young athletes. However, the results in throwing athletes are less successful with a significant amount of patients who will not regain their pre-injury level of performance. The clinical results of SLAP repairs in middle-aged and older patients are mixed, with worse results and higher revision rates as compared to younger patients. In this population, tenotomy or tenodesis of the biceps tendon is a viable alternative to SLAP repairs in order to improve clinical outcomes. The present article introduces a treatment algorithm for SLAP lesions based upon the recent literature as well as the authors' clinical experience. The type of lesion, age of patient, concomitant lesions, and functional requirements, as well as sport activity level of the patient, need to be considered. Moreover, normal variations and degenerative changes in the SLAP complex have to be distinguished from "true" SLAP lesions in order to improve results and avoid overtreatment. The suggestion for a treatment algorithm includes: type I: conservative treatment or arthroscopic debridement, type II: SLAP repair or biceps tenotomy/tenodesis, type III: resection of the instable bucket-handle tear, type IV: SLAP repair (biceps tenotomy/tenodesis if >50 % of biceps tendon is affected), type V: Bankart repair and SLAP repair, type VI: resection of the flap and SLAP repair, and type VII: refixation of the anterosuperior labrum and SLAP repair.

  19. Clinical monitoring of early caries lesions using cross polarization optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Fried, Daniel; Staninec, Michal; Darling, Cynthia L.; Chan, Kenneth H.; Pelzner, Roger B.

    New methods are needed for the nondestructive measurement of tooth demineralization and remineralization and to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role, since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm. It is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we present early results from two clinical studies underway to measure the effect of fluoride intervention on early lesions. CP-OCT was used to monitor early lesions on enamel and root surfaces before and after intervention with fluoride varnish. The lesion depth and internal structure were resolved for all the lesions examined and some lesions had well defined surface zones of lower reflectivity that may be indicative of arrested lesions. Changes were also noted in the structure of some of the lesions after fluoride intervention.

  20. Iron aluminide alloy coatings and joints, and methods of forming

    DOEpatents

    Wright, R.N.; Wright, J.K.; Moore, G.A.

    1994-09-27

    Disclosed is a method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: (a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; (b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; (c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600 C to less than the melting point of the lower melting point body; (d) applying pressure on the juxtaposed surfaces; and (e) maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. The method can also effectively be used to coat a body with an iron aluminide coating.

  1. Iron aluminide alloy coatings and joints, and methods of forming

    DOEpatents

    Wright, Richard N.; Wright, Julie K.; Moore, Glenn A.

    1994-01-01

    A method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the lower melting point body; d) applying pressure on the juxtaposed surfaces; and e) maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. The method can also effectively be used to coat a body with an iron aluminide coating.

  2. Static and dynamic mechanics of the temporomandibular joint: plowing forces, joint load and tissue stress.

    PubMed

    Nickel, J; Spilker, R; Iwasaki, L; Gonzalez, Y; McCall, W D; Ohrbach, R; Beatty, M W; Marx, D

    2009-08-01

    OBJECTIVES - To determine the combined effects 1) of stress-field aspect ratio and velocity and compressive strain and 2) joint load, on temporomandibular joint (TMJ) disc mechanics. SETTING AND SAMPLE POPULATION - Fifty-two subjects (30 female; 22 male) participated in the TMJ load experiments. MATERIAL AND METHODS - In the absence of human tissue, pig TMJ discs were used to determine the effects of variables 1) on surface plowing forces, and to build a biphasic finite element model (bFEM) to test the effect of human joint loads and 2) on tissue stresses. In the laboratory, discs received a 7.6 N static load via an acrylic indenter before cyclic movement. Data were recorded and analysed using anova. To determine human joint loads, Research Diagnostic Criteria calibrated investigators classified subjects based on signs of disc displacement (DD) and pain (+DD/+pain, n = 18; +DD/-pain, n = 17; -DD/-pain, n = 17). Three-dimensional geometries were produced for each subject and used in a computer model to calculate joint loads. RESULTS - The combined effects of compressive strain, and aspect ratio and velocity of stress-field translation correlated with plowing forces (R(2) = 0.85). +DD/-pain subjects produced 60% higher joint loads (ANOVA, p < 0.05), which increased bFEM-calculated compressive strain and peak total normal stress. CONCLUSIONS - Static and dynamic variables of the stress-field and subject-dependent joint load significantly affect disc mechanics.

  3. Proliferative and nonproliferative lesions of the rat and mouse central and peripheral nervous systems.

    PubMed

    Kaufmann, Wolfgang; Bolon, Brad; Bradley, Alys; Butt, Mark; Czasch, Stephanie; Garman, Robert H; George, Catherine; Gröters, Sibylle; Krinke, Georg; Little, Peter; McKay, Jenny; Narama, Isao; Rao, Deepa; Shibutani, Makoto; Sills, Robert

    2012-06-01

    Harmonization of diagnostic nomenclature used in the pathology analysis of tissues from rodent toxicity studies will enhance the comparability and consistency of data sets from different laboratories worldwide. The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of four major societies of toxicologic pathology to develop a globally recognized nomenclature for proliferative and nonproliferative lesions in rodents. This article recommends standardized terms for classifying changes observed in tissues of the mouse and rat central (CNS) and peripheral (PNS) nervous systems. Sources of material include academic, government, and industrial histopathology databases from around the world. Covered lesions include frequent, spontaneous, and aging-related changes as well as principal toxicant-induced findings. Common artifacts that might be confused with genuine lesions are also illustrated. The neural nomenclature presented in this document is also available electronically on the Internet at the goRENI website (http://www.goreni.org/).

  4. [Biomechanics of the ankle joint].

    PubMed

    Zwipp, H

    1989-03-01

    According to Fick, the tree-dimensional patterns of foot motion are best characterized as jawlike movement. Anatomically and biomechanically, this process represents conjoined, synchronous motion within the three mobile segments of the hindfoot: the ankle joint, the posterior subtalar joint, and the anterior subtalar joint. Foot kinematics can be described more completely if the anterior subtalar joint is defined not only as the talocalcaneal navicular joint, but as including the calcaneocuboid joint, thus representing the transverse joint of the tarsus, i.e., the Chopart joint. The axes of these three joints can be defined precisely. In some parts they represent a screwlike motion, clockwise or counter-clockwise, around the central ligamentous structures (fibulotibial ligament, talocalcaneal interosseous ligament, bifurcate ligament). The individual anatomy and structure of these ligaments provide variations in the degree and direction of foot motion. A precise knowledge of foot kinematics is important in surgical ligament and joint reconstruction and in selective foot arthrodeses.

  5. Osteolytic Cystic Lesion of Naviculum: The Great Mimicker

    PubMed Central

    Saindane, K A; Ghodke, Aashish B; Patil, Sameer S; Godghate, Neha N; Kelkar, Sagar

    2016-01-01

    Introduction: Children show a higher predisposition to the development of extrapulmonary tuberculosis. Osteoarticular tuberculosis, especially in the foot is uncommon therefore it has remained a diagnostic enigma. The non-specific, often indolent, clinical presentation of foot (navicular) tuberculosis, whose low prevalence and low index of suspicion among clinicians may convert a purely osseous lesion into one involving a joint with more local destruction and functional disability. However, prompt diagnosis and treatment of this curable disease remains critical for initiation of proper management, prevention of joint deformity and permanent bone destruction. Case Presentation: A 6-year-old female child with pain and swelling over the mid-foot was the subject of this study. Clinical, haematological, radiological examination and FNAC was done which revealed it to be of tuberculous pathology. Treatment consisted of anti-tubercular regimen for a period of 15 months. Within 4 months of starting anti tubercular therapy the patient was pain free and fully weight bearing on the affected foot. Conclusion: To make a diagnosis of tuberculosis one must consider it as a possibility. Long standing pain and swelling of the midfoot should include TB in the differential diagnosis of destructive osteoarticular lesions. Since the radiological features are non-specific, so a high degree of suspicion is required to avoid permanent articular disability, to obtain a supple, painless and weight bearing foot. PMID:27299123

  6. The discovery of columnar jointing on Mars

    USGS Publications Warehouse

    Milazzo, M.P.; Keszthelyi, L.P.; Jaeger, W.L.; Rosiek, M.; Mattson, S.; Verba, C.; Beyer, R.A.; Geissler, P.E.; McEwen, A.S.; ,

    2009-01-01

    We report on the discovery of columnar jointing in Marte Valles, Mars. These columnar lavas were discovered in the wall of a pristine, 16-km-diameter impact crater and exhibit the features of terrestrial columnar basalts. There are discontinuous outcrops along the entire crater wall, suggesting that the columnar rocks covered a surface area of at least 200 km2, assuming that the rocks obliterated by the impact event were similarly jointed. We also see columns in the walls of other fresh craters in the nearby volcanic plains of Elysium Planitia–Amazonis Planitia, which include Marte Vallis, and in a well-preserved crater in northeast Hellas.

  7. Joint Air Sea Interaction (JASIN) experiment, Northwest coast of Scotland

    NASA Technical Reports Server (NTRS)

    Businger, J. A.

    1981-01-01

    The joint air sea interaction (JASIN) experiment took place off the Northwest coast of Scotland. Sea surface and boundary layer parameters were measured. The JASIN data was used as ground truth for various sensors on the SEASAT satellite.

  8. Joint ventures in medical services.

    PubMed

    Rublee, D A

    1987-01-01

    This paper is an overview of joint-venture activity in healthcare, describing trends in joint ventures and raising issues for physicians. The purposes are to discuss the major current facets of joint-venture alliances in healthcare and to identify policy issues that arise from the trend to use joint ventures as an organizational tool. Speculation is made about the future role of joint ventures in the organization of healthcare.

  9. 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.

  10. [Cystic testicular lesions in infancy].

    PubMed

    Calleja Escudero, J; Pascual Samaniego, M; Garrido Redondo, M; Matas Gómez, V; Fernández Domínguez, L; Fernández del Busto, E

    2004-09-01

    The present article reports a case 11 month-old infant with a right intratesticular cyst. We analyze the etiology, differential diagnosis and management off all cystic lesions of the pediatric testis. Patient age at presentation, examination features, tumor markers and sonographic appearance may assist in making a presumptive and occasionally definitive diagnosis preoperatively. The differential diagnosis include intratesticular simple cyst, epidermoid cyst, tunica albuginea cyst, testicular teratoma, juvenil granulosa cell tumor-gonadal stromal tumor, cystic dysplasia of the rete testis, cystic lymphangioma, and testicular torsion. Usually enucleation is the best treatment. A thorough understanding of potentially cystic testis lesions in children leads to the best management choices and often to preservation of a substantial portion of the affected testis.

  11. Automatic segmentation of psoriasis lesions

    NASA Astrophysics Data System (ADS)

    Ning, Yang; Shi, Chenbo; Wang, Li; Shu, Chang

    2014-10-01

    The automatic segmentation of psoriatic lesions is widely researched these years. It is an important step in Computer-aid methods of calculating PASI for estimation of lesions. Currently those algorithms can only handle single erythema or only deal with scaling segmentation. In practice, scaling and erythema are often mixed together. In order to get the segmentation of lesions area - this paper proposes an algorithm based on Random forests with color and texture features. The algorithm has three steps. The first step, the polarized light is applied based on the skin's Tyndall-effect in the imaging to eliminate the reflection and Lab color space are used for fitting the human perception. The second step, sliding window and its sub windows are used to get textural feature and color feature. In this step, a feature of image roughness has been defined, so that scaling can be easily separated from normal skin. In the end, Random forests will be used to ensure the generalization ability of the algorithm. This algorithm can give reliable segmentation results even the image has different lighting conditions, skin types. In the data set offered by Union Hospital, more than 90% images can be segmented accurately.

  12. Imaging of skull base lesions.

    PubMed

    Kelly, Hillary R; Curtin, Hugh D

    2016-01-01

    Skull base imaging requires a thorough knowledge of the complex anatomy of this region, including the numerous fissures and foramina and the major neurovascular structures that traverse them. Computed tomography (CT) and magnetic resonance imaging (MRI) play complementary roles in imaging of the skull base. MR is the preferred modality for evaluation of the soft tissues, the cranial nerves, and the medullary spaces of bone, while CT is preferred for demonstrating thin cortical bone structure. The anatomic location and origin of a lesion as well as the specific CT and MR findings can often narrow the differential diagnosis to a short list of possibilities. However, the primary role of the imaging specialist in evaluating the skull base is usually to define the extent of the lesion and determine its relationship to vital neurovascular structures. Technologic advances in imaging and radiation therapy, as well as surgical technique, have allowed for more aggressive approaches and improved outcomes, further emphasizing the importance of precise preoperative mapping of skull base lesions via imaging. Tumors arising from and affecting the cranial nerves at the skull base are considered here. PMID:27432686

  13. Imaging of skull base lesions.

    PubMed

    Kelly, Hillary R; Curtin, Hugh D

    2016-01-01

    Skull base imaging requires a thorough knowledge of the complex anatomy of this region, including the numerous fissures and foramina and the major neurovascular structures that traverse them. Computed tomography (CT) and magnetic resonance imaging (MRI) play complementary roles in imaging of the skull base. MR is the preferred modality for evaluation of the soft tissues, the cranial nerves, and the medullary spaces of bone, while CT is preferred for demonstrating thin cortical bone structure. The anatomic location and origin of a lesion as well as the specific CT and MR findings can often narrow the differential diagnosis to a short list of possibilities. However, the primary role of the imaging specialist in evaluating the skull base is usually to define the extent of the lesion and determine its relationship to vital neurovascular structures. Technologic advances in imaging and radiation therapy, as well as surgical technique, have allowed for more aggressive approaches and improved outcomes, further emphasizing the importance of precise preoperative mapping of skull base lesions via imaging. Tumors arising from and affecting the cranial nerves at the skull base are considered here.

  14. Biofluid lubrication for artificial joints

    NASA Astrophysics Data System (ADS)

    Pendleton, Alice Mae

    This research investigated biofluid lubrication related to artificial joints using tribological and rheological approaches. Biofluids studied here represent two categories of fluids, base fluids and nanostructured biofluids. Base fluids were studied through comparison of synthetic fluids (simulated body fluid and hyaluronic acid) as well as natural biofluids (from dogs, horses, and humans) in terms of viscosity and fluid shear stress. The nano-structured biofluids were formed using molecules having well-defined shapes. Understanding nano-structured biofluids leads to new ways of design and synthesis of biofluids that are beneficial for artificial joint performance. Experimental approaches were utilized in the present research. This includes basic analysis of biofluids' property, such as viscosity, fluid shear stress, and shear rate using rheological experiments. Tribological investigation and surface characterization were conducted in order to understand effects of molecular and nanostructures on fluid lubrication. Workpiece surface structure and wear mechanisms were investigated using a scanning electron microscope and a transmission electron microscope. The surface topography was examined using a profilometer. The results demonstrated that with the adding of solid additives, such as crown ether or fullerene acted as rough as the other solids in the 3-body wear systems. In addition, the fullerene supplied low friction and low wear, which designates the lubrication purpose of this particular particle system. This dissertation is constructed of six chapters. The first chapter is an introduction to body fluids, as mentioned earlier. After Chapter II, it examines the motivation and approach of the present research, Chapter III discusses the experimental approaches, including materials, experimental setup, and conditions. In Chapter IV, lubrication properties of various fluids are discussed. The tribological properties and performance nanostructured biofluids are

  15. Rib lesions in a prehistoric Puebloan sample from southwestern Colorado.

    PubMed

    Lambert, Patricia M

    2002-04-01

    An unusually high frequency of periosteal lesions of visceral rib surfaces was observed in a small, prehistoric skeletal series from southwestern Colorado. Lesions of this type have been concordant with pulmonary tuberculosis in three studies of human skeletal collections with known cause of death, and in a recent clinical investigation of rib dimensions in living patients with lung disorders. Diseases such as pneumonia and actinomycosis have also been found to cause these lesions, but in much lower frequencies. Archaeological evidence suggests that Puebloan farmers of Sleeping Ute Mountain's southern piedmont, from which the sample is drawn, endured unusually harsh environmental conditions punctuated by severe drought and exacerbated by escalating warfare. It is argued here that these environmental stressors increased susceptibility to an opportunistic respiratory infection reminiscent of tuberculosis, and possibly also some form of pneumonia, resulting in high rates of active disease previously noted only in historic Puebloan peoples.

  16. Elbow and Shoulder Lesions of Baseball Players*

    PubMed Central

    2008-01-01

    plays a part in the disability and should be the first thought in the mind of the examiner” [2]. Dr. George Bennett is shown. Photograph is reproduced with permission and ©American Academy of Orthopaedic Surgeons. Fifty Years of Progress, 1983. References Bennett GE. Shoulder and elbow lesions of the professional baseball player. JAMA. 1941;117:510–514. Bennett GE. Elbow and shoulder lesions of baseball players. Am J Surg. 1959;98:484–492. George Eli Bennett. J Bone Joint Surg Am. 1962;44:1711–1713. Scorecard. Mender of immortals. Sports Illustrated. July 30,1962:7. PMID:18196375

  17. Visualization of Epicardial Cryoablation Lesions using Endogenous Tissue Fluorescence

    PubMed Central

    Swift, Luther; Gil, Daniel A.B.; Jaimes, Rafael; Kay, Matthew; Mercader, Marco; Sarvazyan, Narine

    2014-01-01

    Background Percutaneous cryoballoon ablation is a commonly used procedure to treat atrial fibrillation. One of the major limitations of the procedure is the inability to directly visualize tissue damage and functional gaps between the lesions. We seek to develop an approach that will enable real-time visualization of tissue necrosis during cryo- or radiofrequency ablation procedures. Methods and Results Cryoablation of either blood-perfused or saline-perfused hearts was associated with a marked decrease in NADH fluorescence leading to a 60-70% loss of signal intensity at the lesion site. The total lesion area observed on the NADH channel exhibited a strong correlation with the area identified by triphenyl tetrazolium staining (r=0.89, p<0.001). At physiological temperatures, loss of NADH became visually apparent within 26±8 sec after detachment of the cryoprobe from the epicardial surface and plateaued within minutes after which the boundaries of the lesions remained stable for several hours. The loss of electrical activity within the cryoablation site exhibited a close spatial correlation with the loss of NADH (r=0.84±0.06, p<0.001). Cryoablation led to a decrease in diffuse reflectance across the entire visible spectrum which was in stark contrast to radiofrequency ablation that markedly increased the intensity of reflected light at the lesion sites. Conclusions We confirmed the feasibility of using endogenous NADH fluorescence for the real-time visualization of cryoablation lesions in blood-perfused cardiac muscle preparations and revealed similarities and differences between imaging cryo- and radiofrequency ablation lesions when using ultraviolet and visible light illumination. PMID:25141861

  18. The natural history of dental caries lesions: a 4-year observational study.

    PubMed

    Ferreira Zandoná, A; Santiago, E; Eckert, G J; Katz, B P; Pereira de Oliveira, S; Capin, O R; Mau, M; Zero, D T

    2012-09-01

    Dental caries is a ubiquitous disease affecting all age groups and segments of the population. It is known that not all caries lesions progress to cavitation, but little is known regarding the progression pattern of caries lesions. This study's purpose was to evaluate the natural history of dental caries using a standardized, visually based system, the International Caries Detection and Assessment System (ICDAS). The study population consisted of 565 consenting children, who were enrolled and examined at baseline and at regular intervals over 48 months with ICDAS and yearly bitewing radiographs. Of these, 338 children completed all examinations. Not all lesions cavitated at the same rate, differing by surface type and baseline ICDAS severity score and activity status. With increasing severity, the percentage of lesions progressing to cavitation increased: 19%, 32%, 68%, and 66% for ICDAS scores 1, 2, 3, and 4, respectively. Lesions on occlusal surfaces were more likely to cavitate, followed by buccal pits, lingual grooves, proximal surfaces, and buccal and lingual surfaces. Cavitation was more likely on molars, followed by pre-molars and anterior teeth. Predictors of cavitation included age, gender, surfaces and tooth types, and ICDAS severity/activity at baseline. In conclusion, characterization of lesion severity with ICDAS can be a strong predictor of lesion progression to cavitation.

  19. 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

  20. Discrimination between benign and malignant lesions of the breast using ultrasound disparity mapping

    NASA Astrophysics Data System (ADS)

    Steinberg, Bernard D.; Carlson, Donald L.; Birnbaum, Julia A.

    2001-05-01

    A technique called disparity mapping (DM) processes pairs of ultrasound B-scan images collected while a sonographer varies the probe pressure slightly on the breast surface. Dm measures the apparent displacement of the tissue about each image point and subsequently constructs a correlation map which represents the similarity between the speckle patterns around each point. The continuity of the lesion perimeter in the correlation image is used to separate benign from malignant lesions, with high continuity corresponding well with benign lesions and highly segmented perimeters correlating with malignancies. Twenty five solid masses were evaluated, and the results were compared with histology from core or surgical biopsy, or with cytology from fine needle aspiration. The results analyzed all lesions correctly (15 cancers and 10 benign lesions). There were no false positives or false negatives. The results suggest that DM may be a useful tool in digitally diagnosing breast lesions and consequently in reducing the number of unnecessary biopsies.

  1. Proliferative and nonproliferative lesions of the rat and mouse male reproductive system.

    PubMed

    Creasy, Dianne; Bube, Axel; de Rijk, Eveline; Kandori, Hitoshi; Kuwahara, Maki; Masson, Regis; Nolte, Thomas; Reams, Rachel; Regan, Karen; Rehm, Sabine; Rogerson, Petrina; Whitney, Katharine

    2012-08-01

    The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature and differential diagnosis for classifying microscopic lesions observed in the male reproductive system of laboratory rats and mice, with color microphotographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available for society members electronically on the Internet (http://goreni.org). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous and aging lesions as well as lesions induced by exposure to test materials. A widely accepted and utilized international harmonization of nomenclature for lesions of the male reproductive system in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.

  2. 78 FR 46682 - CSX Transportation, Inc.-Joint Use-Louisville & Indiana Railroad Company, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... Surface Transportation Board CSX Transportation, Inc.--Joint Use--Louisville & Indiana Railroad Company..., Inc. (L&I). The application seeks Board approval under 49 U.S.C. 11323 et seq., for joint use by CSXT... confidential versions of Section 4 of Attachment C to the Joint Use Operating Agreement. For more...

  3. Giant Solitary Synovial Chondromatosis of the Temporomandibular Joint with Intracranial Extension

    PubMed Central

    Gil-Salú, José L.; Lázaro, Rafael; Aldasoro, José; Gonzalez-Darder, José M.

    1998-01-01

    Synovial chondromatosis are rare entities but are well-described lesions in the literature that can affect many joint areas of the body. A case of tumoral synovial chondromatosis involving the temporomandibular joint with intracranial extension through mandibular fossa is reported. As long as there was significant infratemporal and extradural invasion of the middle and posterior fossa, a transtemporal and infratemporal approach was performed and total removal of the lesions was achieved. A brief review of skull base synovial chondromatosis is presented. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 10Figure 11 PMID:17171059

  4. [Two cystic retroperitoneal lesions mimicking adrenal cysts].

    PubMed

    Grabellus, F; Dereskewitz, C; Schmitz, K J; Kaiser, G M; Kühl, H; Kersting, C; Frilling, A; Metz, K A; Baba, H A

    2005-05-01

    Adrenal cysts are uncommon lesions and most of them are found incidentally during abdominal imaging. We report on two benign extraadrenal lesions mimicking adrenal tumors in abdominal imaging. The histopathological investigation of the lesions revealed a foregut duplication cyst of the lesser gastric curvature and an epithelial inclusion cyst (epidermoid cyst) in an intrapancreatic accessory spleen respectively.

  5. In vivo diagnostics of human knee cartilage lesions using delayed CBCT arthrography.

    PubMed

    Kokkonen, Harri T; Suomalainen, Juha-Sampo; Joukainen, Antti; Kröger, Heikki; Sirola, Joonas; Jurvelin, Jukka S; Salo, Jari; Töyräs, Juha

    2014-03-01

    The aim of this study was to investigate the feasibility of delayed cone beam (CBCT) arthrography for clinical diagnostics of knee cartilage lesions. Knee joints with cartilage lesions were imaged using native radiography, MRI, and delayed CBCT arthrography techniques in vivo. The joints were imaged three times with CBCT, just before, immediately after (arthrography) and 45 min after the intra-articular injection of contrast agent. The arthrographic images enabled sensitive detection of the cartilage lesions. Use of arthrographic and delayed images together with their subtraction image enabled also detection of cartilage with inferior integrity. The contrast agent partition in intact cartilage (ICRS grade 0) was lower (p < 0.05) than that of cartilage surrounding the ICRS grade I-IV lesions. Delayed CBCT arthrography provides a novel method for diagnostics of cartilage lesions. Potentially, it can also be used in diagnostics of cartilage degeneration. Due to shorter imaging times, higher resolution, and lower costs of CT over MRI, this technique could provide an alternative for diagnostics of knee pathologies. However, for comprehensive evaluation of the clinical potential of the technique a further clinical study with a large pool of patients having a wide range of cartilage pathologies needs to be conducted.

  6. Monitoring the Remineralization of Early Simulated Lesions using a pH Cycling Model with CP-OCT

    PubMed Central

    Kang, Hobin; Chan, Kenneth; Darling, Cynthia L.; Fried, Daniel

    2013-01-01

    If caries lesions are detected early enough they can be arrested by chemical intervention and dietary changes without the need for chemical intervention. Optical coherence tomography is ideally suited to monitor the changes that occur in caries lesions as a result of nonsurgical intervention, since OCT can nondestructively image the internal structure of the lesion. One of the most important changes that occurs in a lesion is preferential deposition of mineral in the outer surface zone. The deposition creates a highly mineralized and weakly scattering surface zone that is clearly visible in OCT images. Since this zone is near the highly reflective surface it is necessary to use cross-polarization OCT imaging to resolve this zone. Several CP-OCT studies have been conducted employing different remineralization models that produce lesions with varying mineral gradients. Previous studies have also demonstrated that automated algorithms can be used to assess the lesion depth and severity even with the presence of the weakly reflective surface zone. In this study we investigated the remineralization of lesions of varying severity using a pH cycling remineralization model and the change of the lesion was monitored using CP-OCT. Although the lesion depth and severity decreased after remineralization, there was still incomplete remineralization of the body of the lesion. PMID:24353383

  7. Monitoring the remineralization of early simulated lesions using a pH cycling model with CP-OCT

    NASA Astrophysics Data System (ADS)

    Kang, Hobin; Chan, Kenneth; Darling, Cynthia L.; Fried, Daniel

    If caries lesions are detected early enough they can be arrested by chemical intervention and dietary changes without the need for chemical intervention. Optical coherence tomography is ideally suited to monitor the changes that occur in caries lesions as a result of nonsurgical intervention, since OCT can nondestructively image the internal structure of the lesion. One of the most important changes that occurs in a lesion is preferential deposition of mineral in the outer surface zone. The deposition creates a highly mineralized and weakly scattering surface zone that is clearly visible in OCT images. Since this zone is near the highly reflective surface it is necessary to use cross-polarization OCT imaging to resolve this zone. Several CP-OCT studies have been conducted employing different remineralization models that produce lesions with varying mineral gradients. Previous studies have also demonstrated that automated algorithms can be used to assess the lesion depth and severity even with the presence of the weakly reflective surface zone. In this study we investigated the remineralization of lesions of varying severity using a pH cycling remineralization model and the change of the lesion was monitored using CP-OCT. Although the lesion depth and severity decreased after remineralization, there was still incomplete remineralization of the body of the lesion.

  8. Optimal tubular adhesive-bonded lap joint of the carbon fiber epoxy composite shaft

    NASA Astrophysics Data System (ADS)

    Kim, Ki S.; Kim, Won T.; Lee, Dai G.; Jun, Eui J.

    The effects of the adhesive thickness and the adherend surface roughness on the fatigue strength of a tubular adhesive-bonded single lap joint were investigated using fatigue test specimens whose adherends were made of S45C carbon steel. Results of fatigue tests showed that the optimal arithmetic surface roughness of the adherends is about 2 microns and the optimal adhesive thickness is about 0.15 mm. Using these values, the prototype torsional adhesive joints were manufactured for power transmission shafts of an automotive vehicle or a small helicopter, and static tests under torque were performed on a single-lap joint, a single-lap joint with scarf, a double-lap joint, and a double-lap joint with scarf. It was found that the double-lap joint was superior among the joints, in terms of torque capacity and manufacturing cost.

  9. Relationship between mineral distributions in dentine lesions and subsequent remineralization in vitro.

    PubMed

    Kawasaki, K; Ruben, J; Tsuda, H; Huysmans, M C; Takagi, O

    2000-01-01

    Though the mineral distribution of the dentine carious lesion varies largely from tooth to tooth and from patient to patient, there are two main distribution profiles that characterize natural carious lesions in dentine. These profiles include softened and subsurface lesion types. The mineral distribution relationship between the starting profile and the profile after remineralization is not known. In order to study the relational aspects, we have produced demineralized dentine samples in vitro with mineral profiles similar to those of typical natural carious lesions, and subsequently remineralized the samples in a remineralizing solution with various fluoride concentrations (0, 2 and 10 ppm F). The mineral distributions were obtained by using an improved microradiographic technique. In addition, the nature of deposited mineral was analyzed by diamond-coupled total internal reflectance spectroscopy. Definite relationship was observed between the original lesion mineral distribution and the mineral distributions following remineralization. The amount of mineral present in approximately the first 50 microm of the lesion influenced the overall mineral profile after remineralization, possibly through influencing ion transport. If the amount was high (> approximately 10 vol%), the deposited mineral was confined to the surface (0-50 microm). The original mineral at those depths acted like a nucleus of mineral regrowth when the amount of residual mineral was intermediate, and like a transport barrier when the surface layer was well mineralized. If a surface barrier was not present, mineral was deposited at deeper depths in the lesion. Fluoride effect on dentine remineralization was dependent on the original mineral content and its distribution in the lesion. Although a high concentration of fluoride was very effective in low-mineral lesions, it produced hyperremineralization on well-mineralized subsurface lesions so that it prevented effective remineralization especially

  10. Mechanisms of degradation in adhesive joint strength: Glassy polymer thermoset bond in a humid environment

    DOE PAGES

    Kropka, Jamie Michael; Adolf, Douglas Brian; Spangler, Scott Wilmer; Austin, Kevin N.; Chambers, Robert S.

    2015-08-06

    The degradation in the strength of napkin-ring (NR) joints bonded with an epoxy thermoset is evaluated in a humid environment. While adherend composition (stainless steel and aluminum) and surface preparation (polished, grit blasted, primed, coupling agent coated) do not affect virgin (time=0) joint strength, they can significantly affect the role of moisture on the strength of the joint. Adherend surface abrasion and corrosion processes are found to be key factors in determining the reliability of joint strength in humid environments. In cases where surface specific joint strength degradation processes are not active, decreases in joint strength can be accounted formore » by the glass transition temperature, Tg, depression of the adhesive associated with water sorption. Under these conditions, joint strength can be rejuvenated to virgin strength by drying. In addition, the decrease in joint strength associated with water sorption can be predicted by the Simplified Potential Energy Clock (SPEC) model by shifting the adhesive reference temperature, Tref, by the same amount as the Tg depression. When surface specific degradation mechanisms are active, they can reduce joint strength below that associated with adhesive Tg depression, and joint strength is not recoverable by drying. Furthermore, a critical relative humidity (or, potentially, critical water sorption concentration), below which the surface specific degradation does not occur, appears to exist for the polished stainless steel joints.« less

  11. Mechanisms of degradation in adhesive joint strength: Glassy polymer thermoset bond in a humid environment

    SciTech Connect

    Kropka, Jamie Michael; Adolf, Douglas Brian; Spangler, Scott Wilmer; Austin, Kevin N.; Chambers, Robert S.

    2015-08-06

    The degradation in the strength of napkin-ring (NR) joints bonded with an epoxy thermoset is evaluated in a humid environment. While adherend composition (stainless steel and aluminum) and surface preparation (polished, grit blasted, primed, coupling agent coated) do not affect virgin (time=0) joint strength, they can significantly affect the role of moisture on the strength of the joint. Adherend surface abrasion and corrosion processes are found to be key factors in determining the reliability of joint strength in humid environments. In cases where surface specific joint strength degradation processes are not active, decreases in joint strength can be accounted for by the glass transition temperature, Tg, depression of the adhesive associated with water sorption. Under these conditions, joint strength can be rejuvenated to virgin strength by drying. In addition, the decrease in joint strength associated with water sorption can be predicted by the Simplified Potential Energy Clock (SPEC) model by shifting the adhesive reference temperature, Tref, by the same amount as the Tg depression. When surface specific degradation mechanisms are active, they can reduce joint strength below that associated with adhesive Tg depression, and joint strength is not recoverable by drying. Furthermore, a critical relative humidity (or, potentially, critical water sorption concentration), below which the surface specific degradation does not occur, appears to exist for the polished stainless steel joints.

  12. Joint Custody and Coparenting.

    ERIC Educational Resources Information Center

    Sell, Kenneth D.

    Results are presented of an intensive search of U.S. newspapers and periodicals on the joint custody of children after divorce, where both parents have continued responsibility for parenting and where the children spend part of each week, month, or year with both of the parents. Areas of concern addressed by these materials include the following:…

  13. Human temporomandibular joint morphogenesis.

    PubMed

    Carini, Francesco; Scardina, Giuseppe Alessandro; Caradonna, Carola; Messina, Pietro; Valenza, Vincenzo

    2007-01-01

    Temporomandibular joint morphogenesis was studied. Ranging in age of fetuses examined was from 6 to14 weeks' gestation. Our results showed the condyle so first element that appear between 6 degrees and 8 degrees week (condylar blastema). After a week appear temporal elements. Disk appear at the same time of glenoid blastema and it reaches an advanced differentation before of the condyle and temporal element, so these don't effect machanical compression on mesenchyma where we find the disk. So we think that the disk result of genetic expression and it isn't the result of mechanical compression. The inferior joint cavity appear to 12 week. The superior joint cavity appear to 13-14 week. In conclusion, the appearance of the condyle is the first event during TMJ morphogenesis, with its initial bud, in form of a mesenchymal thickening, becoming detectable between the sixth and eight week of development, when all the large joints of the limbs are already well defined. PMID:18333411

  14. Intraarticular osteoblastoma with subluxation of the hip joint

    PubMed Central

    Okada, Kyoji; Nagasawa, Hiroyuki; Chida, Schuichi; Nanjo, Hiroshi

    2013-01-01

    Patient: Male, 5 Final Diagnosis: Osteoblastoma Symptoms: — Medication: — Clinical Procedure: — Specialty: Oncology Objective: Rare disease Background: Osteoblastomas are relatively uncommon bone tumors that account for <1% of all bone tumors. They usually occur in the medullary region of the bone. As such, intraarticular osteoblastomas are quite rare. Case Report: In this report, we present the case of a 5-year-old boy who presented with vague pain and subluxation of the hip joint due to an intraarticular osteoblastoma. Radiological examinations showed an irregular calcified mass lesion in the hip joint. The final diagnosis of osteoblastoma was made by histological examination. The patient’s symptoms completely subsided following surgical removal of the tumor. Conclusions: Osteoblastomas can occur in the intraarticular region. Although quite rare, osteoblastoma should be considered among the differential diagnoses for patients with pain and subluxation of the hip joint. PMID:23901353

  15. 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…

  16. Gum containing calcium fluoride reinforces enamel subsurface lesions in situ.

    PubMed

    Kitasako, Y; Sadr, A; Hamba, H; Ikeda, M; Tagami, J

    2012-04-01

    The aim of this study was to assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and a low concentration of fluoride (F) on the hardness of enamel subsurface lesions, utilizing a double-blind, randomized, and controlled in situ model. Fifteen individuals wore removable lingual appliances with 3 bovine-enamel insets containing subsurface demineralized lesions. Three times a day for 14 days, they chewed one of the 3 chewing gums (placebo, POs-Ca, POs-Ca+F). After the treatment period, cross-sectional mineral content, nanoindentation hardness, and fluoride ion mapping by time-of-flight secondary ion mass spectrometry (TOF-SIMS) were evaluated. Although there were no statistical differences in overall mineral content and hardness recovery rates between POs-Ca and POs-Ca+F subsurface lesions (p > 0.05), nanoindentation at 1-μm distance increments from the surface showed statistical differences in hardness recovery rate between POs-Ca and POs-Ca+F in the superficial 20-μm region (p < 0.05). Fluoride mapping revealed distribution of the ion up to 20 μm from the surface in the POs-Ca+F group. Nanoindentation and TOF-SIMS results highlighted the benefits of bioavailability of fluoride ion on reinforcement of the superficial zone of subsurface lesions in situ (NCT01377493).

  17. [HPV-associated cutaneous lesions].

    PubMed

    Kiyofumi, Egawa

    2008-12-01

    More than 100 HPV genotypes are presently distinguished by comparing the DNA sequence of the L1 ORF of each HPV. Two important aspects of the nature of this group of heterogeneous viruses are the way in which specific HPV genotypes are associated with distinct clinical and histological morphologies and the way specific HPV genotypes affect distinct anatomical sites. The former is best evidenced by the HPV type specific cytopathic or cytopathogenic effect (CPE), whereas the latter is suggested by the marked preference of each HPV genotype for specific tissues and sites. Recent studies have also suggested that specific HPV genotypes may target epithelial stem cells at specific anatomical sites. HPV type-specific CPE is the central schema when we analyze and understand the HPV-associated diseases. The concept was suggested by the characterization of distinct HPVs from different types of warts: HPV 2/27/57 from common warts, HPV 3/10/28 from flat warts, HPV 6/11 from condyloma acuminatum, and HPV 5/8 from lesions of epidermodysplasia verruciformis (EV). In this paper, I summarize recent advances in HPV study field, especially on HPV-associated cutaneous lesions. These include inclusion warts, HPV-associated epidermoid cysts, HPV type specific activation of melanogenesis, a double infection with HPV 1 and HPV 63 within a single cell, primary target cells and life cycle of the virus, and the identification of novel genes that are associated EV. The HPV-associated cutaneous lesions thus pose important problems to be resolved in virology and human pathology. PMID:19374195

  18. Anaerobic prosthetic joint infection.

    PubMed

    Shah, Neel B; Tande, Aaron J; Patel, Robin; Berbari, Elie F

    2015-12-01

    In an effort to improve mobility and alleviate pain from degenerative and connective tissue joint disease, an increasing number of individuals are undergoing prosthetic joint replacement in the United States. Joint replacement is a highly effective intervention, resulting in improved quality of life and increased independence [1]. By 2030, it is predicted that approximately 4 million total hip and knee arthroplasties will be performed yearly in the United States [2]. One of the major complications associated with this procedure is prosthetic joint infection (PJI), occurring at a rate of 1-2% [3-7]. In 2011, the Musculoskeletal Infectious Society created a unifying definition for prosthetic joint infection [8]. The following year, the Infectious Disease Society of America published practice guidelines that focused on the diagnosis and management of PJI. These guidelines focused on the management of commonly encountered organisms associated with PJI, including staphylococci, streptococci and select aerobic Gram-negative bacteria. However, with the exception of Propionibacterium acnes, management of other anaerobic organisms was not addressed in these guidelines [1]. Although making up approximately 3-6% of PJI [9,10], anaerobic microorganisms cause devastating complications, and similar to the more common organisms associated with PJI, these bacteria also result in significant morbidity, poor outcomes and increased health-care costs. Data on diagnosis and management of anaerobic PJI is mostly derived from case reports, along with a few cohort studies [3]. There is a paucity of published data outlining factors associated with risks, diagnosis and management of anaerobic PJI. We therefore reviewed available literature on anaerobic PJI by systematically searching the PubMed database, and collected data from secondary searches to determine information on pathogenesis, demographic data, clinical features, diagnosis and management. We focused our search on five commonly

  19. Multiple lesion track structure model

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

    1992-01-01

    A multilesion cell kinetic model is derived, and radiation kinetic coefficients are related to the Katz track structure model. The repair-related coefficients are determined from the delayed plating experiments of Yang et al. for the C3H10T1/2 cell system. The model agrees well with the x ray and heavy ion experiments of Yang et al. for the immediate plating, delaying plating, and fractionated exposure protocols employed by Yang. A study is made of the effects of target fragments in energetic proton exposures and of the repair-deficient target-fragment-induced lesions.

  20. The relations between joint action and theory of mind: a neuropsychological analysis.

    PubMed

    Humphreys, Glyn W; Bedford, Jo

    2011-06-01

    We examined the relations between joint action and Theory of Mind (ToM) in neurological patients with impairments in ToM, in control patients (who passed ToM tasks) and non-lesioned controls. In two experiments, joint action was assessed in a "social Simon" procedure where spatial compatibility effects were tested under two-alternative forced-choice and under go/nogo conditions, which participants performed in isolation or alongside another participant (the joint action condition). In Experiment 1, patients with impaired ToM showed evidence of increased spatial compatibility effects under standard (two-alternative forced-choice) conditions but, unlike the control participants, these effects disappeared in the joint action condition. In Experiment 2, the ToM patients were asked to pay particular attention to their co-actor. With these instructions, ToM patients with lesions of posterior parietal cortex now showed a sustained spatial compatibility effect in the joint action condition, while ToM patients with lesions primarily involving frontal regions showed an initial effect of spatial compatibility that decreased across trials. The data suggest common processes involved in ToM processing and joint action effects, related to either the ability to attend to appropriate social cues (affected in posterior parietal patients) or the ability to recruit sufficient resources to code another's actions (affected in frontal patients).

  1. Computer-aided tracking of MS lesions

    NASA Astrophysics Data System (ADS)

    Sturm, Deborah; Gurwitz Kletenik, Devorah; Koshy, Philip

    2011-03-01

    Multiple Sclerosis (MS) lesions are known to change over time. The location, size and shape characteristics of lesions are often used to diagnose and to track disease progression. We have improved our lesion-browsing tool that allows users to automatically locate successive significant lesions in a MRI stack. In addition, an automatic alignment feature was implemented to facilitate comparisons across stacks. A lesion stack is formed that can be browsed independently or in tandem with the image windows. Lesions of interest can then be measured, rendered and rotated. Multiple windows allow the viewer to compare the size and shape of lesions from the MRI images of the same patient taken at different time intervals.

  2. Investigation of Essential Element Distribution in the Equine Metacarpophalangeal Joint using a Synchrotron Radiation Micro X-Ray Fluorescence Technique

    NASA Astrophysics Data System (ADS)

    Kaabar, Wejdan; Gundogdu, O.; Tzaphlidou, M.; Janousch, M.; Attenburrow, D.; Bradley, D. A.

    2008-05-01

    In articular cartilage, Ca, P, K and S are among some of the well known co-factors of the metalloproteinases enzymatic family, the latter playing a pivotal role in the growth and degeneration of the collagenous bone-cartilage interface of articulating joints. Current study forms part of a larger investigation concerning the distribution of these and other key elements in such media. For the purpose of evaluating these low atomic number elements (Z⩽20), use was made of the capabilities of the LUCIA Station, located at the synchrotron facility of the Paul Scherrer Institute (PSI). Using an incident radiation energy of 4.06 keV, a synchrotron radiation micro x-ray fluorescence (SR-μXRF) technique was applied in examining the distribution of the essential elements Ca, P, K and S in the bone-cartilage interface of both healthy and diseased (osteoarthritic) areas of an equine metacarpophalangeal joint. The SR-μXRF mappings and line profile patterns have revealed remarkable changes in both the pattern and absolute distributions of these elements, agreeing with the findings of others. The elemental presence shown in the individual area scans encompassing the lesion each reflect the visibly abraded outer surface of the cartilage and change in shape of the bone surface. One of the area scans for the bone-cartilage interface shows a marked change in both the pattern and absolute elemental presence for all three elements compared to that observed at two other scan sites. The observation of change in bone cartilage composition around the surface of the articulating joint is thought to be novel, the variation being almost certainly due to the differing weight-bearing role of the subchondral bone at each location.

  3. Investigation of Essential Element Distribution in the Equine Metacarpophalangeal Joint using a Synchrotron Radiation Micro X-Ray Fluorescence Technique

    SciTech Connect

    Kaabar, Wejdan; Gundogdu, O.; Attenburrow, D.; Bradley, D. A.; Tzaphlidou, M.; Janousch, M.

    2008-05-20

    In articular cartilage, Ca, P, K and S are among some of the well known co-factors of the metalloproteinases enzymatic family, the latter playing a pivotal role in the growth and degeneration of the collagenous bone-cartilage interface of articulating joints. Current study forms part of a larger investigation concerning the distribution of these and other key elements in such media. For the purpose of evaluating these low atomic number elements (Z{<=}20), use was made of the capabilities of the LUCIA Station, located at the synchrotron facility of the Paul Scherrer Institute (PSI). Using an incident radiation energy of 4.06 keV, a synchrotron radiation micro x-ray fluorescence (SR-{mu}XRF) technique was applied in examining the distribution of the essential elements Ca, P, K and S in the bone-cartilage interface of both healthy and diseased (osteoarthritic) areas of an equine metacarpophalangeal joint. The SR-{mu}XRF mappings and line profile patterns have revealed remarkable changes in both the pattern and absolute distributions of these elements, agreeing with the findings of others. The elemental presence shown in the individual area scans encompassing the lesion each reflect the visibly abraded outer surface of the cartilage and change in shape of the bone surface. One of the area scans for the bone-cartilage interface shows a marked change in both the pattern and absolute elemental presence for all three elements compared to that observed at two other scan sites. The observation of change in bone cartilage composition around the surface of the articulating joint is thought to be novel, the variation being almost certainly due to the differing weight-bearing role of the subchondral bone at each locati0008.

  4. Shoulder Joint For Protective Suit

    NASA Technical Reports Server (NTRS)

    Kosmo, Joseph J.; Smallcombe, Richard D.

    1994-01-01

    Shoulder joint allows full range of natural motion: wearer senses little or no resisting force or torque. Developed for space suit, joint offers advantages in protective garments for underwater work, firefighting, or cleanup of hazardous materials.

  5. Development of the bus joint for the ITER Central Solenoid

    SciTech Connect

    Martovetsky, Nicolai N; Irick, David Kim; Kenney, Steven J

    2013-01-01

    The terminations of the Central Solenoid (CS) modules are connected to the bus extensions by joints located outside the CS in the gap between the CS and Torodial Field (TF) assemblies. These joints have very strict space limitations. Low resistance is a common requirement for all ITER joints. In addition, the CS bus joints will experience and must be designed to withstand significant variation in the magnetic field of several tenths of a Tesla per second during initiation of plasma. The joint resistance is specified to be less than 4 nOhm. The joints also have to be soldered in the field and designed with the possibility to be installed and dismantled in order to allow cold testing in the cold test facility. We have developed coaxial joints that meet these requirements and have demonstrated the feasibility to fabricate and assemble them in the vertical configuration. We introduced a coupling cylinder with superconducting strands soldered to the surface of the cable that can be installed in the ITER assembly hall and at the Cold Test Facility. This cylinder serves as a transition area between the CS module and the bus extension. We made two racetrack samples and tested four bus joints in our Joint Test Apparatus. Resistance of the bus joints was measured by a decay method and by a microvoltmeter; the value of the current was measured by the Hall probes. This measurement method was verified in the previous tests. The resistance of the joints varied insignificantly from 1.5 to 2 nOhm. One of the challenges associated with a soldered joint is the inability to use corrosive chemicals that are difficult to clean. This paper describes our development work on cable preparation, chrome removal, compaction, soldering, and final assembly and presents the test results.

  6. Shocking behavior of fluid flow in deformable joints

    SciTech Connect

    Murphy, H.; Dash, Z.

    1985-01-01

    If fluid is injected into joints in rock masses, several types of joint deformations can take place. At first the pressure rise in the joint is small enough that the joint does not actually open. Nevertheless the effective closure stress, i.e., the difference between the total earth stress acting normal to the joint plane and the fluid pressure, is reduced. Consequently the tightness of joint closure is lessened, resulting in a small increase of the effective open space, or aperture, of the joint. If the fluid pressure rise is small enough, the aperture can still be treated as nearly constant, and the pressure response therefore follows the usual laws of linear diffusion. But if the pressure increase is large, aperture increases must be accounted for, and the flow will be affected by nonlinear diffusion due to pressure-dependent aperture, as well as a new storativity term due to joint compressibility. Eventually the fluid pressure may attain a value equal to, and even slightly greater than, the original total earth stress, and the opposing surfaces of the rock that meet at the joint can actually part. We refer to this behavior as joint ''lift off,'' or ''jacking.'' During lift off, the changes in joint aperture and compressibility are very large compared to changes while the joint is still in roughness-to-roughness contact and the flow equation becomes so highly nonlinear that pressure pulses are no longer transmitted in a smooth, diffusive manner, but more like a propagating shock wave. 7 refs., 3 figs.

  7. Determination of Parachute Joint Factors using Seam and Joint Testing

    NASA Technical Reports Server (NTRS)

    Mollmann, Catherine

    2015-01-01

    This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

  8. Interplay between surface properties of standard, vitamin E blended and oxidised ultra high molecular weight polyethylene used in total joint replacement and adhesion of Staphylococcus aureus and Escherichia coli.

    PubMed

    Banche, G; Allizond, V; Bracco, P; Bistolfi, A; Boffano, M; Cimino, A; Brach del Prever, E M; Cuffini, A M

    2014-04-01

    We have assessed the different adhesive properties of some of the most common bacteria associated with periprosthetic joint infection on various types of ultra high molecular Weight Polyethylene (UHMWPE). Quantitative in vitro analysis of the adhesion of biofilm producing strains of Staphylococcus aureus and Escherichia coli to physically and chemically characterised standard UHMWPE (PE), vitamin E blended UHMWPE (VE-PE) and oxidised UHMWPE (OX-PE) was performed using a sonication protocol. A significant decreased bacterial adhesion was registered for both strains on VE-PE, in comparison with that observed on PE, within 48 hours of observation (S. aureus p = 0.024 and E. coli p = 0.008). Since Vitamin E reduces bacterial adhesive ability, VE-stabilised UHMWPE could be valuable in joint replacement by presenting excellent mechanical properties, while reducing bacterial adhesiveness.

  9. Prediction of Drug Penetration in Tuberculosis Lesions.

    PubMed

    Sarathy, Jansy P; Zuccotto, Fabio; Hsinpin, Ho; Sandberg, Lars; Via, Laura E; Marriner, Gwendolyn A; Masquelin, Thierry; Wyatt, Paul; Ray, Peter; Dartois, Véronique

    2016-08-12

    The penetration of antibiotics in necrotic tuberculosis lesions is heterogeneous and drug-specific, but the factors underlying such differential partitioning are unknown. We hypothesized that drug binding to macromolecules in necrotic foci (or caseum) prevents passive drug diffusion through avascular caseum, a critical site of infection. Using a caseum binding assay and MALDI mass spectrometry imaging of tuberculosis drugs, we showed that binding to caseum inversely correlates with passive diffusion into the necrotic core. We developed a high-throughput assay relying on rapid equilibrium dialysis and a caseum surrogate designed to mimic the composition of native caseum. A set of 279 compounds was profiled in this assay to generate a large data set and explore the physicochemical drivers of free diffusion into caseum. Principle component analysis and modeling of the data set delivered an in silico signature predictive of caseum binding, combining 69 molecular descriptors. Among the major positive drivers of binding were high lipophilicity and poor solubility. Determinants of molecular shape such as the number of rings, particularly aromatic rings, number of sp(2) carbon counts, and volume-to-surface ratio negatively correlated with the free fraction, indicating that low-molecular-weight nonflat compounds are more likely to exhibit low caseum binding properties and diffuse effectively through caseum. To provide simple guidance in the property-based design of new compounds, a rule of thumb was derived whereby the sum of the hydrophobicity (clogP) and aromatic ring count is proportional to caseum binding. These tools can be used to ensure desirable lesion partitioning and guide the selection of optimal regimens against tuberculosis. PMID:27626295

  10. Achieving joint benefits from joint implementation

    SciTech Connect

    Moomaw, W.R.

    1995-11-01

    Joint Implementation (JI) appears to have been born with Applied Energy Services Guatemala project in 1988. That project, to plant 52 million trees, protect existing forests from cutting and fire, and enhance rural development, is being implemented by CARE Guatemala to offset 120 per cent of the emissions of a small coal burning power plant that has been built in Connecticut. Since that time, several utilities and governments have initiated additional projects. Not all of these necessarily consist of tree planting in other countries, but may consist of energy efficiency or energy conservation programs designed to reduce carbon emissions by at least as much as the additional releases from a new facility. All JI projects share the characteristic of linking the release of greenhouse gases in an industrial country with an offset that reduces or absorbs a comparable amount in another country. The emitter in the industrial country is willing to pay for the reduction elsewhere because costs are less than they would be at home.

  11. Phase 1 Program Joint Report

    NASA Technical Reports Server (NTRS)

    Nield, George C. (Editor); Vorobiev, Pavel Mikhailovich (Editor)

    1999-01-01

    This report consists of inputs from each of the Phase I Program Joint Working Groups. The Working Groups were tasked to describe the organizational structure and work processes that they used during the program, joint accomplishments, lessons learned, and applications to the International Space Station Program. This report is a top-level joint reference document that contains information of interest to both countries.

  12. Double slotted socket spherical joint

    DOEpatents

    Bieg, Lothar F.; Benavides, Gilbert L.

    2001-05-22

    A new class of spherical joints is disclosed. These spherical joints are capable of extremely large angular displacements (full cone angles in excess of 270.degree.), while exhibiting no singularities or dead spots in their range of motion. These joints can improve or simplify a wide range of mechanical devices.

  13. Swivel Joint For Liquid Nitrogen

    NASA Technical Reports Server (NTRS)

    Milner, James F.

    1988-01-01

    Swivel joint allows liquid-nitrogen pipe to rotate through angle of 100 degree with respect to mating pipe. Functions without cracking hard foam insulation on lines. Pipe joint rotates on disks so mechanical stress not transmitted to thick insulation on pipes. Inner disks ride on fixed outer disks. Disks help to seal pressurized liquid nitrogen flowing through joint.

  14. Dry arthroscopy with a retraction system for matrix-aided cartilage repair of patellar lesions.

    PubMed

    Sadlik, Boguslaw; Wiewiorski, Martin

    2014-02-01

    Several commercially available cartilage repair techniques use a natural or synthetic matrix to aid cartilage regeneration (e.g., autologous matrix-induced chondrogenesis or matrix-induced cartilage implantation). However, the use of matrix-aided techniques during conventional knee joint arthroscopy under continuous irrigation is challenging. Insertion and fixation of the matrix can be complicated by the presence of fluid and the confined patellofemoral joint space with limited access to the lesion. To overcome these issues, we developed a novel arthroscopic approach for matrix-aided cartilage repair of patellar lesions. This technical note describes the use of dry arthroscopy assisted by a minimally invasive retraction system. An autologous matrix-induced chondrogenesis procedure is used to illustrate this novel approach.

  15. Association between Experimental Bacterial Meningitis and Periapical Lesion

    PubMed Central

    Netto, Soraia; Ceretta, Renan Antonio; Generoso, Jaqueline S.; Simões, Lutiana R.; Ribeiro, Patrícia Ávila; Budni, Josiane; Quevedo, João

    2015-01-01

    Introduction Mortality and morbidity from bacterial meningitis in African adults is significantly higher than those in better resourced settings. At the same time, the periodontal diseases are highly prevalent and can affect up to 90% of the population. Dental caries in Uganda was recorded in 40% and 62.5% of the children and adults, respectively. We hypothesize that pneumococcal meningitis could interfere in the development of periapical lesion. The aim of this study was to evaluate periapical lesion in Wistar rats subjected to pneumococcal meningitis. Materials and Methods The animals were divided in control, control/periapical lesion, meningitis, and meningitis/periapical lesion groups. The surgical exposure of molars and the infection of the dental pulp were from the oral environment. Pulp necrosis was induced on the left mandibular first molars during adulthood. Dental pulps were exposed by drilling cavities on the central portion of the occlusal surface with a 1011 HL round bur in high speed to a depth nearly equal to the bur diameter. Animals were subjected to behavioral task and evaluation of the size of periodontal ligament. Data from periodontal ligament space and open field task were reported as mean ± SEM and analysed by Two-way ANOVA and paired Student’s t-test, respectively. Results and Conclusion Meningitis/periapical increased the periodontal ligament space by 61% when compared with control/periapical. In the open-field task, there were no differences in the number of crossings and rearing movements between training and test session in meningitis and periapical lesion groups demonstrating habituation memory impairment. Bacterial meningitis and periapical lesion may play an important role in development of cognitive impairment. PMID:26155479

  16. Joint hypermobility syndrome pain.

    PubMed

    Grahame, Rodney

    2009-12-01

    Joint hypermobility syndrome (JHS) was initially defined as the occurrence of musculoskeletal symptoms in the presence of joint laxity and hypermobility in otherwise healthy individuals. It is now perceived as a commonly overlooked, underdiagnosed, multifaceted, and multisystemic heritable disorder of connective tissue (HDCT), which shares many of the phenotypic features of other HDCTs such as Marfan syndrome and Ehlers-Danlos syndrome. Whereas the additional flexibility can confer benefits in terms of mobility and agility, adverse effects of tissue laxity and fragility can give rise to clinical consequences that resonate far beyond the confines of the musculoskeletal system. There is hardly a clinical specialty to be found that is not touched in one way or another by JHS. Over the past decade, it has become evident that of all the complications that may arise in JHS, chronic pain is arguably the most menacing and difficult to treat. PMID:19889283

  17. Laundry joint venture.

    PubMed

    Giancola, D; Voyvodich, M

    1984-12-01

    Many hospitals are concerned about the loss of control which is associated with contracting for linen service. On the the hand, many laundries do not have the resources or experience to serve hospitals in a comprehensive and trouble-free manner. In many communities a joint venture, such as the one described here, can successfully combine the interests of the hospital and laundry communities without causing the hospitals to lose control of the service and without requiring the laundry operator to have detailed knowledge of hospital operations. As more hospitals opt for contract service, and if this service is to be provided at the lowest total cost, the hospitals and the laundries must come to grips with the problems surrounding the laundry-hospital interface. A joint venture, such as that described here, is one way to accomplish this.

  18. Selected Background Findings and Interpretation of Common Lesions in the Female Reproductive System in Macaques

    PubMed Central

    Cline, J. Mark; Wood, Charles E; Vidal, Justin D.; Tarara, Ross P.; Buse, Eberhard; Weinbauer, Gerhard F.; de Rijk, Eveline P. C. T.; van Esch, Eric

    2009-01-01

    The authors describe a selection of normal findings and common naturally occurring lesions in the reproductive system of female macaques, including changes in the ovaries, uterus, cervix, vagina, and mammary glands. Normal features of immature ovaries, uteri, and mammary glands are described. Common non-neoplastic lesions in the ovaries include cortical mineralization, polyovular follicles, cysts, ovarian surface epithelial hyperplasia, and ectopic ovarian tissue. Ovarian neoplasms include granulosa cell tumors, teratomas, and ovarian surface epithelial tumors. Common non-neoplastic uterine findings include loss of features of normal cyclicity, abnormal bleeding, adenomyosis, endometriosis, epithelial plaques, and pregnancy-associated vascular remodeling. Hyperplastic and neoplastic lesions of the uterus include endometrial polyps, leiomyomas, and rarely endometrial hyperplasia and endometrial adenocarcinoma. Vaginitis is common. Cervical lesions include endocervical squamous metaplasia, polyps, and papillomavirus-associated lesions. Lesions in the mammary gland are most often proliferative and range from ductal hyperplasia to invasive carcinoma. Challenges to interpretation include the normal or pathologic absence of menstrual cyclicity and the potential misinterpretation of sporadic lesions, such as epithelial plaques or papillomavirus-associated lesions. Interpretation of normal and pathologic findings is best accomplished with knowledge of the life stage, reproductive history, and hormonal status of the animal. PMID:21475639

  19. Communication joint for use in a well

    SciTech Connect

    Nichols, R.P.

    1986-11-18

    This patent describes a communication joint for use in a well, comprising: a solid body having an exterior surface adapted to form a slidable fluid seal with a wellhead member of the well such that the solid body may slide within the wellhead member while maintaining the seal therewith; the solid body including first and second conduits positioned in and extending axially within the solid body, each conduit having the capability of providing a fluid passageway independent of the other conduit.

  20. Joint multisensor exploitation for mine detection

    NASA Astrophysics Data System (ADS)

    Beaven, Scott G.; Stocker, Alan D.; Winter, Edwin M.

    2004-09-01

    Robust, timely, and remote detection of mines and minefields is central to both tactical and humanitarian demining efforts, yet remains elusive for single-sensor systems. Here we present an approach to jointly exploit multisensor data for detection of mines from remotely sensed imagery. LWIR, MWIR, laser, multispectral, and radar sensor have been applied individually to the mine detection and each has shown promise for supporting automated detection. However, none of these sources individually provides a full solution for automated mine detection under all expected mine, background and environmental conditions. Under support from Night Vision and Electronic Sensors Directorate (NVESD) we have developed an approach that, through joint exploitation of multiple sensors, improves detection performance over that achieved from a single sensor. In this paper we describe the joint exploitation method, which is based on fundamental detection theoretic principles, demonstrate the strength of the approach on imagery from minefields, and discuss extensions of the method to additional sensing modalities. The approach uses pre-threshold anomaly detector outputs to formulate accurate models for marginal and joint statistics across multiple detection or sensor features. This joint decision space is modeled and decision boundaries are computed from measured statistics. Since the approach adapts the decision criteria based on the measured statistics and no prior target training information is used, it provides a robust multi-algorithm or multisensor detection statistic. Results from the joint exploitation processing using two different imaging sensors over surface mines acquired by NVESD will be presented to illustrate the process. The potential of the approach to incorporate additional sensor sources, such as radar, multispectral and hyperspectral imagery is also illustrated.

  1. Temporomandibular joint dislocation

    PubMed Central

    Sharma, Naresh Kumar; Singh, Akhilesh Kumar; Pandey, Arun; Verma, Vishal; Singh, Shreya

    2015-01-01

    Temporomandibular joint (TMJ) dislocation is an uncommon but debilitating condition of the facial skeleton. The condition may be acute or chronic. Acute TMJ dislocation is common in clinical practice and can be managed easily with manual reduction. Chronic recurrent TMJ dislocation is a challenging situation to manage. In this article, we discuss the comprehensive review of the different treatment modalities in managing TMJ dislocation. PMID:26668447

  2. Evaluating the function of total joint replacements - biomed 2010.

    PubMed

    Jones, Lynne C; Drobisch, Justin; Tsao, Audrey; Hungerford, Marc W

    2010-01-01

    The primary function of hip and knee joints is to permit movement. The pathology of arthritic diseases leads to loss of articular surface anatomy and deformity which will impede motion. Consequently, one of the primary goals of total joint replacement is to restore mobility. The assessment of implants in the research and development phase includes the use of computer models, joint simulators and clinical trials. Clinical evaluation assesses motion, the ability of a patient to perform certain activities and the potential use of assistive devices. These assessments encompass patient examination and measurement of motion about the joint, instrumented tools (accelerometers, gait analysis), questionnaires (self-report, interview-based), and performance-based evaluations. In order to fully appreciate the functional outcome of a total joint implant, more than one type of assessment is required.

  3. Acromioclavicular joint disorders.

    PubMed

    Turnbull, J R

    1998-04-01

    The acromioclavicular joint is commonly involved in athletic injuries. Most commonly, a sprain to the joint occurs with variability in the amount of ligamentous damage and displacement that occurs. In all but the most severe dislocations, treatment consists of initial sling immobilization and early functional rehabilitation. The outcome is usually excellent with full return of function following these injuries. The rarer types (IV, V, and VI) require operative reduction and fixation. Distal clavicle fractures are related injuries, which many times disrupt the stabilizing ligaments of the acromioclavicular joint. Many can be treated nonoperatively, but there are several subtypes that should be considered for early fixation to reduce complications of pain and shoulder dysfunction. An atraumatic, overuse condition, which is becoming more prevalent and seems related to weight training, is osteolysis of the distal clavicle. There is insidious onset of shoulder pain with symptoms and signs consistent with acromioclavicular pathology. Activity modification is the best method of controlling symptoms. Failure of the conservative approach necessitates operative excision of the distal clavicle.

  4. Proliferative and nonproliferative lesions of the rat and mouse urinary system.

    PubMed

    Frazier, Kendall S; Seely, John Curtis; Hard, Gordon C; Betton, Graham; Burnett, Roger; Nakatsuji, Shunji; Nishikawa, Akiyoshi; Durchfeld-Meyer, Beate; Bube, Axel

    2012-06-01

    The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying lesions observed in the urinary tract of rats and mice. The standardized nomenclature of urinary tract lesions presented in this document is also available electronically on the Internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous developmental and aging lesions as well as those induced by exposure to test materials. A widely accepted and utilized international harmonization of nomenclature for urinary tract lesions in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.

  5. Explorer probing of root caries lesions: an in vitro study.

    PubMed

    Warren, John J; Levy, Steven M; Wefel, James S

    2003-01-01

    Probing with a dental explorer is the preferred method of root caries diagnoses. However, studies suggest that use of a dental explorer in coronal caries detection may damage tooth structure. This pilot study investigated the effect of probing on remineralization of root surface lesions in vitro. Root-surface lesions were created on 10 extracted teeth by exposing them to a demineralizing solution for 21 days. One side of each lesion was then randomly selected and probed with an explorer, while the other side was not probed. The teeth then were placed in a remineralizing solution containing 10 parts per million (ppm) fluoride for 21 days. Of the 9 teeth with usable sections, all showed frank evidence of defects on the probed halves. Sites of remineralization were seen in the non-probed halves and adjacent to the probed defects, but not within or at the base of these defects. These results suggest that probing of root surfaces may create defects that do not fully remineralize.

  6. Bacteriology of diabetic foot lesions.

    PubMed

    Anandi, C; Alaguraja, D; Natarajan, V; Ramanathan, M; Subramaniam, C S; Thulasiram, M; Sumithra, S

    2004-01-01

    Clinical grading and bacteriological study of 107 patients with diabetic foot lesions revealed polymicrobial aetiology in 69 (64.4%) and single aetiology in 21 (19.6%). Among 107 patients 62 had ulcer. Of these 31 had mixed aerobes. Twenty six patients with cellulitis and 12 with gangrene had more than 5 types of aerobes and anaerobes such as E. coli, Klebsiella spp., Pseudomonas spp., Proteus spp., Enterobactor spp., Enterococci spp., Clostridium perfringens, Bacteroides spp., Prevotella spp. and Peptostreptococcus spp. It was noted that 50 out of 62 patients with ulcer, and all the patients with cellulitis and gangrene were given surgical management and treated with appropriate antibiotics based on antimicrobial susceptibility testing. PMID:17642727

  7. Congenital lung lesions: Postnatal management and outcome.

    PubMed

    Parikh, Dakshesh H; Rasiah, Shree Vishna

    2015-08-01

    Antenatal diagnosis of lung lesion has become more accurate resulting in dilemma and controversies of its antenatal and postnatal management. Majority of antenatally diagnosed congenital lung lesions are asymptomatic in the neonatal age group. Large lung lesions cause respiratory compromise and inevitably require urgent investigations and surgery. The congenital lung lesion presenting with hydrops requires careful postnatal management of lung hypoplasia and persistent pulmonary hypertension. Preoperative stabilization with gentle ventilation with permissive hypercapnia and delayed surgery similar to congenital diaphragmatic hernia management has been shown to result in good outcome. The diagnostic investigations and surgical management of the asymptomatic lung lesions remain controversial. Postnatal management and outcome of congenital cystic lung lesions are discussed. PMID:26051048

  8. Hemidystonia secondary to cervical demyelinating lesions.

    PubMed

    Yücesan, C; Tuncel, D; Akbostanci, M C; Yücemen, N; Mutluer, N

    2000-09-01

    Hemidystonia is usually associated with a structural lesion in the contralateral basal ganglia. We report a patient with definite multiple sclerosis, according to Poser's criteria, presenting with an acute-onset sustained left hemidystonia. Cranial T2-weighted magnetic resonance imaging (MRI) showed several hyperintense lesions in the centri semiovali and in the periventricular area without basal ganglia involvement. Moreover cervical spinal cord T2-weighted MRI showed two hyperintense lesions in the left posterolateral spine at C2 and C3, and one lesion in the right posterolateral spine at C4 levels. The hemidystonia improved completely after daily treatment with 1000 mg of methylprednisolone, and cervical MRI was performed after the improvement which showed that the lesions had become smaller and less intense. Finally we consider that the hemidystonia may be caused by the cervical spinal cord lesions of multiple sclerosis. PMID:11054144

  9. Detection of Fundus Lesions Using Classifier Selection

    NASA Astrophysics Data System (ADS)

    Nagayoshi, Hiroto; Hiramatsu, Yoshitaka; Sako, Hiroshi; Himaga, Mitsutoshi; Kato, Satoshi

    A system for detecting fundus lesions caused by diabetic retinopathy from fundus images is being developed. The system can screen the images in advance in order to reduce the inspection workload on doctors. One of the difficulties that must be addressed in completing this system is how to remove false positives (which tend to arise near blood vessels) without decreasing the detection rate of lesions in other areas. To overcome this difficulty, we developed classifier selection according to the position of a candidate lesion, and we introduced new features that can distinguish true lesions from false positives. A system incorporating classifier selection and these new features was tested in experiments using 55 fundus images with some lesions and 223 images without lesions. The results of the experiments confirm the effectiveness of the proposed system, namely, degrees of sensitivity and specificity of 98% and 81%, respectively.

  10. Malignancy and the benign lymphoepithelial lesion.

    PubMed

    Batsakis, J G; Bernacki, E G; Rice, D H; Stebler, M E

    1975-02-01

    The benign lymphoepithelial lesion of salivary glands is now considered the histological hallmark of a variety of clinical and pathological disorders affecting salivary tissues. Malignancy arising in the lesion is uncommon, but may take origin in either the epithelial or lymphoreticular components. Lymphomas and pseudolymphomas associated with salivary gland lymphoepithelial lesions have been predominately extra-salivary and strongly correlated with Sjögren's syndrome. Epithelial malignancy has not been associated with autoimmunity and with few exceptions has been of the anaplastic type. This report presents two patients with intra-salivary lymphomas arising in a benign lymphoepithelial lesion of salivary glands and a patient with anaplastic carcinoma arising in the epithelial islands of the lesion. The fourth patient manifested pseudolymphomatous lymphoreticular hyperplasia in lung and submandibular gland and illustrates the possible multiple organ involvement that may occur in patients with benign lymphoepithelial lesion, even without clinical evidence of concommitant autoimmune disorders.

  11. Facial Skin Lesions Dentists Should Know.

    PubMed

    Sibai, Louna; Kudsi, Zaki

    2015-01-01

    Facial skin lesions are common; patients may present with a.nodule, crack, ulcer or abnormal discoloration of the skin that is not normally present. Ideally, dentists should include face examination in their routine clinical examination. Any suspicious lesion should be referred to a dermatologist as an early diagnosis and treatment could be life-saving. This article will discuss the diagnosis and treatment of common lesions of the face.

  12. Method of forming a ceramic to ceramic joint

    DOEpatents

    Cutler, Raymond Ashton; Hutchings, Kent Neal; Kleinlein, Brian Paul; Carolan, Michael Francis

    2010-04-13

    A method of joining at least two sintered bodies to form a composite structure, includes: providing a joint material between joining surfaces of first and second sintered bodies; applying pressure from 1 kP to less than 5 MPa to provide an assembly; heating the assembly to a conforming temperature sufficient to allow the joint material to conform to the joining surfaces; and further heating the assembly to a joining temperature below a minimum sintering temperature of the first and second sintered bodies. The joint material includes organic component(s) and ceramic particles. The ceramic particles constitute 40-75 vol. % of the joint material, and include at least one element of the first and/or second sintered bodies. Composite structures produced by the method are also disclosed.

  13. The biology of lubricin: near frictionless joint motion.

    PubMed

    Jay, Gregory D; Waller, Kimberly A

    2014-10-01

    Lubricin is a surface-active mucinous glycoprotein secreted in the synovial joint that plays an important role in cartilage integrity. In healthy joints, lubricin molecules coat the cartilage surface, providing boundary lubrication and preventing cell and protein adhesion. Arthropathy occurring in patients with joint trauma, inflammatory arthritis or genetically mediated lubricin deficiencies have insufficient lubricin to prevent damage to articular cartilage. Recent studies in lubricin null joints indicate that lubricin (Prg4) plays a role in preventing damage to the superficial zone and preservation of chondrocytes. Progress in the production of recombinant forms of lubricin and the successes of lubricin supplementation in small animal models identify rhPRG4 as a potential therapeutic for patients with transient lubricin deficiency in the setting of trauma or autoimmune arthritis.

  14. Energy cost of walking with hip joint impairment.

    PubMed

    Gussoni, M; Margonato, V; Ventura, R; Veicsteinas, A

    1990-05-01

    The energy cost of walking was measured in 12 patients (age 39-73 years) with hip joint impairment and 10 healthy controls during unassisted walking (2-6 km.h-1) on a level treadmill surface and on a 5% incline. The energy cost of locomotion in most patients increased up to 50% and 70% during level-surface and uphill walking, respectively. This difference between patients and controls was probably due to the increased external mechanical work. The energy cost of walking, although related to pain experienced during walking but not to hip joint range of motion or to joint status evaluated radiographically, provides an additional variable when defining the conditions of disability and functional impairment in individuals with this pathological condition. [Gussoni M, Margonato V, Ventura R, et al: Energy cost of walking with hip joint impairment.

  15. 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

  16. Matching osteochondritis dissecans lesions in identical twin brothers.

    PubMed

    Richie, Lucas B; Sytsma, Mark J

    2013-09-01

    Osteochondritis dissecans is a disorder of unknown etiology that can result in fragmentation of osteochondral surfaces, most commonly of the knee, shoulder, elbow, and ankle. This may lead to sequelae of pain and an inability to participate in desired activities. Multiple theories exist as to the true cause of the disorder, but none have been fully proven. One such proposed etiology is genetic causation. Familial cases of osteochondritis dissecans are rare, yet these cases offer support to growing evidence that may support a genetic link. This article describes osteochondritis dissecans lesions of the femoral trochlea in monozygotic (identical) twins. Both twins presented with similar symptoms 1 year apart. Neither twin had any clear inciting trauma. Magnetic resonance imaging revealed osteochondral lesions in similar positions of the lateral trochlear of the same knee in both brothers. Osteochondral autograft transfer and tibial tubercle anteromedialization were performed on both patients. An identical postoperative protocol was followed, and recovery with full return to sport was comparable for the brothers. To the authors' knowledge, only 1 other case report exists of osteochondritis dissecans lesions in monozygotic twins. Although debate continues regarding the true etiology of this disorder, cases of identical twins presenting with a similar disease process are highly suggestive of a genetic component and may lead to early identification and treatment of these lesions. Continued research in the area of osteochondritis dissecans and its genetic basis is needed to completely understand this disorder. PMID:24025016

  17. Human papillomavirus DNA in oral mucosal lesions.

    PubMed

    Giovannelli, Lucia; Campisi, Giuseppina; Lama, Anna; Giambalvo, Ornella; Osborn, John; Margiotta, Valerio; Ammatuna, Pietro

    2002-03-15

    This study determined the presence of human papillomavirus (HPV) DNA in oral mucosa cells from 121 patients with different types of oral mucosal lesions (13 squamous cell carcinomas, 59 potentially malignant lesions, 49 benign erosive ulcerative lesions) and from 90 control subjects. HPV DNA was detected by nested polymerase chain reaction, and genotype was determined by DNA sequencing. HPV prevalence was 61.5% in carcinomas, 27.1% in potentially malignant lesions, 26.5% in erosive ulcerative lesions, and 5.5% in control subjects. The risk of malignant or potentially malignant lesions was associated with HPV and was statistically significant. HPV-18 was found in 86.5% of HPV-positive lesions but was not associated with a particular type of lesion and was found in 80% of the HPV-positive control subjects. HPV infection was related to older age but not to sex, smoking, or alcohol use; the presence of lesions in the oral cavity increased the risk of HPV infection.

  18. Histopathological characterization of a Cameron lesion.

    PubMed

    Katz, Jordan; Brar, Sonia; Sidhu, Jagmohan S

    2012-10-01

    Cameron lesions are linear erosions located at the neck of a hiatal hernia (HH) in patients with a large HH. The prevalence has been seen in up to 5% of patients with HH who undergo esophagogastroduodenoscopy, and they can be associated with overt gastrointestinal bleeding or anemia. These lesions occur due to vascular compression by the diaphragm in a large sliding HH. Histopathologic changes seen in the biopsy tissue of a Cameron lesion are due to ischemia, but this ischemia is reversible with treatment of HH. The existence of this entity and the histopathologic picture of a Cameron lesion is not well known to pathologists, and therefore, a microscopic picture of a Cameron lesion can be easily confused with ischemic gastritis. Ischemic gastritis is the result of atherosclerosis, usually seen in older people, unrelated to HH, and is not easily reversible. The authors received a gastric biopsy of a hiatal hernia without any associated clinical diagnosis of a Cameron lesion conveyed to the pathologist. This biopsy tissue showed ischemic changes in the gastric mucosa on microscopic examination. Diagnosis of ischemic gastritis was considered but ruled out after the case was discussed with the gastroenterologist. The correct diagnosis was made once the clinical diagnosis of HH with Cameron lesion (ie, a vertical red erosion) was made known to the pathologist. By reporting this case, the authors aim to increase awareness of Cameron lesion among pathologists so that they ask about the presence of a Cameron lesion before making the diagnosis of ischemic gastritis.

  19. Polypoid Lesions of the Gallbladder in Children

    PubMed Central

    Beneck, Debra; Bostwick, Howard E.

    1997-01-01

    Polypoid lesions of the gallbladder in children are rare. We report a case of a gallbladder polyp in a 14-year-old boy who presented with recurrent right upper quadrant abdominal pain. Ultrasound examination of the abdomen revealed a polypoid lesion of the gallbladder. His symptoms resolved after laparoscopic cholecystectomy. Histological examination of the gallbladder demonstrated a benign adenomatous polyp. Although the experience with polypoid lesions of the gallbladder in children is limited, we currently recommend cholecystectomy because these lesions are associated with acalculous cholecystitis, and because their long-term effects are unknown. PMID:9876680

  20. Visual evoked potentials in occipital lobe lesions.

    PubMed

    Streletz, L J; Bae, S H; Roeshman, R M; Schatz, N J; Savino, P J

    1981-02-01

    Recording of visual evoked potentials (VEPs) to pattern reversal is considered to be a reliable diagnostic procedure for examining patients with anterior visual pathway lesions (optic nerves and chiasm). Less consistent results have been reported in studies of more posterior lesions. The VEPs were recorded in 20 patients with occipital lobe lesions. A maximal VEP response (P94) was recorded at the scalp electrodes situated over the involved occipital lobes and contralateral to the hemianoptic visual field defect, indicating a positive correlation of unilateral occipital lobe lesions, homonymous visual field loss, and the VEP abnormality.