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Sample records for crystal deposition disease

  1. Bilateral Olecranon Bursitis – A Rare Clinical presentation of Calcium Pyrophosphate Crystal Deposition Disease

    PubMed Central

    Patel, Jignesh; Girishkumar; Mruthyunjaya; Rupakumar, C. S

    2014-01-01

    Introduction: Calcium pyrophosphate crystal deposition disease (CPPD) is the most common form of crystal arthropathy second only to gout. Common clinical presentation is an acute monoarticular arthritis commonly occurring in knee joints. We presented a case of bilateral olecranon bursitis in a calcium pyrophosphate crystal deposition disease. Case Report: A 42-year-old female patient is presented with golf ball sized painless swellings in the posterior aspect of her elbows. Elbow joints were clinically normal except for restriction of terminal flexion. X-ray showed mild erosion at the tip of olecranon. Excision biopsy of the swelling showed positive birefringent calcium pyrophosphate dehydrate crystals on the inner wall of the specimen on polarized light microscopy. Conclusion: Bilateral olecranon bursitis may be part of the extraarticular manifestations of calcium pyrophosphate dihydrate crystal deposition disease with good prognosis following in toto bursa excision. PMID:27298934

  2. The "crowned dens" revisited: imaging findings in calcium crystal deposition diseases around the odontoid.

    PubMed

    Viana, Sergio L; Fernandes, João L; De Araújo Coimbra, Pablo P; De Mendonça, José L F; Freitas, Flávia M O; De Carvalho Barbosa Viana, Maria A

    2010-10-01

    The so-called "crowned dens" is a peculiar manifestation of calcium crystal deposition diseases, either caused by calcium pyrophosphate dihydrate or caused by calcium hydroxiapatite crystals, characterized by the presence of calcific deposits around the odontoid, often showing a crown-like configuration on imaging. It has protean clinical and radiological pictures, and care should be taken to avoid misinterpretation and diagnostic errors. Although asymptomatic in many patients, this entity may present as a predominantly algic or febrile condition, and in some cases, signs of compression of the spinal cord may be the major complaint. The detection of calcifications in the periodontoid tissues is the key to the diagnosis, erosive osseous changes, and variably calcified soft-tissue masses being occasionally associated. Computed tomography is the most important imaging study to be performed in this setting. PMID:19344369

  3. A Rare Case of Tumoral Calcium Pyrophosphate Dihydrate Crystal Deposition Disease of the Wrist Joint

    PubMed Central

    Nakamura, Osamu; Kaji, Yoshio; Yamagami, Yoshiki; Yamaguchi, Kounosuke; Nishimura, Hideki; Fukuoka, Natsuko; Yamamoto, Tetsuji

    2015-01-01

    Introduction. Tumoral calcium pyrophosphate dihydrate (CPPD) crystal deposition disease (CPPDCD), also known as tophaceous calcium pyrophosphate deposition disease (CPDD), is a tumorlike lesion, and it should be distinguished from usual CPDD that causes severe joint inflammation and arthralgia. A case of tumoral CPPDCD of the wrist joint that required differentiation from synovial osteochondromatosis is described. Case Presentation. The patient was a 78-year-old woman with a 5-year history of nodular lesions at the right wrist that had gradually increased in size. An excisional biopsy and a histological examination of the excised nodular lesions by hematoxylin and eosin (H&E) staining were performed, demonstrating numerous polarizable, rhabdoid, and rectangular crystals, surrounded by fibroblasts, macrophages, and foreign body-type giant cells, consistent with tumoral CPPDCD. Conclusion. Tumoral CPPDCD, especially at the wrist joint, is rare, and, to the best of our knowledge, only 2 articles have been published. This case seems to need further follow-up for recurrence, because tumoral CPPDCD may recur after complete or incomplete surgical excision. PMID:26783477

  4. Posterior C1-C2 calcium pyrophosphate dihydrate crystal deposition disease.

    PubMed

    Ng, Isaac Bing-Yi; Arkun, Knarik; Riesenburger, Ron I

    2016-01-01

    Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease rarely occurs in the posterior aspect of the craniocervical junction (CCJ). To the best of our knowledge, there have been only 2 previously reported cases of patients with posterior CPPD lesions in this region that have led to cervical myelopathy. We report the case of a 70-year-old man presenting with neck pain and cervical myelopathy with multilevel stenosis from C1-C6. The stenosis was worst at C1-C2, secondary to compression by a CPPD lesion posterior to the spinal cord. The patient underwent a C2-C6 laminectomy and fusion with resection of the CPPD lesion. In this report, we discuss the patient and present a novel theory to explain the preponderance of CPPD lesions in the CCJ occurring anteriorly and not posteriorly to the spinal cord. PMID:26976840

  5. Diagnosis and clinical manifestations of calcium pyrophosphate and basic calcium phosphate crystal deposition diseases.

    PubMed

    Ea, Hang-Korng; Lioté, Frédéric

    2014-05-01

    Basic calcium phosphate and pyrophosphate calcium crystals are the 2 main calcium-containing crystals that can deposit in all skeletal tissues. These calcium crystals give rise to numerous manifestations, including acute inflammatory attacks that can mimic alarming and threatening differential diagnoses, osteoarthritis-like lesions, destructive arthropathies, and calcific tendinitis. Awareness of uncommon localizations and manifestations such as intraspinal deposition (eg, crowned dens syndrome, tendinitis of longus colli muscle, massive cervical myelopathy compression) prevents inappropriate procedures and cares. Coupling plain radiography, ultrasonography, computed tomography, and synovial fluid analysis allow accurate diagnosis by directly or indirectly identifying the GRAAL of microcrystal-related symptoms. PMID:24703344

  6. [Calcium pyrophosphate dihydrate deposition disease].

    PubMed

    Koitschev, C; Kaiserling, E; Koitschev, A

    2003-08-01

    Calcium pyrophosphate dihydrate deposition disease (CPPD) of the temporomandibular joint is rare. The disorder is characterized by the presence of crystal deposits within the affected joint. The deposition of crystals in adjacent soft tissue may lead to the formation of pseudotumors. This form of the disease is called tophaceous pseudogout and typically affects the temporomandibular joint. It is difficult to differentiate the disease, particularly from malignant tumors, on the clinical and radiographic findings alone. The diagnosis is based on histological identification of the calcium pyrophosphate crystals. We present an unusually advanced case of tophaceous pseudogout of the temporomandibular joint. The etiology, clinical and diagnostic criteria as well as treatment options are discussed on the basis of our own experience and a review of the literature. PMID:12942180

  7. Update on Oxalate Crystal Disease

    PubMed Central

    Lorenz, Elizabeth C.; Michet, Claude J.; Milliner, Dawn S.; Lieske, John C.

    2013-01-01

    Oxalate arthropathy is a rare cause of arthritis characterized by deposition of calcium oxalate crystals within synovial fluid. This condition typically occurs in patients with underlying primary or secondary hyperoxaluria. Primary hyperoxaluria constitutes a group of genetic disorders resulting in endogenous overproduction of oxalate, whereas secondary hyperoxaluria results from gastrointestinal disorders associated with fat malabsorption and increased absorption of dietary oxalate. In both conditions oxalate crystals can deposit in the kidney leading to renal failure. Since oxalate is primarily renally eliminated, it accumulates throughout the body in renal failure, a state termed oxalosis. Affected organs can include bones, joints, heart, eyes and skin. Since patients can present with renal failure and oxalosis before the underlying diagnosis of hyperoxaluria has been made, it is important to consider hyperoxaluria in patients who present with unexplained soft tissue crystal deposition. The best treatment of oxalosis is prevention. If patients present with advanced disease, treatment of oxalate arthritis consists of symptom management and control of the underlying disease process. PMID:23666469

  8. The prevalence of chondrocalcinosis (CC) of the acromioclavicular (AC) joint on chest radiographs and correlation with calcium pyrophosphate dihydrate (CPPD) crystal deposition disease

    PubMed Central

    Carrera, Guillermo; Baynes, Keith; Mautz, Alan; DuBois, Melissa; Cerniglia, Ross; Ryan, Lawrence M.

    2016-01-01

    Digital imaging combined with picture archiving and communication system (PACS) access allows detailed image retrieval and magnification. Calcium pyrophosphate dihydrate (CPPD) crystals preferentially deposit in fibrocartilages, the cartilage of the acromioclavicular (AC) joint being one such structure. We sought to determine if examination of the AC joints on magnified PACS imaging of chest films would be useful in identifying chondrocalcinosis (CC). Retrospective radiographic readings and chart reviews involving 1,920 patients aged 50 or more who had routine outpatient chest radiographs over a 4-month period were performed. Knee radiographs were available for comparison in 489 patients. Medical records were reviewed to abstract demographics, chest film reports, and diagnoses. AC joint CC was identified in 1.1 % (21/1,920) of consecutive chest films. Patients with AC joint CC were 75 years of age versus 65.4 in those without CC (p<0.0002). Four hundred eighty-nine patients had knee films. Six of these patients had AC joint CC, and of these, five also had knee CC (83 %). Of the 483 without AC joint CC, 62 (12 %) had knee CC (p=0.002). Patients with AC joint CC were more likely to have a recorded history of CPPD crystal deposition disease than those without AC joint CC (14 versus 1 %, p=0.0017). The prevalence of AC joint CC increases with age and is associated with knee CC. A finding of AC joint CC should heighten suspicion of pseudogout or secondary osteoarthritis in appropriate clinical settings and, in a young patient, should alert the clinician to the possibility of an associated metabolic condition. PMID:23609408

  9. Chemical vapor deposition of graphene single crystals.

    PubMed

    Yan, Zheng; Peng, Zhiwei; Tour, James M

    2014-04-15

    As a two-dimensional (2D) sp(2)-bonded carbon allotrope, graphene has attracted enormous interest over the past decade due to its unique properties, such as ultrahigh electron mobility, uniform broadband optical absorption and high tensile strength. In the initial research, graphene was isolated from natural graphite, and limited to small sizes and low yields. Recently developed chemical vapor deposition (CVD) techniques have emerged as an important method for the scalable production of large-size and high-quality graphene for various applications. However, CVD-derived graphene is polycrystalline and demonstrates degraded properties induced by grain boundaries. Thus, the next critical step of graphene growth relies on the synthesis of large graphene single crystals. In this Account, we first discuss graphene grain boundaries and their influence on graphene's properties. Mechanical and electrical behaviors of CVD-derived polycrystalline graphene are greatly reduced when compared to that of exfoliated graphene. We then review four representative pathways of pretreating Cu substrates to make millimeter-sized monolayer graphene grains: electrochemical polishing and high-pressure annealing of Cu substrate, adding of additional Cu enclosures, melting and resolidfying Cu substrates, and oxygen-rich Cu substrates. Due to these pretreatments, the nucleation site density on Cu substrates is greatly reduced, resulting in hexagonal-shaped graphene grains that show increased grain domain size and comparable electrical properties as to exfoliated graphene. Also, the properties of graphene can be engineered by its shape, thickness and spatial structure. Thus, we further discuss recently developed methods of making graphene grains with special spatial structures, including snowflakes, six-lobed flowers, pyramids and hexagonal graphene onion rings. The fundamental growth mechanism and practical applications of these well-shaped graphene structures should be interesting topics and

  10. Crystallization behavior of vapor-deposited hexanitroazobenzene (HNAB) films

    NASA Astrophysics Data System (ADS)

    Knepper, Robert; Tappan, Alexander; Alam, Kathy; Rodriguez, Mark

    2011-06-01

    Hexanitroazobenzene is an interesting material for microenergetic research on explosive behavior at sub-millimeter geometries due to its small critical thickness for detonation and its chemical stability at temperatures above its melting point, which allows for fast deposition rates. HNAB films have been observed to deposit in an amorphous state, provided the substrate remains sufficiently cool during deposition. These amorphous films crystallize over a period of hours to weeks, depending on the ambient temperature, to a structure consisting of primarily HNAB-II crystallites. Several films were deposited to a thickness of ~100 microns and subjected to a variety of temperatures ranging from 30 -- 75°C to observe crystallization behavior. Crystallization rates were observed using time-lapse optical microscopy and were also characterized using scanning electron microscopy, atomic force microscopy, x-ray diffraction, and Raman spectroscopy at various stages of crystallization.

  11. Crystallization behavior of vapor-deposited hexanitroazobenzene (HNAB) films

    NASA Astrophysics Data System (ADS)

    Knepper, Robert; Tappan, Alexander S.; Rodriguez, Mark A.; Alam, M. Kathleen; Martin, Laura; Marquez, Michael P.

    2012-03-01

    Vapor-deposited hexanitroazobenzene (HNAB) has been shown to form an amorphous structure as-deposited that crystallizes over a period ranging from several hours to several weeks, depending on the ambient temperature. Raman spectroscopy and x-ray diffraction were used to identify three distinct phases during the crystallization process: the as-deposited amorphous structure, the HNAB-II crystal structure, and an as-yet unidentified crystal structure. Significant qualitative differences in the nucleation and growth of the crystalline phases were observed between 65°C and 75°C. While the same two polymorphs form in all cases, significant variation in the quantities of each phase was observed as a function of temperature.

  12. Hydroxyapatite deposition disease of the joint.

    PubMed

    Molloy, Eamonn S; McCarthy, Geraldine M

    2003-06-01

    Basic calcium phosphate (BCP) crystals include partially carbonate-substituted hydroxyapatite, octacalcium phosphate, and tricalcium phosphate. They may form deposits, which are frequently asymptomatic but may give rise to a number of clinical syndromes including calcific periarthritis, Milwaukee shoulder syndrome, and osteoarthritis, in and around joints. Recent data suggest that magnesium whitlockite, another form of BCP, may play a pathologic role in arthritis. Data from the past year have provided further understanding of the mechanisms by which BCP crystals induce inflammation and degeneration. There remains no specific treatment to modify the effects of BCP crystals. Although potential drugs are being identified as the complex pathophysiology of BCP crystals is unraveled, much work remains to be done in order to translate research advances to date into tangible clinical benefits. PMID:12744814

  13. Ultrasonically assisted deposition of colloidal crystals

    SciTech Connect

    Wollmann, Sabine; Patel, Raj B.; Wixforth, Achim; Krenner, Hubert J.

    2014-07-21

    Colloidal particles are a versatile physical system which have found uses across a range of applications such as the simulation of crystal kinetics, etch masks for fabrication, and the formation of photonic band-gap structures. Utilization of colloidal particles often requires a means to produce highly ordered, periodic structures. One approach is the use of surface acoustic waves (SAWs) to direct the self-assembly of colloidal particles. Previous demonstrations using standing SAWs were shown to be limited in terms of crystal size and dimensionality. Here, we report a technique to improve the spatial alignment of colloidal particles using traveling SAWs. Through control of the radio frequency power, which drives the SAW, we demonstrate enhanced quality and dimensionality of the crystal growth. We show that this technique can be applied to a range of particle sizes in the μm-regime and may hold potential for particles in the sub-μm-regime.

  14. Fluidized-Bed Deposition Of Single-Crystal Silicon

    NASA Technical Reports Server (NTRS)

    Hsu, George C.; Rohatgi, Naresh K.

    1988-01-01

    Uniformly thin single-crystal films of silicon produced by modification of fluidized-bed-reactor technique producing polysilicon by chemical vapor deposition. Proposed for silicon wafers for flat-plate solar arrays and results in different structural and electronic properties in deposition layer desirable for specific microelectronic or solar-cell processing. In process deposition occurs on silicon wafers, kept individually at temperatures above 1,000 degree C. Heated wafers held in unheated and minimally-agitated-fluidized bed of silicon particles and in low concentration of silane.

  15. Electrochemical deposition of silver crystals aboard Skylab 4

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.; Facemire, B. R.; Johnston, M. H.; Gates, D. W.

    1976-01-01

    Silver crystals were grown aboard Skylab 4 by an electro-chemical reaction and subsequently returned to earth for comparison with crystals grown at 1- and 5-g. Both the Skylab and earth-grown crystals show a variety of structures. Certain tendencies in structure dependency on gravity level, however, can be discerned. In addition, downward growing dendrite streamers; upward growing chunky crystal streamers; growth along an air/liquid interface; and ribbon, film, and fiber crystal habits were observed in experiments conducted on the ground with solutions of varying concentrations. It was also observed that the crystal structures of space and ground electro-deposited silver crystals were very similar to the structures of germanium selenide and germanium telluride crystals grown in space and on the ground by a vapor transport technique. Consideration of the data leads to the conclusions that: (1) the rate of electrochemical displacement of silver ions from a 5 percent aqueous solution by copper is predominantly diffussion controlled in space and kinetically controlled in 1- and higher-g because of augmentation of mass transport by convection; (2) downward and upward crystal streamers are the result of gravity-driven convection, the flow patterns of which can be delineated. Lateral growths along an air/liquid interface are the result of surface-tension-driven convection, the pattern of which also can be delineated; (3) electrolysis in space or low-g environments can produce either dendritic crystals with more perfect microcrystalline structures or massive, single crystals with fewer defects than those grown on ground or at higher g-levels. Ribbons or films of space-grown silicon crystals would find a ready market for electronic substrate and photocell applications. Space-grown dendritic, metal crystals present the possibility of unique catalysts. Large perfect crystals of various materials are desired for a number of electronic and optical applications; and (4) vapor

  16. Crystal Nucleation in Plasma Deposited Dlc Coatings during Annealing

    NASA Astrophysics Data System (ADS)

    Chaliampalias, D.; Pavlidou, E.; Psyllaki, P.; Chrissafis, K.; Vourlias, G.

    2010-01-01

    Diamond-like carbon (DLC) films, hard carbon coatings, with unique physical and mechanical properties which approach those of natural diamond, such as high hardness, low coefficient of friction and chemical inertness. In several applications, heavy loads and high friction forces are generated and lead to local temperature increase. In such cases these coatings must be thermal stable and with enhanced high temperature oxidation resistance in order to be good candidates for wear protection of metallic components. In the present study a radio frequency plasma deposition system was used for the deposition of 2 μm-thick amorphous DLC coatings onto AISI D2 substrates. The as deposited DLC covered samples were dense, homogeneous and well bonded to the substrate, while no cracks were observed. In order to study the thermal stability of the coatings' DLC nature, in-situ Transmission Electron Microscopic (TEM) observations were carried out during slow annealing of the specimen in the microscope vacuum chamber, as well as thermo-gravimetric (TG) measurements in argon atmosphere, up to 800° C. The first crystallites appeared within the DLC amorphous matrix at about 450° C as surface crystallization, while the mass crystallization started at 600° C as the TG measurements indicated. Finally, the nucleation was completed at 700° C. The oxidation results, performed from ambient temperature up to 1000° C, showed that DLC covered coupons are remarkably resistant as their mass gain was significantly lower than that of the uncovered substrates.

  17. Generation of fluorescent nanodroplets of liquid crystal utilizing electrospray deposition

    NASA Astrophysics Data System (ADS)

    Ohdaira, Yasuo; Oka, Hisaki; Shinbo, Kazunari; Baba, Akira; Kato, Keizo; Kaneko, Futao

    2016-02-01

    Fluorescent nanodroplets of liquid crystal (LC) were generated by the electrospray deposition of LC solvent containing rhodamine 6G (Rh6G) dye molecules. The shape and density of the nanodroplets strongly depended on the concentration of LC diluted with ethanol solution. The fluorescent spectra from the Rh6G molecules in LC nanodroplets were obviously blue-shifted compared with the LC films of the bulk state. Furthermore, the LC nanodroplets were dispersed on a metallic nanograting formed by optically modifying an azobenzene thin-film layer under the metallic film. The nanodroplets were size-selectively aligned on the metallic nanograting.

  18. Aluminum citrate prevents renal injury from calcium oxalate crystal deposition.

    PubMed

    Besenhofer, Lauren M; Cain, Marie C; Dunning, Cody; McMartin, Kenneth E

    2012-12-01

    Calcium oxalate monohydrate crystals are responsible for the kidney injury associated with exposure to ethylene glycol or severe hyperoxaluria. Current treatment strategies target the formation of calcium oxalate but not its interaction with kidney tissue. Because aluminum citrate blocks calcium oxalate binding and toxicity in human kidney cells, it may provide a different therapeutic approach to calcium oxalate-induced injury. Here, we tested the effects of aluminum citrate and sodium citrate in a Wistar rat model of acute high-dose ethylene glycol exposure. Aluminum citrate, but not sodium citrate, attenuated increases in urea nitrogen, creatinine, and the ratio of kidney to body weight in ethylene glycol-treated rats. Compared with ethylene glycol alone, the addition of aluminum citrate significantly increased the urinary excretion of both crystalline calcium and crystalline oxalate and decreased the deposition of crystals in renal tissue. In vitro, aluminum citrate interacted directly with oxalate crystals to inhibit their uptake by proximal tubule cells. These results suggest that treating with aluminum citrate attenuates renal injury in rats with severe ethylene glycol toxicity, apparently by inhibiting calcium oxalate's interaction with, and retention by, the kidney epithelium. PMID:23138489

  19. Aluminum Citrate Prevents Renal Injury from Calcium Oxalate Crystal Deposition

    PubMed Central

    Besenhofer, Lauren M.; Cain, Marie C.; Dunning, Cody

    2012-01-01

    Calcium oxalate monohydrate crystals are responsible for the kidney injury associated with exposure to ethylene glycol or severe hyperoxaluria. Current treatment strategies target the formation of calcium oxalate but not its interaction with kidney tissue. Because aluminum citrate blocks calcium oxalate binding and toxicity in human kidney cells, it may provide a different therapeutic approach to calcium oxalate-induced injury. Here, we tested the effects of aluminum citrate and sodium citrate in a Wistar rat model of acute high-dose ethylene glycol exposure. Aluminum citrate, but not sodium citrate, attenuated increases in urea nitrogen, creatinine, and the ratio of kidney to body weight in ethylene glycol–treated rats. Compared with ethylene glycol alone, the addition of aluminum citrate significantly increased the urinary excretion of both crystalline calcium and crystalline oxalate and decreased the deposition of crystals in renal tissue. In vitro, aluminum citrate interacted directly with oxalate crystals to inhibit their uptake by proximal tubule cells. These results suggest that treating with aluminum citrate attenuates renal injury in rats with severe ethylene glycol toxicity, apparently by inhibiting calcium oxalate’s interaction with, and retention by, the kidney epithelium. PMID:23138489

  20. The influence of a small amount of maleic acid on crystal deposition phenomena of methacrylic acid in melt crystallization

    NASA Astrophysics Data System (ADS)

    Hino, Tomomichi; Kato, Shinpei; Takiyama, Hiroshi

    2013-06-01

    Crystal deposition phenomena were investigated in the suspension melt crystallization of an organic acid. Methacrylic acid was used as the target substance, a certain amount of methanol was used as the solvent, and the effect of a small amount of maleic acid by-produced in methacrylic acid synthesis was focused on. Batch crystallizations were carried out on a laboratory scale using various concentrations of maleic acid. In the presence of maleic acid, a certain deviation from equilibrium of the pure binary system was observed in the final composition of mother liquor. Moreover, nevertheless the final temperature in the crystallizer was same, the amount of crystal deposition in the presence of maleic acid was smaller than in the absence of maleic acid. It was suggested that the final amount of crystal deposition decreased in the presence of maleic acid. Additionally, it was observed that the obtained crystal size was smaller in the presence of maleic acid. Hence, a simplified kinetic analysis of crystal deposition rates was carried out to make the effect of maleic acid clear. Consequently, it was suggested that the cause of the above-mentioned phenomena was the existence of the maleic acid concentration dependent pseudo-liquidus line.

  1. Single crystal diamond detectors grown by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Tuvè, C.; Angelone, M.; Bellini, V.; Balducci, A.; Donato, M. G.; Faggio, G.; Marinelli, M.; Messina, G.; Milani, E.; Morgada, M. E.; Pillon, M.; Potenza, R.; Pucella, G.; Russo, G.; Santangelo, S.; Scoccia, M.; Sutera, C.; Tucciarone, A.; Verona-Rinati, G.

    2007-01-01

    The detection properties of heteropitaxial (polycrystalline, pCVD) and homoepitaxial (single crystal, scCVD) diamond films grown by microwave chemical vapor deposition (CVD) in the Laboratories of Roma "Tor Vergata" University are reported. The pCVD diamond detectors were tested with α-particles from different sources and 12C ions produced by 15 MV Tandem accelerator at Southern National Laboratories (LNS) in Catania (Italy). pCVDs were also used to monitor 14 MeV neutrons produced by the D-T plasma at Joint European Torus (JET), Culham, U.K. The limit of pCVDs is the poor energy resolution. To overcome this problem, we developed scCVD diamonds using the same reactor parameters that optimized pCVD diamonds. scCVD were grown on a low cost (1 0 0) HPHT single crystal substrate. A detector 110 μm thick was tested under α-particles and under 14 MeV neutron irradiation. The charge collection efficiency spectrum measured under irradiation with a triple α-particle source shows three clearly resolved peaks, with an energy resolution of about 1.1%. The measured spectra under neutron irradiation show a well separated C(n,α0)9Be12 reaction peak with an energy spread of 0.5 MeV for 14.8 MeV neutrons and 0.3 MeV for 14.1 MeV neutrons, which are fully compatible with the energy spread of the incident neutron beams.

  2. [Amyloid deposition in chronic joint disease].

    PubMed

    Saitou, H

    1994-07-01

    As a screening procedure for the detection of amyloidosis secondary to rheumatoid arthritis, abdominal subcutaneous fat tissues were aspirated, and were examined after Congo red staining by polarized microscopy. Positive amyloid deposits were found in 7.1 percent of the rheumatoid patients, and the amyloid in the subcutaneous fat was determined to be AA type by permanganate oxidation. The occurrence of amyloid deposition was significantly correlated with the duration of the articular symptoms, the progression of the class, and also with proteinuria. Additionally the joint capsules, including the synovium and synovial fluid sediment, from patients with rheumatoid arthritis and osteoarthritis were examined for amyloid deposition. Deposits of amyloid in the hip and knee joints were found more frequently in those with rheumatoid arthritis than in those with osteoarthritis. In osteoarthritis, the frequency of amyloid deposition tended to increase with advancing age. However these amyloid deposits in the joint structure were discovered to be resistant to permanganate oxidation. Therefore it was suspected that these amyloid deposits were of a type different from AA amyloid. PMID:8071579

  3. Vacuum Ultraviolet Radiation Desorption of Molecular Contaminants Deposited on Quartz Crystal Microbalances

    NASA Technical Reports Server (NTRS)

    Albyn, Keith; Burns, Dewitt

    2006-01-01

    Recent quartz crystal microbalance measurements made in the Marshall Space Flight Center, Photo-Deposition Facility, for several materials, recorded a significant loss of deposited contaminants when the deposition surface of the microbalance was illuminated by a deuterium lamp. These measurements differ from observations made by other investigators in which the rate of deposition increased significantly when the deposition surface was illuminated with vacuum ultraviolet radiation. These observations suggest that the accelerated deposition of molecular contaminants on optically sensitive surfaces is dependant upon the contaminant being deposited and must be addressed during the materials selection process by common material screening techniques.

  4. Laboratory studies on the uptake of aromatic hydrocarbons by ice crystals during vapor depositional crystal growth

    NASA Astrophysics Data System (ADS)

    Fries, Elke; Starokozhev, Elena; Haunold, Werner; Jaeschke, Wolfgang; Mitra, Subir K.; Borrmann, Stephan; Schmidt, Martin U.

    Uptake of aromatic hydrocarbons (AH) by ice crystals during vapor deposit growth was investigated in a walk-in cold chamber at temperatures of 242, 251, and 260 K, respectively. Ice crystals were grown from ambient air in the presence of gaseous AH namely: benzene (C 6H 6), toluene (methylbenzene, C 7H 8), the C 8H 10 isomers ethylbenzene, o-, m-, p-xylene (dimethylbenzenes), the C 9H 12 isomers n-propylbenzene, 4-ethyltoluene, 1,3,5-trimethylbenzene (1,3,5-TMB), 1,2,4-trimethylbenzene (1,2,4-TMB), 1,2,3-trimethylbenzene (1,2,3-TMB), and the C 10H 14 compound tert.-butylbenzene. Gas-phase concentrations calculated at 295 K were 10.3-20.8 μg m -3. Uptake of AH was detected by analyzing vapor deposited ice with a very sensitive method composed of solid-phase micro-extraction (SPME), followed by gas chromatography/mass spectrometry (GC/MS). Ice crystal size was lower than 1 cm. At water vapor extents of 5.8, 6.0 and 8.1 g m -3, ice crystal shape changed with decreasing temperatures from a column at a temperature of 260 K, to a plate at 251 K, and to a dendrite at 242 K. Experimentally observed ice growth rates were between 3.3 and 13.3×10 -3 g s -1 m -2 and decreased at lower temperatures and lower value of water vapor concentration. Predicted growth rates were mostly slightly higher. Benzene, toluene, ethylbenzene, and xylenes (BTEX) were not detected in ice above their detection limits (DLs) of 25 pg g ice-1 (toluene, ethylbenzene, xylenes) and 125 pg g ice-1 (benzene) over the entire temperature range. Median concentrations of n-propylbenzene, 4-ethyltoluene, 1,3,5-TMB, tert.-butylbenzene, 1,2,4-TMB, and 1,2,3-TMB were between 4 and 176 pg g ice-1 at gas concentrations of 10.3-10.7 μg m -3 calculated at 295 K. Uptake coefficients ( K) defined as the product of concentration of AH in ice and density of ice related to the product of their concentration in the gas phase and ice mass varied between 0.40 and 10.23. K increased with decreasing temperatures. Values of

  5. On the origin of fiber calcite crystals in moonmilk deposits.

    PubMed

    Cañaveras, Juan Carlos; Cuezva, Soledad; Sanchez-Moral, Sergio; Lario, Javier; Laiz, Leonila; Gonzalez, Juan Miguel; Saiz-Jimenez, Cesareo

    2006-01-01

    In this study, we show that moonmilk subaerial speleothems in Altamira Cave (Spain) consist of a network of fiber calcite crystals and active microbial structures. In Altamira moonmilks, the study of the typology and distribution of fiber crystals, extracellular polymeric substances, and microorganisms allowed us to define the initial stages of fiber crystal formation in recent samples as well as the variations in the microstructural arrangement in more evolved stages. Thus, we have been able to show the existence of a relationship among the different types of fiber crystals and their origins. This allowed us to outline a model that illustrates the different stages of formation of the moonmilk, developed on different substrata, concluding that microbes influence physicochemical precipitation, resulting in a variety of fiber crystal morphologies and sizes. PMID:16240102

  6. Electrochemical Quartz Crystal Microbalance Monitoring of the Cyclic Voltammetric Deposition of Polyaniline

    ERIC Educational Resources Information Center

    Xie, Qingji; Li, Zhili; Deng, Chunyan; Liu, Meiling; Zhang, Youyu; Ma, Ming; Xia, Shaoxi; Xiao, Xiaoming; Yin, Dulin; Yao, Shouzhuo

    2007-01-01

    A real-time, labeled-free and nanogram-sensitive mass sensor, electrochemical quartz crystal microbalance (EQCM) is used to monitor a cyclic voltammetric deposition of polyaniline (PANI). The results determined that the efficiency for PANI deposition and the anion-doping ratio is calculated in one single cyclic voltammetric.

  7. The Role of ANK in Calcium Pyrophosphate Deposition Disease.

    PubMed

    Mitton-Fitzgerald, Elizabeth; Gohr, Claudia M; Bettendorf, Brittany; Rosenthal, Ann K

    2016-05-01

    The protein product of the progressive ankylosis gene, known as ANK, is a 492-amino acid multi-pass transmembrane protein. This protein is critical for the regulation of pyrophosphate, and gain of function ANK mutations is associated with calcium pyrophosphate deposition disease. Much about the structure, function, and regulation of ANK remain unstudied. This review of the current literature examines recent contributions to our understanding of ANK. We focus on new work on the function, binding partners, and regulators of ANK. A more complete understanding of this important protein may help to identify future therapeutic targets for the treatment of calcium pyrophosphate deposition disease. PMID:27032788

  8. Unusual Presentation of Light Chain Deposition Disease: A Case Report

    PubMed Central

    Uppal, Mayank; Amitabh, Vindu; Agrawal, Usha

    2016-01-01

    Light Chain Deposition Disease (LCDD) is a rare disease characterized by deposition of monoclonal non-amyloid light chains in multiple organs. We report an unusual histologic manifestation of LCDD in a 55-year-old female patient, who presented with nephrotic syndrome and an increased serum creatinine. This case of LCDD had features of cast nephropathy on biopsy which is diagnostic of myeloma kidney, when the patient was clinically asymptomatic. Serum electrophoresis showed no abnormal band. There was no other evidence of a B-cell clonal disorder or amyloidosis. Following chemotherapy, improvement in renal function correlated with a reduction in circulating light-chain levels. PMID:27437235

  9. Low-temperature crystallization of TiO2 films by sputter deposition

    NASA Astrophysics Data System (ADS)

    Taga, Yasunori; Yamada, Naoomi

    2010-04-01

    Crystalline TiO2 film was formed on PET(polyethlene terephthalate) film by radio frequency sputter deposition method using a sintered TiO2 target by adding H2O gas to Ar gas for sputtering. X-ray diffraction analysis revealed that the crystal structure of the film of 100 nm thick was confirmed to be anatase crystallites of TiO2. In order to elucidate the mechanism of low temperature crystallization thus observed, direct measurement of surface temperature of growing films during sputter deposition was carried out by two methods of an infrared thermometer from the outside of vacuum chamber and a thermocouple attached to the growing film surface. Upon the beginning of sputter deposition in Ar gas, film temperature increased rapidly and became constant at 120°C after 30 min. Addition of H2O gas to Ar gas for sputtering resulted in further increase in film temperature and reached to 230 °C depending on the deposition conditions. Furthermore, photocatalytic performance of decomposition of methylene blue was examined to be enhanced remarkably as a result of crystallization of the film. It was concluded that low temperature crystallization of TiO2 film by sputter deposition was explained in terms of local heating of thin shallow surface region of growing film by kinetic energy deposition of sputtered particles.

  10. Crystallization kinetics of GeTe phase-change thin films grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Sun, Xinxing; Thelander, Erik; Gerlach, Jürgen W.; Decker, Ulrich; Rauschenbach, Bernd

    2015-07-01

    Pulsed laser deposition was employed to the growth of GeTe thin films on Silicon substrates. X-ray diffraction measurements reveal that the critical crystallization temperature lies between 220 and 240 °C. Differential scanning calorimetry was used to investigate the crystallization kinetics of the as-deposited films, determining the activation energy to be 3.14 eV. Optical reflectivity and in situ resistance measurements exhibited a high reflectivity contrast of ~21% and 3-4 orders of magnitude drop in resistivity of the films upon crystallization. The results show that pulsed laser deposited GeTe films can be a promising candidate for phase-change applications.

  11. Chemical Vapor Deposition of Large-Sized Hexagonal WSe₂ Crystals on Dielectric Substrates.

    PubMed

    Chen, Jianyi; Liu, Bo; Liu, Yanpeng; Tang, Wei; Nai, Chang Tai; Li, Linjun; Zheng, Jian; Gao, Libo; Zheng, Yi; Shin, Hyun Suk; Jeong, Hu Young; Loh, Kian Ping

    2015-11-01

    High-quality large-sized hexagoal WSe2 crystals can be grown on dielectric substrates using atmospheric chemical vapor deposition in the presence of hydrogen gas. These hexagonal crystals (lateral width >160 um) have a carrier mobility of 100 cm(2) V(-1) s(-1) and a photoresponsivity of ≈1100 mA W(-1), which is comparable to that of exfoliated flakes. PMID:26414106

  12. The Response of a Quartz Crystal Microbalance to a Liquid Deposit

    NASA Technical Reports Server (NTRS)

    Glassford, A. P. M.

    1977-01-01

    A theory was developed for predicting the loss of response of a QCM (Quartz Crystal Microbalance) to a liquid deposit due to viscous effects in the deposit. The loss of response is expressed by a response factor, equal to the response of the QCM to a liquid film divided by its response to a solid film of the same mass per unit area. The theory assumes a droplet-type deposit morphology, and considers the influence of droplet distribution parameters. Experiments were conducted to examine the validity of the theory, using DC 704 silicone oil as the subject deposit material. Experiments were made in two series: one with constant deposit mass and variable temperature, the other with variable deposit mass and constant temperature. Interpretation of the data using the theory has enabled information on droplet area coverage and number density to be deduced.

  13. Influence of snow and ice crystal formation and accumulation on mercury deposition to the Arctic.

    PubMed

    Douglas, Thomas A; Sturm, Matthew; Simpson, William R; Blum, Joel D; Alvarez-Aviles, Laura; Keeler, Gerald J; Perovich, Donald K; Biswas, Abir; Johnson, Kelsey

    2008-03-01

    Mercury is deposited to the Polar Regions during springtime atmospheric mercury depletion events (AMDEs) but the relationship between snow and ice crystal formation and mercury deposition is not well understood. The objective of this investigation was to determine if mercury concentrations were related to the type and formation of snow and ice crystals. On the basis of almost three hundred analyses of samples collected in the Alaskan Arctic, we suggestthat kinetic crystals growing from the vapor phase, including surface hoar, frost flowers, and diamond dust, yield mercury concentrations that are typically 2-10 times higher than that reported for snow deposited during AMDEs (approximately 80 ng/L). Our results show that the crystal type and formation affect the mercury concentration in any given snow sample far more than the AMDE activity prior to snow collection. We present a conceptual model of how snow grain processes including deposition, condensation, reemission, sublimation, and turbulent diffusive uptake influence mercury concentrations in snow and ice. These processes are time dependent and operate collectively to affect the retention and fate of mercury in the cryosphere. The model highlights the importance of the formation and postdeposition crystallographic history of snow or ice crystals in determining the fate and concentration of mercury in the cryosphere. PMID:18441801

  14. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon

    PubMed Central

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications. PMID:22901341

  15. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon.

    PubMed

    Ben Slama, Sonia; Hajji, Messaoud; Ezzaouia, Hatem

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications. PMID:22901341

  16. Multiple substrate microwave plasma-assisted chemical vapor deposition single crystal diamond synthesis

    SciTech Connect

    Asmussen, J.; Grotjohn, T. A.; Reinhard, D. K.; Schuelke, T.; Becker, M. F.; Yaran, M. K.; King, D. J.; Wicklein, S.

    2008-07-21

    A multiple substrate, microwave plasma-assisted chemical vapor deposition synthesis process for single crystal diamond (SCD) is demonstrated using a 915 MHz reactor. Diamond synthesis was performed using input chemistries of 6-8% of CH{sub 4}/H{sub 2}, microwave input powers of 10-11.5 kW, substrate temperatures of 1100-1200 deg. C, and pressures of 110-135 Torr. The simultaneous synthesis of SCD over 70 diamond seeds yielded good quality SCD with deposition rates of 14-21 {mu}m/h. Multiple deposition runs totaling 145 h of deposition time added 1.8-2.5 mm of diamond material to each of the 70 seed crystals.

  17. Patterns of biomediated CaCO3 crystal bushes in hot spring deposits

    NASA Astrophysics Data System (ADS)

    Peng, Xiaotong; Jones, Brian

    2013-08-01

    In the Eryuan hot spring, located in south China, the vent pool is covered with “crystal bushes”, up to 2 cm high, 1 cm in diameter, that grew in the biofilms that thrive in the spring waters that have a pH of 7.5 and a temperature of 88 °C. The biofilms are formed largely of phototrophic purple bacteria and green bacteria. Growth of the crystal bushes, which are formed of aragonite crystals (wheat-sheaves, radiating clusters), rhombohedral and dodecahedral calcite crystals, amorphous CaCO3 (ACC), and opal-A, is attributed to precipitation in the micro-domains of the biofilms where physiochemical conditions can vary on the sub-micron scale. There is no evidence that the calcite was formed through recrystallization of the metastable aragonite and most of the calcite crystals developed as mesocrystals that are characterized by incomplete growth and porous crystal faces. With the onset of diagenesis, there is a high probability that the crystal bushes will lose much of their identity as the (1) biofilm is lost through decay, (2) ACC and aragonite change to calcite, (3) identities of the mesocrystals and incompletely formed crystals are lost through continued precipitation and/or recrystallization, and (4) porous crystal faces are converted to solid crystal faces. This means that most of the features considered indicative of biomediated calcite precipitation have a low preservation potential and that the recognition of biomediated precipitates in old spring deposits may remain problematical.

  18. Controlled deposition or organic semiconductor single crystals and its application in field-effect transistors

    NASA Astrophysics Data System (ADS)

    Liu, Shuhong

    The search for low-cost, large area, flexible devices has led to a remarkable increase in the research and development of organic semiconductors. Single-crystal organic field-effect transistors (OFETs) are ideal device structures for studying fundamental science associated with charge transport in organic materials and have demonstrated high mobility and outstanding electrical characteristics. For example, an exceptionally high carrier mobility of 20 cm2/Vs has been demonstrated for rubrene single crystal field effect transistors. However, it remains a technical challenge to integrate single-crystal devices into practical electronic applications. A key difficulty is that organic single-crystal devices are usually fabricated one device at a time by handpicking a single crystal and placing it onto the device substrate. This makes it impossible to mass-produce at high density with reasonable throughput. Therefore, there is a great need for a high-throughput method for depositing large arrays of organic semiconductor single crystals directly onto device structures. In this dissertation, I develop several approaches towards realizing this goal. The first approach is a solution-processing technique, which relies on solvent wetting and de-wetting on substrates with patterned wettability to selectively direct the deposition or removal of organic crystals. The assembly of different organic crystals over centimeter-squared areas on Au, SiO 2 and flexible plastic substrates is demonstrated. By designing line features on the substrate, alignment of needle-like crystals is also achieved. As a demonstration of the potential application of this approach, arrays of organic single crystal FETs are fabricated by patterning organic single crystals directly onto and between transistor source and drain electrodes. Besides organic single crystals, this self-assembly strategy is also applicable for patterning other objects such as metallic nanowires. In the second technique, organic

  19. Vapor deposition of a smectic liquid crystal: highly anisotropic, homogeneous glasses with tunable molecular orientation.

    PubMed

    Gómez, Jaritza; Jiang, Jing; Gujral, Ankit; Huang, Chengbin; Yu, Lian; Ediger, M D

    2016-03-01

    Physical vapor deposition (PVD) has been used to prepare glasses of itraconazole, a smectic A liquid crystal. Glasses were deposited onto subtrates at a range of temperatures (Tsubstrate) near the glass transition temperature (Tg), with Tsubstrate/Tg ranging from 0.70 to 1.02. Infrared spectroscopy and spectroscopic ellipsometry were used to characterize the molecular orientation using the orientational order parameter, Sz, and the birefringence. We find that the molecules in glasses deposited at Tsubstrate = Tg are nearly perpendicular to the substrate (Sz = +0.66) while at lower Tsubstrate molecules are nearly parallel to the substrate (Sz = -0.45). The molecular orientation depends on the temperature of the substrate during preparation, allowing layered samples with differing orientations to be readily prepared. In addition, these vapor-deposited glasses are macroscopically homogeneous and molecularly flat. We interpret the combination of properties obtained for vapor-deposited glasses of itraconazole to result from a process where molecular orientation is determined by the structure and dynamics at the free surface of the glass during deposition. Vapor deposition of liquid crystals is likely a general approach for the preparation of highly anisotropic glasses with tunable molecular orientation for use in organic electronics and optoelectronics. PMID:26875700

  20. Treatment of Nongout Joint Deposition Diseases: An Update

    PubMed Central

    Richette, Pascal; Flipo, René-Marc

    2014-01-01

    This update develops the actual therapeutic options in the management of the joint involvement of calcium pyrophosphate deposition disease (CPPD), basic calcium phosphate (BCP) deposition disease, hemochromatosis (HH), ochronosis, oxalosis, and Wilson's disease. Conventional pharmaceutical treatment provides benefits for most diseases. Anti-interleukine-1 (IL-1) treatment could provide similar results in CPPD than in gout flares. There is only limited evidence about the efficacy of preventive long-term colchicine intake, methotrexate, and hydroxychloroquine in chronic CPPD. Needle aspiration and lavage have satisfactory short and midterm results in BCP. Extracorporeal shockwave therapy has also proved its efficacy for high-doses regimes. Phlebotomy does not seem to have shown real efficacy on joint involvement in HH so far. Iron chelators' effects have not been assessed on joint involvement either, while IL-1 blockade may prove useful. NSAIDs have limited efficacy on joint involvement of oxalosis, while colchicine and steroids have not been assessed either. The use of nitisinone for ochronotic arthropathy is still much debated, but it could provide beneficial effects on joint involvement. The effects of copper chelators have not been assessed either in the joint involvement of Wilson's disease. NSAIDs should be avoided because of the liver affection they may worsen. PMID:24895535

  1. Treatment of nongout joint deposition diseases: an update.

    PubMed

    Pascart, Tristan; Richette, Pascal; Flipo, René-Marc

    2014-01-01

    This update develops the actual therapeutic options in the management of the joint involvement of calcium pyrophosphate deposition disease (CPPD), basic calcium phosphate (BCP) deposition disease, hemochromatosis (HH), ochronosis, oxalosis, and Wilson's disease. Conventional pharmaceutical treatment provides benefits for most diseases. Anti-interleukine-1 (IL-1) treatment could provide similar results in CPPD than in gout flares. There is only limited evidence about the efficacy of preventive long-term colchicine intake, methotrexate, and hydroxychloroquine in chronic CPPD. Needle aspiration and lavage have satisfactory short and midterm results in BCP. Extracorporeal shockwave therapy has also proved its efficacy for high-doses regimes. Phlebotomy does not seem to have shown real efficacy on joint involvement in HH so far. Iron chelators' effects have not been assessed on joint involvement either, while IL-1 blockade may prove useful. NSAIDs have limited efficacy on joint involvement of oxalosis, while colchicine and steroids have not been assessed either. The use of nitisinone for ochronotic arthropathy is still much debated, but it could provide beneficial effects on joint involvement. The effects of copper chelators have not been assessed either in the joint involvement of Wilson's disease. NSAIDs should be avoided because of the liver affection they may worsen. PMID:24895535

  2. Opening of triangular hole in triangular-shaped chemical vapor deposited hexagonal boron nitride crystal

    PubMed Central

    Sharma, Subash; Kalita, Golap; Vishwakarma, Riteshkumar; Zulkifli, Zurita; Tanemura, Masaki

    2015-01-01

    In-plane heterostructure of monolayer hexagonal boron nitride (h-BN) and graphene is of great interest for its tunable bandgap and other unique properties. Here, we reveal a H2-induced etching process to introduce triangular hole in triangular-shaped chemical vapor deposited individual h-BN crystal. In this study, we synthesized regular triangular-shaped h-BN crystals with the sizes around 2-10 μm on Cu foil by chemical vapor deposition (CVD). The etching behavior of individual h-BN crystal was investigated by annealing at different temperature in an H2:Ar atmosphere. Annealing at 900 °C, etching of h-BN was observed from crystal edges with no visible etching at the center of individual crystals. While, annealing at a temperature ≥950 °C, highly anisotropic etching was observed, where the etched areas were equilateral triangle-shaped with same orientation as that of original h-BN crystal. The etching process and well-defined triangular hole formation can be significant platform to fabricate planar heterostructure with graphene or other two-dimensional (2D) materials. PMID:25994455

  3. Opening of triangular hole in triangular-shaped chemical vapor deposited hexagonal boron nitride crystal.

    PubMed

    Sharma, Subash; Kalita, Golap; Vishwakarma, Riteshkumar; Zulkifli, Zurita; Tanemura, Masaki

    2015-01-01

    In-plane heterostructure of monolayer hexagonal boron nitride (h-BN) and graphene is of great interest for its tunable bandgap and other unique properties. Here, we reveal a H2-induced etching process to introduce triangular hole in triangular-shaped chemical vapor deposited individual h-BN crystal. In this study, we synthesized regular triangular-shaped h-BN crystals with the sizes around 2-10 μm on Cu foil by chemical vapor deposition (CVD). The etching behavior of individual h-BN crystal was investigated by annealing at different temperature in an H2:Ar atmosphere. Annealing at 900 °C, etching of h-BN was observed from crystal edges with no visible etching at the center of individual crystals. While, annealing at a temperature ≥ 950 °C, highly anisotropic etching was observed, where the etched areas were equilateral triangle-shaped with same orientation as that of original h-BN crystal. The etching process and well-defined triangular hole formation can be significant platform to fabricate planar heterostructure with graphene or other two-dimensional (2D) materials. PMID:25994455

  4. Opening of triangular hole in triangular-shaped chemical vapor deposited hexagonal boron nitride crystal

    NASA Astrophysics Data System (ADS)

    Sharma, Subash; Kalita, Golap; Vishwakarma, Riteshkumar; Zulkifli, Zurita; Tanemura, Masaki

    2015-05-01

    In-plane heterostructure of monolayer hexagonal boron nitride (h-BN) and graphene is of great interest for its tunable bandgap and other unique properties. Here, we reveal a H2-induced etching process to introduce triangular hole in triangular-shaped chemical vapor deposited individual h-BN crystal. In this study, we synthesized regular triangular-shaped h-BN crystals with the sizes around 2-10 μm on Cu foil by chemical vapor deposition (CVD). The etching behavior of individual h-BN crystal was investigated by annealing at different temperature in an H2:Ar atmosphere. Annealing at 900 °C, etching of h-BN was observed from crystal edges with no visible etching at the center of individual crystals. While, annealing at a temperature ≥950 °C, highly anisotropic etching was observed, where the etched areas were equilateral triangle-shaped with same orientation as that of original h-BN crystal. The etching process and well-defined triangular hole formation can be significant platform to fabricate planar heterostructure with graphene or other two-dimensional (2D) materials.

  5. Shell disease: abnormal conchiolin deposit in the abalone Haliotis tuberculata.

    PubMed

    Huchette, Sylvain; Paillard, Christine; Clavier, Jacques; Day, Robert

    2006-03-01

    Shell disease in the abalone Haliotis tuberculata L. is characterized by a conchiolin deposit on the inner surface of the shell. The gross clinical signs appear similar to the Brown Ring Disease (BRD) of clams. BRD has been extensively described in clams and is known to be responsible for severe mortalities and the collapse of the clam aquaculture industry in western France. In the clam, it was found to be caused by the infection of the mantle by Vibrio tapetis. Brown protein deposits have been observed in various abalone species around the world; some of these have been associated with a fungal infection in New Zealand, but the ones described here are similar to bacterial infections observed in clams. Larger animals appeared to be more affected by the disease, and a positive correlation of the number of successive infections found in the shells with the level of infestation of the shell by borers suggests that boring polychaetes and sponges may be vectors of the disease, or that the parasite infestation may increase the susceptibility of the animal to this infection. There is no evidence, however, that this infection causes mortality in abalone. PMID:16610593

  6. Crystal chemistry of diagenetic zeolites in volcanoclastic deposits of Italy

    NASA Astrophysics Data System (ADS)

    Passaglia, Elio; Vezzalini, Giovanna

    1985-07-01

    Zeolites from the most important volcanoclastic deposits of Italy include: (1) phillipsite and heulandite from the cinerite of the central northern Apennines; (2) chabazite and phillipsite from the phonolitic tephritic ignimbrite with black pumices; (3) phillipsite from the “tufo lionato” of Vulcano Laziale; (4) chabazite and phillipsite from the Campanian ignimbrite; (5) phillipsite from the Neapolitan yellow tuff; and (6) chabazite and phillipsite from the pyroclastics of Monte Vulture. Compared with sedimentary phillipsites and chabazites described in the literature, the chabazites and phillipsites studied here have lower Si/Al ratios and higher K contents. These chemical peculiarities are correlated with both the K-rich vesuvitic-leucititic, latitic-phonolitic, and potassic alkali-trachytic chemistry of the ash from which they were derived and, very likely, with the character of the hydrologically open system environment in which they formed. The zeolite of the heulandite-clinoptilolite group from the cinerite of the central northern Apennines is classified as a true heulandite on the basis of its chemical composition and thermal behavior.

  7. Assessment of cigarette smoke particle deposition within the Vitrocell® exposure module using quartz crystal microbalances

    PubMed Central

    2013-01-01

    Background Cigarette smoking is a cause of a variety of serious diseases, and to understand the toxicological impact of tobacco smoke in vitro, whole smoke exposure systems can be used. One of the main challenges of the different whole smoke exposure systems that are commercially available is that they dilute and deliver smoke in different ways, limiting/restricting the cross-comparison of biological responses. This is where dosimetry – dose quantification – can play a key role in data comparison. Quartz crystal microbalance (QCM) technology has been put forward as one such tool to quantify smoke particle deposition in vitro, in real-time. Results Using four identical QCMs, installed into the Vitrocell® mammalian 6/4 CF Stainless exposure module, we were able to quantify deposited smoke particle deposition, generated and diluted by a Vitrocell® VC 10 Smoking Robot. At diluting airflows 0.5-4.0 L/min and vacuum flow rate 5 ml/min/well through the exposure module, mean particle deposition was in the range 8.65 ± 1.51 μg/cm2-0.72 ± 0.13 μg/cm2. Additionally, the effect of varying vacuum flow rate on particle deposition was assessed from 5 ml/min/well - 100 ml/min/well. Mean deposited mass for all four airflows tested per vacuum decreased as vacuum rate was increased: mean deposition was 3.79, 2.75, 1.56 and 1.09 μg/cm2 at vacuum rates of 5, 10, 50 and 100 ml/min/well respectively. Conclusions QCMs within the Vitrocell® exposure module have demonstrated applicability at defining particle dose ranges at various experimental conditions. This tool will prove useful for users of the Vitrocell® system for dose–response determination and QC purposes. PMID:23497606

  8. Preparing anisotropic glasses from structural analogs of liquid crystal formers by physical vapor deposition

    NASA Astrophysics Data System (ADS)

    Gomez, Jaritza; Ediger, Mark

    Physical vapor deposition (PVD) can be used to tune molecular orientation in glasses by depositing at substrate temperatures (Tsubstrates) just below the glass transition temperature (Tg) . Glasses of a smectic A liquid crystal (LC) former, itraconazole, deposited at a Tsubstrate = Tg have been shown to inherit the structure of the equilibrium smectic liquid and orient nearly perpendicular to the substrate. Here we report the deposition of glasses prepared from molecules that are structural analogs to known LC formers: posaconazole and a functionalized perylenemonoimide (PMI), analogs to itraconazole and a previously reported columnar LC, respectively. Spectroscopic ellipsometry and infrared spectroscopy are used to characterize average molecular orientation in the as-deposited glasses. Surprisingly, we find that molecular orientation in glasses of posaconazole deposited at different Tsubstrates does not follow the previously observed trends for linear molecules without LC states, but more closely follows itraconazole. In addition, we find that glasses deposited at Tg are not isotropic, even though liquid-cooled glasses do not show preferential molecular orientation. Similarly, glasses from a functionalized PMI, structural analog to a known columnar LC, show molecular orientation at Tsubstrate = Tg. These results may provide insights into the mechanism by which physical vapor deposition can produce glasses with tunable molecular orientation.

  9. Seawater spray injury to Quercus acutissima leaves: crystal deposition, stomatal clogging, and chloroplast degeneration.

    PubMed

    Kim, Ki Woo; Koo, Kyosang; Kim, Pan-Gi

    2011-05-01

    Effects of seawater spray on leaf structure were investigated in Quercus acutissima by electron microscopy and X-ray microanalysis. Two-year-old seedlings of Q. acutissima were sprayed with seawater and kept in a greenhouse maintained at 25°C. The most recognizable symptoms of seawater-sprayed seedlings included leaf necrosis, crystal deposition, stomatal clogging, and chloroplast degeneration. Field emission scanning electron microscopy revealed that the leaf surface was covered with additional layers of remnants of seawater spray. Composed of sodium and chloride, cube-shaped crystals (halite) were prevalently found on trichomes and epidermis, and formed aggregates. Meanwhile, wedge-shaped crystals were deposited on epidermis and consisted of calcium and sulfur. As a result of stomatal clogging by crystal deposition on the abaxial surface, it was conceivable that plant respiration became severely hampered. Transmission electron microscopy showed degenerated cytoplasm of seawater-sprayed leaves. It was common to observe severe plasmolysis and disrupted chloroplasts with a reduced number of thylakoids in grana. These results indicate that foliar applications of seawater were sufficient to induce necrosis of Q. acutissima seedlings as an abiotic disturbance factor. PMID:20931628

  10. Single-crystal nanowires grown via electron-beam-induced deposition

    SciTech Connect

    Klein, Kate L; Randolph, Steven J; Fowlkes, Jason Davidson; Allard Jr, Lawrence Frederick; Meyer III, Harry M; Simpson, Michael L; Rack, Philip D

    2008-01-01

    Electron-beam-induced deposition (EBID) is a useful technique for direct-writing of 3-dimensional dielectric, semiconductor, and metallic materials with nanoscale precision and resolution. The EBID process, however, has been limited in many cases because precursor byproducts (typically from organic precursors like W(CO)6) are incorporated into the deposited material resulting in contaminated and amorphous structures. In this manuscript, we have investigated the structure and composition of EBID tungsten nanostructures as-deposited from a tungsten hexafluoride (WF6) precursor. High-resolution transmission electron microscopy, electron diffraction and electron spectroscopy were employed to determine the effects that the electron beam scanning conditions have on the deposit characteristics. The results show that slow, one-dimensional lateral scanning produces textured -tungsten nanowire cores surrounded by an oxide secondary layer, while stationary vertical growth leads to single-crystal [100]-oriented W3O nanowires. Furthermore we correlate how the growth kinetics affect the resultant nanowire structure and composition.

  11. Preparation and Optical Properties of Spherical Inverse Opals by Liquid Phase Deposition Using Spherical Colloidal Crystals

    NASA Astrophysics Data System (ADS)

    Aoi, Y.; Tominaga, T.

    2013-03-01

    Titanium dioxide (TiO2) inverse opals in spherical shape were prepared by liquid phase deposition (LPD) using spherical colloidal crystals as templates. Spherical colloidal crystals were produced by ink-jet drying technique. Aqueous emulsion droplets that contain polystyrene latex particles were ejected into air and dried. Closely packed colloidal crystals with spherical shape were obtained. The obtained spherical colloidal crystals were used as templates for the LPD. The templates were dispersed in the deposition solution of the LPD, i.e. a mixed solution of ammonium hexafluorotitanate and boric acid and reacted for 4 h at 30 °C. After the LPD process, the interstitial spaces of the spherical colloidal crystals were completely filled with titanium oxide. Subsequent heat treatment resulted in removal of templates and spherical titanium dioxide inverse opals. The spherical shape of the template was retained. SEM observations indicated that the periodic ordered voids were surrounded by titanium dioxide. The optical reflectance spectra indicated that the optical properties of the spherical titanium dioxide inverse opals were due to Bragg diffractions from the ordered structure. Filling in the voids of the inverse opals with different solvents caused remarkable changes in the reflectance peak.

  12. Synthesis of single-crystalline anisotropic gold nano-crystals via chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Manna, Sohini; Kim, Jong Woo; Takahashi, Yukiko; Shpyrko, Oleg G.; Fullerton, Eric E.

    2016-05-01

    We report on a novel one-step catalyst-free, thermal chemical vapor deposition procedure to synthesize gold nanocrystals on silicon substrates. This approach yields single-crystal nanocrystals with various morphologies, such as prisms, icosahedrons, and five-fold twinned decahedrons. Our approach demonstrates that high-quality anisotropic crystals composed of fcc metals can be produced without the need for surfactants or templates. Compared with the traditional wet chemical synthesis processes, our method enables direct formation of highly pure and single crystalline nanocrystals on solid substrates which have applications in catalysis. We investigated the evolution of gold nanocrystals and established their formation mechanism.

  13. Blockade of Alternative Complement Pathway in Dense Deposit Disease

    PubMed Central

    Sacquépée, Mathieu; Fila, Marc; Peuchmaur, Michel; Perrier-Cornet, Emilia; Frémeaux-Bacchi, Véronique; Deschênes, Georges

    2014-01-01

    A patient aged 17 with dense deposit disease associated with complement activation, circulating C3 Nef, and Factor H mutation presented with nephrotic syndrome and hypertension. Steroid therapy, plasma exchange, and rituximab failed to improve proteinuria and hypertension despite a normalization of the circulating sC5b9 complex. Eculizumab, a monoclonal antibody directed against C5, was used to block the terminal product of the complement cascade. The dose was adapted to achieve a CH50 below 10%, but proteinuria and blood pressure were not improved after 3 months of treatment. PMID:24672732

  14. Blockade of alternative complement pathway in dense deposit disease.

    PubMed

    Berthe-Aucejo, Aurore; Sacquépée, Mathieu; Fila, Marc; Peuchmaur, Michel; Perrier-Cornet, Emilia; Frémeaux-Bacchi, Véronique; Deschênes, Georges

    2014-01-01

    A patient aged 17 with dense deposit disease associated with complement activation, circulating C3 Nef, and Factor H mutation presented with nephrotic syndrome and hypertension. Steroid therapy, plasma exchange, and rituximab failed to improve proteinuria and hypertension despite a normalization of the circulating sC5b9 complex. Eculizumab, a monoclonal antibody directed against C5, was used to block the terminal product of the complement cascade. The dose was adapted to achieve a CH50 below 10%, but proteinuria and blood pressure were not improved after 3 months of treatment. PMID:24672732

  15. Quasi-two-dimensional diamond crystals: Deposition from a gaseous phase and structural-morphological properties

    NASA Astrophysics Data System (ADS)

    Alexeev, A. M.; Ismagilov, R. R.; Ashkinazi, E. E.; Orekhov, A. S.; Malykhin, S. A.; Obraztsov, A. N.

    2016-07-01

    Diamond films predominantly consisting of plane micrometer-size crystallites with a thickness of several dozen nanometers have been deposited from a methane-hydrogen gas mixture activated by a dc gas discharge. The crystallite structure has been studied by scanning and transmission electron microscopy and diffraction. A possible mechanism of formation of plane crystallites during deposition of diamond from the gas phase has been discussed. It has been shown that the results agree with the theoretical concepts of formation of crystals with a face-centered cubic lattice.

  16. Nanoscale arrays of antimony telluride single crystals by selective chemical vapor deposition

    PubMed Central

    Huang, Ruomeng; Benjamin, Sophie L.; Gurnani, Chitra; Wang, Yudong; Hector, Andrew L.; Levason, William; Reid, Gillian; De Groot, C. H. (Kees)

    2016-01-01

    Arrays of individual single nanocrystals of Sb2Te3 have been formed using selective chemical vapor deposition (CVD) from a single source precursor. Crystals are self-assembled reproducibly in confined spaces of 100 nm diameter with pitch down to 500 nm. The distribution of crystallite sizes across the arrays is very narrow (standard deviation of 15%) and is affected by both the hole diameter and the array pitch. The preferred growth of the crystals in the <1 1 0> orientation along the diagonal of the square holes strongly indicates that the diffusion of adatoms results in a near thermodynamic equilibrium growth mechanism of the nuclei. A clear relationship between electrical resistivity and selectivity is established across a range of metal selenides and tellurides, showing that conductive materials result in more selective growth and suggesting that electron donation is of critical importance for selective deposition. PMID:27283116

  17. Nanoscale arrays of antimony telluride single crystals by selective chemical vapor deposition.

    PubMed

    Huang, Ruomeng; Benjamin, Sophie L; Gurnani, Chitra; Wang, Yudong; Hector, Andrew L; Levason, William; Reid, Gillian; De Groot, C H Kees

    2016-01-01

    Arrays of individual single nanocrystals of Sb2Te3 have been formed using selective chemical vapor deposition (CVD) from a single source precursor. Crystals are self-assembled reproducibly in confined spaces of 100 nm diameter with pitch down to 500 nm. The distribution of crystallite sizes across the arrays is very narrow (standard deviation of 15%) and is affected by both the hole diameter and the array pitch. The preferred growth of the crystals in the <1 1 0> orientation along the diagonal of the square holes strongly indicates that the diffusion of adatoms results in a near thermodynamic equilibrium growth mechanism of the nuclei. A clear relationship between electrical resistivity and selectivity is established across a range of metal selenides and tellurides, showing that conductive materials result in more selective growth and suggesting that electron donation is of critical importance for selective deposition. PMID:27283116

  18. Nanoscale arrays of antimony telluride single crystals by selective chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Huang, Ruomeng; Benjamin, Sophie L.; Gurnani, Chitra; Wang, Yudong; Hector, Andrew L.; Levason, William; Reid, Gillian; de Groot, C. H. (Kees)

    2016-06-01

    Arrays of individual single nanocrystals of Sb2Te3 have been formed using selective chemical vapor deposition (CVD) from a single source precursor. Crystals are self-assembled reproducibly in confined spaces of 100 nm diameter with pitch down to 500 nm. The distribution of crystallite sizes across the arrays is very narrow (standard deviation of 15%) and is affected by both the hole diameter and the array pitch. The preferred growth of the crystals in the <1 1 0> orientation along the diagonal of the square holes strongly indicates that the diffusion of adatoms results in a near thermodynamic equilibrium growth mechanism of the nuclei. A clear relationship between electrical resistivity and selectivity is established across a range of metal selenides and tellurides, showing that conductive materials result in more selective growth and suggesting that electron donation is of critical importance for selective deposition.

  19. Silver- and Gold-Ordered Structures on Single-Crystal Silicon Surface After Thermal Deposition

    NASA Astrophysics Data System (ADS)

    Karbivskyy, Vladimir; Karbivska, Love; Artemyuk, Viktor

    2016-02-01

    The formation mechanisms of Ag- and Au-ordered structures on single-crystal silicon (Si) (111) and Si (110) surfaces were researched using high-resolution scanning tunneling microscopy method. It was shown that different patterns of self-assembled nanostructures with very precise and regular geometric shapes can be produced by controlling process parameters of thermal metal spraying on the substrate. The surfaces of nanorelieves at each stage of deposition were researched, and the main stages of morphological transformation were fixed.

  20. Furnace Tubes For Depositing Parylene-N(TM) On Hgl(2) Crystals

    NASA Technical Reports Server (NTRS)

    Iwanczyk, Jan S.; Wang, Yuzhong, J.

    1994-01-01

    Shapes of quartz pyrolysis tubes used to deposit Parylene-N on Hgl(2) crystals modified to improve quality of coating. Use of zigzag tube, along with higher processing temperature, resulted in coating of better quality, including greater transparency and more uniformity of appearance. In addition, longer path taken by dimer in passing by baffles increases time spent in high-temperature region, increasing degree of cracking even more.

  1. Sedimentology, stratigraphy, and depositional environment of the Crystal Geyser Dinosaur Quarry, east-central Utah

    USGS Publications Warehouse

    Suarez, M.B.; Suarez, C.A.; Kirkland, J.I.; Gonzalez, Luis A.; Grandstaff, D.E.; Terry, D.O., Jr.

    2007-01-01

    The Crystal Geyser Dinosaur Quarry, near Green River, Utah, is located at the base of the Lower Cretaceous (Barremian) Yellow Cat Member of the Cedar Mountain Formation. The quarry preserves a nearly monospecific accumulation of a new basal therizinosauroid, Falcarius utahensis. We used field descriptions and petrographic analysis to determine the depositional environment and development of the quarry strata. Results of these analyses suggest that the quarry represents multiple episodes of bone accumulation buried by spring and overbank flood deposits. Evidence for these previously undescribed spring deposits includes calcite macroscopic structures within the quarry strata - such as pisolites and travertine fragments - and calcite micromorphologies - including radial-fibrous, feather, and scandulitic dendrite morphologies and tufa clasts. At least two episodes of bone incorporation are preserved in the quarry based on their stratigraphic position and lithologic associations. The unique depositional setting in and around the Crystal Geyser Dinosaur Quarry appears to have been favorable for the preservation of vertebrate fossils and provides insight into early Cretaceous environments in North America. Copyright ?? 2007, SEPM (Society for Sedimentary Geology).

  2. Design and implementation of an integral wall-mounted quartz crystal microbalance for atomic layer deposition.

    PubMed

    Riha, Shannon C; Libera, Joseph A; Elam, Jeffrey W; Martinson, Alex B F

    2012-09-01

    Quartz crystal microbalance (QCM) measurements have played a vital role in understanding and expediting new atomic layer deposition (ALD) processes; however, significant barriers remain to their routine use and accurate execution. In order to turn this exclusively in situ technique into a routine characterization method, an integral QCM fixture was developed. This new design is easily implemented on a variety of chemical vapor deposition (CVD) tools, allows rapid sample exchange, prevents backside deposition, and minimizes both the footprint and flow disturbance. Unlike previous QCM designs, the fast thermal equilibration enables tasks such as temperature-dependent studies and ex situ sample exchange, further highlighting the utility of this QCM design for day-to-day use. Finally, the in situ mapping of thin film growth rates across the ALD reactor was demonstrated in a popular commercial tool operating in both continuous and quasi-static ALD modes. PMID:23020393

  3. Influence of atomic oxygen irradiation during deposition on crystallization of post-annealed barium zirconate thin films

    NASA Astrophysics Data System (ADS)

    Iguchi, Fumitada; Shibata, Yoshikazu; Miyazaki, Takamichi; Sata, Noriko; Yugami, Hiroo

    2014-11-01

    The role of atomic oxygen irradiation in the epitaxial crystallization of yttrium-doped barium zirconate thin films fabricated by pulsed laser deposition (PLD) was investigated. X-ray diffraction and transmission electron microscopy revealed that, for films deposited without irradiation, random nucleation and growth occurred below the onset temperature for continuous crystallization at the film-interlayer interface. In contrast, for films deposited with oxygen irradiation, random nucleation and growth was not detected at the temperature of continuous crystallization, which facilitates epitaxial crystallization in these films. This study suggests the combined low temperature deposition with atomic oxygen irradiation and post-annealing could control microstructure of solid-state electrochemical devices such as solid oxide fuel cells and solid-state lithium secondary batteries.

  4. Crystallization process of zircon and fergusonite during hydrothermal alteration in Nechalacho REE deposit, Thor Lake, Canada

    NASA Astrophysics Data System (ADS)

    Hoshino, M.; Watanabe, Y.; Murakami, H.; Kon, Y.; Tsunematsu, M.

    2012-04-01

    The core samples of two drill holes, which penetrate sub-horizontal mineralized horizons at Nechalacho REE deposit in the Proterozoic Thor Lake syenite, Canada, were studied in order to clarify magmatic and hydrothermal processes that enriched HFSE (e.g. Zr, Nb, Y and REE). Zircon is the most common REE minerals in Nechalacho REE deposit. The zircon is divided into five types as follows: Type-1 zircon occurs as single grain in phlogopite and the chondrite-normalized REE pattern is characterized by a steeply-rising slope from the LREE to the HREE with a positive Ce-anomaly and negative Eu-anomaly. This chemical characteristic is similar to that of igneous zircon. Type-2 zircon consists of HREE-rich magmatic porous core and LREE-Nb-F-rich hydrothermal rim. This type zircon is mostly included in phlogopite and fluorite, and occasionally in microcline. Type-3 zircon is characterized by euhedral to anhedral crystal, occurring in a complex intergrowth with REE fluorocarbonates. Type-3 zircons have high contents of REE, Nb and fluorine. Type-4 zircon consists of porous-core and -rim zones, but their chemical compositions are similar to each other. This type zircon is a subhedral crystal rimmed by fergusonite. Type-5 zircon is characterized by smaller, porous and subhedral to anhedral crystals. The interstices between small zircons are filled by fergusonite. Type-4 and -5 zircons show low REE and Nb contents. Occurrences of these five types of zircon are different according to the depth and degree of the alteration by hydrothermal solutions rich in F- and CO3 of the two drill holes, which permit a model for evolution of the zircon crystallization in Nechalacho REE deposit as follows: (1) type-1 (single magmatic zircon) is formed in miaskitic syenite. (2) LREE-Nb-F-rich hydrothermal zircon formed around HREE-rich magmatic zircon (type-2 zircon); (3) type-3 zircon crystallized thorough F and CO3-rich hydrothermal alteration of type-2 zircon which formed the complex

  5. Thermodynamics and kinetic behaviors of thickness-dependent crystallization in high-k thin films deposited by atomic layer deposition

    SciTech Connect

    Nie, Xianglong; Ma, Fei; Ma, Dayan; Xu, Kewei

    2015-01-15

    Atomic layer deposition is adopted to prepare HfO{sub 2} and Al{sub 2}O{sub 3} high-k thin films. The HfO{sub 2} thin films are amorphous at the initial growth stage, but become crystallized when the film thickness (h) exceeds a critical value (h{sub critical}{sup *}). This phase transition from amorphous to crystalline is enhanced at higher temperatures and is discussed, taking into account the effect of kinetic energy. At lower temperatures, the amorphous state can be maintained even when h>h{sub critical}{sup *} owing to the small number of activated atoms. However, the number of activated atoms increases with the temperature, allowing crystallization to occur even in films with smaller thickness. The Al{sub 2}O{sub 3} thin films, on the other hand, maintain their amorphous state independent of the film thickness and temperature owing to the limited number of activated atoms. A thermodynamic model is proposed to describe the thickness-dependent phase transition.

  6. Investigations of high mobility single crystal chemical vapor deposition diamond for radiotherapy photon beam monitoring

    SciTech Connect

    Tromson, D.; Descamps, C.; Tranchant, N.; Bergonzo, P.; Nesladek, M.; Isambert, A.

    2008-03-01

    The intrinsic properties of diamond make this material theoretically very suitable for applications in medical physics. Until now ionization chambers have been fabricated from natural stones and are commercialized by PTW, but their fairly high costs and long delivery times have often limited their use in hospital. The properties of commercialized intrinsic polycrystalline diamond were investigated in the past by many groups. The results were not completely satisfactory due to the nature of the polycrystalline material itself. In contrast, the recent progresses in the growth of high mobility single crystal synthetic diamonds prepared by chemical vapor deposition (CVD) technique offer new alternatives. In the framework of the MAESTRO project (Methods and Advanced Treatments and Simulations for Radio Oncology), the CEA-LIST is studying the potentialities of synthetic diamond for new techniques of irradiation such as intensity modulated radiation therapy. In this paper, we present the growth and characteristics of single crystal diamond prepared at CEA-LIST in the framework of the NoRHDia project (Novel Radiation Hard CVD Diamond Detector for Hadrons Physics), as well as the investigations of high mobility single crystal CVD diamond for radiotherapy photon beam monitoring: dosimetric analysis performed with the single crystal diamond detector in terms of stability and repeatability of the response signal, signal to noise ratio, response speed, linearity of the signal versus the absorbed dose, and dose rate. The measurements performed with photon beams using radiotherapy facilities demonstrate that single crystal CVD diamond is a good alternative for air ionization chambers for beam quality control.

  7. Ultrastrucural Investigation of Crystal deposits in Npt2a knockout mice: Are they similar to Human Randall's plaques?

    PubMed Central

    Khan, Saeed R.; Canales, Benjamin K.

    2013-01-01

    Purpose Idiopathic calcium oxalate (CaOx) stones are suggested to develop attached to renal interstitial calcium phosphate (CaP) deposits, the Randall's plaques (RP), Sodium phosphate co-transporter (Npt2a) null mice are hypercalciuric, hyperphosphaturic, and produce tubular and interstitial CaP deposits. To determine if this mouse is suitable for RP investigations, we chronologically studied their location, structure, and composition. Materials and Methods Kidneys of Npt2a null mice of two days to a year old were examined by light, scanning (SEM) and transmission electron microscopy (TEM). Electron diffraction and energy dispersive x-ray microanalyses were performed to determine the mineral composition. Results Poorly crystalline biological apatite deposits were seen in lumens of collecting ducts. Deposits consisted of aggregates of approx 5μm diameter microspheres of concentrically organized needle or plate-like matrix rich crystals. Epithelium/ crystal interfaces were filled with membrane bound vesicles. Some tubules were completely occluded by crystals, occasionally lost their epithelium and crystals moved into the interstitium. Conclusions CaP crystals formed in tubular lumen and organized as microspheres. The aggregation of CaP crystals produced nuclei, which grew by the addition of crystals on periphery, eventually becoming large enough to occlude tubular lumen and obliterate tubular epithelium, leading to the relocation of microliths into interstitium. The pathogenesis of interstitial deposits of the Npt2a null mice appears different from that proposed for RP's. Since Npt2a null mice purge their renal crystal deposits, these mice may serve as a model to investigate elimination of crystal deposits seen in children and adults with nephrocalcinosis PMID:21784483

  8. Deposition of metallic gallium on re-crystallized ceramic material during focused ion beam milling

    SciTech Connect

    Muñoz-Tabares, J.A.; Reyes-Gasga, J.

    2013-12-15

    We report a new kind of artifact observed in the preparation of a TEM sample of zirconia by FIB, which consists in the deposition of metallic gallium nano-dots on the TEM sample surface. High resolution TEM images showed a microstructure of fine equiaxed grains of ∼ 5 nm, with some of them possessing two particular characteristics: high contrast and well-defined fast Fourier transform. These grains could not be identified as any phase of zirconia but it was possible to identify them as gallium crystals in the zone axis [110]. Based on HRTEM simulations, the possible orientations between zirconia substrate and deposited gallium are discussed in terms of lattice mismatch and oxygen affinity. - Highlights: • We show a new type of artifact induced during preparation of TEM samples by FIB. • Deposition of Ga occurs due to its high affinity for oxygen. • Materials with small grain size (∼ 5 nm) could promote Ga deposition. • Small grain size permits the elastic accommodation of deposited Ga.

  9. Effect of deposition temperature on electron-beam evaporated polycrystalline silicon thin-film and crystallized by diode laser

    SciTech Connect

    Yun, J. Varalmov, S.; Huang, J.; Green, M. A.; Kim, K.

    2014-06-16

    The effects of the deposition temperature on the microstructure, crystallographic orientation, and electrical properties of a 10-μm thick evaporated Si thin-film deposited on glass and crystallized using a diode laser, are investigated. The crystallization of the Si thin-film is initiated at a deposition temperature between 450 and 550 °C, and the predominant (110) orientation in the normal direction is found. Pole figure maps confirm that all films have a fiber texture and that it becomes stronger with increasing deposition temperature. Diode laser crystallization is performed, resulting in the formation of lateral grains along the laser scan direction. The laser power required to form lateral grains is higher in case of films deposited below 450 °C for all scan speeds. Pole figure maps show 75% occupancies of the (110) orientation in the normal direction when the laser crystallized film is deposited above 550 °C. A higher density of grain boundaries is obtained when the laser crystallized film is deposited below 450 °C, which limits the solar cell performance by n = 2 recombination, and a performance degradation is expected due to severe shunting.

  10. Silver- and Gold-Ordered Structures on Single-Crystal Silicon Surface After Thermal Deposition.

    PubMed

    Karbivskyy, Vladimir; Karbivska, Love; Artemyuk, Viktor

    2016-12-01

    The formation mechanisms of Ag- and Au-ordered structures on single-crystal silicon (Si) (111) and Si (110) surfaces were researched using high-resolution scanning tunneling microscopy method. It was shown that different patterns of self-assembled nanostructures with very precise and regular geometric shapes can be produced by controlling process parameters of thermal metal spraying on the substrate. The surfaces of nanorelieves at each stage of deposition were researched, and the main stages of morphological transformation were fixed.Self-ordered hexagonal pyramid-shaped nanostructures were formed at thermal deposition of gold on the Si (111), whereas only monolayer hexagonal formation could be observed on the plane Si (110). Gold monolayer flake nanostructures were obtained under certain technological parameters.Atomically smooth Ag film cannot be obtained on the Si (111) surface by means of thermal spraying at room temperature. The formation of two-dimensional (2D) clusters takes place; heating of these clusters at several hundred degrees Celsius leads to their transformation into atomically smooth covering.The weak interaction between Ag multilayer coatings and substrate was established that allows to clear crystal surface from metal with reproduction of the reconstructed Si (111) 7 × 7 surface by slight warming. The offered method can be used for single-crystal surface protection from destruction. PMID:26847695

  11. Influence of reactive sputter deposition conditions on crystallization of zirconium oxide thin films

    SciTech Connect

    Sethi, Guneet; Sunal, Paul; Horn, Mark W.; Lanagan, Michael T.

    2009-05-15

    Zirconium oxide thin films were prepared through reactive magnetron sputtering with a zirconium target using pulsed-dc and radio frequency (rf) sources. The film crystallization was studied with respect to sputtering growth variables such as sputtering power, sputtering pressure, source frequency, oxygen pressure, substrate temperature, and substrate material. The crystallization was studied through x-ray diffraction (XRD) 2{theta} scans and was quantified with peak full width at half maximum and crystallite size. Crystallization of the films was found to occur over a broad range of sputter deposition parameters, while the amorphous phase was produced only at high sputtering pressure and low sputtering power. With a decrease in sputtering pressure or power, the crystallite size decreased. Energy dispersive x-ray spectroscopy, electron microscopy, and XRD analysis revealed that at very low pressures, these films are polyphase assemblages of cubic phases of oxygen deficient zirconium oxides such as ZrO and Zr{sub 2}O. When the sputtering oxygen content of these films is increased above 25%, monoclinic-ZrO{sub 2} phase is stabilized in the films and the deposition rate decreases. However, in the case of rf sputtering, an additional peak corresponding to tetragonal phase of ZrO{sub 2} is observed. The sputtering parameters were related to physical parameters such as sputtering mode, ion energy, and substrate temperature, which influence crystallinity.

  12. The mechanical properties of various chemical vapor deposition diamond structures compared to the ideal single crystal

    NASA Astrophysics Data System (ADS)

    Hess, Peter

    2012-03-01

    The structural and electronic properties of the diamond lattice, leading to its outstanding mechanical properties, are discussed. These include the highest elastic moduli and fracture strength of any known material. Its extreme hardness is strongly connected with the extreme shear modulus, which even exceeds the large bulk modulus, revealing that diamond is more resistant to shear deformation than to volume changes. These unique features protect the ideal diamond lattice also against mechanical failure and fracture. Besides fast heat conduction, the fast vibrational movement of carbon atoms results in an extreme speed of sound and propagation of crack tips with comparable velocity. The ideal mechanical properties are compared with those of real diamond films, plates, and crystals, such as ultrananocrystalline (UNC), nanocrystalline, microcrystalline, and homo- and heteroepitaxial single-crystal chemical vapor deposition (CVD) diamond, produced by metastable synthesis using CVD. Ultrasonic methods have played and continue to play a dominant role in the determination of the linear elastic properties, such as elastic moduli of crystals or the Young's modulus of thin films with substantially varying impurity levels and morphologies. A surprising result of these extensive measurements is that even UNC diamond may approach the extreme Young's modulus of single-crystal diamond under optimized deposition conditions. The physical reasons for why the stiffness often deviates by no more than a factor of two from the ideal value are discussed, keeping in mind the large variety of diamond materials grown by various deposition conditions. Diamond is also known for its extreme hardness and fracture strength, despite its brittle nature. However, even for the best natural and synthetic diamond crystals, the measured critical fracture stress is one to two orders of magnitude smaller than the ideal value obtained by ab initio calculations for the ideal cubic lattice. Currently

  13. Artificial silver sulfide Ag2S: Crystal structure and particle size in deposited powders

    NASA Astrophysics Data System (ADS)

    Sadovnikov, S. I.; Gusev, A. I.; Rempel, A. A.

    2015-07-01

    Chemical deposition from aqueous solutions of silver nitrate and sodium sulfide was used for synthesis of coarse-crystalline and nanocrystalline silver sulfide Ag2S powders. Sodium citrate was used as a complexing and stabilizing agent during synthesis. X-ray diffraction study shows that synthesized Ag2S powders have monoclinic (space group P21/c) α-Ag2S acanthite type crystal structure. The unit cell of artificial monoclinic silver sulfide Ag2S contains four Ag2S formula units and has the following parameters: a = 0.42264 nm, b = 0.69282 nm, c = 0.95317 nm and β = 125.554°. The size of silver sulfide particles in deposited powders was estimated by the X-ray diffraction and BET methods. By varying the ratio between the concentrations of reagents in the initial reaction mixture it is possible to deposit Ag2S nanoparticles with average size ranging in the interval from ∼1000 to ∼30 nm. Ag2S nanopowders have no deformation distortions of the crystal lattice practically because the microstrains ε in the synthesized powders do not exceed 0.15%. All the Ag2S powders with different particle size have an identical morphology.

  14. Distinctive Accessory Minerals, Textures and Crystal Habits in Biofilm Associated Gypsum Deposits

    NASA Astrophysics Data System (ADS)

    Vogel, M.; Des Marais, D.; Jahnke, L.; Parenteau, M.

    2008-12-01

    Gypsum-depositing environments near Guerrero Negro, Baja California Sur, Mexico were investigated in order to differentiate the influence of microbial activity versus nonbiological processes upon sedimentary fabrics and minerals. Field sites were located in sabkhas (mudflats and anchialine pools) and in seawater concentration ponds in the salt production facility operated by Exportadora de Sal, S. A. Gypsum (CaSO4.2H2O) was classified according to sedimentary environment (e.g., mudflats, anchialine pools, saltern ponds, surface and subsurface sediments), sedimentary texture, mineral composition, crystal habit, brine composition and other geochemical and biological factors. Gypsum types that develop in the absence of biofilms include water column precipitates (pelagic grains) and subsedimentary crystalline discs that form from phreatic brine ripening. Subsedimentary gypsum forming in sabkha environments had a sinuous axial microtexture and poikilitically enclosed detrital particles whereas water column precipitates exhibited euhedral prismatic habits and extensive penetrative twinning. Gypsum that was influenced by biofilms included cumulate crusts and gypsooids / gypsolite developing in anchialine pools and in saltern concentration ponds. Gypsum precipitating within subaqueous benthic microbial mats, or biofilm/sediment surfaces offered compelling evidence of biofilm influence on crystal textures and habits. Biofilm effects include irregular high relief surface textures, accessory minerals (elemental sulfur, Ca-carbonate, Sr/Ca-sulfate, Mg-oxide and Mg- sulfate) and distinctive crystal habits. Elemental sulfur, Ca-carbonate, and Sr/Ca-sulfate are known byproducts of bacterially mediated sulfate reduction (BSR). Populations of gypsum crystals within biofilms exhibited euhedral to lensoidal morphologies with unique equant and distorted prismatic forms. These forms had been shown to arise from form- and face-specific inhibition by bioorganic functional groups (Cody

  15. Island shape and electronic structure in diindenoperylene thin films deposited on Au(110) single crystals.

    PubMed

    Ciccullo, Francesca; Savu, Sabine A; Glaser, Mathias; Rocco, Maria Luiza M; Chassé, Thomas; Casu, M Benedetta

    2016-05-11

    We have investigated diindenoperylene (DIP) thin films deposited on Au(110) single crystals, by using a multi-technique approach based on X-ray photoemission spectroscopy (XPS), resonant photoemission spectroscopy (RPES), near edge X-ray absorption fine structure (NEXAFS) spectroscopy, atomic force microscopy (AFM) and photoemission electron microscopy (PEEM). DIP molecules are physisorbed on gold, with image-charge screening playing the major role as an interface phenomenon. DIP thin films show Stranski-Krastanov growth mode and the structural herringbone arrangement mimics the arrangement found in DIP single crystals. These results are common with the (100) and (111) gold substrate geometries. On the contrary, the island aggregation is substrate geometry-dependent. This paves the way to exploit the degree of anisotropy in different lattice geometries as a tool for molecular patterning of inorganic surfaces, keeping the electronic structure preserved. PMID:27140434

  16. Thin film of sol-gel deposited in photonic crystal fiber for cholesterol detection

    NASA Astrophysics Data System (ADS)

    Razo-Medina, D. A.; Alvarado-Méndez, E.; Trejo-Durán, M.

    2015-04-01

    In this work, the fabrication of thin films mixed with cholesterol enzyme as recognition component is shown, using solgel technique. The film was deposited at one end of photonic crystal fiber (optrode), which was used as carrier medium of sol-gel matrix. The concentration of cholesterol in the test sample was determined by the use of transmittance. Measuring device consists of a power source (laser diode), optrode and a light detector. The laser beam is transmitted through the optrode; the variations of intensity depending on cholesterol concentration are emitted to be detected by a photoresistor.

  17. Photonic crystal thin films of GaAs prepared by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Povey, I. M.; Whitehead, D.; Thomas, K.; Pemble, M. E.; Bardosova, M.; Renard, J.

    2006-09-01

    Photonic crystal thin films were fabricated via the self-assembly of a lattice of silica spheres on silicon (100) substrates. Progressive infilling of the air spaces within the structure with GaAs was achieved using trimethylgallium and arsine under atomic-layer-deposition conditions. Samples with the highest levels of GaAs infill were subsequently inverted using selective etching. Reflectance spectra are interpreted via the Bragg expression and calculated photonic band structure diagrams. For GaAs infilled and inverted samples, the relative positions of the first and second order Bragg reflections are strongly influenced by the wavelength dependent refractive index.

  18. Single crystal chemical vapor deposit diamond detector for energetic plasma measurement in space

    NASA Astrophysics Data System (ADS)

    Ogasawara, K.; Broiles, T. W.; Coulter, K. E.; Dayeh, M. A.; Desai, M. I.; Livi, S. A.; McComas, D. J.; Walther, B. C.

    2015-03-01

    This study reports the performance of single crystal chemical vapor deposit diamond detectors for measuring space plasma and energetic particles: ~7 keV energy resolution for protons with a 14 keV threshold level, and good response linearity for ions and electrons as expected from Monte-Carlo calculations of primary particle energy loss. We investigated that these diamond detectors are able to operate at high temperature (> 70 ° C) and have fast response times (< 1 ns rise time). While silicon detectors have proven capability over this energy range for space plasma measurements, diamond detectors offer a faster response, higher temperature operation, greater radiation tolerance, and immunity to light.

  19. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect

    Harris Kagan; K.K. Gan; Richard Kass

    2009-03-31

    Diamond was studied as a possible radiation hard technology for use in future high radiation environments. With the commissioning of the LHC expected in 2009, and the LHC upgrades expected in 2013, all LHC experiments are planning for detector upgrades which require radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is installed in all LHC experiments. As a result, this material is now being discussed as an alternative sensor material for tracking very close to the interaction region of the super-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications.

  20. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect

    Rainer Wallny

    2012-10-15

    Diamond was studied as a possible radiation hard technology for use in future high radiation environments. With the commissioning of the LHC expected in 2010, and the LHC upgrades expected in 2015, all LHC experiments are planning for detector upgrades which require radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is installed and operational in all LHC experiments. As a result, this material is now being discussed as an alternative sensor material for tracking very close to the interaction region of the super-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications.

  1. Quantification of Cigarette Smoke Particle Deposition In Vitro Using a Triplicate Quartz Crystal Microbalance Exposure Chamber

    PubMed Central

    Adamson, Jason; Thorne, David; McAughey, John; Dillon, Deborah; Meredith, Clive

    2013-01-01

    There are a variety of smoke exposure systems available to the tobacco industry and respiratory toxicology research groups, each with their own way of diluting/delivering smoke to cell cultures. Thus a simple technique to measure dose in vitro needs to be utilised. Dosimetry—assessment of dose—is a key element in linking the biological effects of smoke generated by various exposure systems. Microbalance technology is presented as a dosimetry tool and a way of measuring whole smoke dose. Described here is a new tool to quantify diluted smoke particulate deposition in vitro. The triplicate quartz crystal microbalance (QCM) chamber measured real-time deposition of smoke at a range of dilutions 1 : 5–1 : 400 (smoke : air). Mass was read in triplicate by 3 identical QCMs installed into one in vitro exposure chamber, each in the location in which a cell culture would be exposed to smoke at the air-liquid interface. This resulted in quantification of deposited particulate matter in the range 0.21–28.00 μg/cm2. Results demonstrated that the QCM could discriminate mass between dilutions and was able to give information of regional deposition where cell cultures would usually be exposed within the chamber. Our aim is to use the QCM to support the preclinical (in vitro) evaluation of tobacco products. PMID:23484139

  2. Controlling single and few-layer graphene crystals growth in a solid carbon source based chemical vapor deposition

    SciTech Connect

    Papon, Remi; Sharma, Subash; Shinde, Sachin M.; Vishwakarma, Riteshkumar; Tanemura, Masaki; Kalita, Golap

    2014-09-29

    Here, we reveal the growth process of single and few-layer graphene crystals in the solid carbon source based chemical vapor deposition (CVD) technique. Nucleation and growth of graphene crystals on a polycrystalline Cu foil are significantly affected by the injection of carbon atoms with pyrolysis rate of the carbon source. We observe micron length ribbons like growth front as well as saturated growth edges of graphene crystals depending on growth conditions. Controlling the pyrolysis rate of carbon source, monolayer and few-layer crystals and corresponding continuous films are obtained. In a controlled process, we observed growth of large monolayer graphene crystals, which interconnect and merge together to form a continuous film. On the other hand, adlayer growth is observed with an increased pyrolysis rate, resulting few-layer graphene crystal structure and merged continuous film. The understanding of monolayer and few-layer crystals growth in the developed CVD process can be significant to grow graphene with controlled layer numbers.

  3. Crystallization from Gels

    NASA Astrophysics Data System (ADS)

    Narayana Kalkura, S.; Natarajan, Subramanian

    Among the various crystallization techniques, crystallization in gels has found wide applications in the fields of biomineralization and macromolecular crystallization in addition to crystallizing materials having nonlinear optical, ferroelectric, ferromagnetic, and other properties. Furthermore, by using this method it is possible to grow single crystals with very high perfection that are difficult to grow by other techniques. The gel method of crystallization provides an ideal technique to study crystal deposition diseases, which could lead to better understanding of their etiology. This chapter focuses on crystallization in gels of compounds that are responsible for crystal deposition diseases. The introduction is followed by a description of the various gels used, the mechanism of gelling, and the fascinating phenomenon of Liesegang ring formation, along with various gel growth techniques. The importance and scope of study on crystal deposition diseases and the need for crystal growth experiments using gel media are stressed. The various crystal deposition diseases, viz. (1) urolithiasis, (2) gout or arthritis, (3) cholelithiasis and atherosclerosis, and (4) pancreatitis and details regarding the constituents of the crystal deposits responsible for the pathological mineralization are discussed. Brief accounts of the theories of the formation of urinary stones and gallstones and the role of trace elements in urinary stone formation are also given. The crystallization in gels of (1) the urinary stone constituents, viz. calcium oxalate, calcium phosphates, uric acid, cystine, etc., (2) the constituents of the gallstones, viz. cholesterol, calcium carbonate, etc., (3) the major constituent of the pancreatic calculi, viz., calcium carbonate, and (4) cholic acid, a steroidal hormone are presented. The effect of various organic and inorganic ions, trace elements, and extracts from cereals, herbs, and fruits on the crystallization of major urinary stone and gallstone

  4. Deposition and field emission properties of highly crystallized silicon films on aluminum-coated polyethylene napthalate

    NASA Astrophysics Data System (ADS)

    Li, Junshuai; Wang, Jinxiao; Yin, Min; Gao, Pingqi; He, Deyan; Chen, Qiang; Shirai, Hajime

    2007-08-01

    Highly crystallized silicon films were deposited on aluminum-coated polyethylene napthalate (PEN) substrates by inductively coupled plasma (ICP-) chemical vapor deposition (CVD) at room temperature. The films with uniform grains about 50 nm have the (1 1 1) preferred orientation. By studying the relation of the silicon film crystallinity to the flow ratio of SiH 4 to H 2, it was found that the interaction between precursors and aluminum layers plays an important role in the crystallization process. The surface roughness of the resultant films was analyzed by atomic force microscopy (AFM). The results reveal that the roughness of the silicon films on aluminum-coated PEN substrates, compared to the films on bare PEN substrates, is dependent on the film phase rather than the substrate morphology. The measurement of field electron emission of the crystalline silicon film indicates that the threshold field is about 8.3 V/μm and the emission is reproducible in the emission region.

  5. Osteopontin knockdown in the kidneys of hyperoxaluric rats leads to reduction in renal calcium oxalate crystal deposition.

    PubMed

    Tsuji, Hidenori; Shimizu, Nobutaka; Nozawa, Masahiro; Umekawa, Tohru; Yoshimura, Kazuhiro; De Velasco, Marco A; Uemura, Hirotsugu; Khan, Saeed R

    2014-06-01

    Osteopontin (OPN) expression is increased in kidneys of rats with ethylene glycol (EG) induced hyperoxaluria and calcium oxalate (CaOx) nephrolithiasis. The aim of this study is to clarify the effect of OPN knockdown by in vivo transfection of OPN siRNA on deposition of CaOx crystals in the kidneys. Hyperoxaluria was induced in 6-week-old male Sprague-Dawley rats by administering 1.5% EG in drinking water for 2 weeks. Four groups of six rats each were studied: Group A, untreated animals (tap water); Group B, administering 1.5% EG; Group C, 1.5% EG with in vivo transfection of OPN siRNA; Group D, 1.5% EG with in vivo transfection of negative control siRNA. OPN siRNA transfections were performed on day 1 and 8 by renal sub-capsular injection. Rats were killed at day 15 and kidneys were removed. Extent of crystal deposition was determined by measuring renal calcium concentrations and counting renal crystal deposits. OPN siRNA transfection resulted in significant reduction in expression of OPN mRNA as well as protein in group C compared to group B. Reduction in OPN expression was associated with significant decrease in crystal deposition in group C compared to group B. Specific suppression of OPN mRNA expression in kidneys of hyperoxaluric rats leads to a decrease in OPN production and simultaneously inhibits renal crystal deposition. PMID:24619192

  6. Osteopontin knockdown in the kidneys of hyperoxaluric rats leads to reduction in renal calcium oxalate crystal deposition

    PubMed Central

    Shimizu, Nobutaka; Nozawa, Masahiro; Umekawa, Tohru; Yoshimura, Kazuhiro; De Velasco, Marco A.; Uemura, Hirotsugu; Khan, Saeed R.

    2016-01-01

    Osteopontin (OPN) expression is increased in kidneys of rats with ethylene glycol (EG) induced hyperoxaluria and calcium oxalate (CaOx) nephrolithiasis. The aim of this study is to clarify the effect of OPN knockdown by in vivo transfection of OPN siRNA on deposition of CaOx crystals in the kidneys. Hyperoxaluria was induced in 6-week-old male Sprague–Dawley rats by administering 1.5 % EG in drinking water for 2 weeks. Four groups of six rats each were studied: Group A, untreated animals (tap water); Group B, administering 1.5 % EG; Group C, 1.5 % EG with in vivo transfection of OPN siRNA; Group D, 1.5 % EG with in vivo transfection of negative control siRNA. OPN siRNA transfections were performed on day 1 and 8 by renal sub-capsular injection. Rats were killed at day 15 and kidneys were removed. Extent of crystal deposition was determined by measuring renal calcium concentrations and counting renal crystal deposits. OPN siRNA transfection resulted in significant reduction in expression of OPN mRNA as well as protein in group C compared to group B. Reduction in OPN expression was associated with significant decrease in crystal deposition in group C compared to group B. Specific suppression of OPN mRNA expression in kidneys of hyperoxaluric rats leads to a decrease in OPN production and simultaneously inhibits renal crystal deposition. PMID:24619192

  7. In-Situ phase and texture characterization of solution deposited PZT thin films during crystallization.

    SciTech Connect

    Brennecka, Geoffrey L.; Nittala, Krishna; Jones, Jacob L.

    2010-08-01

    Ferroelectric lead zirconate titanate (PZT) thin films are used for integrated capacitors, ferroelectric memory, and piezoelectric actuators. Solution deposition is routinely used to fabricate these thin films. During the solution deposition process, the precursor solutions are spin coated onto the substrate and then pyrolyzed to form an amorphous film. The amorphous film is then heated at a higher temperature (650-700 C) to crystallize the film into the desired perovskite phase. Phase purity is critical in achieving high ferroelectric properties. Moreover, due to the anisotropy in the structure and properties of PZT, it is desirable to control the texture obtained in these thin films. The heating rate during crystallization process is known to affect the sequence of phase evolution and texture obtained in these thin films. However, to date, a comprehensive understanding of how phase and texture evolution takes place is still lacking. To understand the effects of heating rate on phase and texture evolution, in-situ diffraction experiments during the crystallization of solution deposited PZT thin films were carried out at beamline 6-ID-B, Advanced Photon Source (APS). The high X-ray flux coupled with the sophisticated detectors available at the APS synchrotron source allow for in-situ characterization of phase and texture evolution at the high ramp rates that are commonly used during processing of PZT thin films. A PZT solution of nominal composition 52/48 (Zr/Ti) was spin coated onto a platinum-coated Si substrate (Pt//TiO{sub x}//SiO{sub 2}//Si). The films were crystallized using an infrared lamp, similar to a rapid thermal annealing furnace. The ramp rate was adjusted by controlling the voltage applied to the infrared lamp and increasing the voltage by a constant step with every acquisition. Four different ramp rates, ranging from {approx}1000 C/s to {approx}1 C/s, were investigated. The sample was aligned in grazing incidence to maximize the signal from the thin

  8. Subclinical Celiac Disease and Crystal-Induced Kidney Disease Following Kidney Transplant

    PubMed Central

    Capolongo, Giovanna; Abul-Ezz, Sameh; Moe, Orson W.; Sakhaee, Khashayar

    2015-01-01

    Decreased kidney function from kidney deposition of calcium oxalate has been previously described in inflammatory bowel disease as well as following jejuno-ileal and Roux-en-Y gastric bypass surgeries. Although celiac disease is the most prevalent bowel abnormality associated with intestinal malabsorption, its relationship to high kidney oxalate burden and decreased kidney function has not been established. We report a case of subclinical celiac disease and hyperoxaluria that presented with loss of kidney function as a result of high oxalate load in the absence of overt diarrhea, documented intestinal fat malabsorption, and nephrolithiasis. Subclinical celiac disease is commonly overlooked and hyperoxaluria is not usually investigated in kidney patients. We propose that this entity should be suspected in patients with chronic kidney disease in which the etiology of kidney damage has not been clearly established. PMID:22739230

  9. Therapeutic effect of Xue Niao An on glyoxylate-induced calcium oxalate crystal deposition based on urinary metabonomics approach

    PubMed Central

    Peng, Zhongjiang; Chen, Wei; Gao, Songyan; Su, Li; Li, Na; Wang, Li; Lou, Ziyang; Dong, Xin; Guo, Zhiyong

    2014-01-01

    The anti-nephrolithiasis effect of Xue Niao An (XNA) capsules is explored by analyzing urine metabolic profiles in mouse models, with ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). An animal model of calcium oxalate crystal renal deposition was established in mice by intra-abdominal injection of glyoxylate. Then, treatment with XNA by intra-gastric administration was performed. At the end of the study, calcium deposition in kidney was measured by Von Kossa staining under light microscopy, and the Von Kossa staining changes showed that XNA significantly alleviated the calcium oxalate crystal deposition. Meanwhile, urine samples for fifteen metabolites, including amino acids and fatty acids, with significant differences were detected in the calcium oxalate group, while XNA treatment attenuated metabolic imbalances. Our study indicated that the metabonomic strategy provided comprehensive insight on the metabolic response to XNA treatment of rodent renal calcium oxalate deposition. PMID:25411524

  10. Metal patterning on silicon surface by site-selective electroless deposition through colloidal crystal templating.

    PubMed

    Asoh, Hidetaka; Sakamoto, Seiji; Ono, Sachiko

    2007-12-15

    Site-selective Cu deposition on a Si substrate was achieved by a combination of colloidal crystal templating, hydrophobic treatment, and electroless plating. Uniformly sized nano/microstructures were produced on the substrate using a monolayer coating of colloidal spheres instead of a conventional resist. The Cu patterns obtained were of two different types: networklike honeycomb and isolated-island patterns with a minimum period of 200 nm. Each ordered pattern with the desired intervals was composed of clusters of Cu nanoparticles with a size range of 50-100 nm. By the present method, it is possible to control the periodicity of metal arrays by changing the diameter of the colloidal spheres used as an initial mask and to adjust the shape of the metal patterns by changing the mask structure for electroless plating. PMID:17915242

  11. Fracture of colloidal single-crystal films fabricated by controlled vertical drying deposition.

    PubMed

    Cao, He; Lan, Ding; Wang, Yuren; Volinsky, Alex A; Duan, Li; Jiang, Heng

    2010-09-01

    Controlled vertical drying deposition method was used to make high-quality single crystal close-packed colloidal films formed of different radii polystyrene latex spheres on glass substrates coming from a low concentration water suspension (0.1% volume fraction). Regardless of the spheres radii the film thickness was about 6.3 microns. However, cracks destroyed the crystalline film structure during the colloidal film growth. The effect of particle radius (85-215 nm range) on film cracking was systematically studied using in situ optical fracture monitoring. Primary parallel cracks run along the vertical growth direction, later followed by secondary branched cracks in-between the primary cracks due to residual water evaporation. Quantitative theoretical relationship between the cracks spacing and particles radius was derived and shows good agreement with experimental observations. Normalized cracks spacing is related to a reciprocal ratio of the dimensionless particle radius. PMID:21230081

  12. Silica Nanowire Growth on Photonic Crystal Fiber by Pulsed Femtosecond Laser Deposition

    NASA Astrophysics Data System (ADS)

    Langellier, Nicholas; Li, Chih-Hao; Furesz, Gabor; Glenday, Alex; Phillips, David; Zhang, Huiliang; Noah Chang, Guoqing; Kaertner, Franz; Szentgyorgyi, Andrew; Walsworth, Ronald

    2012-06-01

    We present a new method of nanowire fabrication using pulsed laser deposition. An 800 mW 1 GHz femtosecond Ti:Sapphire laser is guided into a polarization-maintaining photonic crystal fiber (PCF). The PCF, with a core tapered to 1.7 micron diameter, converts femtosecond laser pulses centered at 800 nm into green light with a spectrum down to 500 nm. The PCF is enclosed in a cylindrical tube with glass windows, sealed in a class 100 clean room with silicone-based RTV adhesive. The high power of each laser pulse in a silica-rich environment leads to growth of a silica nanowire at the output end of the PCF. SEM analysis shows that the nanowire is 720 nm in diameter and grows at a rate of about 0.6 um/s. Details of nanowire performance along with potential applications will be presented.

  13. Optical emission diagnostics of plasmas in chemical vapor deposition of single-crystal diamond

    SciTech Connect

    Hemawan, Kadek W. Hemley, Russell J.

    2015-11-15

    A key aspect of single crystal diamond growth via microwave plasma chemical vapor deposition is in-process control of the local plasma–substrate environment, that is, plasma gas phase concentrations of activated species at the plasma boundary layer near the substrate surface. Emission spectra of the plasma relative to the diamond substrate inside the microwave plasma reactor chamber have been analyzed via optical emission spectroscopy. The spectra of radical species such as CH, C{sub 2}, and H (Balmer series) important for diamond growth were identified and analyzed. The emission intensities of these electronically excited species were found to be more dependent on operating pressure than on microwave power. Plasma gas temperatures were calculated from measurements of the C{sub 2} Swan band (d{sup 3}Π → a{sup 3}Π transition) system. The plasma gas temperature ranges from 2800 to 3400 K depending on the spatial location of the plasma ball, microwave power and operating pressure. Addition of Ar into CH{sub 4}+H{sub 2} plasma input gas mixture has little influence on the Hα, Hβ, and Hγ intensities and single-crystal diamond growth rates.

  14. Cooperative Island Growth of Large Area Single-Crystal Graphene by Chemical Vapor Deposition on Cu

    SciTech Connect

    Regmi, Murari; Rouleau, Christopher; Puretzky, Alexander A; Ivanov, Ilia N; Geohegan, David B; Chen, Jihua; Eastman, Jeffrey; Eres, Gyula

    2014-01-01

    We describe a two-step approach for suppressing nucleation of graphene on Cu using chemical vapor deposition. In the first step, as received Cu foils are oxidized in air at temperatures up to 500 C to remove surface impurities and to induce the regrowth of Cu grains during subsequent annealing in H2 flow at 1040 C prior to graphene growth. In the second step, transient reactant cooling is performed by using a brief Ar pulse at the onset of growth to induce collisional deactivation of the carbon growth species. The combination of these two steps results in a three orders of magnitude reduction in the graphene nucleation density, enabling the growth of millimeter-size single crystal graphene grains. A kinetic model shows that suppressing nucleation promotes a cooperative island growth mode that favors the formation of large area single crystal graphene, and it is accompanied by a roughly 3 orders of magnitude increase in the reactive sticking probability of methane compared to that in random nucleation growth.

  15. Triggering the Growth of Large Single Crystal Graphene by Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Wu, Tianru; Wang, Haomin; Ding, Guqiao; Jiang, Da; Xie, Xiaoming; Jiang, Mianheng

    2013-03-01

    Graphene, a monolayer of sp2 carbon atoms, has been attracting great interests as an ideal two dimensional crystalline material. Fabrication technique for wafer scale graphene via chemical vapor deposition (CVD) was developed several years ago. However, large scale graphene films from CVD method so far are found to be polycrystalline, consisting of numerous grain boundaries, which greatly degrade the electrical and mechanical properties of graphene. Recently, we obtained hexagonal-shaped single-crystal monolayer graphene domains (~1.2 mm). We adapted a strategy to synthesize larger size single crystal grains by regulating the supply of reactants and hytrogen. Nucleation density can be decreased to less than 1000 nuclei /m2. Gradually increase in the supply of reactants could break the equilibrium of growth and etching at the edge of hexagonal-shaped graphene grains. It drives the reaction toward quick growth of graphene domains during the whole CVD process. The graphene grains we obtained show high crystalline quality with high mobility of ~13000 cm2V-1s-1, which is comparable to that of exfoliated graphene. The results achieved will definitely benefit for further practical application of graphene electronics.

  16. Ion-beam-induced epitaxial crystallization of implanted and chemical vapor deposited amorphous silicon

    NASA Astrophysics Data System (ADS)

    La Ferla, A.; Priolo, F.; Spinella, C.; Rimini, E.; Baroetto, F.; Ferla, G.

    1989-03-01

    The dependence of ion-beam enhanced epitaxial growth of amorphous Si layers on impurities either dissolved in the film or present at the film-substrate interface is considered. In the case of ion implanted layers, electrically active dopants, like B, P, As at concentrations above 1 × 10 20/cm 3, enhance the rate by a factor of 2 with respect to the undoped layer. The enhancement shows also a weak dependence on the dopant concentration. Inert impurities, like Ar, which prevent pure thermal regrowth, do not show any appreciable influence on the ion-beam-induced growth rate. Chemical vapor deposited Si layers with a thin native interfacial oxide layer can also be epitaxially regrown under ion irradiation. A critical fluence is needed before the interfacial oxide breaks down and broadens, allowing the epitaxial crystallization to take place. This process is characterized by an activation energy of 0.44 eV. The complex phenomenon of ion-beam-induced crystallization involves a dynamical interaction between production and annealing of point defects. The presence of electrically active dopants probably influences the lifetime of point defects. Impurities which prevent thermal regrowth are instead dissolved by ballistic effects and/or radiation-enhanced mixing.

  17. Drying, phase separation, and deposition in droplets of sunset yellow chromonic liquid crystal

    NASA Astrophysics Data System (ADS)

    Gross, Adam; Davidson, Zoey S.; Huang, Yongyang; Still, Tim; Zhou, Chao; Yodh, A. G.

    We investigate the drying process and the final deposition patterns of multi-phase sessile droplets containing aqueous lyotropic chromonic liquid crystal (LC). The experiments employ a variety of optical techniques including profilometry, polarization optical microscopy and optical coherence microscopy. An unusual hierarchical LC assembly is observed during drying; in particular, LC mesogens are first formed at the start of drying and then compartments of isotropic, nematic and columnar phases arise. Nonuniform evaporation creates concentration gradients in droplets such that LC phases emerge from the outer edge of the drop and advance to the center over the course of drying. Distinct outward flows associated with the ``coffee-ring effect'' are seen initially, but the assembly of the mesogens creates viscosity, density, and surface tension gradients that effectively introduce new convective flows and complex LC phase boundaries within the drop. Finally, we show that the final deposit shape of chromonic materials changes with rate of evaporation. We gratefully acknowledge financial support through NSF DMR12-05463, MRSEC DMR11-20901, NASA NNX08AO0G, and NSF DBI-1455613.

  18. Graphene-deposited photonic crystal fibers for continuous refractive index sensing applications.

    PubMed

    Tan, Y C; Tou, Z Q; Chow, K K; Chan, C C

    2015-11-30

    We present a pilot demonstration of an optical fiber based refractive index (RI) sensor involving the deposition of graphene onto the surface of a segment of a photonic crystal fiber (PCF) in a fiber-based Mach-Zehnder Interferometer (MZI). The fabrication process is relatively simple and only involves the fusion splicing of a PCF between two single mode fibers. The deposition process relies only on the cold transfer of graphene onto the PCF segment, without the need for further physical or chemical treatment. The graphene overlay modified the sensing scheme of the MZI RI sensor, allowing the sensor to overcome limitations to its detectable RI range due to free spectral range issues. This modification also allows for continuous measurements to be obtained without the need for reference values for the range of RIs studied and brings to light the potential for simultaneous dual parameter sensing. The sensor was able to achieve a RI sensitivity of 9.4 dB/RIU for the RIs of 1.33-1.38 and a sensitivity of 17.5 dB/RIU for the RIs of 1.38-1.43. It also displayed good repeatability and the results obtained were consistent with the modeling. PMID:26698755

  19. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect

    Kagan, Harris; Kass, Richard; Gan, K. K.

    2014-01-23

    With the LHC upgrades in 2013, and further LHC upgrades scheduled in 2018, most LHC experiments are planning for detector upgrades which require more radiation hard technologies than presently available. At present all LHC experiments now have some form of diamond detector. As a result Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of all LHC experiments. Moreover CVD diamond is now being discussed as an alternative sensor material for tracking very close to the interaction region of the HL-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications. Our accomplishments include: • Developed a two U.S.companies to produce electronic grade diamond, • Worked with companies and acquired large area diamond pieces, • Performed radiation hardness tests using various proton energies: 70 MeV (Cyric, Japan), 800 MeV (Los Alamos), and 24 GeV (CERN).

  20. Pulsed Laser Deposition of Thin YBCO Films on Faceted YSZ Single Crystal Fibers

    NASA Astrophysics Data System (ADS)

    Snigirev, O.; Chukharkin, M.; Porokhov, N.; Rusanov, S. Y.; Kashin, V. V.; Tsvetkov, V. B.; Kalabukhov, A.; Winkler, D.

    2014-05-01

    Flexible rods of single crystals of 9% Y2O3-stabilized ZrO2 (YSZ) were used as substrates for deposition of high-critical temperature superconducting (HTS) thin films. YSZ fibers were prepared by mini-pedestal method with laser heating and had average diameter of 300 micrometers and 30 mm length. X-ray diffraction analysis demonstrated high crystalline quality of obtained fibers and also indicated the presence of 15° deviation of the fiber axis from the [001] YSZ direction. Thin YBa2Cu3O7-x films were grown by pulsed laser deposition on YSZ rods using CeO2 buffer layer. Films have shown high critical temperature of 90 K with sharp superconducting transition. Critical current density was estimated to about 3×104 A/cm2 at 80 K. Temperature dependence of critical current density suggests granular structure of films with grain size about several microns. Our results demonstrate feasibility of flexible YSZ fibers coated by HTS thin films for practical use.

  1. Diagnostic value of ultrasound in calcium pyrophosphate deposition disease: a systematic review and meta-analysis

    PubMed Central

    Gamon, Etienne; Combe, Bernard; Barnetche, Thomas; Mouterde, Gaël

    2015-01-01

    Objective A systematic review and meta-analysis of data from cohort studies to analyse the diagnostic performances (ie, sensitivity and specificity) of ultrasound (US) for diagnosis of calcium pyrophosphate deposition (CPPD) disease with microscopic crystal detection used as a gold standard. Methods We performed a systematic review of articles published up to December 2014 using EMBASE, MEDLINE and Cochrane databases and abstracts from the past two EULAR and ACR annual meetings. Only studies reporting the performance of US for diagnosis of CPPD disease were selected. A meta-analysis involved the inverse variance method to evaluate global sensitivity and specificity of US. Statistical heterogeneity was assessed by the Cochran Q-test and I2 values. Results The search resulted in 85 articles and 11 abstracts; 17 and 4, respectively, were selected for the systematic review. A total of 262 patients with CPPD disease and 335 controls from 4 original articles and 4 abstracts were included in the meta-analysis. The US diagnostic patterns most frequently recorded were thin hyperechoic bands in the hyaline cartilage (8 articles); hyperechoic spots in fibrous cartilage or in tendons (7 articles); and homogeneous hyperechoic nodules localised in bursa or articular recesses (4 articles). The meta-analysis revealed a heterogeneity of the data, with a sensitivity of 87.9% (95% CI 80.9% to 94.9%) and specificity of 91.5% (95% CI 85.5% to 97.5%) using a random model. Conclusions This meta-analysis confirmed that US has high sensitivity and specificity for the diagnosis of CPPD and may be a promising tool for the diagnosis and management of CPPD. PMID:26535143

  2. IgD Heavy-Chain Deposition Disease: Detection by Laser Microdissection and Mass Spectrometry

    PubMed Central

    Royal, Virginie; Quint, Patrick; Leblanc, Martine; LeBlanc, Richard; Duncanson, Garrett F.; Perrizo, Robert L.; Fervenza, Fernando C.; Kurtin, Paul

    2015-01-01

    Monoclonal Ig deposition disease (MIDD) is a rare complication of monoclonal gammopathy characterized by deposition of monoclonal Ig light chains and/or heavy chains along the glomerular and tubular basement membranes. Here, we describe a unique case of IgD deposition disease. IgD deposition is difficult to diagnose, because routine immunofluorescence does not detect IgD. A 77-year-old man presented with proteinuria and renal failure, and kidney biopsy analysis showed a nodular sclerosing GN with extensive focal global glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Immunofluorescence was negative for Ig deposits, although electron microscopy showed deposits in the glomeruli and along tubular basement membranes. Laser microdissection of glomeruli and mass spectrometry of extracted peptides showed a large spectra number for IgD, and immunohistochemistry showed intense glomerular and tubular staining for IgD. Together, these findings are consistent with IgD deposition disease. Bone marrow biopsy analysis showed 5% plasma cells, which stained for IgD. The patient was treated with bortezomib and dexamethasone, which resulted in improvement of hematologic parameters but no improvement of renal function. The diagnosis of IgD deposition disease underscores the value of laser microdissection and mass spectrometry in further evaluating renal biopsies when routine assessment fails to reach an accurate diagnosis. PMID:25194005

  3. Atomic layer deposition of epitaxial layers of anatase on strontium titanate single crystals: Morphological and photoelectrochemical characterization

    SciTech Connect

    Kraus, Theodore J.; Nepomnyashchii, Alexander B.; Parkinson, B. A.

    2015-01-15

    Atomic layer deposition was used to grow epitaxial layers of anatase (001) TiO{sub 2} on the surface of SrTiO{sub 3} (100) crystals with a 3% lattice mismatch. The epilayers grow as anatase (001) as confirmed by x-ray diffraction. Atomic force microscope images of deposited films showed epitaxial layer-by-layer growth up to about 10 nm, whereas thicker films, of up to 32 nm, revealed the formation of 2–5 nm anatase nanocrystallites oriented in the (001) direction. The anatase epilayers were used as substrates for dye sensitization. The as received strontium titanate crystal was not sensitized with a ruthenium-based dye (N3) or a thiacyanine dye (G15); however, photocurrent from excited state electron injection from these dyes was observed when adsorbed on the anatase epilayers. These results show that highly ordered anatase surfaces can be grown on an easily obtained substrate crystal.

  4. AEROSOL DEPOSITION AS A FUNCTION OF AIRWAY DISEASE: CYSTIC FIBROSIS

    EPA Science Inventory

    Progressive lung disease associated with cystic fibrosis (CF) is a continuous interaction of the processes of airway obstruction, infection and inflammation. ecent literature has suggested that the manifestation of CF could compromise the successful administration of pharmacologi...

  5. Near single crystal-level dielectric loss and nonlinearity in pulsed laser deposited SrTiO3 thin films

    NASA Astrophysics Data System (ADS)

    Li, Hong-Cheng; Si, Weidong; West, Alexander D.; Xi, X. X.

    1998-07-01

    We present low-frequency dielectric loss and nonlinearity measurements in SrTiO3 thin films grown by pulsed laser deposition on SrRuO3 electrode layers. A low loss tangent in the order of 10-4, close to the level found in SrTiO3 single crystals, was observed. Combined with a large tunability, this resulted in a figure of merit for frequency and phase agile materials that can rival that observed in single crystals. The result is potentially significant for tunable microwave device applications, and it points to stress and interface effects as the possible causes for higher dielectric losses in thin films.

  6. Influence of a thin interfacial oxide layer on the ion beam assisted epitaxial crystallization of deposited Si

    NASA Astrophysics Data System (ADS)

    Priolo, F.; La Ferla, A.; Spinella, C.; Rimini, E.; Ferla, G.; Baroetto, F.; Licciardello, A.

    1988-12-01

    The epitaxial crystallization of chemical vapor deposited Si layers on <100> Si substrates with a thin interfacial oxide layer was induced by a 600 keV Kr beam in the temperature range 350-500 °C. During irradiation the single crystal-amorphous interface velocity was measured in situ by monitoring the reflectivity of He-Ne laser light. We show that a critical irradiation dose is needed before the interfacial oxide breaks down and epitaxial regrowth can take place. This critical dose depends exponentially on the reciprocal temperature with an activation energy of 0.44 eV.

  7. Kinetics of structuring of submonolayer carbon coatings on silicon (100) crystals during microwave vacuum-plasma deposition

    NASA Astrophysics Data System (ADS)

    Yafarov, R. K.; Shanygin, V. Ya.

    2015-06-01

    The kinetics of self-organization of nanodomains during the deposition of submonolayer carbon coatings on (100) silicon in the microwave plasma of low-pressure ethanol vapors is studied by atomic force microscopy and scanning electron microscopy. The laws of influence of the substrate temperature and the kinetic energy of carbon-containing ions on the mechanisms of formation and structuring of the forming silicon-carbon surface phases are established. It is shown that the deposited carbon-containing nanodomains can be used as nonlithographic mask coatings for the formation of spatial low-dimensional systems on single-crystal silicon upon selective highly anisotropic plasma-chemical etching.

  8. Temperature cycling vapor deposition HgI.sub.2 crystal growth

    DOEpatents

    Schieber, Michael M.; Beinglass, Israel; Dishon, Giora

    1977-01-01

    A method and horizontal furnace for vapor phase growth of HgI.sub.2 crystals which utilizes controlled axial and radial airflow to maintain the desired temperature gradients. The ampoule containing the source material is rotated while axial and radial air tubes are moved in opposite directions during crystal growth to maintain a desired distance and associated temperature gradient with respect to the growing crystal, whereby the crystal interface can advance in all directions, i.e., radial and axial according to the crystallographic structure of the crystal. Crystals grown by this method are particularly applicable for use as room-temperature nuclear radiation detectors.

  9. A case of Alzheimer's disease in magmatic crystals

    NASA Astrophysics Data System (ADS)

    Costa Rodriguez, F.; Bouvet de Maisonneuve, C.

    2012-12-01

    The reequilibration of chemical zoning in crystals from volcanic rocks is increasingly used to determine the duration of the processes involved in their origin, residence and transport. There now exist a good number of determinations of diffusion coefficients in olivine (Fe-Mg, Mn, Ca, Ni, Cr), plagioclase (CaAl-NaSi, Mg, Sr, Ba, REE), pyroxenes (Fe-Mg, Mn, Ca, REE) and quartz (Ti), but most studies have used a single element or component in a single mineral group. Although this is a good approach, it can only access a limited range of time scales, typically the short-term memory of the crystal. In other words, for process durations that are longer than the combination of the diffusivity and diffusion distance (and for a constant boundary), the long-term memory of the crystal might have been lost. This could explain why most time determinations of magmatic processes from volcanic rocks give times of about < 100 years, and why these are shorter than the thousands of years obtained from U-Th series disequilibrium isotopes. We have done a series of numerical calculations and natural observation to determine the time windows that can be accessed with different elements and minerals, and how they may affect the time scales and interpretations of processes that the crystals might be recording. We have looked at two end-members representative of mafic and silicic magmas by changing the temperature and mineral compositions. 3 dimensional calculations of diffusion reequilibration at the center of a 1 x 0.5 x 0.5 mm crystal and using a constant boundary as first case. We find that for mafic magma and olivine, 90 % of equilibration of Fe-Mg, Mn, and Ni occurs in a few decades, but gradients in Ca and Cr persist for a few thousand years. These results can for example explain the large ranges of Ca and Cr contents at a given Fe/Mg of olivine, and why apparently contradictory times can be obtained from elements with different diffusivities in the same crystal. At the same time

  10. Enhanced growth of high quality single crystal diamond by microwave plasma assisted chemical vapor deposition at high gas pressures

    SciTech Connect

    Liang Qi; Chin Chengyi; Lai, Joseph; Yan Chihshiue; Meng Yufei; Mao Hokwang; Hemley, Russell J.

    2009-01-12

    Single crystals of diamond up to 18 mm in thickness have been grown by microwave plasma assisted chemical vapor deposition at gas pressures of up to 350 torr. Growth rates of up to 165 {mu}m/h at 300 torr at high power density have been achieved. The processes were evaluated by optical emission spectroscopy. The high-quality single-crystal diamond grown at optimized conditions was characterized by UV-visible absorption and photoluminescence spectroscopy. The measurements reveal a direct relationship between residual absorption and nitrogen content in the gas chemistry. Fabrication of high quality single-crystal diamond at higher growth rates should be possible with improved reactor design that allows still higher gas synthesis pressures.

  11. Growth of large size diamond single crystals by plasma assisted chemical vapour deposition: Recent achievements and remaining challenges

    NASA Astrophysics Data System (ADS)

    Tallaire, Alexandre; Achard, Jocelyn; Silva, François; Brinza, Ovidiu; Gicquel, Alix

    2013-02-01

    Diamond is a material with outstanding properties making it particularly suited for high added-value applications such as optical windows, power electronics, radiation detection, quantum information, bio-sensing and many others. Tremendous progresses in its synthesis by microwave plasma assisted chemical vapour deposition have allowed obtaining single crystal optical-grade material with thicknesses of up to a few millimetres. However the requirements in terms of size, purity and crystalline quality are getting more and more difficult to achieve with respect to the forecasted applications, thus pushing the synthesis method to its scientific and technological limits. In this paper, after a short description of the operating principles of the growth technique, the challenges of increasing crystal dimensions both laterally and vertically, decreasing and controlling point and extended defects as well as modulating crystal conductivity by an efficient doping will be detailed before offering some insights into ways to overcome them.

  12. Chemical Vapor Deposition of Monolayer Mo(1-x)W(x)S2 Crystals with Tunable Band Gaps.

    PubMed

    Wang, Ziqian; Liu, Pan; Ito, Yoshikazu; Ning, Shoucong; Tan, Yongwen; Fujita, Takeshi; Hirata, Akihiko; Chen, Mingwei

    2016-01-01

    Band gap engineering of monolayer transition metal dichalcogenides, such as MoS2 and WS2, is essential for the applications of the two-dimensional (2D) crystals in electronic and optoelectronic devices. Although it is known that chemical mixture can evidently change the band gaps of alloyed Mo(1-x)W(x)S2 crystals, the successful growth of Mo(1-x)W(x)S2 monolayers with tunable Mo/W ratios has not been realized by conventional chemical vapor deposition. Herein, we developed a low-pressure chemical vapor deposition (LP-CVD) method to grow monolayer Mo(1-x)W(x)S2 (x = 0-1) 2D crystals with a wide range of Mo/W ratios. Raman spectroscopy and high-resolution transmission electron microscopy demonstrate the homogeneous mixture of Mo and W in the 2D alloys. Photoluminescence measurements show that the optical band gaps of the monolayer Mo(1-x)W(x)S2 crystals strongly depend on the Mo/W ratios and continuously tunable band gap can be achieved by controlling the W or Mo portion by the LP-CVD. PMID:26899364

  13. Chemical Vapor Deposition of Monolayer Mo1−xWxS2 Crystals with Tunable Band Gaps

    PubMed Central

    Wang, Ziqian; Liu, Pan; Ito, Yoshikazu; Ning, Shoucong; Tan, Yongwen; Fujita, Takeshi; Hirata, Akihiko; Chen, Mingwei

    2016-01-01

    Band gap engineering of monolayer transition metal dichalcogenides, such as MoS2 and WS2, is essential for the applications of the two-dimensional (2D) crystals in electronic and optoelectronic devices. Although it is known that chemical mixture can evidently change the band gaps of alloyed Mo1−xWxS2 crystals, the successful growth of Mo1−xWxS2 monolayers with tunable Mo/W ratios has not been realized by conventional chemical vapor deposition. Herein, we developed a low-pressure chemical vapor deposition (LP-CVD) method to grow monolayer Mo1−xWxS2 (x = 0–1) 2D crystals with a wide range of Mo/W ratios. Raman spectroscopy and high-resolution transmission electron microscopy demonstrate the homogeneous mixture of Mo and W in the 2D alloys. Photoluminescence measurements show that the optical band gaps of the monolayer Mo1−xWxS2 crystals strongly depend on the Mo/W ratios and continuously tunable band gap can be achieved by controlling the W or Mo portion by the LP-CVD. PMID:26899364

  14. Sulfur isotope and trace element systematics of zoned pyrite crystals from the El Indio Au-Cu-Ag deposit, Chile

    NASA Astrophysics Data System (ADS)

    Tanner, Dominique; Henley, Richard W.; Mavrogenes, John A.; Holden, Peter

    2016-04-01

    We present a comparative study between early, massive pyrite preceding (Cu-Ag) sulfosalt mineralization in high-temperature feeder zones (`early pyrite') and late pyrite that formed during silicic alteration associated with Au deposition (`late pyrite') at the El Indio high-sulfidation Au-Ag-Cu deposit, Chile. We use coupled in situ sulfur isotope and trace element analyses to chronologically assess geochemical variations across growth zones in these pyrite crystals. Early pyrite that formed in high-temperature feeder zones shows intricate oscillatory zonation of Cu, with individual laminae containing up to 1.15 wt% Cu and trace Co, As, Bi, Ni, Zn, Se, Ag, Sb, Te, Au, Pb and Bi. Late pyrite formed after (Cu-Ag) sulfosalt mineralization. It contains up to 1.14 wt% As with trace Cu, Zn, Pb, V, Mn, Co, Ni, Ge, Se, Ag, Sb, Te, Pb and Bi, as well as colloform Cu-rich growth bands containing vugs toward the outer edges of some crystals. Plotting the trace element data in chronological order (i.e., from core to rim) revealed that Co and Ni were the only elements to consistently co-vary across growth zones. Other trace elements were coupled in specific growth zones, but did not consistently co-vary across any individual crystal. The δ34S of early pyrite crystals in high-temperature feeder zones range from -3.19 to 1.88 ‰ (±0.5 ‰), consistent with sublimation directly from a high-temperature magmatic vapor phase. Late pyrite crystals are distinctly more enriched in δ34S than early pyrite (δ34S = 0.05-4.77 ‰, ±0.5 ‰), as a consequence of deposition from a liquid phase at lower temperatures. It is unclear whether the late pyrite was deposited from a small volume of liquid condensate, or a larger volume of hydrothermal fluid. Both types of pyrite exhibit intracrystalline δ34S variation, with a range of up to 3.31 ‰ recorded in an early pyrite crystal and up to 4.48 ‰ in a late pyrite crystal. Variations in δ34Spyrite at El Indio did not correspond with

  15. Deposition of AlN Thin Films with Cubic Crystal Structures on Silicon Substrates at Room Temperature

    NASA Astrophysics Data System (ADS)

    Ren, Zhong-Min; Lu, Yong-Feng; Goh, Yeow-Whatt; Chong, Tow-Chong; Ng, Mei-Ling; Wang, Jian-Ping; Cheong, Boon-Aik; Liew, Yun-Fook

    2000-05-01

    Cubic AlN thin films were deposited at room temperature by nitrogen-ion-assisted pulsed laser ablation of a hexagonal AlN target. The full-width at half maximum (FWHM) of the X-ray diffraction peak in the θ˜ 2θ scan can reach a value of 0.27 degrees. In the Raman spectroscopy measurement, a new peak at 2333 cm-1 originating from cubic AlN polycrystalline was observed. Nitrogen ions not only effectively promote the formation of stable Al-N bonds but also improve the crystal properties of the deposited thin films. A nitrogen ion energy of 400 eV is proposed for the thin-film deposition.

  16. A Physically Based Theoretical Model of Spore Deposition for Predicting Spread of Plant Diseases.

    PubMed

    Isard, Scott A; Chamecki, Marcelo

    2016-03-01

    A physically based theory for predicting spore deposition downwind from an area source of inoculum is presented. The modeling framework is based on theories of turbulence dispersion in the atmospheric boundary layer and applies only to spores that escape from plant canopies. A "disease resistance" coefficient is introduced to convert the theoretical spore deposition model into a simple tool for predicting disease spread at the field scale. Results from the model agree well with published measurements of Uromyces phaseoli spore deposition and measurements of wheat leaf rust disease severity. The theoretical model has the advantage over empirical models in that it can be used to assess the influence of source distribution and geometry, spore characteristics, and meteorological conditions on spore deposition and disease spread. The modeling framework is refined to predict the detailed two-dimensional spatial pattern of disease spread from an infection focus. Accounting for the time variations of wind speed and direction in the refined modeling procedure improves predictions, especially near the inoculum source, and enables application of the theoretical modeling framework to field experiment design. PMID:26595112

  17. Effect of dietary calcium and magnesium on experimental renal tubular deposition of calcium oxalate crystal induced by ethylene glycol administration and its prevention with phytin and citrate.

    PubMed

    Ebisuno, S; Morimoto, S; Yoshida, T; Fukatani, T; Yasukawa, S; Ohkawa, T

    1987-01-01

    Oral administration of ethylene glycol to rats, and the resultant intratubular depositions of microcrystals of calcium oxalate were studied investigating the influences of dietary calcium or magnesium and assessing the protective efficacies against the crystallizations by treatment with phytin and sodium citrate. With increase of calcium intake and consequent increase of urinary calcium excretion there was a marked increase in the amount of tubular deposit of calcium oxalate crystal and in the calcium content of renal tissue. Although magnesium deficiency accelerated renal tubular calcium oxalate deposition, the protection against the crystal formation was not observed with excessive dietary magnesium. When rats were fed a high-calcium diet supplemented with phytin, a significant inhibition of the intratubular crystallization was observed. It appeared obvious that a hypocalciuric action of phytin was attributed to the effect of the prevention. There was vigorous protection of crystal formation by treatment with sodium citrate, which correlated with the level of citrate concentration in the drinking water. PMID:3433579

  18. Effects of fiber characteristics on lung deposition, retention, and disease.

    PubMed Central

    Lippmann, M

    1990-01-01

    There is abundant epidemiologic evidence that asbestos fibers can cause lung fibrosis (asbestosis), bronchial cancer, and mesothelioma in humans, as well as limited evidence for such effects in workers exposed to slag and rockwool fibers. Epidemiological evidence for human disease from inhalation exposures to conventional fibrous glass is negative. While health concerns based on the morphological and toxicological similarities between man-made fibers and asbestos are warranted, it is important to note that most of the toxicological evidence for glass fiber toxicity in laboratory animals is based on nonphysiological exposures such as intratracheal instillation or intraperitoneal injection of fiber suspensions. Man-made fibers have produced lung fibrosis and mesotheliomas in such tests, albeit at much lower yields than asbestos. For all durable mineral fibers, critical length limits must be exceeded to warrant concern about chronic toxicity; i.e., 2 microns for asbestosis, 5 microns for mesothelioma, and 10 microns for lung cancer. Fiber width must be less than 0.1 microns for mesothelioma, and larger than this limit for asbestosis and lung cancer. The human health risks for most fibrous glass products are either low or negligible for a variety of reasons. First, most commercial fibrous glass products have mean fiber diameters of approximately 7.5 microns, which results in mean aero-dynamic diameters approximately 22 microns. Thus, most glass fibers, even if dispersed into the air, do not penetrate into the lung to any great extent. Second, the small fraction of smaller diameter fibers that do penetrate into the lungs are not persistent within the lungs for most fibrous glass products due to mechanical breakage into shorter lengths and overall dissolution.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2272328

  19. Origin of the giant Allard Lake ilmenite ore deposit (Canada) by fractional crystallization, multiple magma pulses and mixing

    NASA Astrophysics Data System (ADS)

    Charlier, Bernard; Namur, Olivier; Malpas, Simon; de Marneffe, Cédric; Duchesne, Jean-Clair; Vander Auwera, Jacqueline; Bolle, Olivier

    2010-06-01

    The late-Proterozoic Allard Lake ilmenite deposit is located in the Havre-Saint-Pierre anorthosite complex, part of the allochtonous polycyclic belt of the Grenville Province. Presently the world's largest Fe-Ti oxide deposit, it had a pre-mining amount in excess of 200 Mt at grades over 60 wt.% hemo-ilmenite. The main ore body is a funnel-shaped intrusion, measuring 1.03 × 1.10 km and 100-300 m-thick. Two smaller bodies are separated by faults and anorthosite. The ore is an ilmenite-rich norite (or ilmenitite) made up of hemo-ilmenite (Hem 22.6-29.4, 66.2 wt.% on average), andesine plagioclase (An 45-50), aluminous spinel and locally orthopyroxene. Whole-rock chemical compositions are controlled by the proportions of ilmenite and plagioclase ± orthopyroxene which supports the cumulate origin of the deposit. Ore-forming processes are further constrained by normal and reverse fractionation trends of Cr concentration in cumulus ilmenite that reveal multiple magma emplacements and alternating periods of fractional crystallization and magma mixing. Mixing of magmas produced hybrids located in the stability field of ilmenite resulted in periodic crystallization of ilmenite alone. The unsystematic differentiation trends in the Allard Lake deposit, arising from a succession of magma pulses, hybridisation, and the fractionation of hemo-ilmenite alone or together with plagioclase suggest that the deposit formed within a magma conduit. This dynamic emplacement mechanism associated with continuous gravity driven accumulation of Fe-Ti oxides and possibly plagioclase buoyancy in a fractionating ferrobasalt explains the huge concentration of hemo-ilmenite. The occurrence of sapphirine associated with aluminous spinel and high-alumina orthopyroxene (7.6-9.1 wt.% Al 2O 3) lacking exsolved plagioclase supports the involvement of a metamorphic overprint during the synchronous Ottawan orogeny, which is also responsible for strong textural equilibration and external granule of

  20. C4 Glomerulopathy: A Disease Entity Associated With C4d Deposition.

    PubMed

    Sethi, Sanjeev; Quint, Patrick S; O'Seaghdha, Conall M; Fervenza, Fernando C; Bijol, Vanesa; Dorman, Anthony; Dasari, Surendra; Smith, Richard J H; Kurtin, Paul J; Rennke, Helmut G

    2016-06-01

    Complement-mediated glomerulonephritis, which includes C3 glomerulopathy, is characterized by dominant staining of C3 with minimal or no immunoglobulin deposits on immunofluorescence studies. We describe a new entity of complement-mediated glomerulonephritis that is characterized by bright C4d staining but with no or minimal C3 or immunoglobulin deposits on immunofluorescence studies. We label this entity as C4 glomerulopathy. C4 glomerulopathy includes C4 dense deposit disease and C4 glomerulonephritis. C4 dense deposit disease is characterized by bright C4d staining and dense deposits along glomerular basement membranes. C4 glomerulonephritis is characterized by bright C4d staining and many mesangial electron-dense deposits, with or without rare intramembranous electron-dense deposits. We describe clinical features and kidney biopsy results in a short series of 3 patients to highlight these findings. All 3 patients presented with proteinuria, and 2 patients also had hematuria. Kidney function was preserved in 2 patients, whereas 1 patient presented with declining kidney function. Evaluation for autoimmune disease, infection, and paraprotein yielded negative results in all patients. Complement levels were normal, although 1 patient had borderline low C4 levels. Kidney biopsy showed mesangial proliferative or membranoproliferative glomerulonephritis with bright C4d staining and absent or minimal C1q, C3, and immunoglobulin. Laser microdissection and mass spectrometry of glomeruli in all 3 patients showed large to moderate numbers of spectra matching C4. Furthermore, analysis of amino acid sequences showed that they were localized to the C4d portion of C4, consistent with immunofluorescence findings. Further studies are required to determine the underlying cause. In summary, we describe a novel complement-mediated glomerulonephritis that is characterized by bright glomerular C4d staining with minimal or absent staining for C1q, C3, and immunoglobulin. PMID

  1. Fine control of perovskite-layered morphology and composition via sequential deposition crystallization process towards improved perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Luo, Yi; Meng, Fanli; Zhao, Erfei; Zheng, Yan-Zhen; Zhou, Yali; Tao, Xia

    2016-04-01

    The ability to prepare high coverage and compact perovskite films via solution-based crystallization manipulation processes still represents a vital issue towards improving the ultimate photoelectric conversion efficiency of devices. In this work, we prepare the active perovskite layer by means of sequential deposition crystallization process i.e. dipping PbI2-infiltrated TiO2 film within CH3NH3I solution from 20s to 60s. The morphology and thickness of the as-prepared perovskite layer, and its overall performance superiority are investigated. X-ray diffraction (XRD) reveals that a maximum conversion of PbI2 to perovskite is completed upon applying a sequential deposition crystallization process of 40s. Field emission scanning electron microscope (FESEM) demonstrates that the coverage of the perovskite capping layer exhibits a trend from rise to decline in the whole dipping time from 20s to 60s. By fine control of the dipping time, a 620 nm-thickness compact perovskite active layer is obtained at the optimized dipping time of 40s and is verified to possess strong light absorption and high electron extraction efficiency, leading to a higher photocurrent. By further optimizing the mesoporous TiO2 film thickness, a high photocurrent of 23.98 mA cm-2 and an efficiency of 13.47% are achieved.

  2. Deposits from Creams Containing 20% (w/w) Urea and Suppression of Crystallization (Part 3): Novel Analytical Methods Based on Raman Spectroscopy for the Characterization of Deposits and Deposition Phenomena of Creams Containing 20% (w/w) Urea.

    PubMed

    Goto, Norio; Morita, Yutaka; Terada, Katsuhide

    2016-01-01

    In drug formulations for external application, variations in the state of pharmaceutical agents within the base formulation may affect the transfer of agents to the skin. Here, we use Raman spectroscopic methods to acquire more detailed information on the state of the active pharmaceutical ingredients within an externally applied formulation. The combination of wide-field Raman spectroscopy with an experimental method in which drug formulations are applied to glass surfaces provided a new method for characterizing the state of pharmaceutical agents within drug formulations. Here, we demonstrate the usefulness of this new method, called application to glass-wide-field Raman spectroscopy (AG-WRS). In addition to allowing rapid and easy wide-field observations, the use of WRS allows Raman imaging in a manner that is insensitive to variations in the thickness of the formulations applied to sample slides. We consider two types of urea-compound creams with different crystal deposition rates, using AG-WRS to characterize the post-application time-evolving state of deposited crystals. Differences in the base pharmaceutical produce different spectra for the deposits, indicating that the deposits differ in composition and structure. In addition, we use microscopic laser Raman measurements to demonstrate that the process of crystal formulation differs significantly for formulations with different compositions. Our results demonstrate that the combination of AG-WRS with existing analytical techniques such as powder X-ray diffraction or thermal analysis yields more detailed and timely post-application information on the state of pharmaceuticals in external application. We believe this will be a valuable analytical tool for future studies related to the development of external application. PMID:27477647

  3. Electron Scattering and Doping Mechanisms in Solid-Phase-Crystallized In2O3:H Prepared by Atomic Layer Deposition.

    PubMed

    Macco, Bart; Knoops, Harm C M; Kessels, Wilhelmus M M

    2015-08-01

    Hydrogen-doped indium oxide (In2O3:H) has recently emerged as an enabling transparent conductive oxide for solar cells, in particular for silicon heterojunction solar cells because its high electron mobility (>100 cm(2)/(V s)) allows for a simultaneously high electrical conductivity and optical transparency. Here, we report on high-quality In2O3:H prepared by a low-temperature atomic layer deposition (ALD) process and present insights into the doping mechanism and the electron scattering processes that limit the carrier mobility in such films. The process consists of ALD of amorphous In2O3:H at 100 °C and subsequent solid-phase crystallization at 150-200 °C to obtain large-grained polycrystalline In2O3:H films. The changes in optoelectronic properties upon crystallization have been monitored both electrically by Hall measurements and optically by analysis of the Drude response. After crystallization, an excellent carrier mobility of 128 ± 4 cm(2)/(V s) can be obtained at a carrier density of 1.8 × 10(20) cm(-3), irrespective of the annealing temperature. Temperature-dependent Hall measurements have revealed that electron scattering is dominated by unavoidable phonon and ionized impurity scattering from singly charged H-donors. Extrinsic defect scattering related to material quality such as grain boundary and neutral impurity scattering was found to be negligible in crystallized films indicating that the carrier mobility is maximized. Furthermore, by comparison of the absolute H-concentration and the carrier density in crystallized films, it is deduced that <4% of the incorporated H is an active dopant in crystallized films. Therefore, it can be concluded that inactive H atoms do not (significantly) contribute to defect scattering, which potentially explains why In2O3:H films are capable of achieving a much higher carrier mobility than conventional In2O3:Sn (ITO). PMID:26168056

  4. Enhanced Optical Properties of Chemical Vapor Deposited Single Crystal Diamond by Low-Pressure/High-Temperature Annealing

    SciTech Connect

    Meng, Y.; Yan, C; Lai, Y; Krasnicki, S; Shu, H; Yu, T; Liang, Q; Mao, H; Hemley, R

    2008-01-01

    Single crystal diamond produced by chemical vapor deposition (CVD) at very high growth rates (up to 150 em/h) has been successfully annealed without graphitization at temperatures up to 2200 C and pressures <300 torr. Crystals were annealed in a hydrogen environment by using microwave plasma techniques for periods of time ranging from a fraction of minute to a few hours. This low-pressure/high-temperature (LPHT) annealing enhances the optical properties of this high-growth rate CVD single crystal diamond. Significant decreases are observed in UV, visible, and infrared absorption and photoluminescence spectra. The decrease in optical absorption after the LPHT annealing arises from the changes in defect structure associated with hydrogen incorporation during CVD growth. There is a decrease in sharp line spectral features indicating a reduction in nitrogen-vacancy-hydrogen (NVH-) defects. These measurements indicate an increase in relative concentration of nitrogen-vacancy (NV) centers in nitrogen-containing LPHT-annealed diamond as compared with as-grown CVD material. The large overall changes in optical properties and the specific types of alterations in defect structure induced by this facile LPHT processing of high-growth rate single-crystal CVD diamond will be useful in the creation of diamond for a variety of scientific and technological applications.

  5. Understanding the crystallization behavior of as-deposited Ti-Sb-Te alloys through real-time radial distribution functions.

    PubMed

    Zhu, Min; Xia, Mengjiao; Song, Zhitang; Cheng, Yan; Wu, Liangcai; Rao, Feng; Song, Sannian; Wang, Miao; Lu, Yegang; Feng, Songlin

    2015-06-01

    Phase change materials, successfully used in optical data-storage and non-volatile electronic memory, are well-known for their ultrafast crystallization speed. However, the fundamental understanding of their crystallization behavior, especially the nucleation process, is limited by present experimental techniques. Here, real-time radial distribution functions (RDFs), derived from the selected area electron diffractions, are employed as structural probes to comprehensively study both nucleation and subsequent growth stages of Ti-doped Sb2Te3 (TST) materials in the electron-irradiation crystallization process. It can be found that the incorporation of Ti atoms in Sb2Te3 forms wrong bonds such as Ti-Te, Ti-Sb, breaks the originally ordered atomic arrangement and diminishes the initial nucleus size of the as-deposited films, which results in better thermal stability. But these nuclei hardly grow until their sizes exceed a critical value, and then a rapid growth period starts. This means that an extended nucleation time is required to form the supercritical nuclei of TST alloys with higher concentration. Also, the increasing formation of four-membered rings, which served as nucleation sites, after doping excessive Ti is responsible for the change of the crystallization behavior from growth-dominated to nucleation-dominated. PMID:25970803

  6. Minimally invasive treatment of pilonidal disease: crystallized phenol and laser depilation.

    PubMed

    Girgin, Mustafa; Kanat, Burhan Hakan; Ayten, Refik; Cetinkaya, Ziya; Kanat, Zekiye; Bozdağ, Ahmet; Turkoglu, Ahmet; Ilhan, Yavuz Selim

    2012-01-01

    Pilonidal disease has been treated surgically and by various other methods for many years. The most important problem associated with such treatment is recurrence, but cosmetic outcome is another important issue that cannot be ignored. Today, crystallized phenol is recognized as a treatment option associated with good medical and cosmetic outcomes. We hypothesized that the addition of laser depilation to crystallized phenol treatment of pilonidal disease might increase the rate of success, and this study aimed to determine if the hypothesis was true. Patients who were treated with crystallized phenol and 755-nm alexandrite laser depilation were retrospectively analyzed. In total, 42 (31 male and 11 female) patients were treated with crystallized phenol and alexandrite laser depilation and were followed up between January 2009 and January 2012. In all, 38 patients (90.5%) had chronic disease and 4 (9.5%) had recurrent disease. Among the patients, 26 (61.9%) recovered following 1 crystallized phenol treatment, and the remaining patients had complete remission following repeated treatment. Some patients needed multiple treatments, even up to 8 times. None of the patients had a recurrence during a mean 24 months (range, 6-30 months) of follow-up. Whatever method of treatment is used for pilonidal disease, hair cleaning positively affects treatment outcome. The present results support the hypothesis that the addition of laser depilation (which provides more permanent and effective depilation than other methods) to crystallized phenol treatment (a non-radical, minimally invasive method associated with very good cosmetic results) can increase the effectiveness of the treatment and also reduce the recurrence rate of the disease. PMID:23294066

  7. Orientating layers with adjustable pretilt angles for liquid crystals deposited by a linear atmospheric pressure plasma source

    SciTech Connect

    Jian, Shih-Jie; Kou, Chwung-Shan; Hwang, Jennchang; Lee, Chein-Dhau; Lin, Wei-Cheng

    2013-06-15

    A method for controlling the pretilt angles of liquid crystals (LC) was developed. Hexamethyldisiloxane polymer films were first deposited on indium tin oxide coated glass plates using a linear atmospheric pressure plasma source. The films were subsequently treated with the rubbing method for LC alignment. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy measurements were used to characterize the film composition, which could be varied to control the surface energy by adjusting the monomer feed rate and input power. The results of LC alignment experiments showed that the pretilt angle continuously increased from 0 Degree-Sign to 90 Degree-Sign with decreasing film surface energy.

  8. Effect of growth rate on crystallization of HfO2 thin films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Dhanunjaya, M.; Manikanthababu, N.; Pathak, A. P.; Rao, S. V. S. Nageswara

    2016-05-01

    Hafnium oxide (HfO2) is the potentially useful dielectric material in both; electronics to replace the conventional SiO2 as gate dielectric and in Optics as anti-reflection coating material. In this present work we have synthesized polycrystalline HfO2 thin films by RF magnetron sputtering deposition technique with varying target to substrate distance. The deposited films were characterized by X-ray Diffraction, Rutherford Backscattering Spectrometry (RBS) and transmission and Reflection (T&R) measurements to study the growth behavior, microstructure and optical properties. XRD measurement shows that the samples having mixed phase of monoclinic, cubic and tetragonal crystal structure. RBS measurements suggest the formation of Inter Layer (IL) in between Substrate and film

  9. Gitelman syndrome disclosed by calcium pyrophosphate deposition disease: early diagnosis by ultrasonographic study.

    PubMed

    Zabotti, A; Della Siega, P; Picco, L; Quartuccio, L; Bassetti, M; De Vita, S

    2016-01-01

    Gitelman's syndrome is a rare autosomal-recessive tubular disorder characterized by hypomagnesemia and hypocalciuria associated to hypokalemia. The clinical spectrum is wide and usually characterized by chronic fatigue, cramps, muscle weakness and paresthesiae. We describe a case of a 43 year-old male patient with early onset of knee arthritis and no other symptoms. Ultrasound revealed diffuse and confluent hyperechoic deposits in cartilage, fibrocartilage of the menisci and synovium and calcium pyrophosphate crystals were observed in the synovial fluid of the knee. The concomitant presence of hypomagnesemia, hypocalciuria and hypokalemia made clear the diagnosis of Gitelman's syndrome associated with chondrocalcinosis. PMID:27339375

  10. Analyzing the Deposition of Titanium Dioxide Nanoparticles at Model Rough Mineral Surfaces Using a Quartz Crystal Microbalance with Dissipation Monitoring

    NASA Astrophysics Data System (ADS)

    Li, Y.; Kananizadeh, N.; Rodenhausen, K. B.; Schubert, M.; Bartelt-Hunt, S.

    2015-12-01

    Titanium dioxide nanoparticles (nTiO2) is the most extensively manufactured engineered materials. nTiO2 from sunscreens was found to enter sediments after released into a lake. nTiO2 may also enter the subsurface via irrigation using effluents from wastewater treatment plants. Interaction of nTiO2 with soils and sediments will largely influence their fate, transport, and ecotoxicity. Measuring the interaction between nTiO2 and natural substrates (e.g. such as sands) is particularly challenging due to highly heterogeneous and rough natural sand surfaces. In this study, an engineered controllable rough surface known as three dimensional nanostructured sculptured columnar thin films (SCTFs) has been used to mimic surface roughness. SCTFs were fabricated by glancing angle deposition (GLAD), a physical vapor deposition technique facilitated by electron beam evaporation. Interaction between nTiO2 and SCTF coated surfaces was investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). In parallel, a Generalized Ellipsometry (GE) was coupled with the QCM-D to measure the deposition of nTiO2. We found that the typical QCM-D modeling approach, e.g. viscoelastic model, would largely overestimate the mass of deposited nTiO2, because the frequency drops due to particle deposition or water entrapment in rough areas were not differentiated. Here, we demonstrate a new approach to model QCM-D data for nTiO2 deposition on rough surfaces, which couples the viscoelastic model with a model of flow on the non-uniform surface.

  11. Light and heavy chain deposition disease associated with CH1 deletion.

    PubMed

    Cohen, Camille; El-Karoui, Khalil; Alyanakian, Marie-Alexandra; Noel, Laure-Hélène; Bridoux, Franck; Knebelmann, Bertrand

    2015-04-01

    Light and heavy chain deposition disease (LHCDD) is a rare complication of monoclonal gammopathy. In all documented cases, LHCDD is the association of deposits of a monoclonal light chain with a normal heavy chain, especially in the kidneys. We describe here a 78-year-old woman whose renal biopsy showed nodular glomerulosclerosis, initially diagnosed as diabetic nephropathy. Detailed kidney biopsy immunofluorescence study corrected the diagnosis to γ1-κ-LHCDD. Advanced immunoblot analysis showed deletion of CH1 in the both blood and kidney heavy chain. We report here, to our knowledge, the first case of γ1 LHCDD associated with a deletion of CH1. PMID:25815184

  12. Light and heavy chain deposition disease associated with CH1 deletion

    PubMed Central

    Cohen, Camille; El-Karoui, Khalil; Alyanakian, Marie-Alexandra; Noel, Laure-Hélène; Bridoux, Franck; Knebelmann, Bertrand

    2015-01-01

    Light and heavy chain deposition disease (LHCDD) is a rare complication of monoclonal gammopathy. In all documented cases, LHCDD is the association of deposits of a monoclonal light chain with a normal heavy chain, especially in the kidneys. We describe here a 78-year-old woman whose renal biopsy showed nodular glomerulosclerosis, initially diagnosed as diabetic nephropathy. Detailed kidney biopsy immunofluorescence study corrected the diagnosis to γ1-κ-LHCDD. Advanced immunoblot analysis showed deletion of CH1 in the both blood and kidney heavy chain. We report here, to our knowledge, the first case of γ1 LHCDD associated with a deletion of CH1. PMID:25815184

  13. Hepatic Primary and Secondary Cholesterol Deposition and Damage in Niemann-Pick Disease.

    PubMed

    Bosch, Marta; Fajardo, Alba; Alcalá-Vida, Rafael; Fernández-Vidal, Andrea; Tebar, Francesc; Enrich, Carlos; Cardellach, Francesc; Pérez-Navarro, Esther; Pol, Albert

    2016-03-01

    Niemann-Pick C disease is a neurovisceral disorder caused by mutations in the NPC gene that result in systemic accumulation of intracellular cholesterol. Although neurodegeneration defines the disease's severity, in most patients it is preceded by hepatic complications such as cholestatic jaundice or hepatomegaly. To analyze the contribution of the hepatic disease in Niemann-Pick C disease progression and to evaluate the degree of primary and secondary hepatic damage, we generated a transgenic mouse with liver-selective expression of NPC1 from embryonic stages. Hepatic NPC1 re-expression did not ameliorate the onset and progression of neurodegeneration of the NPC1-null animal. However, the mice showed reduced hepatomegalia and dramatic, although not complete, reduction of hepatic cholesterol and serum bile salts, bilirubin, and transaminase levels. Therefore, hepatic primary and secondary cholesterol deposition and damage occur simultaneously during Niemann-Pick C disease progression. PMID:26784526

  14. Growth of crystals of several boron-carbon compositions by chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Kevill, D. N.; Rissmann, T. J.; Brewe, D.; Wood, C.

    1986-01-01

    Boron-carbon compounds have been deposited by the flow of carbon tetrachloride and boron trichloride, in the presence of a large excess of hydrogen, over a graphite surface maintained at 1000-1300 C. Deposits were formed on either an RF-heated disc or a tube or insert heated by a resistance furnace. Crystalline materials ranging in composition from B2C to B17C have been obtained.

  15. Atomistic study of xenon crystal growth via low-temperature atom beam deposition

    NASA Astrophysics Data System (ADS)

    Totò, Nicola; Schön, Christian; Jansen, M.

    2010-09-01

    We studied theoretically the deposition of Xe atoms on a sapphire substrate and the subsequent growth of ordered Xe phases via the low-temperature atom beam deposition method. This chemical synthesis method [D. Fischer and M. Jansen, J. Am. Chem. Soc. 41, 1755 (2002)10.1002/1521-3773(20020517)41:10<1755::AID-ANIE1755>3.0.CO;2-C] is particularly suitable for synthesizing metastable solid compounds. The modeling procedure consisted of several steps, where we used empirical potentials to model the interactions within the substrate, the Xe-Xe interactions in the gas phase and the solid, and the interactions between the Xe atoms and the substrate. In a first step, we established that under the experimental conditions, no Xe clusters formed in the gas phase, and thus the deposition could be described by the adsorption of single Xe atoms on the substrate at low temperatures. Next, we simulated the Xe deposition process and we studied the growth mode depending on various synthesis parameters such as the deposition rate and the temperature of the substrate. Finally, the deposited Xe layers were tempered and the structure of the resulting compound was analyzed. We studied the establishment of locally ordered regions as a function of time, both during the deposition and the tempering. We observed that the final configuration was always crystalline, although defects such as stacking faults and dislocations were likely to form. The occurrence of different growth modes and the formation of defects were explained by studying diffusion and adsorption processes on the surface of both the substrate and the depositing phase.

  16. Devitrification and delayed crazing of SiO2 on single-crystal silicon and chemically vapor-deposited silicon nitride

    NASA Technical Reports Server (NTRS)

    Choi, Doo Jin; Scott, William D.

    1987-01-01

    The linear growth rate of cristobalite was measured in thin SiO2 films on silicon and chemically vapor-deposited silicon nitride. The presence of trace impurities from alumina furnace tubes greatly increased the crystal growth rate. Under clean conditions, the growth rate was still 1 order-of-magnitude greater than that for internally nucleated crystals in bulk silica. Crystallized films cracked and lifted from the surface after exposure to atmospheric water vapor. The crystallization and subsequent crazing and lifting of protective SiO2 films on silicon nitride should be considered in long-term applications.

  17. Lattice dynamics of a mist-chemical vapor deposition-grown corundum-like Ga2O3 single crystal

    NASA Astrophysics Data System (ADS)

    Cuscó, R.; Domènech-Amador, N.; Hatakeyama, T.; Yamaguchi, T.; Honda, T.; Artús, L.

    2015-05-01

    The lattice dynamical properties of the corundum-like α-phase of Ga2O3 are investigated by means of Raman scattering experiments and ab-initio calculations. A high-quality, single-crystal thick epilayer was grown on sapphire by the mist-chemical vapor deposition method. The phonon frequencies at the Brillouin zone center of all the Raman-active modes are determined by polarized Raman scattering measurements on an α-Ga2O3 single crystal. By performing backscattering measurements from (0001) and (10 1 ¯ 0 ) faces, all Raman active modes are unambiguously identified. Density functional perturbation theory calculations were carried out to determine the symmetry and the frequency of the α-Ga2O3 lattice modes. We find a good agreement between the theoretical predictions and the Raman spectra. The relative intensity of the different modes and their polarizability are discussed. The Raman spectrum is dominated by a narrow A1g peak which indicates the high crystalline quality of the layers grown by the mist chemical vapor deposition method.

  18. Calcification in the ovine intervertebral disc: a model of hydroxyapatite deposition disease

    PubMed Central

    Burkhardt, D.; Taylor, T. K. F.; Dillon, C. T.; Read, R.; Cake, M.; Little, C. B.

    2009-01-01

    The study design included a multidisciplinary examination of the mineral phase of ovine intervertebral disc calcifications. The objective of the study was to investigate the mineral phase and its mechanisms of formation/association with degeneration in a naturally occurring animal model of disc calcification. The aetiology of dystrophic disc calcification in adult humans is unknown, but occurs as a well-described clinical disorder with hydroxyapatite as the single mineral phase. Comparable but age-related pathology in the sheep could serve as a model for the human disorder. Lumbar intervertebral discs (n = 134) of adult sheep of age 6 years (n = 4), 8 years (n = 12) and 11 years (n = 2) were evaluated using radiography, morphology, scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, histology, immunohistology and proteoglycan analysis. Half of the 6-year, 84% of the 8-year and 86% of the 11-year-old discs had calcific deposits. These were not well delineated by plain radiography. They were either: (a) punctate deposits in the outer annulus, (b) diffuse deposits in the transitional zone or inner annulus fibrosus with occasional deposits in the nucleus, or (c) large deposits in the transitional zone extending variably into the nucleus. Their maximal incidence was in the lower lumbar discs (L4/5–L6/7) with no calcification seen in the lumbosacral or lower thoracic discs. All deposits were hydroxyapatite with large crystallite sizes (800–1,300 Å) compared to cortical bone (300–600 Å). No type X-collagen, osteopontin or osteonectin were detected in calcific deposits, although positive staining for bone sialoprotein was evident. Calcified discs had less proteoglycan of smaller hydrodynamic size than non-calcified discs. Disc calcification in ageing sheep is due to hydroxyapatite deposition. The variable, but large, crystal size and lack of protein markers indicate that this does not occur by

  19. Calcium oxalate nephrolithiasis: effect of renal crystal deposition on the cellular composition of the renal interstitium.

    PubMed

    de Water, R; Noordermeer, C; van der Kwast, T H; Nizze, H; Boevé, E R; Kok, D J; Schröder, F H

    1999-04-01

    Urinary calcium oxalate (CaOx) crystals and crystal agglomerates are normally harmlessly excreted, but in nephrolithiasis they are retained by tubular epithelial cells and shifted into the renal interstitium. This crystalline material induces an inflammatory response consisting of an increase in the number of interstitial cells and an expansion of the extracellular matrix. The newly arrived cells either derive from the blood or the connective tissue or they are formed by local proliferation. Identification of the cells that surround the interstitial crystals is a first step in investigating the question of whether the interstitial cells could remove the crystalline material. Therefore, we performed an immunohistochemical study on the kidneys of rats made hyperoxaluric by ethylene glycol (EG) and ammonium chloride (AC). Attention was paid to expression of the leukocyte common antigen (LCA), which identifies all types of leukocytes, the ED1 antigen, which is specific for monocytes and macrophages, and the major histocompatibility class II antigen (MHC II), which is present on dendritic cells, B lymphocytes, and activated macrophages. The results obtained were compared with those seen in two human kidney specimens with acute and chronic oxalosis. In both rat and humans, macrophages and multinucleated giant cells are the major cells that encapsulate the interstitial crystals. This similarity in response underlines the relevance of the rat nephrolithiasis model. The rat experiments showed, furthermore, that the number of interstitial crystals and the amount of biochemically measured kidney-associated oxalate both decrease with time, if the nephrolithiatic agents EG and AC are omitted from the drinking water. Further studies must clarify whether macrophages and multinucleated giant cells are able to remove the interstitial crystals and how these cells are recruited at the inflammatory site. PMID:10196021

  20. Visual Hallucinations and Amyloid Deposition in Parkinson's Disease Dementia: A Case Report.

    PubMed

    Um, Yoo Hyun; Kim, Tae-Won; Jeong, Jong-Hyun; Seo, Ho-Jun; Han, Jin-Hee; Hong, Seung-Chul; Jung, Won-Sang; Choi, Woo Hee; Lee, Chang-Uk; Lim, Hyun Kook

    2016-05-01

    Parkinson's disease dementia (PDD) is notorious for its debilitating clinical course and high mortality rates. Consequently, various attempts to investigate predictors of cognitive decline in Parkinson's disease (PD) have been made. Here we report a case of a 75-year-old female patient with PD who visited the clinic with complaints of recurrent visual hallucinations and cognitive decline, whose symptoms were ameliorated by the titration of rivastigmine. Imaging results showed pronounced diffuse cortical amyloid deposition evidenced by 18F-florbetaben amyloid positron emission tomography (PET) imaging. This observation suggests that pronounced amyloid deposition and visual hallucinations in PD patients could be clinically significant predictors of cognitive decline in PD patients. Future research should concentrate on accumulating more evidence for possible predictors of cognitive decline and their association with PD pathology that can enable an early intervention and standardized treatment in PDD patients. PMID:27247605

  1. Visual Hallucinations and Amyloid Deposition in Parkinson's Disease Dementia: A Case Report

    PubMed Central

    Um, Yoo Hyun; Kim, Tae-Won; Jeong, Jong-Hyun; Seo, Ho-Jun; Han, Jin-Hee; Hong, Seung-Chul; Jung, Won-Sang; Choi, Woo Hee; Lee, Chang-Uk

    2016-01-01

    Parkinson's disease dementia (PDD) is notorious for its debilitating clinical course and high mortality rates. Consequently, various attempts to investigate predictors of cognitive decline in Parkinson's disease (PD) have been made. Here we report a case of a 75-year-old female patient with PD who visited the clinic with complaints of recurrent visual hallucinations and cognitive decline, whose symptoms were ameliorated by the titration of rivastigmine. Imaging results showed pronounced diffuse cortical amyloid deposition evidenced by 18F-florbetaben amyloid positron emission tomography (PET) imaging. This observation suggests that pronounced amyloid deposition and visual hallucinations in PD patients could be clinically significant predictors of cognitive decline in PD patients. Future research should concentrate on accumulating more evidence for possible predictors of cognitive decline and their association with PD pathology that can enable an early intervention and standardized treatment in PDD patients. PMID:27247605

  2. Recurrence of light chain deposit disease after renal allograft transplantation: potential role of rituximab?

    PubMed

    Kuypers, Dirk R J; Lerut, Evelyne; Claes, Kathleen; Evenepoel, Pieter; Vanrenterghem, Yves

    2007-04-01

    Light chain deposit disease (LCDD) is a monoclonal plasma cell disorder characterized by tissue deposition of nonamyloid immunoglobulin light chains, predominantly kappa chains, causing renal insufficiency. LCDD reoccurs almost invariably after renal grafting, leading to early graft loss, usually within a time span of months to years. We describe a female patient with LCDD who lost her first living donor graft after 1 year due to extensive recurrence of kappa chain deposition. Rituximab was administered on the seventh day after her second transplantation with a graft from a deceased donor, in order to prevent early recurrence of LCDD. The 2-year protocol biopsy - similarly to the completely normal 1-year protocol biopsy - revealed persistent absence of light chain deposition on light microscopy but immunohistochemical staining and electron microscopy showed very mild recurrence of light chain deposits. A second 4-week course of rituximab was repeated because of these electron microscopic findings. Subsequently, free kappa light chain concentration decreased from 693 to 74 mg/l and remained low 4 months after completion of therapy. Rituximab could be considered for delaying early LCDD recurrence in patients in whom treatment of the underlying bone marrow disorder failed or is contraindicated, but maintenance therapy is apparently necessary to consolidate this response. PMID:17326779

  3. Evolution of crystal structure during the initial stages of ZnO atomic layer deposition

    DOE PAGESBeta

    Boichot, R.; Tian, L.; Richard, M. -I.; Crisci, A.; Chaker, A.; Cantelli, V.; Coindeau, S.; Lay, S.; Ouled, T.; Guichet, C.; et al

    2016-01-05

    In this study, a complementary suite of in situ synchrotron X-ray techniques is used to investigate both structural and chemical evolution during ZnO growth by atomic layer deposition. Focusing on the first 10 cycles of growth, we observe that the structure formed during the coalescence stage largely determines the overall microstructure of the film. Furthermore, by comparing ZnO growth on silicon with a native oxide with that on Al2O3(001), we find that even with lattice-mismatched substrates and low deposition temperatures, the crystalline texture of the films depend strongly on the nature of the interfacial bonds.

  4. Silicon oxide deposition for enhanced optical switching in polydimethylsiloxane-liquid crystal hybrids.

    PubMed

    De Sio, Luciano; Vasdekis, Andreas E; Cuennet, Julien G; De Luca, Antonio; Pane, Alfredo; Psaltis, Demetri

    2011-11-01

    We report an optical switch based on a diffraction grating by combining PDMS microstructures with a photo-responsive Nematic Liquid Crystal (NLC). The grating was realized via replica molding and was subsequently coated with a thin SiO layer. SiO induced a full planar alignment of the liquid crystal. The induced parallel alignment of the LC reduces the response time of the structure by approximately an order of magnitude compared to the same structures without SiO. We explored the effect of the pump intensity on the transmission properties and time response of the switch and identified a strong dependence on the probe polarization, due to the full planar alignment in this structure. The aforementioned inclusion of the SiO layer enables enhanced performance of optical devices based on the fusion of nematogens with soft and flexible substrates. PMID:22109231

  5. Inverse solution for crystal fractionation in a periodically tapped magma chamber, Sierrita porphyry copper deposit, Arizona

    SciTech Connect

    Anthony, E.Y.; Titley, S.R.

    1985-01-01

    Inversion techniques have been used to simultaneously solve for the initial concentrations, distribution coefficients, and degrees of crystallization for a suite of Laramide rocks related to subduction and porphyry copper mineralization. The suite includes diorite, andesite, and granodiorite. The granodiorite has differentiated in place to a granite core and it is this granite which immediately precedes mineralization. To perform the inversion one must verify that the rocks are genetically related by crystallization or melting. Their comagmatic nature is suggested by the similarity throughout the suite in the ratios of incompatible elements and in the few available isotopic determinations. The geochemical path of crystallization is indicated by the decrease in compatible elements and increase in incompatible elements. Inversion of the trace element data yields high initial concentrations for elements such as Ba and Ce and low concentrations for the transition metals, which is consistent with crustal melting. Thus, there was s substantial magma chamber at depth from which the more felsic liquids the authors sample have separated. The residence time of this chamber was not less than 6 million years. Such a prolonged history has been observed in other porphyry systems for which 10 million years of igneous activity and 2 million years of intermittent mineralization are recorded.

  6. Amyloid deposition in Parkinson Disease and Cognitive Impairment: A Systematic Review

    PubMed Central

    Petrou, Myria; Dwamena, Ben A.; Foerster, Bradley R.; MacEachern, Mark P.; Bohnen, Nicolaas I.; Muller, Martijn; Albin, Roger L.; Frey, Kirk A.

    2015-01-01

    Background Varying degrees of cortical amyloid deposition are reported in the setting of Parkinsonism with cognitive impairment. We performed a systematic review to estimate the prevalence of Alzheimer disease (AD) range cortical amyloid deposition amongst patients with Parkinson disease with dementia (PDD), Parkinson disease with mild cognitive impairment (PD-MCI) and dementia with Lewy bodies (DLB). We included amyloid PET imaging studies using Pittsburgh Compound B (PiB). Methods We searched the databases Ovid MEDLINE, PubMed, Embase, Scopus, and Web of Science for articles pertaining to amyloid imaging in Parkinsonism and impaired cognition. We identified 11 articles using PiB imaging to quantify cortical amyloid. We used the metan module in Stata, version 11.0, to calculate point prevalence estimates of patients with “PiB-positive” studies, ie patients showing AD range cortical Aβ-amyloid deposition. Heterogeneity was assessed. A scatterplot was used to assess publication bias. Results Overall pooled prevalence of “PiB-positive” studies across all three entities along the spectrum of Parkinson disease and impaired cognition (specifically PDD, PD-MCI and DLB) was 0.41 (95% CI 0.24-0.57). Prevalence of “PiB-positive” studies was 0.68 (95% CI 0.55-0.82) in the DLB group, 0.34 (95% CI 0.13-0.56) in the PDD group and 0.05 (95% CI -0.07-0.17) in the PD-MCI group. Conclusion There is substantial variability in the prevalence of “PiB-positive” studies in subjects with Parkinsonism and cognitive impairment. Higher prevalence of PiB positive studies was encountered among subjects with DLB as opposed to subjects with PDD. PD-MCI subjects showed overall lower prevalence of PiB positive studies than reported findings in non-PD related MCI. PMID:25879534

  7. Effect of epicuticular wax crystals on the localization of artificially deposited sub-micron carbon-based aerosols on needles of Cryptomeria japonica.

    PubMed

    Nakaba, Satoshi; Yamane, Kenichi; Fukahori, Mie; Nugroho, Widyanto Dwi; Yamaguchi, Masahiro; Kuroda, Katsushi; Sano, Yuzou; Wuled Lenggoro, I; Izuta, Takeshi; Funada, Ryo

    2016-09-01

    Elucidation of the mechanism of adsorption of particles suspended in the gas-phase (aerosol) to the outer surfaces of leaves provides useful information for understanding the mechanisms of the effect of aerosol particles on the growth and physiological functions of trees. In the present study, we examined the localization of artificially deposited sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica, a typical Japanese coniferous tree species, by field-emission scanning electron microscopy. The clusters (aggregates) of carbon-based particles were deposited on the needle surface regions where epicuticular wax crystals were sparsely distributed. By contrast, no clusters of the particles were found on the needle surface regions with dense distribution of epicuticular wax crystals. Number of clusters of carbon-based particles per unit area showed statistically significant differences between regions with sparse epicuticular wax crystals and those with dense epicuticular wax crystals. These results suggest that epicuticular wax crystals affect distribution of carbon-based particles on needles. Therefore, densely distributed epicuticular wax crystals might prevent the deposition of sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica to retain the function of stomata. PMID:27294967

  8. Gas flow-field induced director alignment in polymer dispersed liquid crystal microdroplets deposited on a glass substrate

    NASA Technical Reports Server (NTRS)

    Parmar, D. S.; Singh, J. J.

    1993-01-01

    Polymer dispersed liquid crystal thin films have been deposited on glass substrates by the processes of polymerization and solvent evaporation induced phase separation. The electron and the optical polarization microscopies of the films reveal that PDLC microdroplets formed during the process of phase separation near the top surface of the film remain exposed and respond to shear stress due to air or gas flow on the surface. Optical response of the film to an air flow-induced shear stress input on the free surface has been measured. Director orientation in the droplets changes with the applied shear stress leading to time varying transmitted light intensity. Director dynamics of the droplet for an applied step shear stress has been discussed from free energy considerations. Results on the measurement of light transmission as a function of the gas flow parameter unambiguously demonstrate the potential of these systems for use as boundary layer and gas flow sensors.

  9. Soft x-ray measurements using photoconductive type-IIa and single-crystal chemical vapor deposited diamond detectors

    SciTech Connect

    Moore, A. S.; Bentley, C. D.; Foster, J. M.; Goedhart, G.; Graham, P.; Taylor, M. J.; Hellewell, E.

    2008-10-15

    Photoconductive detectors (PCDs) are routinely used alongside vacuum x-ray diodes (XRDs) to provide an alternative x-ray flux measurement at laser facilities such as HELEN at AWE Aldermaston, UK, and Omega at the Laboratory for Laser Energetics. To evaluate diamond PCDs as an alternative to XRD arrays, calibration measurements made at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory are used to accurately calculate the x-ray flux from a laser-heated target. This is compared to a flux measurement using the Dante XRD diagnostic. Estimates indicate that the photoinduced conductivity from measurements made at Omega are too large, and calculations using the radiometric calibrations made at the NSLS agree with this hypothesis. High-purity, single-crystal, chemical vapor deposited (CVD) diamond samples are compared to natural type-IIa PCDs and show promising high resistivity effects, the corollary of which preliminary results show is a slower response time.

  10. Experimental determination of the respiratory tract deposition of diesel combustion particles in patients with chronic obstructive pulmonary disease

    PubMed Central

    2012-01-01

    Background Air pollution, mainly from combustion, is one of the leading global health risk factors. A susceptible group is the more than 200 million people worldwide suffering from chronic obstructive pulmonary disease (COPD). There are few data on lung deposition of airborne particles in patients with COPD and none for combustion particles. Objectives To determine respiratory tract deposition of diesel combustion particles in patients with COPD during spontaneous breathing. Methods Ten COPD patients and seven healthy subjects inhaled diesel exhaust particles generated during idling and transient driving in an exposure chamber. The respiratory tract deposition of the particles was measured in the size range 10–500 nm during spontaneous breathing. Results The deposited dose rate increased with increasing severity of the disease. However, the deposition probability of the ultrafine combustion particles (< 100 nm) was decreased in COPD patients. The deposition probability was associated with both breathing parameters and lung function, but could be predicted only based on lung function. Conclusions The higher deposited dose rate of inhaled air pollution particles in COPD patients may be one of the factors contributing to their increased vulnerability. The strong correlations between lung function and particle deposition, especially in the size range of 20–30 nm, suggest that altered particle deposition could be used as an indicator respiratory disease. PMID:22839109

  11. Quartz crystal microbalance as a tool for scale deposition monitoring in Bayer process conditions

    NASA Astrophysics Data System (ADS)

    Brisach, F.; Brisach-Wittmeyer, A.; Bouchard, N.-A.; Ménard, H.

    2012-07-01

    This paper describes the study of bayerite or gibbsite scale formation and growth from supersaturated sodium aluminate solutions using a quartz crystal microbalance. Analysis of frequency vs time curves and scanning electron microscopy images allowed us to propose a surface nucleation mechanism that leads to cementation of particles produced by catastrophic secondary nucleation. We also highlighted the influence of the filtration of the supersaturated sodium aluminate solution step on the scale nucleation kinetics. It was observed that use of filter with porosity below 2.5 μm delays the formation of scale.

  12. On the Effect of the Film Hydrogen Content and Deposition Type on the Grain Nucleation and Grain Growth During Crystallization of a-Si:H Films: Preprint

    SciTech Connect

    Mahan, A. H.; Ahrenkiel, S. P.; Roy, B.; Schropp, R.E.I.; Li, H.; Ginley, D. S.

    2006-05-01

    We report the effect of the initial film hydrogen content (CH) on the crystallization kinetics, crystallite nucleation rate and grain growth rate when HWCVD and PECVD a-Si:H films are crystallized by annealing at 600 C. For the HWCVD films, both the incubation time and crystallization time decrease, and the full width at half maximum (FWHM) of the XRD (111) peak decreases with decreasing film CH. However, other sources of XRD line broadening exist in such materials in addition to crystallite size, including the density of crystallite defects. To address these issues, TEM measurements have also been performed on a-Si:H films deposited directly onto TEM grids.

  13. Monolayer Single-Crystal 1T'-MoTe2 Grown by Chemical Vapor Deposition Exhibits Weak Antilocalization Effect.

    PubMed

    Naylor, Carl H; Parkin, William M; Ping, Jinglei; Gao, Zhaoli; Zhou, Yu Ren; Kim, Youngkuk; Streller, Frank; Carpick, Robert W; Rappe, Andrew M; Drndić, Marija; Kikkawa, James M; Johnson, A T Charlie

    2016-07-13

    Growth of transition metal dichalcogenide (TMD) monolayers is of interest due to their unique electrical and optical properties. Films in the 2H and 1T phases have been widely studied but monolayers of some 1T'-TMDs are predicted to be large-gap quantum spin Hall insulators, suitable for innovative transistor structures that can be switched via a topological phase transition rather than conventional carrier depletion [ Qian et al. Science 2014 , 346 , 1344 - 1347 ]. Here we detail a reproducible method for chemical vapor deposition of monolayer, single-crystal flakes of 1T'-MoTe2. Atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy confirm the composition and structure of MoTe2 flakes. Variable temperature magnetotransport shows weak antilocalization at low temperatures, an effect seen in topological insulators and evidence of strong spin-orbit coupling. Our approach provides a pathway to systematic investigation of monolayer, single-crystal 1T'-MoTe2 and implementation in next-generation nanoelectronic devices. PMID:27223343

  14. Novel chemical-vapor deposition technique for the synthesis of high-quality single-crystal nanowires and nanotubes

    NASA Astrophysics Data System (ADS)

    He, Maoqi; Mohammad, S. Noor

    2006-02-01

    The strength and versatility of a chemical-vapor deposition technique for thin, long, uniform, single-crystal, good-quality nanowire growth, without the use of template, have been described. Remarkably, while the full width at half maximum of a high-quality GaN thin film is 4 meV, that of a GaN whisker is 9 meV, which confirms high quality of the grown whiskers and nanowires. The versatility of the method is reflected by its ability to produce II-VI and III-V binary, ternary, and even, for the first time, quaternary nanowires in a controlled manner. The same versatility enables the realization of both cubic and hexagonal phases of nanowires and nanotubes. Chemical-vapor deposition technique generally makes use of highly poisonous arsine and phosphine for the synthesis of As- and P-based films. The present one is free from this shortcoming; it can produce As- and P-based nanowires without the use of these poisonous gases. A notable feature of the method is that properties of nanowires thus synthesized depend strongly on their shape, size, and geometry, and that certain growth conditions can only lead to such shapes and sizes.

  15. An abnormal lymphatic phenotype is associated with subcutaneous adipose tissue deposits in Dercum’s disease

    PubMed Central

    Rasmussen, John C.; Herbst, Karen L.; Aldrich, Melissa B.; Darne, Chinmay D.; Tan, I-Chih; Zhu, Banghe; Guilliod, Renie; Fife, Caroline A.; Maus, Erik A.; Sevick-Muraca, Eva M.

    2014-01-01

    Objective Investigational, near-infrared fluorescence (NIRF) lymphatic imaging was used to assess lymphatic architecture and contractile function in participants diagnosed with Dercum’s disease, a rare, poorly understood disorder characterized by painful lipomas in subcutaneous adipose tissues. Design and Methods After informed consent and as part of an FDA-approved feasibility study to evaluate lymphatics in diseases in which their contribution has been implicated, three women diagnosed with Dercum’s disease and four control subjects were imaged. Each participant received multiple intradermal and subcutaneous injections of indocyanine green (ICG, total dose ≤400µg) in arms, legs, and/or trunk. Immediately after injection, ICG was taken up by the lymphatics and NIRF imaging was conducted. Results The lymphatics in the participants with Dercum’s disease were intact and dilated, yet sluggishly propelled lymph when compared to control lymphatics. Palpation of regions containing fluorescent lymphatic pathways revealed tender, fibrotic, tubular structures within the subcutaneous adipose tissue that were associated with painful nodules, and, in some cases, masses of fluorescent tissue indicating that some lipomas may represent tertiary lymphoid tissues. Conclusions These data support the hypothesis that Dercum’s disease may be a lymphovascular disorder and suggest a possible association between abnormal adipose tissue deposition and abnormal lymphatic structure and function. PMID:25044620

  16. Oxidation of chemically-vapor-deposited silicon nitride and single-crystal silicon

    NASA Technical Reports Server (NTRS)

    Choi, Doo J.; Fischbach, David B.; Scott, William D.

    1989-01-01

    The present 1000 C and 1300 C oxidation tests on 111-oriented single-crystal Si and dense CVD Si3N4 notes the oxidation rates of the latter in wet O2, dry O2, wet inert gas, and steam atmosphere conditions to be several orders of magnitude lower than the rates for the former in identical atmospheric conditions. Although the parabolic rate constant for Si increased linearly as the water vapor pressure increased, the parabolic rate constant for Si3N4 exhibited a nonlinear dependency on water vapor pressure in the presence of O2. NO and NH3 formation at the reaction interface of Si3N4, and the counterpermeation of these reaction products, are noted to dominate reaction kinetics.

  17. Free-standing thin film Ge single crystals grown by plasma-enhanced chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Outlaw, R. A.; Hopson, P., Jr.

    1984-01-01

    The films, which are approximately 10 microns in thickness, are grown epitaxially on polished (100) NaCl substrates at 450 C by plasma enhanced chemical vapor deposition. Upon cooling, the films are separated from the substrate by differential shear stress, leaving free-standing films of Ge which can be handled. Growths are attained by nucleating at minimum plasma power for very brief intervals and then raising the power to 65 W to increase the growth rate to approximately 10 microns/h. It is found that substrate exposure to the plasma at too high a power for too long a time sputters and erodes the surface, thereby substantially degrading the nucleation process and the ultimate growths. It is noted that the free-standing films are visually specular and exhibit a high degree of crystalline order when examined by X-ray diffraction. Auger electron spectroscopy and energy dispersive analysis of X-rays reveal no detectable bulk contamination.

  18. Progranulin Protects against Amyloid β Deposition and Toxicity in Alzheimer’s Disease Mouse Models

    PubMed Central

    Minami, S. Sakura; Min, Sang-Won; Krabbe, Grietje; Wang, Chao; Zhou, Yungui; Asgarov, Rustam; Li, Yaqiao; Martens, Lauren H.; Elia, Lisa P.; Ward, Michael E.; Mucke, Lennart; Farese, Robert V.; Gan, Li

    2014-01-01

    Haploinsufficiency of progranulin (PGRN) gene (GRN) causes familial frontotemporal lobar degeneration (FTLD), and modulates an innate immune response in humans and mouse models. GRN polymorphism may be linked to late-onset Alzheimer’s disease (AD). However, PRGN’s role in AD pathogenesis is unknown. Here, we show PGRN inhibits amyloid β (Aβ) deposition. Selectively reducing microglial PGRN in AD mice impaired phagocytosis and increased plaque load threefold. Lentivirus-mediated PGRN overexpression lowered plaque load in AD mice with aggressive amyloid plaque pathology. Aβ plaque load correlated negatively with levels of hippocampal PGRN, showing PGRN’s dose-dependent inhibitory effects on plaque deposition. PGRN also protected against Aβ toxicity. Reducing microglial PGRN exacerbated cognitive deficits in AD mice. Lentivirus-mediated PGRN overexpression prevented spatial memory deficits and hippocampal neuronal loss in AD mice. PGRN’s protective effects against Aβ deposition and toxicity have important therapeutic implications. We propose enhancing PGRN as a potential treatment for PGRN-deficient FTD and AD. PMID:25261995

  19. Progranulin protects against amyloid β deposition and toxicity in Alzheimer's disease mouse models.

    PubMed

    Minami, S Sakura; Min, Sang-Won; Krabbe, Grietje; Wang, Chao; Zhou, Yungui; Asgarov, Rustam; Li, Yaqiao; Martens, Lauren H; Elia, Lisa P; Ward, Michael E; Mucke, Lennart; Farese, Robert V; Gan, Li

    2014-10-01

    Haploinsufficiency of the progranulin (PGRN) gene (GRN) causes familial frontotemporal lobar degeneration (FTLD) and modulates an innate immune response in humans and in mouse models. GRN polymorphism may be linked to late-onset Alzheimer's disease (AD). However, the role of PGRN in AD pathogenesis is unknown. Here we show that PGRN inhibits amyloid β (Aβ) deposition. Selectively reducing microglial expression of PGRN in AD mouse models impaired phagocytosis, increased plaque load threefold and exacerbated cognitive deficits. Lentivirus-mediated PGRN overexpression lowered plaque load in AD mice with aggressive amyloid plaque pathology. Aβ plaque load correlated negatively with levels of hippocampal PGRN, showing the dose-dependent inhibitory effects of PGRN on plaque deposition. PGRN also protected against Aβ toxicity. Lentivirus-mediated PGRN overexpression prevented spatial memory deficits and hippocampal neuronal loss in AD mice. The protective effects of PGRN against Aβ deposition and toxicity have important therapeutic implications. We propose enhancing PGRN as a potential treatment for PGRN-deficient FTLD and AD. PMID:25261995

  20. Retinal pigment epithelial detachments and tears, and progressive retinal degeneration in light chain deposition disease

    PubMed Central

    Spielberg, Leigh H; Heckenlively, John R; Leys, Anita M

    2013-01-01

    Background/purpose Light-chain deposition disease (LCDD) is a rare condition characterised by deposition of monoclonal immunoglobulin light chains (LCs) in tissues, resulting in varying degrees of organ dysfunction. This study reports the characteristic clinical ocular findings seen in advanced LCDD upon development of ocular fundus changes. This is the first report to describe this entity in vivo in a series of patients. Methods A case series of ocular fundus changes in three patients with kidney biopsy-proven LCDD. All patients underwent best corrected visual acuity (BCVA) exam, perimetry, colour fundus photography and fluorescein angiography; two patients underwent indocyanine green angiography, optical coherence tomography, ultrasound and electroretinography; and one patient underwent fundus autofluorescence. Results Three patients, 53–60 years old at initial presentation, were studied. All three presented with night blindness, poor dark adaptation, metamorphopsia and visual loss. Examination revealed serous and serohaemorrhagic detachments, multiple retinal pigment epithelial (RPE) tears, diffuse RPE degeneration and progressive fibrotic changes. Neither choroidal neovascularisation nor other vascular abnormalities were present. Final best corrected visual acuity (BCVA) ranged from 20/40 to 20/300. Conclusions Progressive LC deposition in the fundus seems to damage RPE pump function with flow disturbance between choroid and retina. This pathogenesis can explain the evolution to RPE detachments and subsequent rips and progressive retinal malfunction. PMID:23385633

  1. Choroideremia Is a Systemic Disease With Lymphocyte Crystals and Plasma Lipid and RBC Membrane Abnormalities

    PubMed Central

    Zhang, Alice Yang; Mysore, Naveen; Vali, Hojatollah; Koenekoop, Jamie; Cao, Sang Ni; Li, Shen; Ren, Huanan; Keser, Vafa; Lopez-Solache, Irma; Siddiqui, Sorath Noorani; Khan, Ayesha; Mui, Jeannie; Sears, Kelly; Dixon, Jim; Schwartzentruber, Jeremy; Majewski, Jacek; Braverman, Nancy; Koenekoop, Robert K.

    2015-01-01

    Purpose Photoreceptor neuronal degenerations are common, incurable causes of human blindness affecting 1 in 2000 patients worldwide. Only half of all patients are associated with known mutations in over 250 disease genes, prompting our research program to identify the remaining new genes. Most retinal degenerations are restricted to the retina, but photoreceptor degenerations can also be found in a wide variety of systemic diseases. We identified an X-linked family from Sri Lanka with a severe choroidal degeneration and postulated a new disease entity. Because of phenotypic overlaps with Bietti's crystalline dystrophy, which was recently found to have systemic features, we hypothesized that a systemic disease may be present in this new disease as well. Methods For phenotyping, we performed detailed eye exams with in vivo retinal imaging by optical coherence tomography. For genotyping, we performed whole exome sequencing, followed by Sanger sequencing confirmations and cosegregation. Systemic investigations included electron microscopy studies of peripheral blood cells in patients and in normal controls and detailed fatty acid profiles (both plasma and red blood cell [RBC] membranes). Fatty acid levels were compared to normal controls, and only values two standard deviations above or below normal controls were further evaluated. Results The family segregated a REP1 mutation, suggesting choroideremia (CHM). We then found crystals in peripheral blood lymphocytes and discovered significant plasma fatty acid abnormalities and RBC membrane abnormalities (i.e., elevated plasmalogens). To replicate our discoveries, we expanded the cohort to nine CHM patients, genotyped them for REP1 mutations, and found the same abnormalities (crystals and fatty acid abnormalities) in all patients. Conclusions Previously, CHM was thought to be restricted to the retina. We show, to our knowledge for the first time, that CHM is a systemic condition with prominent crystals in lymphocytes and

  2. Variant Creutzfeldt-Jakob Disease With Extremely Low Lymphoreticular Deposition of Prion Protein

    PubMed Central

    Mead, Simon; Wadsworth, Jonathan D. F.; Porter, Marie-Claire; Linehan, Jacqueline M.; Pietkiewicz, Wojciech; Jackson, Graham S.; Brandner, Sebastian; Collinge, John

    2014-01-01

    IMPORTANCE Human transmission of bovine spongiform encephalopathy causes the fatal neurodegenerative condition variant Creutzfeldt-Jakob disease (vCJD) and, based on recent human prevalence studies, significant subclinical prion infection of the UK population. To date, all clinical cases have been fatal, totaling 228 mostly young adults residing in the United Kingdom. OBSERVATIONS Here we describe the investigation and case history of a patient recently diagnosed as having vCJD in the United Kingdom. Although his presentation, imaging findings, cerebrospinal fluid investigation results, and clinical progression were typical of other cases, tonsillar biopsy and subsequent examination of multiple tissues at autopsy showed minimal deposition of disease-associated prion protein in peripheral lymphoreticular tissue. The result of a blood test for vCJD, the Direct Detection Assay for vCJD, was negative. CONCLUSIONS AND RELEVANCE These findings suggest that some patients with vCJD have very low peripheral prion colonization and therefore may not have detectable prion deposition in diagnostic tonsillar biopsy or markers of prion infection in blood. These results have implications for accurate interpretation of diagnostic tests and prevalence studies based on lymphoreticular tissue or blood. PMID:24445428

  3. [Randall-type monoclonal immunoglobulin deposition disease: From diagnosis to treatment].

    PubMed

    Cohen, Camille; Javaugue, Vincent; Joly, Florent; Arnulf, Bertrand; Fermand, Jean-Paul; Jaccard, Arnaud; Sirac, Christophe; Knebelmann, Bertrand; Bridoux, Frank; Touchard, Guy

    2016-06-01

    Monoclonal immunoglobulin (Ig) deposition disease (MIDD) is a rare complication of plasma cell disorders, defined by linear Congo red-negative deposits of monoclonal light chain (LCDD), heavy chain (HCDD) or both (LHCDD) along basement membranes. MIDD should be suspected in patients presenting with glomerular proteinuria and monoclonal gammopathy, but none of these criteria is necessary for the diagnosis although renal involvement is prominent. Since an abnormal serum κ/λ ratio is found in virtually all MIDD patients, including those with HCDD, serum free light chain assay should be included in the initial workup in patients older than 50 presenting with kidney disease. Bortezomib-based regimens are efficient and well tolerated, resulting in improvement in both renal and global survival, comparatively to historical series. High dose melphalan with autologous stem cell transplantation may be proposed as second line therapy in selected patients. The achievement of hematological response, based on the difference between involved and uninvolved serum free light chains (dFLC), is mandatory. In a recent series, post-treatment dFLC<40mg/L was the major predictive factor of renal response and was associated with improvement of both renal and global survival. In MIDD, bortezomib-based therapy is safe and efficient when introduced early after diagnosis. dFLC response is a favorable prognostic factor for renal survival. PMID:27117766

  4. Beta-protein deposition: a pathogenetic link between Alzheimer's disease and cerebral amyloid angiopathies.

    PubMed

    Coria, F; Prelli, F; Castaño, E M; Larrondo-Lillo, M; Fernandez-Gonzalez, J; van Duinen, S G; Bots, G T; Luyendijk, W; Shelanski, M L; Frangione, B

    1988-10-25

    Cerebral amyloid angiopathy (CAA) refers to a group of hereditary (hereditary cerebral hemorrhage with amyloidosis, HCHWA and sporadic (SCAA) disorders characterized by amyloid fibril deposition restricted to the leptomeningeal and cortical vasculature leading to recurrent hemorrhagic and/or ischemic accidents. On clinical and biochemical grounds, two forms of HCHWA can be distinguished. The amyloid subunit of the HCHWA of Icelandic origin is related to Cystatin C, while amyloid from patients of Dutch origin (HCHWA-D) is related to the beta-protein (or A4), the main component of vascular and plaque core amyloid in Alzheimer's disease (AD) and Down's syndrome (DS) [corrected]. SCAA is an increasingly recognized cause of stroke in normotensive individual amounting to 5-10% of all cerebrovascular accidents. We now report the isolation and partial amino acid sequence of the amyloid subunit from a case of SCAA and a new case of HCHWA-D. The recognition that a heterogeneous group of diseases are linked by similar pathological and chemical features suggests that diversity of etiological factors may promote a common pathogenetic mechanism leading to amyloid-beta (A beta) deposition, and open new ways of research in AD and CAA as they are related to dementia and stroke. PMID:3058268

  5. Characterizing iron deposition in Parkinson's disease using susceptibility-weighted imaging: an in vivo MR study.

    PubMed

    Zhang, Jiuquan; Zhang, Yanling; Wang, Jian; Cai, Ping; Luo, Chunxia; Qian, Zhongming; Dai, Yongming; Feng, Hua

    2010-05-12

    Brain-iron deposition has been proposed to play an important role in the pathophysiology of Parkinson's disease (PD). The aim of this study was to evaluate the feasibility of characterizing iron deposition in PD using susceptibility-weighted imaging (SWI), and to investigate the correlation of brain-iron accumulation with the clinical status in patients with PD. Forty patients with PD without dementia and 26 age- and sex-matched healthy controls underwent high-resolution susceptibility-weighted magnetic resonance (MR) imaging. The phase shift values of the bilateral red nucleus (RN), substantia nigra (SN), caudate nucleus (CA), globus pallidus (GP), putamen (PU), thalamus (TH) and frontal white matter (FWM) were examined for their relationship with the clinical status. The iron concentrations of the regions involved in PD, such as the SN, increased more significantly, while those in other regions of interest (ROI) did not elevate significantly. No correlation between the increase of the iron concentrations of the SN and duration of PD was observed. PD, however, was closely associated with the Unified Parkinson's Disease Rating Scale motor score (UPDRS-III). No significant differences were found between earlier-onset and later-onset PD patients in terms of the iron concentrations of the SN. Brain-iron concentration can be evaluated by SWI. Also, the brain-iron concentration in the SN correlated with UPDRS motor score, indicating that iron concentration can function as an in vivo biomarker to objectively evaluate the status of PD. PMID:20303339

  6. No evidence for increased brain iron deposition in patients with ischemic white matter disease.

    PubMed

    Gattringer, Thomas; Khalil, Michael; Langkammer, Christian; Jehna, Margit; Pichler, Alexander; Pinter, Daniela; Kneihsl, Markus; Petrovic, Katja; Ropele, Stefan; Fazekas, Franz; Enzinger, Christian

    2016-09-01

    Besides specific iron accumulation in some neurodegenerative disorders, increased iron deposition in cerebral deep gray matter (DGM) is found in multiple sclerosis. As this is considered largely a white matter (WM) disease, we speculated that patients with more severe ischemic WM hyperintensities (WMH) might also have an increased iron concentration in DGM structures and tested this assumption by using magnetic resonance imaging-based quantitative R2* relaxometry. WMH severity was measured in 61 patients with acute transient neurological symptoms (mean age: 71.5 ± 8.3 years) undergoing 3-Tesla magnetic resonance imaging. Despite a 6-year higher age of patients with more severe (i.e., early confluent or confluent) WMH, their DGM R2* rates did not differ from patients with punctate or no WMH. In the globus pallidum, R2* rates were even lower in patients with severe WMH. WMH volume was not correlated with R2* levels in any of the analyzed DGM structures. These findings argue against WM damage per se causing increased DGM iron deposition in multiple sclerosis and suggest no role of iron accumulation in ischemic small vessel disease. PMID:27459926

  7. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance

    NASA Astrophysics Data System (ADS)

    Sharma, Shailesh; Gahan, David; Scullin, Paul; Doyle, James; Lennon, Jj; Vijayaraghavan, Rajani K.; Daniels, Stephen; Hopkins, M. B.

    2016-04-01

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.

  8. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance.

    PubMed

    Sharma, Shailesh; Gahan, David; Scullin, Paul; Doyle, James; Lennon, Jj; Vijayaraghavan, Rajani K; Daniels, Stephen; Hopkins, M B

    2016-04-01

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system. PMID:27131678

  9. Citrus Bioflavonoids Ameliorate Hyperoxaluria Induced Renal Injury and Calcium Oxalate Crystal Deposition in Wistar Rats

    PubMed Central

    Badrinathan, Sridharan; Shiju, Micheal Thomas; Arya, Ramachandran; Rajesh, Ganesh Nachiappa; Viswanathan, Pragasam

    2015-01-01

    Purpose: Citrus is considered as a medically important plant from ancient times and the bioflavonoids of different variety of citrus fruits were well explored for their biological activities. The study aim was to explore the effect of citrus bioflavonoids (CB) to prevent and cure hyperoxaluria induced urolithiasis. Methods: Twenty four Wistar rats were segregated into 4 Groups. Group 1: Control; Group 2: Urolithic (EG-0.75%); Group 3: Preventive study (EG+CB, day 1-50); Group 4: Curative study (EG+CB, day 30-50). Animals received CB orally (20mg/kg body weight) after performing a toxicity study. Results: Urinary risk factors and serum renal function parameters were significantly reduced by CB administration in both preventive and curative study (p<0.001). Hematoxylin & Eosin and von Kossa staining demonstrated that renal protection was offered by CB against EG insult. Immunohistochemical analyses revealed over expression and abnormal localization of THP and NF-κB in urolithic rats, while it was effectively regulated by CB supplementation. Conclusion: CB prevented and significantly controlled lithogenic factors and CaOx deposition in rats. We propose CB as a potential therapy in management of urolithiasis. PMID:26504765

  10. Disease Mutations in the Ryanodine Receptor Central Region: Crystal Structures of a Phosphorylation Hot Spot Domain

    SciTech Connect

    Yuchi, Zhiguang; Lau, Kelvin; Van Petegem, Filip

    2015-02-09

    Ryanodine Receptors (RyRs) are huge Ca{sup 2+} release channels in the endoplasmic reticulum membrane and form targets for phosphorylation and disease mutations. We present crystal structures of a domain in three RyR isoforms, containing the Ser2843 (RyR1) and Ser2808/Ser2814 (RyR2) phosphorylation sites. The RyR1 domain is the target for 11 disease mutations. Several of these are clustered near the phosphorylation sites, suggesting that phosphorylation and disease mutations may affect the same interface. The L2867G mutation causes a drastic thermal destabilization and aggregation at room temperature. Crystal structures for other disease mutants show that they affect surface properties and intradomain salt bridges. In vitro phosphorylation experiments show that up to five residues in one long loop of RyR2 can be phosphorylated by PKA or CaMKII. Docking into cryo-electron microscopy maps suggests a putative location in the clamp region, implying that mutations and phosphorylation may affect the allosteric motions within this area.

  11. Bortezomib produces high hematological response rates with prolonged renal survival in monoclonal immunoglobulin deposition disease.

    PubMed

    Cohen, Camille; Royer, Bruno; Javaugue, Vincent; Szalat, Raphael; El Karoui, Khalil; Caulier, Alexis; Knebelmann, Bertrand; Jaccard, Arnaud; Chevret, Sylvie; Touchard, Guy; Fermand, Jean-Paul; Arnulf, Bertrand; Bridoux, Frank

    2015-11-01

    Monoclonal immunoglobulin deposition disease (MIDD) is a rare complication of plasma cell disorders, defined by linear Congo red-negative deposits of monoclonal light chain, heavy chain, or both along basement membranes. While renal involvement is prominent, treatment strategies, such as the impact of novel anti-myeloma agents, remain poorly defined. Here we retrospectively studied 49 patients with MIDD who received a median of 4.5 cycles of intravenous bortezomib plus dexamethasone. Of these, 25 received no additional treatment, 18 also received cyclophosphamide, while 6 also received thalidomide or lenalidomide. The hematological diagnoses identified 38 patients with monoclonal gammopathy of renal significance, 10 with symptomatic multiple myeloma, and 1 with Waldenstrom macroglobulinemia. The overall hematologic response rate, based on the difference between involved and uninvolved serum-free light chains (dFLCs), was 91%. After median follow-up of 54 months, 5 patients died and 10 had reached end-stage renal disease. Renal response was achieved in 26 patients, with a 35% increase in median eGFR and an 86% decrease in median 24-h proteinuria. Predictive factors were pre-treatment eGFR over 30 ml/min per 1.73 m(2) and post-treatment dFLC under 40 mg/l; the latter was the sole predictive factor of renal response by multivariable analysis. Thus, bortezomib-based therapy is a promising treatment strategy in MIDD, mainly when used early in the disease course. dFLC response is a favorable prognostic factor for renal survival. PMID:26176826

  12. Thermal and fast neutron detection in chemical vapor deposition single-crystal diamond detectors

    NASA Astrophysics Data System (ADS)

    Almaviva, S.; Marinelli, M.; Milani, E.; Prestopino, G.; Tucciarone, A.; Verona, C.; Verona-Rinati, G.; Angelone, M.; Lattanzi, D.; Pillon, M.; Montereali, R. M.; Vincenti, M. A.

    2008-03-01

    Recently, a compact solid-state neutron detector capable of simultaneously detecting thermal and fast neutrons was proposed [M. Marinelli et al., Appl. Phys. Lett. 89, 143509 (2006)]. Its design is based on a p-type/intrinsic/metal layered structure obtained by Microwave Plasma Chemical Vapor Deposition (CVD) of homoepitaxial diamond followed by thermal evaporation of an Al contact and a L6iF converting layer. Fast neutrons are directly detected in the CVD diamond bulk, since they have enough energy to produce the C12(n,α)B9e reaction in diamond. Thermal neutrons are instead converted into charged particles in the L6iF layer through the L6i(n ,α)T nuclear reaction. These charged particles are then detected in the diamond layer. The thickness of the L6iF converting layer and the CVD diamond sensing layer affect the counting efficiency and energy resolution of the detector both for low- (thermal) and high-energy neutrons. An analysis is carried out on the dynamics of the L6i(n ,α)T and the C12(n,α)B9e reactions products, and the distribution of the energy released inside the sensitive layer is calculated. The detector counting efficiency and energy resolution were accordingly derived as a function of the thickness of the L6iF and CVD diamond layers, both for thermal and fast neutrons, thus allowing us to choose the optimum detector design for any particular application. Comparison with experimental results is also reported.

  13. Crystal structure of glycogen debranching enzyme and insights into its catalysis and disease-causing mutations

    PubMed Central

    Zhai, Liting; Feng, Lingling; Xia, Lin; Yin, Huiyong; Xiang, Song

    2016-01-01

    Glycogen is a branched glucose polymer and serves as an important energy store. Its debranching is a critical step in its mobilization. In animals and fungi, the 170 kDa glycogen debranching enzyme (GDE) catalyses this reaction. GDE deficiencies in humans are associated with severe diseases collectively termed glycogen storage disease type III (GSDIII). We report crystal structures of GDE and its complex with oligosaccharides, and structure-guided mutagenesis and biochemical studies to assess the structural observations. These studies reveal that distinct domains in GDE catalyse sequential reactions in glycogen debranching, the mechanism of their catalysis and highly specific substrate recognition. The unique tertiary structure of GDE provides additional contacts to glycogen besides its active sites, and our biochemical experiments indicate that they mediate its recruitment to glycogen and regulate its activity. Combining the understanding of the GDE catalysis and functional characterizations of its disease-causing mutations provides molecular insights into GSDIII. PMID:27088557

  14. Crystal structure of glycogen debranching enzyme and insights into its catalysis and disease-causing mutations.

    PubMed

    Zhai, Liting; Feng, Lingling; Xia, Lin; Yin, Huiyong; Xiang, Song

    2016-01-01

    Glycogen is a branched glucose polymer and serves as an important energy store. Its debranching is a critical step in its mobilization. In animals and fungi, the 170 kDa glycogen debranching enzyme (GDE) catalyses this reaction. GDE deficiencies in humans are associated with severe diseases collectively termed glycogen storage disease type III (GSDIII). We report crystal structures of GDE and its complex with oligosaccharides, and structure-guided mutagenesis and biochemical studies to assess the structural observations. These studies reveal that distinct domains in GDE catalyse sequential reactions in glycogen debranching, the mechanism of their catalysis and highly specific substrate recognition. The unique tertiary structure of GDE provides additional contacts to glycogen besides its active sites, and our biochemical experiments indicate that they mediate its recruitment to glycogen and regulate its activity. Combining the understanding of the GDE catalysis and functional characterizations of its disease-causing mutations provides molecular insights into GSDIII. PMID:27088557

  15. A potential role for crystallization inhibitors in treatment of Alzheimer's disease.

    PubMed

    Grases, Fèlix; Costa-Bauzà, Antònia; Prieto, Rafael M

    2010-01-01

    Melatonin is a hormone synthesized from the neurotransmitter serotonin and is found mainly in the pineal gland. Melatonin has been suggested to have several properties, acting both as an antioxidant and a neuroprotective agent. Melatonin synthesis decreases with age in all humans, but this decline is more pronounced in Alzheimer's patients. In fact, melatonin inhibits the formation of beta-amyloid protein. The mechanism responsible for this decline has not been fully elucidated, although it is known that the human pineal gland calcifies with age. Such calcification necessarily implies the existence of a tissue injury that, if not reabsorbed by the immune system, will act as heterogeneous nucleant for hydroxyapatite and will induce calcification. For this reason, it is hypothesized that a lack of inhibitors of calcium salt crystallization, such as pyrophosphate and phytate, will favor calcification. Therefore, the absence of crystallization inhibitors may be a risk factor for development of Alzheimer's disease, and this hypothesis should be evaluated. PMID:19666212

  16. Crystallization of sputtered-deposited and ion implanted amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} thin films

    SciTech Connect

    Rimini, E.; De Bastiani, R.; Carria, E.; Grimaldi, M. G.; Nicotra, G.; Bongiorno, C.; Spinella, C.

    2009-06-15

    X-ray diffraction and transmission electron microscopy have been utilized to measure the ion irradiation-induced modification in amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} thin films. The isothermal crystallization of sputtered-deposited and Sb{sup +} ion irradiated amorphous samples has been studied, focusing on the evolution of the microstructure during the initial stage of the transformation. In both samples, the amorphous to crystal transition occurs through the nucleation of face centered cubic (fcc) crystal domains at the film surface. A fast bidimensional growth of the crystalline nuclei in the sputtered-deposited films occurs by the generation of transrotational grains. The lattice parameter decreases as the crystalline fraction increases above 80%, and it approaches the fcc bulk value at the end of the transformation. Ion irradiation produces a densification of the deposited amorphous film (approx4% vertical shrinkage measured by atomic force microscopy) and an enhancement of the crystallization rate. Even in the irradiated amorphous, the nucleation occurs at the film surface and proceeds by the growth of the grains through the thickness of the layer although the density of the transrotational grains is strongly reduced with respect to the unirradiated amorphous. A link between the ion beam induced densification and the reduction of transrotational grains is proposed.

  17. Influence of lattice parameters on the dielectric constant of tetragonal ZrO2 and La-doped ZrO2 crystals in thin films deposited by atomic layer deposition on Ge(001)

    NASA Astrophysics Data System (ADS)

    Wiemer, C.; Debernardi, A.; Lamperti, A.; Molle, A.; Salicio, O.; Lamagna, L.; Fanciulli, M.

    2011-12-01

    In ZrO2 crystals, the highest dielectric constant (k) is ascribed to the tetragonal phase. By the use of density functional theory and synchrotron radiation x-ray diffraction, we show how the a and c lattice parameters of the tetragonal phase influence the resulting k. Highest k values are obtained at increasing both a and c, while k is reduced for compressive strained cells. The determination of a and c on La-doped ZrO2 and ZrO2 thin films deposited by atomic layer deposition on Ge (001) allowed us to elucidate the influence of La doping and Ge diffusion on the k value.

  18. Composition and crystal structure of N doped TiO2 film deposited at different O2 flow rate by direct current sputtering.

    PubMed

    Ding, Wanyu; Ju, Dongying; Chai, Weiping

    2011-06-01

    N doped Ti02 films were deposited by direct current pulse magnetron sputtering system at room temperature. The influence of 02 flow rate on the crystal structure of deposited films was studied by Stylus profilometer, X-ray photoelectron spectroscopy, and X-ray diffractometer. The results indicate that the 02 flow rate strongly controls the growth behavior and crystal structure of N doped Ti02 film. It is found that N element mainly exists as substitutional doped state and the chemical stiochiometry is near to TiO1.68±0.06N0.11±0.01 for all film samples. N doped Ti02 film deposited with 2 sccm (standard-state cubic centimeter per minute) 02 flow rate is amorphous structure with high growth rate, which contains both anatase phase and rutile phase crystal nucleuses. In this case, the film displays the mix-phase of anatase and rutile after annealing treatment. While N doped Ti02 film deposited with 12 cm(3)/min 02 flow rate displays anatase phase before and after annealing treatment. And it should be noticed that no TiN phase appears for all samples before and after annealing treatment. PMID:25084571

  19. Protein-resistant properties of a chemical vapor deposited alkyl-functional carboxysilane coating characterized using quartz crystal microbalance

    NASA Astrophysics Data System (ADS)

    Vaidya, Shyam V.; Yuan, Min; Narváez, Alfredo R.; Daghfal, David; Mattzela, James; Smith, David

    2016-02-01

    The protein-resistant properties of a chemical vapor deposited alkyl-functional carboxysilane coating (Dursan®) were compared to that of an amorphous fluoropolymer (AF1600) coating and bare 316L grade stainless steel by studying non-specific adsorption of various proteins onto these surfaces using quartz crystal microbalance with dissipation monitoring (QCM-D). A wash solution with nonionic surfactant, polyoxyethyleneglycol dodecyl ether (or Brij 35), facilitated 100% removal of the adsorbed bovine serum albumin (BSA), mouse immunoglobulin G (IgG), and normal human plasma proteins from the Dursan surface and of the adsorbed normal human plasma proteins from the AF1600 surface, whereas these proteins remained adsorbed on the bare stainless steel surface. Mechanical stress in the form of sonication demonstrated durability of the Dursan coating to mechanical wear and showed no negative impact on the coating's ability to prevent adsorption of plasma proteins. Surface delamination was observed in case of the sonicated AF1600 coating, which further led to adsorption of normal human plasma proteins.

  20. Growth of high-quality thin-film Ge single crystals by plasma-enhanced chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Outlaw, R. A.; Hopson, P., Jr.

    1986-01-01

    Thin-film Ge single crystals (approx. 10 microns) have been epitaxially grown on polished NaCl(100) substrates at 450C by using plasma-enhanced chemical vapor deposition. Films on approximately 1 sq cm and larger were separated from the NaCl by either melting the salt or by differential shear stress upon cooling to room temperature. The ordered growth of the Ge was found to be most sensitive to the initial plasma power and to the continuum flow dynamics within the carbon susceptor. The films were visually specular and exhibited a high degree of crysalline order when examined by X-ray diffraction. The films were found to be p-type with a carrier concentration of approximately 3 x 10 to the 16th power/cu cm, a resistivity of 0.11 ohm-cm, and a Hall hole mobility of 1820 sq cm/v/s at room temperature. Vacuum firing minimized the primary contaminant, Na, and corresponding lowered the carrier concentration to 4 x 10 to the 14th power/cu cm.

  1. Development of optical biosensor based on photonic crystal made of TiO2 using liquid phase deposition

    NASA Astrophysics Data System (ADS)

    Aono, Keigo; Aki, Shoma; Sueyoshi, Kenji; Hisamoto, Hideaki; Endo, Tatsuro

    2016-08-01

    We fabricated a titanium dioxide (TiO2)-based photonic crystal (PhC) using liquid phase deposition (LPD) to develop highly sensitive optical biosensors. The optical characteristics of the PhCs in the visible region were sensitive to the change in the refractive index of the surrounding medium due to an antigen–antibody reaction; thus, applications using the optical biosensor are expected to be highly sensitive. However, a base material with a high refractive index is indispensable for the fabrication of the PhC. Here, TiO2, which has optical transparency in the visible region, was selected as the high refractive index base material. The present LPD method allowed fabrication using low-cost apparatus. Furthermore, the mild conditions of the LPD method led to formation of TiO2-based PhC with fewer crack structures. Finally, the anti-neuron-specific enolase antibody was immobilized onto the TiO2-based PhC surface, and 1–1000 ng/mL of the neuron-specific enolase antigen was successfully detected.

  2. Early cortical thickness changes predict β-amyloid deposition in a mouse model of Alzheimer's disease.

    PubMed

    Grand'maison, Marilyn; Zehntner, Simone P; Ho, Ming-Kai; Hébert, François; Wood, Andrew; Carbonell, Felix; Zijdenbos, Alex P; Hamel, Edith; Bedell, Barry J

    2013-06-01

    Magnetic resonance imaging (MRI) studies have identified aberrant cortical structure in Alzheimer's disease (AD). The association between MRI-derived cortical morphometry measures and β-amyloid, however, remains poorly understood. In this study, we explored the potential relationship between early alterations in cortical thickness and later stage β-amyloid deposition, using a novel approach, in a transgenic AD mouse model. We acquired longitudinal anatomical MRI scans from mutant amyloid precursor protein (APP) transgenic mice and age-matched wild-type mice at 1 and 3.5months-of-age, and employed fully-automated image processing methods to derive objective, quantitative measures of cortical thickness on a region-of-interest basis. We also generated 3D quantitative immunohistochemistry (qIHC) volumes of deposited β-amyloid burden from 18month-old transgenic mice using an automated, production-level process. These studies revealed thinner cortex in most regions in the 1month-old transgenic mice relative to age-matched wild-types, with the exception of the frontal, perirhinal/entorhinal, posterior cingulate, and retrosplenial cortical regions. Between 1 and 3.5months-of-age, the transgenic mice demonstrated stable or increasing cortical thickness, while the wild-type mice showed cortical thinning. Based on data from co-registered 3D MRI and qIHC volumes, we identified an association between abnormal, early, regional cortical thickness change over 2.5months and later β-amyloid deposition. These observations suggest that the spatio-temporal pattern of early (pre-plaque) alterations in cerebral cortical structure is indicative of regional predisposition to later β-amyloid pathology in a transgenic AD mouse model. PMID:23454197

  3. Thickness-dependent crystallization on thermal anneal for titania/silica nm-layer composites deposited by ion beam sputter method.

    PubMed

    Pan, Huang-Wei; Wang, Shun-Jin; Kuo, Ling-Chi; Chao, Shiuh; Principe, Maria; Pinto, Innocenzo M; DeSalvo, Riccardo

    2014-12-01

    Crystallization following thermal annealing of thin film stacks consisting of alternating nm-thick titania/silica layers was investigated. Several prototypes were designed, featuring a different number of titania/silica layer pairs, and different thicknesses (in the range from 4 to 40 nm, for the titania layers), but the same nominal refractive index (2.09) and optical thickness (a quarter of wavelength at 1064 nm). The prototypes were deposited by ion beam sputtering on silicon substrates. All prototypes were found to be amorphous as-deposited. Thermal annealing in air at progressive temperatures was subsequently performed. It was found that the titania layers eventually crystallized forming the anatase phase, while the silica layers remained always amorphous. However, progressively thinner layers exhibited progressively higher threshold temperatures for crystallization onset. Accordingly it can be expected that composites with thinner layers will be able to sustain higher annealing temperatures without crystallizing, and likely yielding better optical and mechanical properties for advanced coatings application. These results open the way to the use of materials like titania and hafnia, that crystallize easily under thermal anneal, but ARE otherwise promising candidate materials for HR coatings necessary for cryogenic 3rd generation laser interferometric gravitational wave detectors. PMID:25606914

  4. Cortical Amyloid β Deposition and Current Depressive Symptoms in Alzheimer Disease and Mild Cognitive Impairment.

    PubMed

    Chung, Jun Ku; Plitman, Eric; Nakajima, Shinichiro; Chakravarty, M Mallar; Caravaggio, Fernando; Gerretsen, Philip; Iwata, Yusuke; Graff-Guerrero, Ariel

    2016-05-01

    Depressive symptoms are frequently seen in patients with dementia and mild cognitive impairment (MCI). Evidence suggests that there may be a link between current depressive symptoms and Alzheimer disease (AD)-associated pathological changes, such as an increase in cortical amyloid-β (Aβ). However, limited in vivo studies have explored the relationship between current depressive symptoms and cortical Aβ in patients with MCI and AD. Our study, using a large sample of 455 patients with MCI and 153 patients with AD from the Alzheimer's disease Neuroimaging Initiatives, investigated whether current depressive symptoms are related to cortical Aβ deposition. Depressive symptoms were assessed using the Geriatric Depression Scale and Neuropsychiatric Inventory-depression/dysphoria. Cortical Aβ was quantified using positron emission tomography with the Aβ probe(18)F-florbetapir (AV-45).(18)F-florbetapir standardized uptake value ratio (AV-45 SUVR) from the frontal, cingulate, parietal, and temporal regions was estimated. A global AV-45 SUVR, defined as the average of frontal, cingulate, precuneus, and parietal cortex, was also used. We observed that current depressive symptoms were not related to cortical Aβ, after controlling for potential confounds, including history of major depression. We also observed that there was no difference in cortical Aβ between matched participants with high and low depressive symptoms, as well as no difference between matched participants with the presence and absence of depressive symptoms. The association between depression and cortical Aβ deposition does not exist, but the relationship is highly influenced by stressful events in the past, such as previous depressive episodes, and complex interactions of different pathways underlying both depression and dementia. PMID:26400248

  5. Platelet aggregability and in vivo platelet deposition in patients with ischemic cerebrovascular disease--evaluation by indium-111-platelet scintigraphy

    SciTech Connect

    Isaka, Y.; Kimura, K.; Uehara, A.; Hashikawa, K.; Mieno, M.; Matsumoto, M.; Handa, N.; Nakabayashi, S.; Imaizumi, M.; Kamada, T. )

    1989-12-15

    In ischemic cerebrovascular disease, it is not clear whether platelet function in vitro actually reflects the situation in vivo. Using indium-111 platelet scintigraphy as a method for detecting platelet activation in vivo, we tried to elucidate this problem. Twenty eight patients with chronic stage of ischemic cerebrovascular disease (CVD) and 17 control subjects were examined. Platelet scintigrams were positive in 9 of 28 patients in CVD, while all were negative in control. A comparison of the results obtained from qualitative platelet imaging and platelet aggregability was performed to evaluate whether threshold aggregation concentration (TAC) grade differed across the three groups (control, CVD patients without platelet deposition and CVD patients with platelet deposition). CVD patients with platelet deposition showed a higher TAC than those patients who did not show platelet deposition (P less than 0.05) or control subjects without platelet deposition (P less than 0.05). These results suggest that some patients in chronic stages of CVD may have active platelet deposition on carotid atheromatous lesions, and presence of platelet deposition in vivo could contribute to reduce platelet reactivity in peripheral blood.

  6. Platelet aggregability and in vivo platelet deposition in patients with ischemic cerebrovascular disease--evaluation by indium-111-platelet scintigraphy.

    PubMed

    Isaka, Y; Kimura, K; Uehara, A; Hashikawa, K; Mieno, M; Matsumoto, M; Handa, N; Nakabayashi, S; Imaizumi, M; Kamada, T

    1989-12-15

    In ischemic cerebrovascular disease, it is not clear whether platelet function in vitro actually reflects the situation in vivo. Using indium-111 platelet scintigraphy as a method for detecting platelet activation in vivo, we tried to elucidate this problem. Twenty eight patients with chronic stage of ischemic cerebrovascular disease (CVD) and 17 control subjects were examined. Platelet scintigrams were positive in 9 of 28 patients in CVD, while all were negative in control. A comparison of the results obtained from qualitative platelet imaging and platelet aggregability was performed to evaluate whether threshold aggregation concentration (TAC) grade differed across the three groups (control, CVD patients without platelet deposition and CVD patients with platelet deposition). CVD patients with platelet deposition showed a higher TAC than those patients who did not show platelet deposition (P less than 0.05) or control subjects without platelet deposition (P less than 0.05). These results suggest that some patients in chronic stages of CVD may have active platelet deposition on carotid atheromatous lesions, and presence of platelet deposition in vivo could contribute to reduce platelet reactivity in peripheral blood. PMID:2633402

  7. Growth and characterization of large, high quality single crystal diamond substrates via microwave plasma assisted chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Nad, Shreya

    Single crystal diamond (SCD) substrates can be utilized in a wide range of applications. Important issues in the chemical vapor deposition (CVD) of such substrates include: shrinking of the SCD substrate area, stress and cracking, high defect density and hence low electronic quality and low optical quality due to high nitrogen impurities. The primary objective of this thesis is to begin to address these issues and to find possible solutions for enhancing the substrate dimensions and simultaneously improving the quality of the grown substrates. The deposition of SCD substrates is carried out in a microwave cavity plasma reactor via the microwave plasma assisted chemical vapor deposition technique. The operation of the reactor was first optimized to determine the safe and efficient operating regime. By adjusting the matching of the reactor cavity with the help of four internal tuning length variables, the system was further matched to operate at a maximum overall microwave coupling efficiency of ˜ 98%. Even with adjustments in the substrate holder position, the reactor remains well matched with a coupling efficiency of ˜ 95% indicating good experimental performance over a wide range of operating conditions. SCD substrates were synthesized at a high pressure of 240 Torr and with a high absorbed power density of 500 W/cm3. To counter the issue of shrinking substrate size during growth, the effect of different substrate holder designs was studied. An increase in the substrate dimensions (1.23 -- 2.5 times) after growth was achieved when the sides of the seeds were shielded from the intense microwave electromagnetic fields in a pocket holder design. Using such pocket holders, high growth rates of 16 -- 32 mum/hr were obtained for growth times of 8 -- 72 hours. The polycrystalline diamond rim deposition was minimized/eliminated from these growth runs, hence successfully enlarging the substrate size. Several synthesized CVD SCD substrates were laser cut and separated

  8. Identification of crystals deposited in brain and kidney after xylitol administration by biochemical, histochemical, and electron diffraction methods

    PubMed Central

    Evans, G. W.; Phillips, Gael; Mukherjee, T. M.; Snow, M. R.; Lawrence, J. R.; Thomas, D. W.

    1973-01-01

    The positive identification of crystals of calcium oxalate occurring in brain and kidney after xylitol administration is described. Biochemical, histochemical, conventional light and electron microscopical methods, including selected area electron diffraction, were used to characterize the crystals. Images PMID:4693896

  9. Identification of crystals deposited in brain and kidney after xylitol administration by biochemical, histochemical, and electron diffraction methods.

    PubMed

    Evans, G W; Phillips, G; Mukherjee, T M; Snow, M R; Lawrence, J R; Thomas, D W

    1973-01-01

    The positive identification of crystals of calcium oxalate occurring in brain and kidney after xylitol administration is described. Biochemical, histochemical, conventional light and electron microscopical methods, including selected area electron diffraction, were used to characterize the crystals. PMID:4693896

  10. The role of hydrogen in oxygen-assisted chemical vapor deposition growth of millimeter-sized graphene single crystals

    NASA Astrophysics Data System (ADS)

    Zhao, Pei; Cheng, Yu; Zhao, Dongchen; Yin, Kun; Zhang, Xuewei; Song, Meng; Yin, Shaoqian; Song, Yenan; Wang, Peng; Wang, Miao; Xia, Yang; Wang, Hongtao

    2016-03-01

    Involving oxygen in the traditional chemical vapor deposition (CVD) process has proven a promising approach to achieve large-scale graphene single crystals (GSCs), but its many relevant fundamental aspects are still not fully understood. Here we report a systematic study on the role of hydrogen in the growth of millimeter-sized GSCs using enclosure-like Cu structures via the oxygen-assisted CVD process. Results show that GSCs have different first layer growth behaviors on the inside and outside surfaces of a Cu enclosure when the H2 environment is varied, and these behaviors will consequently and strongly influence the adlayer formation in these GSCs, leading to two entirely different growth modes. Low H2 partial pressure (PH2) tends to result in fast growth of dendritically shaped GSCs with multiple small adlayers, but high PH2 can modify the GSC shape into hexagons with single large adlayer nuclei. This difference of adlayers is attributed to the different C diffusion paths determined by the shapes of their host GSCs. On the basis of these observations, we developed an isothermal two-step method to obtain GSCs with significantly improved growth rate and sample quality, in which low PH2 is first set to accelerate the growth rate followed by high PH2 to restrict the adlayer nuclei. Our results prove that the growth of GSCs can reach a reasonable optimization between their growth rates and sample quality by simply adjusting the CVD H2 environment, which we believe will lead to more improvements in graphene synthesis and fundamental insight into the related growth mechanisms.Involving oxygen in the traditional chemical vapor deposition (CVD) process has proven a promising approach to achieve large-scale graphene single crystals (GSCs), but its many relevant fundamental aspects are still not fully understood. Here we report a systematic study on the role of hydrogen in the growth of millimeter-sized GSCs using enclosure-like Cu structures via the oxygen-assisted CVD

  11. The role of hydrogen in oxygen-assisted chemical vapor deposition growth of millimeter-sized graphene single crystals.

    PubMed

    Zhao, Pei; Cheng, Yu; Zhao, Dongchen; Yin, Kun; Zhang, Xuewei; Song, Meng; Yin, Shaoqian; Song, Yenan; Wang, Peng; Wang, Miao; Xia, Yang; Wang, Hongtao

    2016-04-14

    Involving oxygen in the traditional chemical vapor deposition (CVD) process has proven a promising approach to achieve large-scale graphene single crystals (GSCs), but its many relevant fundamental aspects are still not fully understood. Here we report a systematic study on the role of hydrogen in the growth of millimeter-sized GSCs using enclosure-like Cu structures via the oxygen-assisted CVD process. Results show that GSCs have different first layer growth behaviors on the inside and outside surfaces of a Cu enclosure when the H2 environment is varied, and these behaviors will consequently and strongly influence the adlayer formation in these GSCs, leading to two entirely different growth modes. Low H2 partial pressure (PH2) tends to result in fast growth of dendritically shaped GSCs with multiple small adlayers, but high PH2 can modify the GSC shape into hexagons with single large adlayer nuclei. This difference of adlayers is attributed to the different C diffusion paths determined by the shapes of their host GSCs. On the basis of these observations, we developed an isothermal two-step method to obtain GSCs with significantly improved growth rate and sample quality, in which low PH2 is first set to accelerate the growth rate followed by high PH2 to restrict the adlayer nuclei. Our results prove that the growth of GSCs can reach a reasonable optimization between their growth rates and sample quality by simply adjusting the CVD H2 environment, which we believe will lead to more improvements in graphene synthesis and fundamental insight into the related growth mechanisms. PMID:26987665

  12. Immune complex disease with a lupus-like pattern of deposition in an antinuclear antibody-negative patient.

    PubMed

    Pirkle, James L; Freedman, Barry I; Fogo, Agnes B

    2013-07-01

    Immune complex-mediated glomerulonephritis can be caused by a multitude of disease processes and may manifest in a variety of histologic patterns. Lupus nephritis is an immune complex disease, the diagnosis of which requires that the affected patient have systemic lupus erythematosus (SLE). In the absence of SLE, the finding of glomerulonephritis with certain patterns of immune complex deposition characteristic of lupus nephritis has been referred to as lupus-like glomerulonephritis. Immunoglobulin G (IgG), IgA, IgM, complement C3, and C1q deposition in glomerular immune deposits is one such pattern. We report a case of immune complex disease in a primarily membranous distribution with mesangial, subendothelial, and tubular basement membrane deposits with IgG, IgA, IgM, C3, and C1q deposition in a patient with proteinuria, photosensitive dermatitis, and a positive lupus anticoagulant test. The patient had 3 of the clinical criteria for SLE, thus failing to meet the diagnosis based on the American College of Rheumatology definition. In this case, a diagnosis of lupus-like glomerulonephritis was made after other causes of membranous glomerulopathy were excluded. This teaching case highlights the broad differential diagnosis of this pattern of injury and reviews similar cases in the literature. PMID:23548558

  13. A New Approach of Polycrystalline Silicon Film on Plastic Substrate Prepared by Ion Beam Deposition Followed by Excimer Laser Crystallization at Room Temperature

    NASA Astrophysics Data System (ADS)

    Kwon, Jang Yeon; Lim, Hyuck; Park, Kyung Bae; Jung, Ji Sim; Kim, Do Young; Cho, Hans S.; Kim, Seok Pil; Park, Young Soo; Kim, Jong Man; Noguchi, Takashi

    2006-05-01

    In this work, we propose a new polycrystalline silicon (poly-Si) film of large grain for thin film transistor on flexible substrate. Thin films of amorphous silicon were deposited on plastic substrate by using ion beam deposition (IBD) and crystallized by excimer laser annealing. The entire process was carried out at room temperature. Si film formed by IBD has much lower impurity such as Ar, O, and H than that deposited by conventional sputtering method. This high purity of Si film makes large grain size (0.5 μm) and shows high endurance of excimer laser energy both on quartz and plastic substrate for flexible active matrix organic light emitting diode (AMOLED).

  14. Comparative Study of Solid-Phase Crystallization of Amorphous Silicon Deposited by Hot-Wire CVD, Plasma-Enhanced CVD, and Electron-Beam Evaporation

    SciTech Connect

    Stradins, P.; Kunz, O.; Young, D. L.; Yan, Y.; Jones, K. M.; Xu, Y.; Reedy, R. C.; Branz, H. M.; Aberle, A. G.; Wang, Q.

    2007-01-01

    Solid-phase crystallization (SPC) rates are compared in amorphous silicon films prepared by three different methods: hot-wire chemical vapor deposition (HWCVD), plasma-enhanced chemical vapor deposition (PECVD), and electron-beam physical vapor deposition (e-beam). Random SPC proceeds approximately 5 and 13 times slower in PECVD and e-beam films, respectively, as compared to HWCVD films. Doping accelerates random SPC in e-beam films but has little effect on the SPC rate of HWCVD films. In contrast, the crystalline growth front in solid-phase epitaxy experiments propagates at similar speed in HWCVD, PECVD, and e-beam amorphous Si films. This strongly suggests that the observed large differences in random SPC rates originate from different nucleation rates in these materials while the grain growth rates are relatively similar. The larger grain sizes observed for films that exhibit slower random SPC support this suggestion.

  15. A[Beta] Deposits in Older Non-Demented Individuals with Cognitive Decline Are Indicative of Preclinical Alzheimer's Disease

    ERIC Educational Resources Information Center

    Villemagne, V. L.; Pike, K. E.; Darby, D.; Maruff, P.; Savage, G.; Ng, S.; Ackermann, U.; Cowie, T. F.; Currie, J.; Chan, S. G.; Jones, G.; Tochon-Danguy, H.; O'Keefe, G.; Masters, C. L.; Rowe, C. C.

    2008-01-01

    Approximately 30% of healthy persons aged over 75 years show A[beta] deposition at autopsy. It is postulated that this represents preclinical Alzheimer's disease (AD). We evaluated the relationship between A[beta] burden as assessed by PiB PET and cognitive decline in a well-characterized, non-demented, elderly cohort. PiB PET studies and…

  16. Pathological tau deposition in Motor Neurone Disease and frontotemporal lobar degeneration associated with TDP-43 proteinopathy.

    PubMed

    Behrouzi, Roya; Liu, Xiawei; Wu, Dongyue; Robinson, Andrew C; Tanaguchi-Watanabe, Sayuri; Rollinson, Sara; Shi, Jing; Tian, Jinzhou; Hamdalla, Hisham H M; Ealing, John; Richardson, Anna; Jones, Matthew; Pickering-Brown, Stuart; Davidson, Yvonne S; Strong, Michael J; Hasegawa, Masato; Snowden, Julie S; Mann, David M A

    2016-01-01

    It has been suggested that patients with motor neurone disease (MND) and those with MND combined with behavioural variant frontotemporal dementia (bvFTD) (ie FTD + MND) or with FTD alone might exist on a continuum based on commonalities of neuropathology and/or genetic risk. Moreover, it has been reported that both a neuronal and a glial cell tauopathy can accompany the TDP-43 proteinopathy in patients with motor neurone disease (MND) with cognitive changes, and that the tauopathy may be fundamental to disease pathogenesis and clinical phenotype. In the present study, we sought to substantiate these latter findings, and test this concept of a pathological continuum, in a consecutive series of 41 patients with MND, 16 with FTD + MND and 23 with FTD without MND. Paraffin sections of frontal, entorhinal, temporal and occipital cortex and hippocampus were immunostained for tau pathology using anti-tau antibodies, AT8, pThr(175) and pThr(217), and for amyloid β protein (Aβ) using 4G8 antibody. Twenty four (59 %) patients with MND, 7 (44 %) patients with FTD + MND and 10 (43 %) patients with FTD showed 'significant' tau pathology (ie more than just an isolated neurofibrillary tangle or a few neuropil threads in one or more brain regions examined). In most instances, this bore the histological characteristics of an Alzheimer's disease process involving entorhinal cortex, hippocampus, temporal cortex, frontal cortex and occipital cortex in decreasing frequency, accompanied by a deposition of Aβ up to Thal phase 3, though 2 patients with MND, and 1 with FTD did show tau pathology beyond Braak stage III. Four other patients with MND showed novel neuronal tau pathology, within the frontal cortex alone, specifically detected by pThr(175) antibody, which was characterised by a fine granular or more clumped aggregation of tau without neurofibrillary tangles or neuropil threads. However, none of these 4 patients had clinically evident cognitive disorder, and

  17. Complement factor H–related hybrid protein deregulates complement in dense deposit disease

    PubMed Central

    Chen, Qian; Wiesener, Michael; Eberhardt, Hannes U.; Hartmann, Andrea; Uzonyi, Barbara; Kirschfink, Michael; Amann, Kerstin; Buettner, Maike; Goodship, Tim; Hugo, Christian; Skerka, Christine; Zipfel, Peter F.

    2013-01-01

    The renal disorder C3 glomerulopathy with dense deposit disease (C3G-DDD) pattern results from complement dysfunction and primarily affects children and young adults. There is no effective treatment, and patients often progress to end-stage renal failure. A small fraction of C3G-DDD cases linked to factor H or C3 gene mutations as well as autoantibodies have been reported. Here, we examined an index family with 2 patients with C3G-DDD and identified a chromosomal deletion in the complement factor H–related (CFHR) gene cluster. This deletion resulted in expression of a hybrid CFHR2-CFHR5 plasma protein. The recombinant hybrid protein stabilized the C3 convertase and reduced factor H–mediated convertase decay. One patient was refractory to plasma replacement and exchange therapy, as evidenced by the hybrid protein quickly returning to pretreatment plasma levels. Subsequently, complement inhibitors were tested on serum from the patient for their ability to block activity of CFHR2-CFHR5. Soluble CR1 restored defective C3 convertase regulation; however, neither eculizumab nor tagged compstatin had any effect. Our findings provide insight into the importance of CFHR proteins for C3 convertase regulation and identify a genetic variation in the CFHR gene cluster that promotes C3G-DDD. Monitoring copy number and sequence variations in the CFHR gene cluster in C3G-DDD and kidney patients with C3G-DDD variations will help guide treatment strategies. PMID:24334459

  18. Crystal structure and interaction of phycocyanin with β-secretase: A putative therapy for Alzheimer's disease.

    PubMed

    Singh, Niraj Kumar; Hasan, Syed S; Kumar, Jitendra; Raj, Isha; Pathan, Amrin A; Parmar, Asha; Shakil, Shazi; Gourinath, Samudrala; Madamwar, Datta

    2014-01-01

    Alzheimer's disease (AD) represents a neurological disorder, which is caused by enzymatic degradation of an amyloid precursor protein into short peptide fragments that undergo association to form insoluble plaques. Preliminary studies suggest that cyanobacterial extracts, especially the light-harvesting protein phycocyanin, may provide a means to control the progression of the disease. However, the molecular mechanism of disease control remains elusive. In the present study, intact hexameric phycocyanin was isolated and crystallized from the cyanobacterium Leptolyngbya sp. N62DM, and the structure was solved to a resolution of 2.6 A. Molecular docking studies show that the phycocyanin αβ-dimer interacts with the enzyme β-secretase, which catalyzes the proteolysis of the amyloid precursor protein to form plaques. The molecular docking studies suggest that the interaction between phycocyanin and β-secretase is energetically more favorable than previously reported inhibitor-β-secretase interactions. Transgenic Caenorhabditis elegans worms, with a genotype to serve as an AD-model, were significantly protected by phycocyanin. Therefore, the present study provides a novel structure-based molecular mechanism of phycocyanin-mediated therapy against AD. PMID:24576002

  19. Investigation of cerebral iron deposition in aged patients with ischemic cerebrovascular disease using susceptibility-weighted imaging

    PubMed Central

    Liu, Yin; Liu, Jun; Liu, Huanghui; Liao, Yunjie; Cao, Lu; Ye, Bin; Wang, Wei

    2016-01-01

    Objective The aim of this study was to investigate focal iron deposition level in the brain in patients with ischemic cerebrovascular disease and its correlation with cerebral small vessel disease imaging markers. Patients and methods Seventy-four patients with first-ever transient ischemic attack (median age: 69 years; 30 males and 44 females) and 77 patients with positive ischemic stroke history (median age: 72 years; 43 males and 34 females) were studied retrospectively. On phase image of susceptibility-weighted imaging and regions of interest were manually drawn at the bilateral head of the caudate nucleus, lenticular nucleus (LN), thalamus (TH), frontal white matter, and occipital white matter. The correlation between iron deposition level and the clinical and imaging variables was also investigated. Results Iron deposition level at LN was significantly higher in patients with previous stroke history. It linearly correlated with the presence and number of cerebral microbleeds (CMBs) but not with white matter hyperintensity and lacunar infarct. Multiple linear regression analysis showed that deep structure CMBs were the most relevant in terms of iron deposition at LN. Conclusion Iron deposition at LN may increase in cases of more severe ischemia in aged patients with transient ischemic attack, and it may be an imaging marker for CMB of ischemic origin. PMID:27574434

  20. A New Generation Fiber Optic Probe: Characterization of Biological Fluids, Protein Crystals and Ophthalmic Diseases

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Suh, Kwang I.

    1996-01-01

    A new fiber optic probe developed for determining transport properties of sub-micron particles in fluids experiments in a microgravity environment has been applied to characterize particulate dispersions/suspensions in various challenging environments which have been hitherto impossible. The probe positioned in front of a sample delivers a low power light (few nW - 3mW) from a laser and guides the light which is back scattered by the suspended particles through a receiving optical fiber to a photo detector and to a digital correlator. The probe provides rapid determination of macromolecular diffusivities and their respective size distributions. It has been applied to characterize various biological fluids, protein crystals, and ophthalmic diseases.

  1. Novel Pattern of Iron Deposition in the Fascicula Nigrale in Patients with Parkinson's Disease: A Pilot Study

    PubMed Central

    Peckham, Miriam E.; Holshouser, Barbara A.; Kani, Camellia; Boscanin, Alex; Kani, Kayvan; Harder, Sheri L.

    2016-01-01

    Background and Purpose. To determine whether the pattern of iron deposition in the fascicula nigrale in patients with Parkinson's disease would be different from age-matched controls by utilizing quantitative susceptibility mapping to measure susceptibility change. Methods. MRIs of the brain were obtained from 34 subjects, 18 with Parkinson's disease and 16 age- and gender-matched controls. Regions of interest were drawn around the fascicula nigrale and substantia nigra using SWI mapping software by blinded investigators. Statistical analyses were performed to determine susceptibility patterns of both of these regions. Results. Measurements showed significantly increased susceptibility in the substantia nigra in Parkinson's patients and an increased rostral-caudal deposition of iron in the fascicula nigrale in all subjects. This trend was exaggerated with significant correlation noted with increasing age in the Parkinson group. Conclusion. The pattern of an exaggerated iron deposition gradient of the fascicula nigrale in the Parkinson group could represent underlying tract dysfunction. Significant correlation of increasing iron deposition with increasing age may be a cumulative effect, possibly related to disease duration. PMID:27471601

  2. Novel Pattern of Iron Deposition in the Fascicula Nigrale in Patients with Parkinson's Disease: A Pilot Study.

    PubMed

    Peckham, Miriam E; Dashtipour, Khashayar; Holshouser, Barbara A; Kani, Camellia; Boscanin, Alex; Kani, Kayvan; Harder, Sheri L

    2016-01-01

    Background and Purpose. To determine whether the pattern of iron deposition in the fascicula nigrale in patients with Parkinson's disease would be different from age-matched controls by utilizing quantitative susceptibility mapping to measure susceptibility change. Methods. MRIs of the brain were obtained from 34 subjects, 18 with Parkinson's disease and 16 age- and gender-matched controls. Regions of interest were drawn around the fascicula nigrale and substantia nigra using SWI mapping software by blinded investigators. Statistical analyses were performed to determine susceptibility patterns of both of these regions. Results. Measurements showed significantly increased susceptibility in the substantia nigra in Parkinson's patients and an increased rostral-caudal deposition of iron in the fascicula nigrale in all subjects. This trend was exaggerated with significant correlation noted with increasing age in the Parkinson group. Conclusion. The pattern of an exaggerated iron deposition gradient of the fascicula nigrale in the Parkinson group could represent underlying tract dysfunction. Significant correlation of increasing iron deposition with increasing age may be a cumulative effect, possibly related to disease duration. PMID:27471601

  3. Effect of pre-deposition RF plasma etching on wafer surface morphology and crystal orientation of piezoelectric AlN thin films.

    PubMed

    Felmetsger, V; Mikhov, M; Laptev, P

    2015-02-01

    In this work, we describe the design and operation of a planarized capacitively coupled RF plasma module and investigate the effects of non-reactive RF plasma etching on Si (100) wafer surface morphology and crystal orientation of Al bottom electrodes and subsequently deposited AlN films. To ensure formation of highly (111) textured Al electrode, a thin 25-nm AlN seed layer was grown before the Al deposition. The seed layer's orientation efficiency improved with increasing the RF power from 70 to 300 W and resulted in narrowing the Al (111) rocking curves. AFM and XRD data have shown that crystal orientations of both the electrode and reactively sputtered AlN film are considerably improved when the substrate micro roughness is reduced from an ordinary level of a few nanometers to atomic level corresponding to root mean square roughness as low as about 0.2 to 0.3 nm. The most perfectly crystallized film stacks of 100-nm Al and 500-nm AlN were obtained in this work using etching in Ar plasma optimized to create an atomically smooth, epi-ready Si surface morphology that enables superior AlN seed layer nucleation conditions. X-ray rocking curves around the Al (111) and AlN (0002) diffraction peaks exhibited extremely low FWHM values of 0.68° and 1.05°, respectively. PMID:25643087

  4. Millimeter-size single-crystal graphene by suppressing evaporative loss of Cu during low pressure chemical vapor deposition.

    PubMed

    Chen, Shanshan; Ji, Hengxing; Chou, Harry; Li, Qiongyu; Li, Hongyang; Suk, Ji Won; Piner, Richard; Liao, Lei; Cai, Weiwei; Ruoff, Rodney S

    2013-04-11

    Millimeter-size single-crystal monolayer graphene is synthesized on polycrystalline Cu foil by a method that involves suppressing loss by evaporation of the Cu at high temperature under low pressure. This significantly diminishes the number of graphene domains, and large single crystal domains up to ∼2 mm in size are grown. PMID:23386288

  5. 3D Petrography - Serendipitous Discovery of Magmatic Vapor Deposition of Anhydrite at Mount Pinatubo by SEM Imaging of Outer Crystal Surfaces

    NASA Astrophysics Data System (ADS)

    Fournelle, J. H.; Jakubowski, R. T.; Welch, S.; Swope, R. J.

    2003-12-01

    A standard petrographic technique focuses upon examination of surfaces or planes cut through rock samples, with one approach studying chemical variations in a core to rim traverse using various microprobes, and more recently, another determining the distribution of crystal sizes to obtain information about nucleation and growth. We show that another mineral domain deserves petrographic attention: the outer surfaces of crystals, which are normally relegated to nearly invisible thin lines in a cut section. In studying anhydrite phenocrysts from the 1991 climactic eruption of Mt. Pinatubo, SEM examination of "raw" pumice fragments showed the existence of a Ca-sulfur-rich phase with hexagonal morphology residing upon plagioclase phenocryst surfaces in vesicles (Fournelle et al,1996, Fig 9). In 1992, Terry Gerlach suggested that the Pinatubo anhydrite phenocrysts should be evaluated with XRD to determine if they were indeed orthorhombic anhydrite (β -CaSO4), and not a lower temperature polymorph (i.e., α or γ ). In 1998, we recommenced this project, mounting several dozen 100-200 micron-size phenocrysts of the proper density fraction on tape (minerals had been separated from the pumices using standard techniques). They were examined by low resolution SEM with EDS to distinguish the anhydrite from apatite, prior to single-crystal XRD. We were surprised to find that many of the anhydrite surfaces were decorated with small mounds, which upon examination by high resolution SEM turned out to be micron and smaller pyramids, with some surfaces bearing hundreds. Single-crystal XRD verified that the phenocrysts were orthorhombic anhydrite, and EBSD verified that the small pyramids were the same. Eventually we found that these surface pyramids are common phenomena in experimental or industrial chemical vapor deposition processes when nucleation overwhelms growth. Textural relations were consistent with these pyramids being deposited in situ, within the Pinatubo magma chamber

  6. Physical vapour deposition growth and transmission electron microscopy characterization of epitaxial thin metal films on single-crystal Si and Ge substrates

    NASA Astrophysics Data System (ADS)

    Westmacott, K. H.; Hinderberger, S.; Dahmen, U.

    2001-06-01

    Epitaxial fcc, bcc and hcp metal and alloy films were grown in high vacuum by physical vapour deposition at high rate ('flash' deposition) on the (111), (110) and (100) surfaces of Si and Ge at different deposition temperatures. The resulting epitaxial relationships and morphological features of these films were characterized by transmission electron microscopy and diffraction. Simple epitaxial relationships were found mainly for the fcc metals that form binary eutectic systems with Si and G e. Of these, Ag exhibited exceptional behaviour by forming in a single crystal cube-cube relationship on all six semiconductor surfaces. Al and Au both formed bicrystal films on (100) substrates but differed in their behaviours on (111) substrates. Silicide formers such as the fcc metals Cu and Ni, as well as all bcc and hcp metals investigated, did not adopt epitaxial relationships on most semiconductor substrates. However, epitaxial single-crystal, bicrystal and tricrystal films of several metals and alloys could be grown by using a Ag buffer layer. The factors controlling the epitaxial growth of metal films are discussed in the light of the observations and compared with the predictions of established models for epitaxial relationships. It is concluded that epitaxial films can be grown easily if the film forms a simple eutectic or monotectic system with the substrate. The epitaxial relationships of those films depend on crystallographic factors for metal-metal epitaxy and on the substrate surface structure for metal-semiconductor epitaxy.

  7. Crystal structure of NOD2 and its implications in human disease

    PubMed Central

    Maekawa, Sakiko; Ohto, Umeharu; Shibata, Takuma; Miyake, Kensuke; Shimizu, Toshiyuki

    2016-01-01

    Nucleotide-binding oligomerization domain-containing protein 2 (NOD2), a member of the NOD-like receptors family, are crucial for innate immune responses. Mutations of NOD2 have been associated with chronic inflammatory disorders such as Crohn's disease (CD), Blau syndrome (BS) and early-onset sarcoidosis (EOS), but little is known about its signalling mechanism and the role it plays in these diseases. Here, we report the crystal structure of rabbit NOD2 in an ADP-bound state. The structure reveals an inactive closed conformation in which the subdomains in the NOD domain are closely packed by ADP-mediated and inter-domain interactions. Mapping of the BS- or EOS-associated gain-of-function mutations reveals that most of these mutations are located in the NOD subdomain interfaces, and are likely to disrupt the inner domain interactions, facilitating a conformational change to the active form. Conversely, mutations associated with CD are distributed throughout the protein, some of which may affect oligomer formation and ligand binding. PMID:27283905

  8. Crystal structure of NOD2 and its implications in human disease.

    PubMed

    Maekawa, Sakiko; Ohto, Umeharu; Shibata, Takuma; Miyake, Kensuke; Shimizu, Toshiyuki

    2016-01-01

    Nucleotide-binding oligomerization domain-containing protein 2 (NOD2), a member of the NOD-like receptors family, are crucial for innate immune responses. Mutations of NOD2 have been associated with chronic inflammatory disorders such as Crohn's disease (CD), Blau syndrome (BS) and early-onset sarcoidosis (EOS), but little is known about its signalling mechanism and the role it plays in these diseases. Here, we report the crystal structure of rabbit NOD2 in an ADP-bound state. The structure reveals an inactive closed conformation in which the subdomains in the NOD domain are closely packed by ADP-mediated and inter-domain interactions. Mapping of the BS- or EOS-associated gain-of-function mutations reveals that most of these mutations are located in the NOD subdomain interfaces, and are likely to disrupt the inner domain interactions, facilitating a conformational change to the active form. Conversely, mutations associated with CD are distributed throughout the protein, some of which may affect oligomer formation and ligand binding. PMID:27283905

  9. Biosensor architecture for enhanced disease diagnostics: lab-in-a-photonic-crystal.

    PubMed

    Feng, Shuai; Jiang, Jian-Hua; Rashid, Abdullah Al; John, Sajeev

    2016-05-30

    A conceptual lab-in-a-photonic-crystal biosensor is demonstrated that can multiplex four or more distinct disease-markers and distinguish their presence and combinations simultaneously with unique spectral fingerprints. This biosensor consists of a photonic-band-gap, multi-mode waveguide coupled to surface modes on either side, encased in a glass slide with microfluidic channels. The spectral fingerprints consist of multiple peaks in optical transmission vs. frequency that respond sensitively and uniquely in both frequency shift and nonmonotonic change of peak transmittance levels to various analyte bindings. This special property enables complete, logical determination of twelve different combinations of four distinct disease-markers through one scan of the transmission spectrum. The results reveal unique phenomena such as switching between the strong-coupling and weak-coupling combinations of surface states by analyte binding at different locations along the central waveguide. The unconventional transmission spectra are explained using a Landauer-Büttiker, multiple-scattering, transmission theory that reproduces the main features of the exact finite-difference-time-domain simulation. PMID:27410136

  10. Adsorption calorimetry during metal vapor deposition on single crystal surfaces: Increased flux, reduced optical radiation, and real-time flux and reflectivity measurements

    SciTech Connect

    Sellers, Jason R. V.; James, Trevor E.; Hemmingson, Stephanie L.; Farmer, Jason A.; Campbell, Charles T.

    2013-12-15

    Thin films of metals and other materials are often grown by physical vapor deposition. To understand such processes, it is desirable to measure the adsorption energy of the deposited species as the film grows, especially when grown on single crystal substrates where the structure of the adsorbed species, evolving interface, and thin film are more homogeneous and well-defined in structure. Our group previously described in this journal an adsorption calorimeter capable of such measurements on single-crystal surfaces under the clean conditions of ultrahigh vacuum [J. T. Stuckless, N. A. Frei, and C. T. Campbell, Rev. Sci. Instrum. 69, 2427 (1998)]. Here we describe several improvements to that original design that allow for heat measurements with ∼18-fold smaller standard deviation, greater absolute accuracy in energy calibration, and, most importantly, measurements of the adsorption of lower vapor-pressure materials which would have previously been impossible. These improvements are accomplished by: (1) using an electron beam evaporator instead of a Knudsen cell to generate the metal vapor at the source of the pulsed atomic beam, (2) changing the atomic beam design to decrease the relative amount of optical radiation that accompanies evaporation, (3) adding an off-axis quartz crystal microbalance for real-time measurement of the flux of the atomic beam during calorimetry experiments, and (4) adding capabilities for in situ relative diffuse optical reflectivity determinations (necessary for heat signal calibration). These improvements are not limited to adsorption calorimetry during metal deposition, but also could be applied to better study film growth of other elements and even molecular adsorbates.

  11. Proliferative glomerulonephritis with monoclonal immunoglobulin deposition disease: The utility of routine staining with immunoglobulin light chains.

    PubMed

    Gowda, K K; Nada, R; Ramachandran, R; Joshi, K; Tewari, R; Kohli, H S; Jha, V; Gupta, K L

    2015-01-01

    Proliferative glomerulonephritis occurring as a consequence of monoclonal glomerular deposits of IgG is uncommon. It is a form of renal involvement in monoclonal gammopathy that mimics immune complex glomerulonephritis. Here, we report the first series of proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) from the Indian subcontinent highlighting use of light chain immunofluorescence (IF) in routine renal biopsy interpretation. We retrieved 6 patients diagnosed as proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) out of 160 biopsies (3.7%) with membranoproliferative patterns over 5 1/2 years (2009-2014), one of whom had recurrence 6 months post-renal transplant. Four (67%) patients presented with rapidly progressive renal failure and two (33%) with nephrotic syndrome. None of these patients had overt multiple myeloma. The predominant histologic pattern was membranoproliferative with all the biopsies showing IgG3 Kappa deposits on IF. The deposits were primarily subendothelial on electron microscopy. PMID:26664209

  12. Proliferative glomerulonephritis with monoclonal immunoglobulin deposition disease: The utility of routine staining with immunoglobulin light chains

    PubMed Central

    Gowda, K. K.; Nada, R.; Ramachandran, R.; Joshi, K.; Tewari, R.; Kohli, H. S.; Jha, V.; Gupta, K. L.

    2015-01-01

    Proliferative glomerulonephritis occurring as a consequence of monoclonal glomerular deposits of IgG is uncommon. It is a form of renal involvement in monoclonal gammopathy that mimics immune complex glomerulonephritis. Here, we report the first series of proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) from the Indian subcontinent highlighting use of light chain immunofluorescence (IF) in routine renal biopsy interpretation. We retrieved 6 patients diagnosed as proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) out of 160 biopsies (3.7%) with membranoproliferative patterns over 5 1/2 years (2009–2014), one of whom had recurrence 6 months post-renal transplant. Four (67%) patients presented with rapidly progressive renal failure and two (33%) with nephrotic syndrome. None of these patients had overt multiple myeloma. The predominant histologic pattern was membranoproliferative with all the biopsies showing IgG3 Kappa deposits on IF. The deposits were primarily subendothelial on electron microscopy. PMID:26664209

  13. One-pot synthesis of single-crystal Pt nanoplates uniformly deposited on reduced graphene oxide, and their high activity and stability on the electrocalalytic oxidation of methanol.

    PubMed

    Hao, Yanfei; Wang, Xudan; Shen, Jianfeng; Yuan, Junhua; Wang, Ai-Jun; Niu, Li; Huang, Shengtang

    2016-04-01

    We demonstrate a one-pot thermoreduction approach towards the preparation of single-crystal Pt nanoplates, which were uniformly deposited on the reduced graphene oxide (RGO) using polyvinylpyrrolidone (PVP) as a stabilizer. The size of Pt nanoplates can be tuned from 6.8 to 10.1 nm by controlling Pt loading. The as-prepared Pt/PVP/RGO catalysts show high stability and activity towards the methanol oxidation reaction (MOR). Their MOR current can reach up to 401 mA mg(-1) Pt and MOR current can maintain 89.4% of its initial value after 10 000 potential cycles. PMID:26906081

  14. Comparison of precursor infiltration into polymer thin films via atomic layer deposition and sequential vapor infiltration using in-situ quartz crystal microgravimetry

    SciTech Connect

    Padbury, Richard P.; Jur, Jesse S.

    2014-07-01

    Previous research exploring inorganic materials nucleation behavior on polymers via atomic layer deposition indicates the formation of hybrid organic–inorganic materials that form within the subsurface of the polymer. This has inspired adaptations to the process, such as sequential vapor infiltration, which enhances the diffusion of organometallic precursors into the subsurface of the polymer to promote the formation of a hybrid organic–inorganic coating. This work highlights the fundamental difference in mass uptake behavior between atomic layer deposition and sequential vapor infiltration using in-situ methods. In particular, in-situ quartz crystal microgravimetry is used to compare the mass uptake behavior of trimethyl aluminum in poly(butylene terephthalate) and polyamide-6 polymer thin films. The importance of trimethyl aluminum diffusion into the polymer subsurface and the subsequent chemical reactions with polymer functional groups are discussed.

  15. Crystal structure of a TSH receptor monoclonal antibody: insight into Graves' disease pathogenesis.

    PubMed

    Chen, Chun-Rong; Hubbard, Paul A; Salazar, Larry M; McLachlan, Sandra M; Murali, Ramachandran; Rapoport, Basil

    2015-01-01

    The TSH receptor (TSHR) A-subunit is more effective than the holoreceptor in inducing thyroid-stimulating antibodies (TSAb) that cause Graves' disease. A puzzling phenomenon is that 2 recombinant, eukaryotic forms of A-subunits (residues 22-289), termed active and inactive, are recognized mutually exclusively by pathogenic TSAb and mouse monoclonal antibody 3BD10, respectively. Understanding the structural difference between these TSHR A-subunit forms could provide insight into Graves' disease pathogenesis. The 3-dimensional structure of the active A-subunit (in complex with a human TSAb Fab, M22) is known, but the structural difference with inactive A-subunits is unknown. We solved the 3BD10 Fab 3-dimensional crystal structure. Guided by prior knowledge of a portion of its epitope, 3BD10 docked in silico with the known active TSHR-289 monomeric structure. Because both TSAb and 3BD10 recognize the active TSHR A-subunit monomer, this form of the molecule can be excluded as the basis for the active-inactive dichotomy, suggesting, instead a role for A-subunit quaternary structure. Indeed, in silico analysis revealed that M22, but not 3BD10, bound to a TSHR-289 trimer. In contrast, 3BD10, but not M22, bound to a TSHR-289 dimer. The validity of these models is supported experimentally by the temperature-dependent balance between active and inactive TSHR-289. In summary, we provide evidence for a structural basis to explain the conformational heterogeneity of TSHR A-subunits (TSHR-289). The pathophysiologic importance of these findings is that affinity maturation of pathogenic TSAb in Graves' disease is likely to involve a trimer of the shed TSHR A-subunit. PMID:25419797

  16. Crystal structure of HLA-DP2 and implications for chronic beryllium disease

    SciTech Connect

    Dai, Shaodong; Murphy, Guinevere A.; Crawford, Frances; Mack, Douglas G.; Falta, Michael T.; Marrack, Philippa; Kappler, John W.; Fontenot, Andrew P.

    2010-06-15

    Chronic beryllium disease (CBD) is a fibrotic lung disorder caused by beryllium (Be) exposure and is characterized by granulomatous inflammation and the accumulation of Be-responsive CD4{sup +} T cells in the lung. Genetic susceptibility to CBD has been associated with certain alleles of the MHCII molecule HLA-DP, especially HLA-DPB1*0201 and other alleles that contain a glutamic acid residue at position 69 of the {beta}-chain ({beta}Glu69). The HLA-DP alleles that can present Be to T cells match those implicated in the genetic susceptibility, suggesting that the HLA contribution to disease is based on the ability of those molecules to bind and present Be to T cells. The structure of HLA-DP2 and its interaction with Be are unknown. Here, we present the HLA-DP2 structure with its antigen-binding groove occupied by a self-peptide derived from the HLA-DR {alpha}-chain. The most striking feature of the structure is an unusual solvent exposed acidic pocket formed between the peptide backbone and the HLA-DP2 {beta}-chain {alpha}-helix and containing three glutamic acids from the {beta}-chain, including {beta}Glu69. In the crystal packing, this pocket has been filled with the guanidinium group of an arginine from a neighboring molecule. This positively charged moiety forms an extensive H-bond/salt bridge network with the three glutamic acids, offering a plausible model for how Be-containing complexes might occupy this site. This idea is strengthened by the demonstration that mutation of any of the three glutamic acids in this pocket results in loss of the ability of DP2 to present Be to T cells.

  17. [The concurrence of light-chain deposition disease, AL-amyloidosis, and cast nephropathy in a patient with multiple myeloma].

    PubMed

    Rekhtina, I G; Zakharova, E V; Stoliarevich, E S; Sinitsina, M N; Denisova, E N

    2015-01-01

    Despite of the fact that their clinical manifestations are similar, AL-amyloidosis (AL-A) and light chain deposition disease (LCDD) are individual nosological entities in view of considerable differences in their pathogenesis and pathomorphology. The paper describes a rare case of the concurrence of LCDD and AL-A in a patient with multiple myeloma. Clinically, there was dialysis-dependent renal failure, flail leg syndrome, myocardiopathy, and rhabdomyolysis. At the disease onset, his nephrobiopsy specimen could diagnose LCDD and myeloma or cast nephropathy. The disease was characterized by an aggressive course. Despite the administration of innovative agents, the patient had a short-term remission and died from disease progression. Autopsy additionally revealed amyloid deposition in the heart and kidney. The development of AL-A in the presence of prior LCDD may reflect the progression of the tumor and the appearance of an additional subclone of plasma cells that produce amyloidogenic light chains. The uncommonness of this case is that renal amyloid was found in the tubular casts and absent in the glomeruli, which may be considered as a special form--tubular AL-amyloidosis. PMID:26281203

  18. Synthesis of SrTiO3 by crystallization of SrO/TiO2 superlattices prepared by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Riedel, Stefan; Neidhardt, Jörg; Jansen, Sören; Wilde, Lutz; Sundqvist, Jonas; Erben, Elke; Teichert, Steffen; Michaelis, Alexander

    2011-05-01

    An approach for the preparation of homogenous SrTiO3 (STO) thin films with unprecedented compositional control is presented. Nanolaminates of SrO and TiO2 were deposited at 300 °C by atomic layer deposition on bare silicon, as well as on ruthenium electrodes using metalorganic precursors [Ti(NEtMe)4 (TEMATi),Sr(iPr3Cp)2 (AbsoluteSr)]. Care was taken that the individual sublayers were grown with a number of subcycles well in the steady-state growth regime. This enabled linear composition tuning with the Sr:Ti pulse ratio, which is beneficial for process control. Still, a substrate-specific growth behavior was observed for the individual precursors leading to different cycle ratio/composition dependence for samples grown on Si as compared to Ru substrates. This could be attributed to specific nucleation conditions, which are most pronounced for the initial cycle, but also prevail throughout the film. The as-deposited layers are well separated and the sublayers are amorphous. Subsequent furnace-annealing generated polycrystalline cubic STO films, but also caused a severe distortion of the metal electrode/STO stack, due to interdiffusion. The latter was suppressed by optimized rapid thermal crystallization anneals.

  19. Magnetic resonance imaging-based computational modelling of blood flow and nanomedicine deposition in patients with peripheral arterial disease

    PubMed Central

    Hossain, Shaolie S.; Zhang, Yongjie; Fu, Xiaoyi; Brunner, Gerd; Singh, Jaykrishna; Hughes, Thomas J. R.; Shah, Dipan; Decuzzi, Paolo

    2015-01-01

    Peripheral arterial disease (PAD) is generally attributed to the progressive vascular accumulation of lipoproteins and circulating monocytes in the vessel walls leading to the formation of atherosclerotic plaques. This is known to be regulated by the local vascular geometry, haemodynamics and biophysical conditions. Here, an isogeometric analysis framework is proposed to analyse the blood flow and vascular deposition of circulating nanoparticles (NPs) into the superficial femoral artery (SFA) of a PAD patient. The local geometry of the blood vessel and the haemodynamic conditions are derived from magnetic resonance imaging (MRI), performed at baseline and at 24 months post intervention. A dramatic improvement in blood flow dynamics is observed post intervention. A 500% increase in peak flow rate is measured in vivo as a consequence of luminal enlargement. Furthermore, blood flow simulations reveal a 32% drop in the mean oscillatory shear index, indicating reduced disturbed flow post intervention. The same patient information (vascular geometry and blood flow) is used to predict in silico in a simulation of the vascular deposition of systemically injected nanomedicines. NPs, targeted to inflammatory vascular molecules including VCAM-1, E-selectin and ICAM-1, are predicted to preferentially accumulate near the stenosis in the baseline configuration, with VCAM-1 providing the highest accumulation (approx. 1.33 and 1.50 times higher concentration than that of ICAM-1 and E-selectin, respectively). Such selective deposition of NPs within the stenosis could be effectively used for the detection and treatment of plaques forming in the SFA. The presented MRI-based computational protocol can be used to analyse data from clinical trials to explore possible correlations between haemodynamics and disease progression in PAD patients, and potentially predict disease occurrence as well as the outcome of an intervention. PMID:25878124

  20. Cooperative island growth of large-area single-crystal graphene on copper using chemical vapor deposition.

    PubMed

    Eres, Gyula; Regmi, Murari; Rouleau, Christopher M; Chen, Jihua; Ivanov, Ilia N; Puretzky, Alexander A; Geohegan, David B

    2014-06-24

    In this work we explore the kinetics of single-crystal graphene growth as a function of nucleation density. In addition to the standard methods for suppressing nucleation of graphene by pretreatment of Cu foils using oxidation, annealing, and reduction of the Cu foils prior to growth, we introduce a new method that further reduces the graphene nucleation density by interacting directly with the growth process at the onset of nucleation. The successive application of these two methods results in roughly 3 orders of magnitude reduction in graphene nucleation density. We use a kinetic model to show that at vanishingly low nucleation densities carbon incorporation occurs by a cooperative island growth mechanism that favors the formation of substrate-size single-crystal graphene. The model reveals that the cooperative growth of millimeter-size single-crystal graphene grains occurs by roughly 3 orders of magnitude increase in the reactive sticking probability of methane compared to that in random island nucleation. PMID:24833238

  1. [Calcium pyrophosphate deposits--a chameleon].

    PubMed

    Beyeler, Ch

    2002-10-01

    Calcium Pyrophosphate Dihydrate (CPPD) crystals deposit in articular fibro- or hyaline cartilage (chondrocalcinosis), joint capsules, synovium, periarticular ligaments and tendons resulting in an age dependent prevalence. These calcifications may be asymptomatic or may manifest as acute pseudogout arthritis, pseudorheumatoid arthritis, bursitis, tenosynovitis, tendinitis, polymyalgic syndrome or chronic pyrophosphate arthropathy. The diagnosis is based on the presence of intracellular CPPD crystals in synovial fluid detected by polarizing microscopy, the characteristic radiological changes and the typical clinical presentations. The therapy is symptom oriented or disease specific in case of an underlying metabolic disease such as hemochromatosis, hyperparathyroidism, hypophosphatasia, hypomagnesemia or hypothyroidism. PMID:12428437

  2. Surgical Management of Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma Associated With Light-Chain Deposition Disease.

    PubMed

    Muñoz-Largacha, Juan A; O'Hara, Carl J; Sloan, J Mark; Fernando, Hiran C; Litle, Virginia R

    2016-06-01

    A 52-year-old woman presented with a right middle lobe (RML) lung nodule suspicious for malignancy. Thoracoscopic middle lobectomy was performed. The pathology report revealed a pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma in association with light-chain deposition disease (LCDD). Pulmonary MALT lymphoma and LCDD are unusual disorders presenting in the lung, and the association between these 2 conditions is even more uncommon. The optimal management for these patients is controversial, although surgical resection of localized well-circumscribed lesions may represent an effective therapeutic approach. PMID:27211983

  3. Method for preparing ultraflat, atomically perfect areas on large regions of a crystal surface by heteroepitaxy deposition

    SciTech Connect

    El Gabaly, Farid; Schmid, Andreas K.

    2013-03-19

    A novel method of forming large atomically flat areas is described in which a crystalline substrate having a stepped surface is exposed to a vapor of another material to deposit a material onto the substrate, which material under appropriate conditions self arranges to form 3D islands across the substrate surface. These islands are atomically flat at their top surface, and conform to the stepped surface of the substrate below at the island-substrate interface. Thereafter, the deposited materials are etched away, in the etch process the atomically flat surface areas of the islands transferred to the underlying substrate. Thereafter the substrate may be cleaned and annealed to remove any remaining unwanted contaminants, and eliminate any residual defects that may have remained in the substrate surface as a result of pre-existing imperfections of the substrate.

  4. Self-organized single crystal mixed magnetite/cobalt ferrite films grown by infrared pulsed-laser deposition

    NASA Astrophysics Data System (ADS)

    de la Figuera, Juan; Quesada, Adrián; Martín-García, Laura; Sanz, Mikel; Oujja, Mohamed; Rebollar, Esther; Castillejo, Marta; Prieto, Pilar; Muñoz-Martín, Ángel; Aballe, Lucía; Marco, José F.

    2015-12-01

    We have grown mixed magnetite/cobalt ferrite epitaxial films on SrTiO3 by infrared pulsed-laser deposition. Diffraction experiments indicate epitaxial growth with a relaxed lattice spacing. The films are flat with two distinct island types: nanometric rectangular mounds in two perpendicular orientations, and larger square islands, attributed to the two main components of the film as determined by Mössbauer spectroscopy. The origin of the segregation is suggested to be the oxygen-deficiency during growth.

  5. Dynamic relationships between age, amyloid-β deposition, and glucose metabolism link to the regional vulnerability to Alzheimer's disease.

    PubMed

    Oh, Hwamee; Madison, Cindee; Baker, Suzanne; Rabinovici, Gil; Jagust, William

    2016-08-01

    SEE HANSSON AND GOURAS DOI101093/AWW146 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Although some brain regions such as precuneus and lateral temporo-parietal cortex have been shown to be more vulnerable to Alzheimer's disease than other areas, a mechanism underlying the differential regional vulnerability to Alzheimer's disease remains to be elucidated. Using fluorodeoxyglucose and Pittsburgh compound B positron emission tomography imaging glucose metabolism and amyloid-β deposition, we tested whether and how life-long changes in glucose metabolism relate to amyloid-β deposition and Alzheimer's disease-related hypometabolism. Nine healthy young adults (age range: 20-30), 96 cognitively normal older adults (age range: 61-96), and 20 patients with Alzheimer's disease (age range: 50-90) were scanned using fluorodeoxyglucose and Pittsburgh compound B positron emission tomography. Among cognitively normal older subjects, 32 were further classified as amyloid-positive, with 64 as amyloid-negative. To assess the contribution of glucose metabolism to the regional vulnerability to amyloid-β deposition, we defined the highest and lowest metabolic regions in young adults and examined differences in amyloid deposition between these regions across groups. Two-way analyses of variance were conducted to assess regional differences in age and amyloid-β-related changes in glucose metabolism. Multiple regressions were applied to examine the association between amyloid-β deposition and regional glucose metabolism. Both region of interest and whole-brain voxelwise analyses were conducted to complement and confirm the results derived from the other approach. Regional differences in glucose metabolism between the highest and lowest metabolism regions defined in young adults (T = 12.85, P < 0.001) were maintained both in Pittsburgh compound B-negative cognitively normal older subjects (T = 6.66, P < 0.001) and Pittsburgh compound B-positive cognitively normal older subjects (T

  6. Vertical alignment of liquid crystal through ion beam exposure on oxygen-doped SiC films deposited at room temperature

    SciTech Connect

    Son, Phil Kook; Park, Jeung Hun; Kim, Jae Chang; Yoon, Tae-Hoon; Rho, Soon Joon; Jeon, Back Kyun; Shin, Sung Tae; Kim, Jang Sub; Lim, Soon Kwon

    2007-09-03

    The authors report the vertical alignment of liquid crystal (LC) through the ion beam exposure on amorphous oxygen-doped SiC (SiOC) film surfaces deposited at room temperature. The optical transmittance of these films was similar to that of polyimide layers, but much higher than that of SiO{sub x} films. The light leakage of a LC cell aligned vertically on SiOC films was much lower than those of a LC cell aligned on polyimide layers or other inorganic films. They found that LC molecules align vertically on ion beam treated SiOC film when the roughness of the electrostatic force microscopy (EFM) data is high on the SiOC film surface, while they align homogeneously when the roughness of the EFM data is low.

  7. Distinct binding of amyloid imaging ligands to unique amyloid-β deposited in the presubiculum of Alzheimer's disease.

    PubMed

    Ji, Bin; Chen, Chun-Jen; Bando, Kazunori; Ashino, Hiroki; Shiraishi, Hideaki; Sano, Hiroaki; Kasahara, Hiroyuki; Minamizawa, Takao; Yamada, Kazutaka; Ono, Maiko; Zhang, Ming-Rong; Seki, Chie; Farde, Lars; Suhara, Tetsuya; Higuchi, Makoto

    2015-12-01

    Non-invasive determination of amyloid-β peptide (Aβ) deposition with radioligands serves for the early diagnosis and clarification of pathogenetic mechanisms of Alzheimer's disease (AD). The polymorphic binding site on multimeric Aβ for current radioligands, however, is little understood. In this study, we investigated the binding of several radioligands including (11)C-Pittsburgh Compound B ((11)C-PiB), (3)H-AZD2184, and two recently developed compounds, (125)I-DRM106 and (125)I-DRK092, with unique presubicular Aβ deposits lacking interaction with the commonly used amyloid dyes FSB. (11)C-PiB, (3)H-AZD2184, and (125)I-DRK092 showed overt binding to presubicular Aβ deposits, while (125)I-DRM106 barely bound to these aggregates despite its strong binding in the hippocampal CA1 sector. Unlike neuritic plaques in the CA1, Aβ lesions in the presubiculum were not accompanied by inflammatory gliosis enriched with 18-kDa translocator protein (TSPO). Thus, there are at least two different components in Aβ aggregates providing distinct binding sites for the current amyloid radioligands, and one of these binding components is distinctly present in the presubicular Aβ deposits. Amyloid radioligands lacking affinity for this component, such as (125)I-DRM106, may selectively capture Aβ deposits tightly associated with TSPO neuroinflammation and neurodegeneration as exemplified by CA1 neuritic plaques. Hence, comparative autoradiographic assessments of radioligand binding in CA1 and presubiculum could serve for the development of an amyloid PET imaging agent visualizing neurotoxicity-related Aβ pathologies. Non-invasive determination of amyloid-β peptide (Aβ) serves for the early diagnosis and clarification of pathogenetic mechanisms of Alzheimer's disease (AD). We found that there are at least two different amyloid components in hippocampal CA1 and presubiculum providing distinct binding sites for the current amyloid radioligands. Comparative analysis for

  8. Investigaction of Switching Behavior in a Ferroelectric Liquid Crystal Aligned on Obliquely Deposited SiO Films

    NASA Astrophysics Data System (ADS)

    Yamada, Yuichiro; Yamamoto, Norio; Inoue, Tetsuya; Orihara, Hiroshi; Ishibashi, Yoshihiro

    1989-01-01

    The effect of oblique evaporation of SiO on the chevron structure and the switching behavior in a ferroelectric liquid crystal have been investigated by means of the X-ray diffraction and the stroboscopic micrographs. It is found experimentally that the chevron direction and the domain structure appearing during the switching are determined by the direction of incidence of evaporated SiO. On the basis of the experimental results, it is clarified that the bow and the stern of the boat-shaped domain correspond to {+}2π and {-}2π internal disclinations, respectively. The structure of the zig-zag defect is determined.

  9. Achieving omnidirectional photonic band gap in sputter deposited TiO2/SiO2 one dimensional photonic crystal

    NASA Astrophysics Data System (ADS)

    Jena, S.; Tokas, R. B.; Sarkar, P.; Haque, S. Maidul; Misal, J. S.; Rao, K. D.; Thakur, S.; Sahoo, N. K.

    2015-06-01

    The multilayer structure of TiO2/SiO2 (11 layers) as one dimensional photonic crystal (1D PC) has been designed and then fabricated by using asymmetric bipolar pulse DC magnetron sputtering technique for omnidirectional photonic band gap. The experimentally measured photonic band gap (PBG) in the visible region is well matched with the theoretically calculated band structure (ω vs. k) diagram. The experimentally measured omnidirectional reflection band of 44 nm over the incident angle range of 0°-70° is found almost matching within the theoretically calculated band.

  10. RESEARCH NOTES FROM COLLABORATIONS: Intercalibration of the CMS electromagnetic calorimeter crystals in φ using symmetry of energy deposition

    NASA Astrophysics Data System (ADS)

    Futyan, D.; Seez, C.

    2003-06-01

    This paper describes the investigation of a first step in a strategy for rapidly obtaining electromagnetic calorimeter crystal intercalibration at start-up in the absence of test beam precalibration of the complete detector. In the case of the CMS (compact muon solenoid) electromagnetic calorimeter, the precision to which crystals can be intercalibrated in phi using 18 million fully simulated minimum-bias events, and assuming complete ignorance of the distribution of material in front of the calorimeter, is determined as a function of the pseudorapidity (eta) and has been found to be close to 1.5% for |eta| < 1.0 and between 2% and 3.5% for the remainder of the barrel. Similar values are found for the endcap. The precision is limited by the inhomogeneity of tracker material. With increasing knowledge of the material distribution in the tracker, after the start of LHC running, the attainable precision of the method will increase, with the potential of providing rapid and repeated calibration of the calorimeter.

  11. On precursor self-organization upon the microwave vacuum-plasma deposition of submonolayer carbon coatings on silicon (100) crystals

    SciTech Connect

    Yafarov, R. K.

    2015-03-15

    Scanning atomic-force and electron microscopies are used to study the self-organization kinetics of nanoscale domains upon the deposition of submonolayer carbon coatings on silicon (100) in the microwave plasma of low-pressure ethanol vapor. Model mechanisms of how silicon-carbon domains are formed are suggested. The mechanisms are based on Langmuir’s model of adsorption from the precursor state and modern concepts of modification of the equilibrium structure of the upper atomic layer in crystalline semiconductors under the influence of external action.

  12. Surface passivation of a photonic crystal band-edge laser by atomic layer deposition of SiO2 and its application for biosensing

    NASA Astrophysics Data System (ADS)

    Cha, Hyungrae; Lee, Jeongkug; Jordan, Luke R.; Lee, Si Hoon; Oh, Sang-Hyun; Kim, Hyo Jin; Park, Juhun; Hong, Seunghun; Jeon, Heonsu

    2015-02-01

    We report on the conformal surface passivation of photonic crystal (PC) laser devices with an ultrathin dielectric layer. Air-bridge-type Γ-point band-edge lasers (BELs) are fabricated by forming a honeycomb lattice two-dimensional PC structure into an InGaAsP multiple-quantum-well epilayer. Atomic layer deposition (ALD) is employed for conformal deposition of a few-nanometer-thick SiO2 layer over the entire device surface, not only on the top and bottom surfaces of the air-bridge membrane but also on the air-hole sidewalls. Despite its extreme thinness, the ALD passivation layer is found to protect the InGaAsP BEL devices from harsh chemicals. In addition, the ALD-SiO2 is compatible with the silane-based surface chemistry, which allows us to use ALD-passivated BEL devices as label-free biosensors. The standard streptavidin-biotin interaction shifts the BEL lasing wavelength by ~1 nm for the dipole-like Γ-point band-edge mode. A sharp lasing line (<0.2 nm, full width at half-maximum) and a large refractive index sensitivity (~163 nm per RIU) produce a figure of merit as high as ~800 for our BEL biosensor, which is at least an order of magnitude higher than those of more common biosensors that rely on a broad resonance peak, showing that our nanolaser structures are suitable for highly sensitive biosensor applications.

  13. Interface Properties of Atomic-Layer-Deposited Al2O3 Thin Films on Ultraviolet/Ozone-Treated Multilayer MoS2 Crystals.

    PubMed

    Park, Seonyoung; Kim, Seong Yeoul; Choi, Yura; Kim, Myungjun; Shin, Hyunjung; Kim, Jiyoung; Choi, Woong

    2016-05-11

    We report the interface properties of atomic-layer-deposited Al2O3 thin films on ultraviolet/ozone (UV/O3)-treated multilayer MoS2 crystals. The formation of S-O bonds on MoS2 after low-power UV/O3 treatment increased the surface energy, allowing the subsequent deposition of uniform Al2O3 thin films. The capacitance-voltage measurement of Au-Al2O3-MoS2 metal oxide semiconductor capacitors indicated n-type MoS2 with an electron density of ∼10(17) cm(-3) and a minimum interface trap density of ∼10(11) cm(-2) eV(-1). These results demonstrate the possibility of forming a high-quality Al2O3-MoS2 interface by proper UV/O3 treatment, providing important implications for their integration into field-effect transistors. PMID:27117229

  14. Application of electrochemically deposited nanostructured ZnO layers on quartz crystal microbalance for NO2 detection

    NASA Astrophysics Data System (ADS)

    Georgieva, B.; Petrov, M.; Lovchinov, K.; Ganchev, M.; Georgieva, V.; Dimova-Malinovska, D.

    2014-11-01

    The research was fixed on sensing behavior of ZnO nanostructured (NS) films to NO2 concentrations in the environment. The ZnO NS layers are deposited by electrochemical method on quartz resonators with Au electrodes. The sorption properties of ZnO layers were defined by measuring the resonant frequency shift (Δf) of the QCM-ZnO structure for different NO2 concentrations. The measurements were based on the correlation between the frequency shift of the QCM and additional mass loading (Δm) on the resonator calculated using Sauerbrey equation for the AT-cut quartz plate. Frequency - Time Characteristics (FTCs) of the samples were measured as a function of different NO2 concentrations in order to define the sorption abilities of ZnO layers. The experiments were carried out on a special set up in a dynamical regime. From FTCs the response and the recovery times of the QCM-ZnO structure were measured with varying NO2. Frequency shift changed from 23 Hz to 58Hz when NO2 was varied in the range of 250ppm - 5000ppm. The process of sorption was estimated as reversible and the sorption as physical. The obtained results demonstrated that QCM covered with the electrochemically deposited nanostructured ZnO films can be used as application in NO2 sensors.

  15. In-situ atomic layer deposition of tri-methylaluminum and water on pristine single-crystal (In)GaAs surfaces: electronic and electric structures

    NASA Astrophysics Data System (ADS)

    Pi, T. W.; Lin, Y. H.; Fanchiang, Y. T.; Chiang, T. H.; Wei, C. H.; Lin, Y. C.; Wertheim, G. K.; Kwo, J.; Hong, M.

    2015-04-01

    The electronic structure of single-crystal (In)GaAs deposited with tri-methylaluminum (TMA) and water via atomic layer deposition (ALD) is presented with high-resolution synchrotron radiation core-level photoemission and capacitance-voltage (CV) characteristics. The interaction of the precursor atoms with (In)GaAs is confined at the topmost surface layer. The Ga-vacant site on the GaAs(111)A-2 × 2 surface is filled with Al, thereby effectively passivating the As dangling bonds. The As-As dimers on the GaAs(001)-2 × 4 surface are entirely passivated by one cycle of TMA and water. The presumed layerwise deposition fails to happen in GaAs(001)-4 × 6. In In0.20Ga0.80As(001)-2 × 4, the edge row As atoms are partially bonded with the Al, and one released methyl then bonds with the In. It is suggested that the unpassivated surface and subsurface atoms cause large frequency dispersions in CV characteristics under the gate bias. We also found that the (In)GaAs surface is immune to water in ALD. However, the momentary exposure of it to air (less than one minute) introduces significant signals of native oxides. This indicates the necessity of in situ works of high κ/(In)GaAs-related experiments in order to know the precise interfacial atomic bonding and thus know the electronic characteristics. The electric CV measurements of the ALD-Al2O3 on these (In)GaAs surfaces are correlated with their electronic properties.

  16. Apparatus for mounting crystal

    DOEpatents

    Longeway, Paul A.

    1985-01-01

    A thickness monitor useful in deposition or etching reactor systems comprising a crystal-controlled oscillator in which the crystal is deposited or etched to change the frequency of the oscillator. The crystal rests within a thermally conductive metallic housing and arranged to be temperature controlled. Electrode contacts are made to the surface primarily by gravity force such that the crystal is substantially free of stress otherwise induced by high temperature.

  17. Hemimorphite as a natural sink for arsenic in zinc deposits and related mine tailings: Evidence from single-crystal EPR spectroscopy and hydrothermal synthesis

    NASA Astrophysics Data System (ADS)

    Mao, Mao; Lin, Jinru; Pan, Yuanming

    2010-05-01

    Hemimorphite is a refractory mineral in surface environments and occurs commonly in supergene non-sulfide Zn deposits and Zn mine tailings. Single-crystal electron paramagnetic resonance (EPR) spectra of gamma-ray-irradiated hemimorphite from Mapimi (Durango, Mexico) reveal two arsenic-associated oxyradicals: [AsO 4] 4- and [AsO 4] 2-. Inductively coupled plasma mass spectrometry analyses confirm this sample to contain 270 ppm As and that hemimorphite from other Zn deposits has appreciable amounts of arsenic as well. Spin Hamiltonian parameters, including matrices g, A ( 75As) and P( 75As), show that the [AsO 4] 4- radical formed from electron trapping by a locally uncompensated [AsO 4] 3- ion substituting for [SiO 4] 4-. Matrices g, A( 75As) and P( 75As) of the [AsO 4] 2- radical show it to have the unpaired spin on the bridging oxygen of an [AsO 4] 3- ion at a Si site and linked to a monovalent impurity ion. This structural model for the [AsO 4] 2- radical is further supported by observed 29Si and 1H superhyperfine structures arising from interactions with a single Si atom (A/g eβe = ˜1 mT at B// c) and two equivalent H atoms (A/g eβe = ˜0.3 mT at B∧ b = 10°), respectively. Hydrothermal experiments at 200 °C and ˜9.5 MPa show that hemimorphite contains up to ˜2.5 wt% As 2O 5 and suggest that both the arsenate concentration and the pH value in the solution affect the As content in hemimorphite. These results demonstrate that hemimorphite is capable of sequestering arsenate in its crystal lattice, hence is a natural sink for attenuating As in supergene non-sulfide Zn deposits and Zn mine tailings. Moreover, results from hemimorphite potentially have more far-reaching implications for major silicates such as zeolites in the immobilization and removal of arsenic in surface environments.

  18. Crystallization and preliminary X-ray analysis of recombinant human acid beta-glucocerebrosidase, a treatment for Gaucher's disease

    NASA Technical Reports Server (NTRS)

    Roeber, Dana; Achari, Aniruddha; Manavalan, Partha; Edmunds, Tim; Scott, David L.

    2003-01-01

    Acid beta-glucocerebrosidase (N-acylsphingosyl-1-O-beta-D-glucoside:glucohydrolase) is a lysosomal glycoprotein that catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide. Inadequate levels of this enzyme underly the pathophysiology of Gaucher's disease. Cerezyme (Genzyme Corporation, Cambridge, MA, USA) is a partially deglycosylated form of recombinant human acid beta-glucocerebrosidase that is used in the treatment of Gaucher patients. Although acid beta-glucocerebrosidase belongs to a large family of glycosidases, relatively little is known regarding its structural biology. Here, the crystallization and the initial diffraction analysis of Cerezyme are reported. The crystals are C-centered orthorhombic, with unit-cell parameters a = 285.0, b = 110.2, c = 91.7 A. A 99.9% complete data set has been collected to 2.75 A with an R(sym) of 8.8%.

  19. Crystallization and Preliminary X-ray analysis of Human Recombinant Acid beta-glucocerebrosidase, a treatment for Gaucher's Disease

    NASA Technical Reports Server (NTRS)

    Roeber, Dana F.; Achari, Aniruddha; Manavalan, Partha; Edmunds, Tim; Scott, David L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Acid beta-glucocerebrosidase (N-acylsphingosyl - O - beta-D - glucoside:glucohydrolase) is a lysosomal glycoprotein that catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide. Inadequate levels of this enzyme underly the pathophysiology of Gaucher's disease. Cerezyme(R) (Genzyme Corporation, Cambridge, MA) is a partially deglycosylated form of recombinant human acid beta-glucocerebrosidase that is commercially available for the treatment of Gaucher patients. Although acid beta-glucocerebrosidase belongs to a large family of glycosidases, relatively little is known regarding its structural biology. We report the crystallization and the initial diffraction analysis of Cerezyme(R). The crystals are C-centered orthorhombic, with unit-cell parameters of a = 285.0 A, b = 110.2 A, and c = 91.7 A. A 99.9 A complete data set has been collected to 2.75 A with an R(sub sym) of 8.8 %.

  20. Leakage Current Suppression on Metal-Induced Laterally Crystallized Polycrystalline Silicon Thin-Film Transistors by Asymmetrically Deposited Nickel

    NASA Astrophysics Data System (ADS)

    Byun, Chang Woo; Son, Se Wan; Lee, Yong Woo; Hyo Park, Jae; Vakilipour Takaloo, Ashkan; Joo, Seung Ki

    2013-10-01

    The electrical performance of low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) fabricated by metal-induced lateral crystallization (MILC) is greatly affected by metal catalyst contaminations, such as Ni and Ni silicide trapped in the channel, since they concentrate in front of laterally grown crystallites. In the present work, the effect of the MILC/MILC boundary (MMB) on MILC polycrystalline silicon (poly-Si) TFTs is investigated by the comparison of MILC poly-Si TFTs with MMB at the center of the channel, and equivalent TFTs with MMB at a position ejected from the channel. The MMB location was controlled by the Ni catalyst position. Both a low off-state leakage current and a free from short channel effect (kink effect) were observed in high electric-field conditions. Furthermore, the field-effect mobility and drain current noise were drastically improved by ejecting the MILC boundary in the source direction.

  1. The Creatine Kinase/Creatine Connection to Alzheimer's Disease: CK Inactivation, APP-CK Complexes, and Focal Creatine Deposits

    PubMed Central

    Bürklen, Tanja S.; Schlattner, Uwe; Homayouni, Ramin; Gough, Kathleen; Rak, Margaret; Szeghalmi, Adriana; Wallimann, Theo

    2006-01-01

    Cytosolic brain-type creatine kinase (BB-CK), which is coexpressed with ubiquitous mitochondrial uMtCK, is significantly inactivated by oxidation in Alzheimer's disease (AD) patients. Since CK has been shown to play a fundamental role in cellular energetics of the brain, any disturbance of this enzyme may exasperate the AD disease process. Mutations in amyloid precursor protein (APP) are associated with early onset AD and result in abnormal processing of APP, and accumulation of Aβ peptide, the main constituent of amyloid plaques in AD brain. Recent data on a direct interaction between APP and the precursor of uMtCK support an emerging relationship between AD, cellular energy levels, and mitochondrial function. In addition, recently discovered creatine (Cr) deposits in the brain of transgenic AD mice, as well as in the hippocampus from AD patients, indicate a direct link between perturbed energy state, Cr metabolism, and AD. Here, we review the roles of Cr and Cr-related enzymes and consider the potential value of supplementation with Cr, a potent neuroprotective substance. As a hypothesis, we consider whether Cr, if given at an early time point of the disease, may prevent or delay the course of AD-related neurodegeneration. PMID:17047305

  2. Detection of Alzheimer’s disease amyloid-beta plaque deposition by deep brain impedance profiling

    NASA Astrophysics Data System (ADS)

    Béduer, Amélie; Joris, Pierre; Mosser, Sébastien; Fraering, Patrick C.; Renaud, Philippe

    2015-04-01

    Objective. Alzheimer disease (AD) is the most common form of neurodegenerative disease in elderly people. Toxic brain amyloid-beta (Aß) aggregates and ensuing cell death are believed to play a central role in the pathogenesis of the disease. In this study, we investigated if we could monitor the presence of these aggregates by performing in situ electrical impedance spectroscopy measurements in AD model mice brains. Approach. In this study, electrical impedance spectroscopy measurements were performed post-mortem in APPPS1 transgenic mice brains. This transgenic model is commonly used to study amyloidogenesis, a pathological hallmark of AD. We used flexible probes with embedded micrometric electrodes array to demonstrate the feasibility of detecting senile plaques composed of Aß peptides by localized impedance measurements. Main results. We particularly focused on deep brain structures, such as the hippocampus. Ex vivo experiments using brains from young and old APPPS1 mice lead us to show that impedance measurements clearly correlate with the percentage of Aβ plaque load in the brain tissues. We could monitor the effects of aging in the AD APPPS1 mice model. Significance. We demonstrated that a localized electrical impedance measurement constitutes a valuable technique to monitor the presence of Aβ-plaques, which is complementary with existing imaging techniques. This method does not require prior Aβ staining, precluding the risk of variations in tissue uptake of dyes or tracers, and consequently ensuring reproducible data collection.

  3. Update on calcium pyrophosphate deposition.

    PubMed

    Abhishek, Abhishek; Doherty, Michael

    2016-01-01

    Calcium pyrophosphate crystal deposition (CPPD) associates with ageing, osteoarthritis (OA), uncommon metabolic diseases, mutations and polymorphisms in the ankylosis human gene (ANKH). CPPD is frequently polyarticular, occurs due to a generalised articular predisposition, and the association between CPPD and OA is joint specific, for example CPPD associates with knee OA, but not with hip OA. Other recently identified associations include knee malalignment (knee CC), low cortical BMD and soft-tissue calcification. CPPD is generally asymptomatic. A recent study reported that knees with OA plus CC at the index joint, or at distant joints (in absence of index joint CC), were more likely to have attrition. CPPD can cause acute CPP crystal arthritis, chronic CPP crystal inflammatory arthritis, and is frequently present in joints with OA. Joint aspiration remains the gold standard for diagnosing CPPD, although other promising techniques are emerging. Patients with polyarticular or young onset CPPD should be screened for underlying metabolic abnormalities, however, such testing can be unrewarding. The treatment of CPPD is symptomatic. Acute CPP crystal arthritis is treated with rest, local application of ice-packs, joint aspiration, colchicine and/or intra-articular corticosteroid injection (once infection is excluded). Colchicine, low-dose corticosteroids, hydroxychloroquine and radiosynovectomy are recommended for the treatment of chronic or recurrent acute CPP crystal arthritis. Recent RCTs did not confirm any benefit from methotrexate, and although there is increasing interest in the use of anti-IL1 agents for acute or chronic CPP crystal arthritis, their efficacy has not been formally examined. Unlike gout, currently there are no treatments to eliminate CPP crystal deposits. PMID:27586801

  4. Photonic Crystal Fiber-Based Surface Plasmon Resonance Sensor with Selective Analyte Channels and Graphene-Silver Deposited Core

    PubMed Central

    Rifat, Ahmmed A.; Mahdiraji, G. Amouzad; Chow, Desmond M.; Shee, Yu Gang; Ahmed, Rajib; Adikan, Faisal Rafiq Mahamd

    2015-01-01

    We propose a surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) with selectively filled analyte channels. Silver is used as the plasmonic material to accurately detect the analytes and is coated with a thin graphene layer to prevent oxidation. The liquid-filled cores are placed near to the metallic channel for easy excitation of free electrons to produce surface plasmon waves (SPWs). Surface plasmons along the metal surface are excited with a leaky Gaussian-like core guided mode. Numerical investigations of the fiber’s properties and sensing performance are performed using the finite element method (FEM). The proposed sensor shows maximum amplitude sensitivity of 418 Refractive Index Units (RIU−1) with resolution as high as 2.4 × 10−5 RIU. Using the wavelength interrogation method, a maximum refractive index (RI) sensitivity of 3000 nm/RIU in the sensing range of 1.46–1.49 is achieved. The proposed sensor is suitable for detecting various high RI chemicals, biochemical and organic chemical analytes. Additionally, the effects of fiber structural parameters on the properties of plasmonic excitation are investigated and optimized for sensing performance as well as reducing the sensor’s footprint. PMID:25996510

  5. Photonic crystal fiber-based surface plasmon resonance sensor with selective analyte channels and graphene-silver deposited core.

    PubMed

    Rifat, Ahmmed A; Mahdiraji, G Amouzad; Chow, Desmond M; Shee, Yu Gang; Ahmed, Rajib; Adikan, Faisal Rafiq Mahamd

    2015-01-01

    We propose a surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) with selectively filled analyte channels. Silver is used as the plasmonic material to accurately detect the analytes and is coated with a thin graphene layer to prevent oxidation. The liquid-filled cores are placed near to the metallic channel for easy excitation of free electrons to produce surface plasmon waves (SPWs). Surface plasmons along the metal surface are excited with a leaky Gaussian-like core guided mode. Numerical investigations of the fiber's properties and sensing performance are performed using the finite element method (FEM). The proposed sensor shows maximum amplitude sensitivity of 418 Refractive Index Units (RIU-1) with resolution as high as 2.4 × 10(-5) RIU. Using the wavelength interrogation method, a maximum refractive index (RI) sensitivity of 3000 nm/RIU in the sensing range of 1.46-1.49 is achieved. The proposed sensor is suitable for detecting various high RI chemicals, biochemical and organic chemical analytes. Additionally, the effects of fiber structural parameters on the properties of plasmonic excitation are investigated and optimized for sensing performance as well as reducing the sensor's footprint. PMID:25996510

  6. Piezoresistive pressure sensor using low-temperature aluminium induced crystallization of sputter-deposited amorphous silicon film

    NASA Astrophysics Data System (ADS)

    Tiwari, Ruchi; Chandra, Sudhir

    2013-09-01

    In the present work, we have investigated the piezoresistive properties of silicon films prepared by the radio frequency magnetron sputtering technique, followed by the aluminium induced crystallization (AIC) process. Orientation and grain size of the polysilicon films were studied by x-ray diffraction analysis and found to be in the range 30-50 nm. Annealing of the Al-Si stack on an oxidized silicon substrate was performed in air ambient at 300-550 °C, resulting in layer exchange and transformation from amorphous to polysilicon phase. Van der Pauw and Hall measurement techniques were used to investigate the sheet resistance and carrier mobility of the resulting polycrystalline silicon film. The effect of Al thickness on the sheet resistance and mobility was also studied in the present work. A piezoresistive pressure sensor was fabricated on an oxidized silicon substrate in a Wheatstone bridge configuration, comprising of four piezoresistors made of polysilicon film obtained by the AIC process. The diaphragm was formed by the bulk-micromachining of silicon substrate. The response of the pressure sensor with applied negative pressure in 10-95 kPa range was studied. The gauge factor was estimated to be 5 and 18 for differently located piezoresistors on the diaphragm. The sensitivity of the pressure sensor was measured to be ˜ 30 mV MPa-1, when the Wheatstone bridge was biased at 1 V input voltage.

  7. Fabrication of gold-deposited plasmonic crystal based on nanoimprint lithography for label-free biosensing application

    NASA Astrophysics Data System (ADS)

    Nishiguchi, Kiichi; Sueyoshi, Kenji; Hisamoto, Hideaki; Endo, Tatsuro

    2016-08-01

    Here, we developed a highly sensitive label-free plasmonic crystal (PC). The PC is composed of two types of nanoperiodic metal structures, nanodiscs and nanohole arrays, fabricated simultaneously by nanoimprint lithography using a nanostructured polymer mold. The PC absorbed light at specific wavelengths based on localized surface plasmon resonance (LSPR). The strongly enhanced electric field was excited by the combined structures of nanodiscs and nanohole arrays; thus, highly sensitive biosensing was possible. The LSPR-based optical characteristics of the PC were analyzed by finite-difference time-domain simulation; the structure (metal layer thickness) was optimized to respond to changes in the surrounding refractive index with high sensitivity. PC-based biosensor chips were prepared by immobilizing anti-human immunoglobulin G, which was successfully detected in the 200 pg/mL to 200 ng/mL range. Our approach introduces an easy and rapid process allowing large-area fabrication of PCs, resulting in a highly sensitive label-free biosensor device.

  8. [Secondary monoclonal gammopathy after bone marrow autotransplantation as a cause of worse renal function in light chain immunoglobulin deposition disease].

    PubMed

    Rekhtina, I G; Mendeleeva, L P; Stolyarevich, E S; Gal'tseva, I V; Povilaitite, P E; Biryukova, L S

    2016-01-01

    The paper describes a clinical case of a female woman with nephropathy due to light chain deposition disease caused by secretion of κ Bence-Jones protein. Complete immunochemical remission was achieved after induction therapy using a bortezomib + cyclophosphamide + dexamethasone regimen. Renal function remained unchanged (glomerular filtration rate 16 ml/min), there was a reduction in proteinuria from 5.8 to 2.6 g/day. High-dose melphalan (200 mg/m2) chemotherapy with peripheral blood stem cell autotransplantation was performed as consolidation of remission. A year posttransplantation, there was no secretion of κ light chains; however, monoclonal IgG lambda emerged in a quantity of 3.2 g/l. At the same period, nephrotic syndrome became progressive (daily proteinuria 12 g) and dialysis-dependent renal failure developed. A repeat renal biopsy specimen revealed changes, suggesting that there was a decrease in renal deposits of κ light chains. Simultaneously with this, the obvious negative trend as progressive nephrosclerosis and fixation of IgG and λ light chains in the glomeruli (in the sclerotic areas) cause IgGλ monoclonal protein to be involved in the genesis of further kidney injury. Attention is also paid to different characteristics of capillary wall deposits by density (according to the electron microscopic findings), which may point to their different qualitative composition and possibly different formation duration. Papaprotein Gλ disappeared after a year without therapy, suggesting its reactivity. The findings confirm that worse renal function is caused by the action of paraprotein Gλ due to secondary (after autologous hematopoietic stem cells transplantation) monoclonal gammopathy. PMID:27296267

  9. Immunohistochemical detection of deposits of eosinophil-derived neurotoxin and eosinophil peroxidase in the myocardium of patients with Chagas' disease.

    PubMed Central

    Molina, H A; Kierszenbaum, F

    1988-01-01

    An immunohistochemical study of eosinophil distribution in the inflammatory cell infiltrates of four different types of myocardial lesions associated with Chagas' disease--caused by Trypanosoma cruzi--showed larger numbers of these cells in areas presenting tissue necrosis and degeneration, most notably in patients with the most severe myocarditis from a histopathological stand-point. Using antisera specific for human eosinophil-derived neurotoxin or eosinophil peroxidase, we detected deposits of these secretion products on myofibres and in the interstitium of chagasic myocardium displaying necrosis and degeneration but rarely in other types of lesions. These deposits were not detectable in the myocardium of non-chagasic patients who had died from myocardial infarction (acute or in the scarring stage) or myocarditis secondary to bacterial endocarditis. When human eosinophil-derived neurotoxin was incubated with myoblast monolayers there was a significant cell injury, detachment and lysis. These effects were abrogated by yeast RNA, added as a competitive ribonuclease substrate, and inhibited by the ribonuclease inhibitor RNasin, suggesting that the ribonuclease activity of the eosinophil-derived neurotoxin was involved in the effect. These results suggest a link between eosinophil infiltration and necrosis in chagasic myocardial lesions and point to EDN, and perhaps other toxic eosinophil secretion products, as possible mediators of tissue damage. Images Figure 1 Figure 2 PMID:3049321

  10. Valproic acid alleviates memory deficits and attenuates amyloid-β deposition in transgenic mouse model of Alzheimer's disease.

    PubMed

    Xuan, Ai-Guo; Pan, Xue-Bing; Wei, Peng; Ji, Wei-Dong; Zhang, Wen-Juan; Liu, Ji-Hong; Hong, Le-Peng; Chen, Wen-Liang; Long, Da-Hong

    2015-02-01

    In the brains of patients with Alzheimer's disease (AD) and transgenic AD mouse models, astrocytes and microglia activated by amyloid-β (Aβ) contribute to the inflammatory process that develops around injury in the brain. Valproic acid (VPA) has been shown to have anti-inflammatory function. The present study intended to explore the therapeutic effect of VPA on the neuropathology and memory deficits in APPswe/PS1ΔE9 (APP/PS1) transgenic mice. Here, we report that VPA-treated APP/PS1 mice markedly improved memory deficits and decreased Aβ deposition compared with the vehicle-treated APP/PS1 mice. Moreover, the extensive astrogliosis and microgliosis as well as the increased expression in interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the hippocampus and cortex of APP/PS1 transgenic mice were significantly reduced following administration of VPA, which attenuated neuronal degeneration. Concomitantly, VPA alleviated the levels of p65 NF-κB phosphorylation and enhanced the levels of acetyl-H3, Bcl-2, and phospho-glycogen synthase kinase (GSK)-3β that occurred in the hippocampus of APP/PS1 transgenic mice. These results demonstrate that VPA could significantly ameliorate spatial memory impairment and Aβ deposition at least in part via the inhibition of inflammation, suggesting that administration of VPA could provide a therapeutic approach for AD. PMID:24854198