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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. Cartilage intermediate layer protein expression in calcium pyrophosphate dihydrate crystal deposition disease.

    PubMed

    Yamakawa, Koji; Iwasaki, Hiroshi; Masuda, Ikuko; Ohjimi, Yuko; Honda, Itsuo; Iyama, Ken-ichi; Shono, Eisuke; Naito, Masatoshi; Kikuchi, Masahiro

    2002-08-01

    To elucidate the mechanisms of calcium pyrophosphate dihydrate crystal deposition disease (CPPDCD) in the meniscus, synovium, labrum, tendon, ligament, and soft tissue, we studied the expression of cartilage intermediate layer protein (CILP). Histological sections and clinical data from 33 patients who fulfilled the criteria of Ryan and McCarty for CPPD were reviewed. Formalin fixed and paraffin embedded tissue sections of 33 patients with CPPDCD were stained with hematoxylin and eosin (H&E) and alizarin red S. Immunostaining was performed using affinity purified polyclonal antibody to synthetic peptide corresponding to the N-terminal sequence of the 61 kDa domain of porcine CILP. The age of patients ranged from 49 to 89 years (median 73). The knee was the commonest site. Radiologically, almost all lesions exhibited fine, radiopaque, linear deposits in the meniscus, articular cartilage, and synovium or joint capsule. Histopathologically, all cases showed deposits of birefringent monoclinic or triclinic crystals, which were visualized by polarized light microscopy with a red analyzer filter. In alizarin red S staining, more numerous crystals were observed than in H&E staining. Crystal deposition was usually associated with adjacent variable amounts of hypertrophic and/or metaplastic chondrocytes in each type of tissue. Variable intensity of CILP immunostaining was found in deposits of each lesion. Hypertrophic/metaplastic chondrocytes in and around CPPD deposits were also positive for CILP. Small cartilaginous islands remote from the CPPD deposits exhibited a weak positivity for CILP. In addition, weakly positive chondrocytes were noted in a transitional zone between cartilaginous islands with and without the deposits. In addition to cytoplasmic immunoreactivity, immunostaining for CILP was observed in the pericellular fibrous matrix. Hypertrophic or metaplastic chondrocytes characteristic of CPPDCD may be directly involved in the formation of CPPD crystals. Our

  3. Synovial chondromatosis of the temporomandibular joint with calcium pyrophosphate dihydrate crystal deposition disease (pseudogout)

    PubMed Central

    Matsumura, Y; Nomura, J; Nakanishi, K; Yanase, S; Kato, H; Tagawa, T

    2012-01-01

    This report describes a very rare case of synovial chondromatosis with deposition of calcium pyrophosphate dihydrate (CPPD) crystals (pseudogout) in the temporomandibular joint (TMJ) of a 46-year-old male patient. Synovial chondromatosis is a non-neoplastic disease characterized by metaplasia of the connective tissue leading to chondrogenesis in the synovial membrane. Pseudogout is an inflammatory disease of the joints caused by the deposition of CPPD, producing similar symptoms to those observed in gout but not hyperuricaemia. Both diseases commonly affect the knee, hip and elbow joints, but rarely affect the TMJ. PMID:23166363

  4. [Calcium pyrophosphate dihydrate crystal deposition disease: a clinicopathologic analysis of 20 cases].

    PubMed

    Fang, Hui-qiong; Li, Qi-ming; Huang, Yao-qu; Xing, Ji-si; Mao, Rong-jun; Xie, Le

    2012-12-01

    To investigate the clinicopathologic features of calcium pyrophosphate dihydrate crystal deposition disease (CPPD-CDD). The clinical and pathologic profiles were retrospectively analysed in 20 cases of CPPD-CDD. CPPD-CDD was far more common in women, most frequently involving joints, especially the knees and presenting with various arthrisis. Abnormally calcified and the articular damages were characteristic features by imageing. Histologically, multifocal indigo granular calcinosis was seen in synovium and sometimes appeared as needle-shaped or rhomboid crystals, which characterized the CPPD. Though clinical symptoms of CPPD are quite variable, the definite diagnosis can be made by the abnormal calcification and joint damage radiographically and the indigo CPPD crystals histopathologically.

  5. The utility of alizarin red s staining in calcium pyrophosphate dihydrate crystal deposition disease.

    PubMed

    Yamakawa, Koji; Iwasaki, Hiroshi; Masuda, Ikuko; Ohjimi, Yuko; Honda, Itsuo; Saeki, Kazuhiko; Zhang, Jingfan; Shono, Eisuke; Naito, Masatoshi; Kikuchi, Masahiro

    2003-05-01

    To determine the most suitable staining method for preservation and detection of calcium pyrophosphate dihydrate (CPPD) crystals in histological sections of patients with CPPD crystal deposition disease. Paraffin sections of CPPD crystal-bearing tissues of 31 patients were stained with hematoxylin and eosin (H&E) and Alizarin red S (ARS). For H&E, the sections were treated with Mayer's hematoxylin (pH 2.3) for 5 min and with eosin alcohol (pH 4.1) for 1 min. For ARS, 1% ARS dissolved in distilled water was adjusted to pH 6.4 by adding 0.1% ammonia solution drop by drop while stirring. As controls, unstained sections were soaked in 1% citric acid monohydrate solution (CAMS, pH 2.3) for 5 or 10 min. The histological preparations were examined under a compensated polarized light using a first-order red compensator. We counted the number of weakly positive birefringent CPPD crystals in 3 high power fields (HPF, 0.272 mm2). CPPD crystals were seen clearly in most specimens stained with ARS, but were markedly reduced in tissue sections stained with H&E or CAMS. The number of CPPD crystals detected in sections stained by ARS (1723 +/- 683 per 3 HPF, mean +/- standard deviation) was significantly higher compared with H&E, CAMS (5 min), and CAMS (10 min) (401 +/- 374, 1022 +/- 616, and 494 +/- 636 per 3 HPF, respectively; p < 0.001, each). Standard H&E staining reduces the number of visible CPPD crystals, probably due to the strong acidity of both hematoxylin and eosin solutions, whereas the ARS stain seems to preserve a large number of CPPD crystals. The utility of ARS staining may improve the identification of CPPD crystals and contribute to a correct diagnosis of CPPD crystal deposition.

  6. CPPD crystal deposition disease of the cervical spine: a common cause of acute neck pain encountered in the neurology department.

    PubMed

    Sekijima, Yoshiki; Yoshida, Takuhiro; Ikeda, Shu-Ichi

    2010-09-15

    Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease is one of the most common forms of crystal-associated arthropathy in the elderly. However, CPPD deposition on the cervical spine is less well known, and only a limited number of cases have been reported to date. Here, we report our recent clinical experience with CPPD crystal deposition disease of the cervical spine and describe the clinical features of this disease. Fourteen patients with clinically diagnosed CPPD crystal deposition disease of the cervical spine at our department during the period from January 2005 to December 2008 were analyzed retrospectively. Patients ranged in age from 54 to 92 (mean+/-SD, 77.5+/-8.5). Chief symptoms of patients were acute posterior neck pain and fever. All patients had markedly restricted neck rotation. Serum CRP level was highly elevated in all patients (10.16+/-5.35 mg/dL). Computed tomography of the cervical spine demonstrated linear calcific deposits in the transverse ligament of atlas (crowned dens syndrome) in all patients. Calcific deposits were also found in other periodontoid structures and the ligamenta flava in some patients. Posterior neck pain, fever, and increased serum inflammatory indicators were relieved within 1 to 3 weeks by nonsteroidal antiinflammatory drugs (NSAIDs) or a combination of NSAIDs and prednisolone. Most of the patients were misdiagnosed as having other diseases before consultation. CPPD crystal deposition disease of the cervical spine is one of the most common underrecognized causes of acute neck pain in the neurology department, especially in elderly patients. 2010 Elsevier B.V. All rights reserved.

  7. Systematic review and quality analysis of emerging diagnostic measures for calcium pyrophosphate crystal deposition disease

    PubMed Central

    Wu, Y; Chen, K; Terkeltaub, R

    2016-01-01

    Objectives Calcium pyrophosphate crystal deposition disease (CPPD) is common, yet prevalence and overall clinical impact remain unclear. Sensitivity and specificity of CPPD reference standards (conventional crystal analysis (CCA) and radiography (CR)) were meta-analysed by EULAR (published 2011). Since then, new diagnostic modalities are emerging. Hence, we updated 2009–2016 literature findings by systematic review and evidence grading, and assessed unmet needs. Methods We performed systematic search of full papers (PubMed, Scopus/EMBASE, Cochrane 2009–2016 databases). Search terms included CPPD, chondrocalcinosis, pseudogout, ultrasound, MRI, dual energy CT (DECT). Paper selection, data abstraction, EULAR evidence level, and Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 bias and applicability grading were performed independently by 3 authors. Results We included 26 of 111 eligible papers, which showed emergence in CPPD diagnosis of ultrasound (U/S), and to lesser degree, DECT and Raman spectroscopy. U/S detected CPPD crystals in peripheral joints with sensitivity >80%, superior to CR. However, most study designs, though analytical, yielded low EULAR evidence level. DECT was marginally explored for CPPD, compared with 35 published DECT studies in gout. QUADAS-2 grading indicated strong applicability of U/S, DECT and Raman spectroscopy, but high study bias risk (in ∼30% of papers) due to non-controlled designs, and non-randomised subject selection. Conclusions Though CCA and CR remain reference standards for CPPD diagnosis, U/S, DECT and Raman spectroscopy are emerging U/S sensitivity appears to be superior to CR. We identified major unmet needs, including for randomised, blinded, controlled studies of CPPD diagnostic performance and rigorous analyses of 4 T MRI and other emerging modalities. PMID:27933211

  8. Comparison of characteristics of patients with and without calcium pyrophosphate dihydrate crystal deposition disease who underwent total knee replacement surgery for osteoarthritis.

    PubMed

    Viriyavejkul, P; Wilairatana, V; Tanavalee, A; Jaovisidha, K

    2007-02-01

    To compare characteristics of patients with severe osteoarthritis with and without calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. Patients undergoing total knee replacement surgery participated in this study and completed questionnaires. Radiographs of the index knee (extended anteroposterior, lateral and skyline) were reviewed for the presence of chondrocalcinosis. Synovial fluids were obtained during surgery and analyzed under compensated polarized light microscopy. The presence of CPPD crystals was identified in 52.9% of 102 patients. The use of both radiographs and synovial fluid analysis increased the identification of crystals. There was no difference in the following characteristics of the patients with and without CPPD crystals: age of pain onset, gender, difficulty in performing daily functions (including cooking, standing up from chairs, using restroom, going upstairs, and going shopping), history of previous joint inflammation, use of walking aids, and number and types of medications ever used. CPPD patients underwent knee arthroplasty at older age compared to non-CPPD patients (70.3+/-6.37 and 67.5+/-7.15 years old, respectively) (P = 0.037). All but one CPPD patients were unaware of the presence of crystals. High prevalence of CPPD crystals was found in patients undergoing total knee replacement surgery. All but one CPPD patients were unaware of calcium deposition in the index joints. Patients with these crystals experienced similar difficulties in performing daily activities and received similar treatment to patients without CPPD crystals. CPPD patients did not undergo knee arthroplasty at earlier age than non-CPPD patients.

  9. Hydroxyapatite Deposition Disease

    DTIC Science & Technology

    2006-11-01

    calcific tendinitis or calcific periarthritis, is characterized by the deposition of calcium phosphate crystals (predominantly hydroxyapatite) in...site of HADD is the hip, where calcifications are usually found in the gluteus medius tendon or along the femur at various sites of tendinous ...posterolateral femoral diaphysis, as well as in various other tendinous attachments to the femur. Computed tomography is also helpful in the demonstration

  10. The prevalence of chondrocalcinosis of the symphysis pubis on CT scan and correlation with calcium pyrophosphate dihydrate crystal deposition disease.

    PubMed

    Patel, Trusha; Ryan, Lawrence; Dubois, Melissa; Carrera, Guillermo; Baynes, Keith; Mannem, Rajeev; Mulkerin, Jennifer; Visotcky, Alexis

    2016-03-01

    Calcium pyrophosphate dihydrate (CPP) crystal deposition in the articular cartilage can often be seen radiographically as chondrocalcinosis (CC). CPP crystals preferentially deposit in fibrocartilages such as the knee menisci and symphysis pubis (SP). We sought to determine the prevalence of CC in the SP on computed tomography (CT) of the abdomen and pelvis. This retrospective study involved readings on 1070 consecutive CTs of the abdomen and pelvis performed over 3 months in patients over 65 years of age. Medical records of 226 patients found to have CC were reviewed to determine age, gender, documentation of CPPD on problem lists or in medical histories, and whether radiology readings of the CTs mentioned CC. SP CC was identified in 21.1 % (226/1070) of consecutive CT scans with the mean age of CT+ patients being 78.6. Of the 226 patients with SP CC, the observation of CC was documented in only 5.3 % (12/226) of the radiology reports. Of the 12 instances in which the radiology reports mentioned CC, this observation was never (0/12) transmitted to the medical history or problem list. The prevalence of SP CC in patients older than 65 was 21.1 %. Since the majority of CTs of the abdomen and pelvis are not ordered for evaluation of musculoskeletal conditions, this is likely a true prevalence without selection bias. When CC of the SP was present on images, radiologists routinely overlooked or chose not to report CC. Even in the rare instances when it was reported, that information was not added to the medical history or problem list. There are several clinical situations (e.g., acute monoarthritis or atypical osteoarthritis) in which recognizing that a patient has CPP deposition would be useful. Taking the time to review images may yield clinically important findings that are not mentioned anywhere on the patient chart.

  11. Dense Deposit Disease

    PubMed Central

    Smith, Richard J.H; Harris, Claire L.; Pickering, Matthew C.

    2011-01-01

    Dense deposit disease (DDD) is an orphan disease that primarily affects children and young adults without sexual predilection. Studies of its pathophysiology have shown conclusively that it is caused by fluid-phase dysregulation of the alternative pathway of complement, however the role played by genetics and autoantibodies like C3 nephritic factors must be more thoroughly defined if we are to make an impact in the clinical management of this disease. There are currently no mechanism-directed therapies to offer affected patients, half of whom progress to end stage renal failure disease within 10 years of diagnosis. Transplant recipients face the dim prospect of disease recurrence in their allografts, half of which ultimately fail. More detailed genetic and complement studies of DDD patients may make it possible to identify protective factors prognostic for naïve kidney and transplant survival, or conversely risk factors associated with progression to renal failure and allograft loss. The pathophysiology of DDD suggests that a number of different treatments warrant consideration. As advances are made in these areas, there will be a need to increase healthcare provider awareness of DDD by making resources available to clinicians to optimize care for DDD patients. PMID:21601923

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

    PubMed

    Parperis, Konstantinos; Carrera, Guillermo; Baynes, Keith; Mautz, Alan; Dubois, Melissa; Cerniglia, Ross; Ryan, Lawrence M

    2013-09-01

    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.

  13. Pathology of glomerular deposition diseases.

    PubMed

    Joh, Kensuke

    2007-09-01

    In routine diagnosis on renal biopsy, one of the confusing fields for pathological diagnoses is the glomerulopathies with fibrillary structure. The primary glomerulopathies with a deposit of ultrastructural fibrillary structure, which are negative for Congo-red stain but positive for immunoglobulins, include fibrillary glomerulonephritis and immunotactoid glomerulopathy. Several paraproteinemias including cryoglobulinemia, monoclonal gammopathy, and light chain deposition disease as well as hematopoietic disorders including plasmacytoma, plasma cell dyscrasia, and B cell lymphoproliferative disorders involve glomerulopathy with an ultrastructural fibrillary structure. A rare glomerulopathy with fibrillary structure that stains negative for Congo-red as well as for immunoglobulins has been also reported. The pathological diagnoses of these glomerulopathies can include either glomerular diseases, or paraproteinemic diseases, or hematopoietic diseases. The terminology is still confusing when glomerular diseases can be combined with paraproteinemic diseases and/or hematopoietic diseases. Therefore, the generic term, 'glomerular deposition disease' (GDD), has been proposed by pathologists with a requirement for clinicians to detect autoantibodies, paraproteins as well as to carry out a bone marrow check. An attempt has been made to rearrange the diseases with related disorders of fibrillary deposits, based on detailed clinical and pathological finding and to elucidate the correlation between GDD, paraproteinemia, and hematopoietic disorder.

  14. 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

  15. Calcium Apatite Deposition Disease: Diagnosis and Treatment

    PubMed Central

    2016-01-01

    Calcium apatite deposition disease (CADD) is a common entity characterized by deposition of calcium apatite crystals within and around connective tissues, usually in a periarticular location. CADD most frequently involves the rotator cuff. However, it can theoretically occur in almost any location in the musculoskeletal system, and many different locations of CADD have been described. When CADD presents in an unexpected location it can pose a diagnostic challenge, particularly when associated with pain or swelling, and can be confused with other pathologic processes, such as infection or malignancy. However, CADD has typical imaging characteristics that usually allows for a correct diagnosis to be made without additional imaging or laboratory workup, even when presenting in unusual locations. This is a review of the common and uncommon presentations of CADD in the appendicular and axial skeleton as well as an updated review of pathophysiology of CADD and current treatments. PMID:28042481

  16. Processing tungsten single crystal by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Xiao, Zhigang; Zee, Ralph H.; Begg, Lester L.

    2000-01-01

    A tungsten single crystal layer has been fabricated on molybdenum single crystal substrate through the hydrogen (H2) reduction of the tungsten hexafluoride (WF6) in low pressure. Substrate temperature, reaction chamber pressure, and flow rate of WF6 and H2, are critical process parameters during deposition. A comprehensive analysis for the effects of these parameters on single crystal layer growth has been processed and optimized growth conditions have been achieved. The different orientation of the substrate shows the different deposition rate for tungsten. Low index plane has higher deposition rate than high index plane. The kinetics of the deposition process has also been investigated. SEM surface analysis indicates that the single crystal layer is smooth in macro-scale and rough and step-growth format in micro-scale. .

  17. Plaque and Deposits in Nine Human Stone Diseases

    PubMed Central

    Coe, Fredric L; Evan, Andrew P; Lingeman, James E; Worcester, Elaine M

    2011-01-01

    Data concerning nine forms of human stone disease, along with observations on normal people give new insights into formation of interstitial apatite plaque and intra-tubular crystal deposits. In general, across multiple disease states, one can reproduce the same relationships between plaque abundance as is seen among patients within individual disease states, so that the link between plaque and high urine calcium excretion, and low urine volume and pH seems increasingly secure. From this, one can propose a specific model of plaque formation, susceptible to experimental test. In many diseases, formation of inner medullary collecting duct and Bellini duct deposits is compatible with simple crystallization driven by urine supersaturations; this is expected in that these segments contain tubule fluid quite close in composition to final urine. But in ileostomy, small bowel disease and obesity bypass patients, crystals found in deposits are not those expected: apatite and urates in deposits, despite formation of highly acidic urine. Also, this discrepancy suggests the possibility of divergence between bulk urine pH and pH of focal collecting ducts, a new kind of possibility that is susceptible to experimental test. PMID:20625890

  18. Study of Polymer Crystallization by Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Jeong, Hyuncheol

    When a polymer is confined under the submicron length scale, confinement size and interfaces can significantly impact the crystallization kinetics and resulting morphology. The ability to tune the morphology of confined polymer systems is of critical importance for the development of high-performance polymer microelectronics. The wisdom from the research on confined crystallization suggests that it would be beneficial to have a processing route in which the crystallization of polymers is driven by interface and temperature effects at a nanometer-scale confinement. In practice, for atomic and small-molecular systems, physical vapor deposition (PVD) has been recognized as the most successful processing route for the precise control of the film structure at surface utilizing confinement effects. While standard PVD technologies are not generally applicable to the deposition of the chemically fragile macromolecules, the development of matrix-assisted pulsed laser evaporation (MAPLE) now enables the non-destructive PVD of high-molecular weight polymers. In this thesis work, we investigated the use of MAPLE for the precise control of the crystallization of polymer films at a molecular level. We also sought to decipher the rules governing the crystallization of confined polymers, by using MAPLE as a tool to form confined polymer systems onto substrates with a controlled temperature. We first explored the early stages of film growth and crystallization of poly(ethylene oxide) (PEO) at the substrate surface formed by MAPLE. The unique mechanism of film formation in MAPLE, the deposition of submicron-sized polymer droplets, allowed for the manifestation of confinement and substrate effects in the crystallization of MAPLE-deposited PEO. Furthermore, we also focused on the property of the amorphous PEO film formed by MAPLE, showing the dependence of polymer crystallization kinetics on the thermal history of the amorphous phase. Lastly, we probed how MAPLE processing affected

  19. Deposition and drying dynamics of liquid crystal droplets

    PubMed Central

    Davidson, Zoey S.; Huang, Yongyang; Gross, Adam; Martinez, Angel; Still, Tim; Zhou, Chao; Collings, Peter J.; Kamien, Randall D.; Yodh, A. G.

    2017-01-01

    Drop drying and deposition phenomena reveal a rich interplay of fundamental science and engineering, give rise to fascinating everyday effects (coffee rings), and influence technologies ranging from printing to genotyping. Here we investigate evaporation dynamics, morphology, and deposition patterns of drying lyotropic chromonic liquid crystal droplets. These drops differ from typical evaporating colloidal drops primarily due to their concentration-dependent isotropic, nematic, and columnar phases. Phase separation occurs during evaporation, and in the process creates surface tension gradients and significant density and viscosity variation within the droplet. As a result, the drying multiphase drops exhibit different convective currents, drop morphologies, and deposition patterns (coffee-rings). PMID:28555621

  20. Deposition and drying dynamics of liquid crystal droplets

    NASA Astrophysics Data System (ADS)

    Davidson, Zoey S.; Huang, Yongyang; Gross, Adam; Martinez, Angel; Still, Tim; Zhou, Chao; Collings, Peter J.; Kamien, Randall D.; Yodh, A. G.

    2017-05-01

    Drop drying and deposition phenomena reveal a rich interplay of fundamental science and engineering, give rise to fascinating everyday effects (coffee rings), and influence technologies ranging from printing to genotyping. Here we investigate evaporation dynamics, morphology, and deposition patterns of drying lyotropic chromonic liquid crystal droplets. These drops differ from typical evaporating colloidal drops primarily due to their concentration-dependent isotropic, nematic, and columnar phases. Phase separation occurs during evaporation, and in the process creates surface tension gradients and significant density and viscosity variation within the droplet. As a result, the drying multiphase drops exhibit different convective currents, drop morphologies, and deposition patterns (coffee-rings).

  1. 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

  2. Up-regulated expression of cartilage intermediate-layer protein and ANK in articular hyaline cartilage from patients with calcium pyrophosphate dihydrate crystal deposition disease.

    PubMed

    Hirose, Jun; Ryan, Lawrence M; Masuda, Ikuko

    2002-12-01

    Excess accumulation of extracellular inorganic pyrophosphate (ePPi) in aged human cartilage is crucial in calcium pyrophosphate dihydrate (CPPD) crystal formation in cartilage matrix. Two sources of ePPi are ePPi-generating ectoenzymes (NTPPPH) and extracellular transport of intracellular PPi by ANK. This study was undertaken to evaluate the role of NTPPPH and ANK in ePPi elaboration, by investigating expression of NTPPPH enzymes (cartilage intermediate-layer protein [CILP] and plasma cell membrane glycoprotein 1 [PC-1]) and ANK in human chondrocytes from osteoarthritic (OA) articular cartilage containing CPPD crystals and without crystals. Chondrocytes were harvested from knee cartilage at the time of arthroplasty (OA with CPPD crystals [CPPD], n = 8; OA without crystals [OA], n = 10). Normal adult human chondrocytes (n = 1) were used as a control. Chondrocytes were cultured with transforming growth factor beta1 (TGFbeta1), which stimulates ePPi elaboration, and/or insulin-like growth factor 1 (IGF-1), which inhibits ePPi elaboration. NTPPPH and ePPi were measured in the media at 48 hours. Media CILP, PC-1, and ANK were determined by dot-immunoblot analysis. Chondrocyte messenger RNA (mRNA) was extracted for reverse transcriptase-polymerase chain reaction to study expression of mRNA for CILP, PC-1, and ANK. NTPPPH and ANK mRNA and protein were also studied in fresh frozen cartilage. Basal ePPi elaboration and NTPPPH activity in conditioned media from CPPD chondrocytes were elevated compared with normal chondrocytes, and tended to be higher compared with OA chondrocytes. Basal expression of mRNA for CILP (chondrocytes) and ANK (cartilage) was higher in both CPPD chondrocytes and CPPD cartilage extract than in OA or normal samples. PC-1 mRNA was less abundant in CPPD chondrocytes and cartilage extract than in OA chondrocytes and extract, although the difference was not significant. CILP, PC-1, and ANK protein levels were similar in CPPD, OA, and normal chondrocytes

  3. Large Crystal Grain Niobium Thin Films Deposited by Energetic Condensation

    SciTech Connect

    Zhao, X.; Valente-Feliciano, A-M.; Xu, C.; Geng, R.L.; Phillips, H.; Reece, Charles; Wright, J.; Seo, K.; Crooks, R.; Krishnan, Mahadevan; Gerhan, A.; Bures, B.; Wilson, K.

    2008-01-01

    This letter presents evidence for unprecedented Nb thin films that were grown on sapphire and copper (Cu) substrates using a vacuum arc process called coaxial energetic deposition CED^TM. Most other deposition techniques with low adatom energy produce amorphous or small crystal-grain films, and typically high substrate temperatures and anneal steps is required to form the large, highly connected grains. The CED^TM technique deposits from plasma consisting of a non-equilibrium, high energy (50-150eV) ion population produced from the ionized source material. At the substrate these fast ions break up columnar structures, intermix with the first few atomic layers of the substrate to improve adhesion, and form dense films at lower substrate temperatures than are typical for low adatom energy techniques, such as physical vapor deposition (PVD). Nano-scale features of the thin films were examined using electron backscatter diffraction (EBSD). The films cryogenic state electrical properties w

  4. Frequency control of photonic crystal membrane resonators by monolayer deposition

    NASA Astrophysics Data System (ADS)

    Strauf, S.; Rakher, M. T.; Carmeli, I.; Hennessy, K.; Meier, C.; Badolato, A.; DeDood, M. J. A.; Petroff, P. M.; Hu, E. L.; Gwinn, E. G.; Bouwmeester, D.

    2006-01-01

    We study the response of GaAs photonic crystal membrane resonators to thin-film deposition. Slow spectral shifts of the cavity mode of several nanometers are observed at low temperatures, caused by cryo-gettering of background molecules. Heating the membrane resets the drift and shielding will prevent drift altogether. In order to explore the drift as a tool to detect surface layers, or to intentionally shift the cavity resonance frequency, we studied the effect of self-assembled monolayers of polypeptide molecules attached to the membranes. The 2-nm-thick monolayers lead to a discrete step in the resonance frequency and partially passivate the surface.

  5. Liquid crystal deposition on poled, single crystalline lithium niobate

    NASA Astrophysics Data System (ADS)

    Bharath, S. C.; Pimputkar, K. R.; Pronschinske, A. M.; Pearl, T. P.

    2008-01-01

    For the purpose of elucidating the mechanisms for molecular organization at poled ferroelectric surfaces, single crystalline lithium niobate (LN), 'Z-cut' along the (0 0 0 1) plane, has been prepared and characterized and subsequently exposed to liquid crystal molecules. As a model system we chose to study the anchoring of 4- n-octyl-4'-cyanobiphenyl (8CB) to LN. Liquid crystalline films are of interest because of their useful electronic and optical properties as well as chemical sensing attributes. Low-energy electron diffraction (LEED), atomic force microscopy (AFM), surface contact angle measurements (CA), and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface of lithium niobate as well as the nature of 8CB films grown on the surface. Atomically flat LN surfaces were prepared as a support for monolayer thick, 8CB molecular domains. 8CB liquid crystal molecules were deposited by an ambient vaporization technique and the films were analyzed using XPS and CA. Understanding electrostatic anchoring mechanisms and thin film organization for this molecule on uniformly poled surfaces allows for a fuller appreciation of how molecular deposition of other polarizable molecules on periodically poled and patterned poled lithium niobate surfaces would occur.

  6. 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

  7. Dense Deposit Disease and C3 Glomerulopathy

    PubMed Central

    Barbour, Thomas D.; Pickering, Matthew C.; Terence Cook, H.

    2013-01-01

    Summary C3 glomerulopathy refers to those renal lesions characterized histologically by predominant C3 accumulation within the glomerulus, and pathogenetically by aberrant regulation of the alternative pathway of complement. Dense deposit disease is distinguished from other forms of C3 glomerulopathy by its characteristic appearance on electron microscopy. The extent to which dense deposit disease also differs from other forms of C3 glomerulopathy in terms of clinical features, natural history, and outcomes of treatment including renal transplantation is less clear. We discuss the pathophysiology of C3 glomerulopathy, with evidence for alternative pathway dysregulation obtained from affected individuals and complement factor H (Cfh)-deficient animal models. Recent linkage studies in familial C3 glomerulopathy have shown genomic rearrangements in the Cfh-related genes, for which the novel pathophysiologic concept of Cfh deregulation has been proposed. PMID:24161036

  8. Multiorgan crystal deposition following intravenous oxalate infusion in rat

    SciTech Connect

    Blumenfrucht, M.J.; Cheeks, C.; Wedeen, R.P.

    1986-06-01

    Deposition of calcium oxalate is responsible for the pathologic manifestations of oxalosis and may contribute to multiorgan dysfunction in uremia and to the progression of renal damage after renal failure is established. We have developed a rat model of oxalosis using a single intravenous injection of sodium oxalate, 0.3 mmol./kg. body weight, in rats. Polarized light microscopy and section freeze-dry autoradiography were used to identify /sup 14/C-oxalate within the renal parenchyma and in extrarenal organs. /sup 14/C-oxalate crystals under three mu in length were identified within one min. of injection in proximal tubule lumens. Section freeze-dry autoradiography showed occasional minute crystals within glomeruli, heart, lung and liver at one hr. In contrast to concentrative cellular uptake demonstrated in rat renal cortical slices in vitro, intracellular accumulation of /sup 14/C-oxalate could not be detected in vivo. Within the first 24 hr., renal oxalate retention reached a maximum of 25 +/- 4 per cent of the injected dose/gm. kidney compared to a maximum of only 7 +/- 3 per cent/gm. kidney after intraperitoneal administration. Although less than one per cent dose/gm. kidney remained after one week, crystal fragments were scattered throughout the cortex and medulla, often surrounded by foci of interstitial nephritis. The retention of crystals in kidney and other body organs following i.v. oxalate provides a model of oxalosis which stimulates pathophysiologic events in a variety of clinical situations characterized by transiently or persistently elevated serum oxalate.

  9. The ANKH gene and familial calcium pyrophosphate dihydrate deposition disease.

    PubMed

    Netter, Patrick; Bardin, Thomas; Bianchi, Arnaud; Richette, Pascal; Loeuille, Damien

    2004-09-01

    Familial calcium pyrophosphate dihydrate deposition (CPPD) disease is a chronic condition in which CPPD microcrystals deposit in the joint fluid, cartilage, and periarticular tissues. Two forms of familial CPPD disease have been identified: CCAL1 and CCAL2. The CCAL1 locus is located on the long arm of chromosome 8 and is associated with CPPD and severe osteoarthritis. The CCAL2 locus has been mapped to the short arm of chromosome 5 and identified in families from the Alsace region of France and the United Kingdom. The ANKH protein is involved in pyrophosphate metabolism and, more specifically, in pyrophosphate transport from the intracellular to the extracellular compartment. Numerous ANKH gene mutations cause familial CCAL2; they enhance ANKH protein activity, thereby elevating extracellular pyrophosphate levels and promoting the formation of pyrophosphate crystals, which produce the manifestations of the disease. Recent studies show that growth factors and cytokines can modify the expression of the normal ANKH protein. These results suggest a role for ANKH in sporadic CPPD disease and in CPPD associated with degenerative disease.

  10. Operation condition for continuous anti-solvent crystallization of CBZ-SAC cocrystal considering deposition risk of undesired crystals

    NASA Astrophysics Data System (ADS)

    Nishimaru, Momoko; Nakasa, Miku; Kudo, Shoji; Takiyama, Hiroshi

    2017-07-01

    Crystallization operation of cocrystal production has deposition risk of undesired crystals. Simultaneously, continuous manufacturing processes are focused on. In this study, conditions for continuous cocrystallization considering risk reduction of undesired crystals deposition were investigated on the view point of thermodynamics and kinetics. The anti-solvent cocrystallization was carried out in four-component system of carbamazepine, saccharin, methanol and water. From the preliminary batch experiment, the relationships among undesired crystal deposition, solution composition decided by mixing ratio of solutions, and residence time for the crystals were considered, and then the conditions of continuous experiment were decided. Under these conditions, the continuous experiment was carried out. The XRD patterns of obtained crystals in the continuous experiment showed that desired cocrystals were obtained without undesired crystals. This experimental result was evaluated by using multi-component phase diagrams from the view point of the operation point's movement. From the evaluation, it was found that there is a certain operation condition which the operation point is fixed with time in the specific domain without the deposition risk of undesired single component crystals. It means the possibility of continuous production of cocrystals without deposition risk of undesired crystals was confirmed by using multi-component phase diagrams.

  11. Elemental bio-imaging of calcium phosphate crystal deposits in knee samples from arthritic patients

    PubMed Central

    Austin, Christine; Hare, Dominic; Rozelle, Andrew L.; Robinson, William H.; Grimm, Rudolf

    2012-01-01

    Laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) was employed to image deposits of calcium phosphate based crystals in knee cartilage and synovial fluid from arthritic patients. A reaction/collision cell containing hydrogen minimised plasma interferences on calcium and also improved the image quality without significant sensitivity reduction. Areas of high calcium and phosphorus intensities consistent with crystal deposits were observed for both the cartilage and synovial fluid samples. These areas were also characterised by high magnesium and strontium intensities. Distribution patterns of other elements such as copper and sulfur did not correlate with the crystal deposits. Filtered and non-filtered solutions of calcium phosphate crystals grown in synthetic synovial fluid were also imaged as further evidence of crystal deposits. The crystal deposits were detected in the unfiltered solution, and were absent from the filtered solutions. PMID:21305107

  12. Modeling of Crystal Orientations in Laser Powder Deposition of Single Crystal Material

    NASA Astrophysics Data System (ADS)

    Qi, Huan; Liu, Zhaoyang

    This paper presents a numerical model which simulates the dynamic molten pool formation and the crystal orientations of solidified SX alloy in a multi-layer laser powder deposition process. Based on the mathematical model of coaxial laser direct deposition, the effect of parameters (laser power, scanning speed, powder feed rate) on the tendency to form [001] direction expitaxial grains during solidification was evaluated. In the transient three- dimensional model, physical phenomena including heat transfer, melting, grain formation during solidification, mass addition, and fluid flow in the melt pool, were modeled in a self-consistent manner. The temperature fields, fluid flow velocity, clad geometry (width, height and melt pool depth) and grain formation in melting pool of single layer are predicted.

  13. Bupivacaine crystal deposits after long-term epidural infusion.

    PubMed

    Balga, I; Gerber, H; Schorno, X H; Aebersold Keller, F; Oehen, H-P

    2013-07-01

    The case of a 45-year-old male patient (body weight 52 kg, height 1.61 m) with a locally invasive gastric carcinoma infiltrating into the retroperitoneal space is reported. Because of severe cancer pain a tunnelled thoracic epidural catheter (EC) was placed at thoracic spinal level 7/8 and a local anesthetic (LA) mixture of bupivacaine 0.25 % and morphine 0.005 % was infused continuously at 6 ml h(-1). To optimize pain therapy the concentration was doubled (bupivacaine 0.5 %, morphine 0.01 %) 3 months later but the infusion rate was reduced to 3 ml h(-1) thus the total daily dose did not change. The patient died 6 months after initiation of the epidural analgesia from the underlying disease. The total amount of bupivacaine infused was 69 g and of morphine 1.37 g. The patient never reported any neurological complications. The autopsy revealed large white crystalline deposits in the thoracic epidural space which were identified as bupivacaine base by infrared spectrometry. Morphine could not be detected. A histological examination showed unreactive fatty tissue necrosis within the crystalline deposits but nerve tissue could not be identified. It is concluded that the bupivacaine crystalline deposits arose due to precipitation but the clinical significance with regard to sensory level and neuraxial tissue toxicity is unknown.

  14. 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.

  15. Skeletal crystals of calcite and trona from hot-spring deposits in Kenya and New Zealand

    SciTech Connect

    Jones, B.; Renaut, R.W.

    1996-01-01

    Skeletal crystals are hollow crystals that develop because their outer walls grow before their cores. The presence of skeletal crystals of calcite (three types--trigonal prisms, hexagonal prisms, and plates) and trona in hot (> 90 C) spring deposits in New Zealand (Waikite Springs and Ohaaki Pool) and Kenya (Lorusio hot springs) shows that they can form in natural sedimentary regimes. Analysis of samples from these deposits shows that this crystal morphology develops under disequilibrium conditions that are unrelated to a specific environmental or diagenetic setting. Skeletal crystals transform into solid crystals when subsequent precipitation fills their hollow cores. In some cases, this may involve precipitation of crystalline material that has a sieve-like texture. In other examples, the skeletal crystal provides a framework upon which other materials can be precipitated. Walls in the skeletal trigonal calcite prisms from Waikite Springs are formed of subcrystals that mimic the shape of the parent crystal. Similarly, plate-like skeletal crystals from Lorusio are formed of densely packed subcrystals that are < 0.5 {micro}m long. Conversely, the walls of the skeletal hexagonal calcite crystals from Ohaaki Pool and the skeletal trona crystals from Lorusio are not formed of subcrystals. Recognition of skeletal crystals is important because they represent growth that follows the reverse pattern of normal growth. Failure to recognize that crystal growth followed the skeletal motif may lead to false interpretations concerning the growth of a crystal.

  16. Dense Deposit Disease Mimicking a Renal Small Vessel Vasculitis

    PubMed Central

    Singh, Lavleen; Bhardwaj, Swati; Sinha, Aditi; Bagga, Arvind; Dinda, Amit

    2016-01-01

    Dense deposit disease is caused by fluid-phase dysregulation of the alternative complement pathway and frequently deviates from the classic membranoproliferative pattern of injury on light microscopy. Other patterns of injury described for dense deposit disease include mesangioproliferative, acute proliferative/exudative, and crescentic GN. Regardless of the histologic pattern, C3 glomerulopathy, which includes dense deposit disease and C3 GN, is defined by immunofluorescence intensity of C3c two or more orders of magnitude greater than any other immune reactant (on a 0–3 scale). Ultrastructural appearances distinguish dense deposit disease and C3 GN. Focal and segmental necrotizing glomerular lesions with crescents, mimicking a small vessel vasculitis such as ANCA-associated GN, are a very rare manifestation of dense deposit disease. We describe our experience with this unusual histologic presentation and distinct clinical course of dense deposit disease, discuss the pitfalls in diagnosis, examine differential diagnoses, and review the relevant literature. PMID:26361799

  17. Dense Deposit Disease Mimicking a Renal Small Vessel Vasculitis.

    PubMed

    Singh, Lavleen; Singh, Geetika; Bhardwaj, Swati; Sinha, Aditi; Bagga, Arvind; Dinda, Amit

    2016-01-01

    Dense deposit disease is caused by fluid-phase dysregulation of the alternative complement pathway and frequently deviates from the classic membranoproliferative pattern of injury on light microscopy. Other patterns of injury described for dense deposit disease include mesangioproliferative, acute proliferative/exudative, and crescentic GN. Regardless of the histologic pattern, C3 glomerulopathy, which includes dense deposit disease and C3 GN, is defined by immunofluorescence intensity of C3c two or more orders of magnitude greater than any other immune reactant (on a 0-3 scale). Ultrastructural appearances distinguish dense deposit disease and C3 GN. Focal and segmental necrotizing glomerular lesions with crescents, mimicking a small vessel vasculitis such as ANCA-associated GN, are a very rare manifestation of dense deposit disease. We describe our experience with this unusual histologic presentation and distinct clinical course of dense deposit disease, discuss the pitfalls in diagnosis, examine differential diagnoses, and review the relevant literature.

  18. Three-dimensional Raman spectroscopic imaging of protein crystals deposited on a nanodroplet.

    PubMed

    Nitahara, Satoshi; Maeki, Masatoshi; Yamaguchi, Hiroshi; Yamashita, Kenichi; Miyazaki, Masaya; Maeda, Hideaki

    2012-12-21

    Confocal Raman spectroscopic imaging has been used to find the location of protein crystals deposited in a nanodroplet. The depth of the protein crystal has been clearly identified by comparing the three-dimensional Raman spectroscopic images of the protein with those of water. Additionally, the low concentration region around a growing protein crystal in the nanodroplet was visualized using two-dimensional Raman spectroscopic imaging.

  19. 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.

  20. 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.

  1. 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.

  2. Origin of platy calcite crystals in hot-spring deposits in the Kenya Rift Valley

    SciTech Connect

    Jones, B.; Renault, R.W.

    1998-09-01

    Platy calcite crystals, which have their c axis parallel to their shortest length axis, are common components of travertine deposits found around some hot springs in the Kenya Rift Valley. They are composite crystals formed of numerous paper-thin subcrystals. Individual plates allowed to grow without obstruction develop a hexagonal motif. The Kenyan crystals typically form in hot (>75 C) waters that have a low Ca content (<10 mg/l), a high CO{sub 2} content, and a high rate of CO{sub 2} degassing. At Chemurkeu, aggregates of numerous small platy crystals collectively form lattice crystals that superficially resemble ray crystals. The walls of the lattice crystals are formed of large platy crystals that have their long and intermediate length axes aligned parallel to the plane of the long axis of the lattice crystal. Internally, the lattice crystals are formed of small platy calcite crystals arranged in a boxlike pattern that creates the appearance of a lattice when viewed in thin section. Lattice crystals are highly porous, with each pore being enclosed by platy crystals. At Lorusio, travertines are mainly formed of pseudodentrites that are constructed by numerous small platy crystals attached to a main stem which is a large platy crystal that commonly curves along its long axis. The pseudodentrites are the main construction blocks in ledges and lilypads that form in the vent pool and spring outflow channels, where the water is too hot for microbes other than hyperthermophiles. The platy calcite crystals in the Kenyan travertines are morphologically similar to platy calcite crystals that form as scale in pipes in the geothermal fields of New Zealand and hydrothermal angel wing calcite from the La Fe mine in Mexico. Comparison of the Kenyan and New Zealand crystals indicates that platy calcite crystals form from waters with a low Ca{sup 2+} content and a high CO{sub 3}/Ca ratio due to rapid rates of CO{sub 2} degassing.

  3. Development of chemically vapor deposited rhenium emitters of (0001) preferred crystal orientation

    NASA Technical Reports Server (NTRS)

    Yang, L.; Hudson, R. G.

    1973-01-01

    Rhenium thermionic emitters were prepared by the pyrolysis of rhenium chlorides formed by the chlorination of rhenium pellets. The impurity contents, microstructures, degrees of (0001) preferred crystal orientation, and vacuum electron work functions of these emitters were determined as a function of deposition parameters, such as substrate temperature, rhenium pellet temperature and chlorine flow rate. A correlation between vacuum electron work function and degree of (0001) preferred crystal orientation was established. Conditions for depositing porosity-free rhenium emitters of high vacuum electron work functions were defined. Finally, three cylindrical rhenium emitters were prepared under the optimum deposition conditions.

  4. [Imaging of diseases with iron deposition].

    PubMed

    Momoshima, Suketaka

    2012-01-01

    Some fundamental technical aspects of magnetic resonance imaging (MRI) in evaluation of iron deposition were discussed. MRI is an imaging modality sensitive to iron deposition of the brain tissue. T(2) weighted imaging (T(2)WI), T(2) weighted imaging (T(2)WI), and susceptibility-weighted imaging (SWI) are particularly available for this purpose. They are different in sensitivity and availability, and should be used in the right places respectively. Susceptibility to iron deposition is also dependent on the strength of static magnetic field, which should be taken into account in the interpretation of the images.

  5. Systemic staging for urate crystal deposits with dual-energy CT and ultrasound in patients with suspected gout.

    PubMed

    Huppertz, Alexander; Hermann, Kay-Geert A; Diekhoff, Torsten; Wagner, Moritz; Hamm, Bernd; Schmidt, Wolfgang A

    2014-06-01

    Objective of the study is to compare the diagnostic accuracy for detecting monosodium urate crystal deposits between dual-energy CT (DECT) and ultrasound (US). Sixty consecutive patients (49 men, mean age 62 years) with clinically suspected gout were included in this case-control study. DECT and US of feet, knees, hands and elbows were performed in all patients. Polarisation microscopy of synovial fluid or a score incorporating serum uric acid level, first MTP joint involvement, gender, previous patient-reported arthritis attack, cardiovascular diseases, joint redness and onset within 1 day was used as standard of reference. Standard of reference classified 39 patients as gout positive. Sixteen patients had gout and a concomitant rheumatic disease. Sensitivities for diagnosis of gout disease were 84.6 % (33/39) for DECT and 100 % (39/39) for US. Specificities were 85.7 % (18/21) for DECT and 76.2 % (16/21) for US. Positive and negative predictive values were 91.7 % (33/36) and 75.0 % (18/24) for DECT, 88.6 % (39/44) and 100 % (16/16) for US, respectively. Urate crystals were detected most frequently in MTP1 joints (DECT 20/78, US 58/78), any other toe joints (DECT 25/78, US 62/78) and knees (DECT 41/78, US 31/78). The volumetry of DECT computed a mean urate crystal deposit load of 2.1 cm(3) (SD 9.6 cm(3)). A mean effective dose of ≤0.5 mSv was estimated. DECT is more specific for the diagnosis of gout than US. However, it fails to detect small urate crystal deposits. It might be particularly useful for patients with ambivalent findings, concomitant rheumatic diseases and with non-conclusive joint aspiration.

  6. Calcium pyrophosphate dihydrate deposition disease (CPPD)/Pseudogout of the temporomandibular joint - FNA findings and microanalysis.

    PubMed

    Naqvi, Asghar H; Abraham, Jerrold L; Kellman, Robert M; Khurana, Kamal K

    2008-04-21

    We report a case of a Calcium pyrophosphate dihydrate deposition disease (CPPD) presenting as a mass in the parotid and temporomandibular joint (TMJ) that simulated a parotid tumor. A 35 year-old man presented with pain in the left ear area. A CT Scan of the area showed a large, calcified mass surrounding the left condylar head, and extending into the infratemporal fossa. FNA of the mass showed birefringent crystals, most of which were rhomboid with occasional ones being needle shaped, embedded in an amorphous pink substance. Scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) of these crystals showed peaks corresponding to calcium and phosphorus. SEM/EDS is a rapid method of diagnosing calcium pyrophosphate dihydrate deposition disease (CPPD) and an alternative to more commonly used method of special staining of cell block sections coupled with polarizing microscopy.

  7. 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.

  8. Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition

    PubMed Central

    Liao, Yu-Kuang; Liu, Yung-Tsung; Hsieh, Dan-Hua; Shen, Tien-Lin; Hsieh, Ming-Yang; Tzou, An-Jye; Chen, Shih-Chen; Tsai, Yu-Lin; Lin, Wei-Sheng; Chan, Sheng-Wen; Shen, Yen-Ping; Cheng, Shun-Jen; Chen, Chyong-Hua; Wu, Kaung-Hsiung; Chen, Hao-Ming; Kuo, Shou-Yi; Charlton, Martin D. B.; Hsieh, Tung-Po; Kuo, Hao-Chung

    2017-01-01

    Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new ”paradigm shift” non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs) with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD) and chemical bath deposition (CBD) as used by the Cu(In,Ga)Se2 (CIGS) thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase. PMID:28383488

  9. Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition.

    PubMed

    Liao, Yu-Kuang; Liu, Yung-Tsung; Hsieh, Dan-Hua; Shen, Tien-Lin; Hsieh, Ming-Yang; Tzou, An-Jye; Chen, Shih-Chen; Tsai, Yu-Lin; Lin, Wei-Sheng; Chan, Sheng-Wen; Shen, Yen-Ping; Cheng, Shun-Jen; Chen, Chyong-Hua; Wu, Kaung-Hsiung; Chen, Hao-Ming; Kuo, Shou-Yi; Charlton, Martin D B; Hsieh, Tung-Po; Kuo, Hao-Chung

    2017-04-06

    Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new "paradigm shift" non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs) with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD) and chemical bath deposition (CBD) as used by the Cu(In,Ga)Se₂ (CIGS) thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.

  10. 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.

  11. Note: Accurate determination of thickness of multiple layers of thin film deposited on a piezoelectric quartz crystal

    NASA Astrophysics Data System (ADS)

    Wajid, Abdul

    2013-10-01

    Modern day piezoelectric quartz crystal microbalances for thin film deposition control are based on Z-match equation, which is mathematically valid for deposition of a single material on a given quartz crystal. When multiple layers are deposited, thickness and deposition rate errors accumulate due to mismatch of acoustic impedance of different materials. Here we present a novel method, based on the acoustic transfer matrix formalism, for accurate determination of thickness of an arbitrary number of layers of dissimilar materials deposited on a quartz crystal. Laboratory data show excellent accuracy of the method compared to conventional Z-match equation.

  12. Note: Accurate determination of thickness of multiple layers of thin film deposited on a piezoelectric quartz crystal.

    PubMed

    Wajid, Abdul

    2013-10-01

    Modern day piezoelectric quartz crystal microbalances for thin film deposition control are based on Z-match equation, which is mathematically valid for deposition of a single material on a given quartz crystal. When multiple layers are deposited, thickness and deposition rate errors accumulate due to mismatch of acoustic impedance of different materials. Here we present a novel method, based on the acoustic transfer matrix formalism, for accurate determination of thickness of an arbitrary number of layers of dissimilar materials deposited on a quartz crystal. Laboratory data show excellent accuracy of the method compared to conventional Z-match equation.

  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.

  14. 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

  15. In situ X-ray diffraction based investigation of crystallization in solution deposited PZT thin films

    NASA Astrophysics Data System (ADS)

    Nittala, Krishna

    Solution deposited PZT based thin films have potential applications in embedded decoupling capacitors and pulse discharge capacitors. During solution deposition, precursor solution is deposited onto a substrate to obtain an amorphous film. The film is then crystallized by heating it at a high temperature (˜600 - 700°C). Conditions during the crystallization anneal such as precursor stoichiometry in solution, heating rate and adhesion layer in the substrate are known to influence phase and texture evolution in these films. However, a mechanistic understanding of the changes taking place in these thin films during crystallization is lacking. A better understanding of the crystallization processes in these thin films could enable tailoring the properties of thin films to suit specific applications. To explore the crystallization process in solution deposited PZT thin films, high temperature in situ laboratory and synchrotron X-ray diffraction based techniques were developed. Taking advantage of the high X-ray flux available at synchrotron facilities such as beamline 6-ID-B, Advanced Photon Source, Argonne National Laboratory, crystalline phases formed in the thin films during crystallization at the high heating rates (0.5 -- 60°C/s) typically used during film processing could be measured. Using a 2-D detector for these measurements allowed the simultaneous measurement of both phase and texture information during crystallization. Analytical treatment of the unconventional diffraction geometry used during the synchrotron based measurements was performed to develop methodologies for quantitative estimation of texture components. The nominal lead content in the starting solutions and the heating rate used during crystallization was observed to influence the sequence of phases formed during crystallization of the films. In films crystallized at fast heating rates, titanium segregation, probably due to diffusion of titanium from the adhesion layer, was observed. To

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

    PubMed

    Namazie, Mohamed Ridzwan bin Mohamed; Fosbender, Murray R

    2012-08-01

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

  17. Review of the ophthalmic manifestations of gout and uric acid crystal deposition.

    PubMed

    Ao, Jack; Goldblatt, Fiona; Casson, Robert J

    2017-01-01

    Gout is a clinical disorder that is characterized by the deposition of monosodium urate crystals (MSU) in joints and tendons, usually in the presence of prolonged hyperuricaemia. Following an asymptomatic phase of hyperuricaemia, gout usually presents as acute monoarthritis followed by periods of remission and exacerbation. Conjunctival hyperaemia and subconjunctival haemorrhage exacerbated by purine intake are two of the more common manifestations that may go unrecognized. Other ocular and adnexal structures can be affected by urate crystal deposition and associated inflammation, with potentially vision-threatening consequences; however, ocular manifestations of gout are rare and may have been over-reported in the older literature, but our understanding of the clinic-pathological features of ocular urate deposits remains limited.

  18. 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

  19. Thermal crystallization of sputter-deposited amorphous Ge films: Competition of diamond cubic and hexagonal phases

    NASA Astrophysics Data System (ADS)

    Okugawa, M.; Nakamura, R.; Ishimaru, M.; Yasuda, H.; Numakura, H.

    2016-12-01

    Following our previous studies on crystallization induced by electron irradiation, we have investigated the crystallization of sputter-deposited amorphous germanium films by heat treatments. On continuous heating, samples aged for 3 days and 4 months at room temperature crystallized at 500°C to form coarse spherical particles of a hexagonal structure, of about 100 nm in diameter, whereas samples aged for 7 months turned to homogeneous nanograins of the diamond cubic structure at 600°C. When the films aged for 4 months at room temperature were annealed at 350°C for 2 h and then heated, they crystallized at 550°C to form a mixture of the two microstructures, and those annealed at 350°C and further at 500°C for 1 h crystallized at 600°C mostly to nanograins. Crystallization by electron irradiation at 350°C to 4-month-aged samples has also been studied. With increasing annealing time at 350°C, coarse particles of a hexagonal structure ceased to appear, and were replaced by fine nanograins of the diamond cubic structure. These observations can be understood in terms of structural instability of sputter-deposited amorphous films. Medium-range ordered clusters must initially be present in the films and serve as nuclei of the metastable hexagonal phase. They are unstable, however, and are eliminated by annealing, resulting in the reduction in size and number of coarse particles with a metastable structure.

  20. High crystalline quality single crystal chemical vapour deposition diamond.

    PubMed

    Martineau, P M; Gaukroger, M P; Guy, K B; Lawson, S C; Twitchen, D J; Friel, I; Hansen, J O; Summerton, G C; Addison, T P G; Burns, R

    2009-09-09

    Homoepitaxial chemical vapour deposition (CVD) on high pressure, high temperature (HPHT) synthetic diamond substrates allows the production of diamond material with controlled point defect content. In order to minimize the extended defect content, however, it is necessary to minimize the number of substrate extended defects that reach the initial growth surface and the nucleation of dislocations at the interface between the CVD layer and its substrate. X-ray topography has indicated that when type IIa HPHT synthetic substrates are used, the density of dislocations nucleating at the interface can be less than 400  cm(-2). X-ray topography, photoluminescence imaging and birefringence microscopy of HPHT grown synthetic type IIa diamond clearly show that the extended defect content is growth sector dependent. ⟨111⟩ sectors contain the highest concentration of both stacking faults and dislocations but ⟨100⟩ sectors are relatively free of both. It has been shown that HPHT treatment of such material can significantly reduce the area of stacking faults and cause dislocations to move. This knowledge, coupled with an understanding of how growth sectors develop during HPHT synthesis, has been used to guide selection and processing of substrates suitable for CVD synthesis of material with high crystalline perfection and controlled point defect content.

  1. OCULAR MANIFESTATIONS OF MONOCLONAL IMMUNOGLOBULIN LIGHT CHAIN DEPOSITION DISEASE.

    PubMed

    Dhrami-Gavazi, Elona; Freund, K Bailey; Lee, Winston; Cohen, Ben Z; Seshan, Surya V; Yannuzzi, Lawrence A

    2017-01-01

    To demonstrate unusual retinal findings in a patient with progressive renal failure due to idiopathic monoclonal immunoglobulin light chain deposition disease, using multimodal imaging. Observational case report of a 43-year-old white man with renal failure due to light chain deposition disease. His course over 6 years was documented with multimodal imaging including fundus photography, fundus autofluorescence, fluorescein angiography, and spectral domain optical coherence tomography. Additional evaluations included ocular ultrasound, electroretinography, positron emission tomography, serum protein electrophoreses, skeletal surveys to detect osteolytic lesions, and renal, liver, and rectal biopsies in search of amyloid. The patient's ocular course mirrored the severity of his renal dysfunction for which he required a renal transplant. Changes observed in the native kidney recurred in the transplant 2 years later, as evidenced by immunohistochemistry, revealing thick linear deposits of kappa chains, with no complement, overlying the glomerular basement membrane. The systemic workup was negative for amyloid but showed an overwhelming ratio of kappa to lambda light chains on serum protein electrophoreses and no clinical signs of plasma cell dyscrasias, all consistent with idiopathic light chain deposition disease. The patient presented with a generalized, bilateral "leopard-spot" fundus appearance on fundus autofluorescence, striking globular subretinal deposits on spectral domain optical coherence tomography, and subfoveal subretinal fluid without retinal pigment epithelium detachment or choroidal effusions. The subfoveal fluid did not respond to intravitreal injections of antiangiogenic agents or steroids but resolved after renal transplantation. A temporary posttransplant visual improvement was associated with lessening of the subretinal drusenoid deposits demonstrated by multimodal imaging. The terminal vision deterioration was associated with amorphous

  2. Do Not Hallow until You Are out of the Wood! Ultrasonographic Detection of CPP Crystal Deposits in Menisci: Facts and Pitfalls

    PubMed Central

    Filippou, Georgios; Adinolfi, Antonella; Bozios, Panagiotis; Lorenzini, Sauro; Picerno, Valentina; Di Sabatino, Valentina; Bertoldi, Ilaria; Gambera, Dario; Galeazzi, Mauro; Frediani, Bruno

    2013-01-01

    Purpose. Ultrasonography (US) has been demonstrated to be an important tool in the diagnosis of calcium pyrophosphate (CPP) crystal deposition disease. The aim of our study was to individuate and describe possible pitfalls in US detection of such deposits in menisci. Patients and Methods. We enrolled all patients waiting to undergo knee replacement surgery due to osteoarthritis, for one-month period. Each patient underwent US examination of the knee, focusing on the menisci. After surgery, the menisci were examined by US, macroscopically and microscopically, using the microscopic analysis as the gold standard for CPP deposition. Results. 11 menisci of 6 patients have been studied. Ex vivo examination of menisci performed better in CPP identification than in vivo examination. The possible reasons of misinterpretation or misdiagnosis of the in vivo exam were identified and are extensively described in the paper. Also a new sign of CPP crystal deposits was found. Conclusions. This study permitted to highlight some difficulties in CPP crystal detection by US in menisci. Further studies are needed to define completely US CPP crystal aspect and to improve the sensibility and specificity of US in CPP deposition diagnosis. PMID:23970829

  3. 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.

  4. Hand and wrist arthropathies of hemochromatosis and calcium pyrophosphate deposition disease: distinct radiographic features

    SciTech Connect

    Adamson, T.C. III; Resnik, C.S.; Guerra, J. Jr.; Vint, V.C.; Weisman, M.H.; Resnick, D.

    1983-05-01

    Radiographic features of hand and wrist involvement in 26 patients with hemochromatosis and in 26 patients with idiopathic calcium pyrophosphate dihydrate (CPPD) crystal deposition disease were compared. Two radiologists independently examined the radiographs without knowledge of the specific group to which the patient belonged. The results of this study clearly establish that structural joint diseases in the two disorders are not identical. Characteristic findings allow the radiologist to favor one diagnosis over the other. These radiograhic differences indicate that the arthropathy of hemochromatosis is related to factors additional to the presence of CPPD crystals, specifically, the more prevalent narrowing of the metacarpophalangeal joint spaces, including those in the fourth and fifth digits, peculiar hook-like osteophytes on the radial aspect of the metacarpal heads, and less prevalent separation of the scaphoid and the lunate.

  5. 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.

  6. 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.

  7. Sporadic late onset nemaline myopathy and immunoglobulin deposition disease.

    PubMed

    Doppler, Kathrin; Knop, Stefan; Einsele, Hermann; Sommer, Claudia; Wessig, Carsten

    2013-12-01

    In monoclonal gammopathy, organ dysfunction can occur due to deposition of immunoglobulin fragments. A rare form of acquired myopathy often associated with monoclonal gammopathy is sporadic late onset nemaline myopathy (SLONM), which is characterized by nemaline rods in myofibers. The pathogenetic link between monoclonal gammopathy and SLONM has not yet been elucidated. Case report of a patient with monoclonal gammopathy who developed a progressive myopathy, finally diagnosed as SLONM. A muscle biopsy showed mild myopathic changes. A second biopsy 1 year after clinical onset demonstrated deposition of immunoglobulin light and heavy chains and the presence of nemaline rods. The patient experienced marked improvement of muscle strength after autologous stem cell transplantation and treatment with bortezomib, a therapy that is known to be effective in light chain deposition disease. We speculate that deposition of light and heavy chains, rather than nemaline bodies, has myotoxic effects on skeletal muscle. Copyright © 2013 Wiley Periodicals, Inc.

  8. Hyaline cartilage involvement in patients with gout and calcium pyrophosphate deposition disease. An ultrasound study.

    PubMed

    Filippucci, E; Riveros, M Gutierrez; Georgescu, D; Salaffi, F; Grassi, W

    2009-02-01

    The main aim of the present study was to determine the sensitivity, specificity and accuracy of ultrasonography (US) in detecting monosodium urate and calcium pyrophosphate dihydrate crystals deposits at knee cartilage level using clinical definite diagnosis as standard reference. A total of 32 patients with a diagnosis of gout and 48 patients with pyrophosphate arthropathy were included in the study. Fifty-two patients with rheumatoid arthritis (RA), psoriatic arthritis or osteoarthritis (OA) were recruited as disease controls. All diagnoses were made using an international clinical criterion. US examinations were performed by an experienced sonographer, blind to clinical and laboratory data. Hyaline cartilage was assessed to detect two US findings recently indicated as indicative of crystal deposits: hyperechoic enhancement of the superficial margin of the hyaline cartilage and hyperechoic spots within the cartilage layer not generating a posterior acoustic shadow. Hyperechoic enhancement of the chondrosynovial margin was found in at least one knee of 14 out of 32 (43.7%) patients with gout and in a single knee of only one patient affected by pyrophosphate arthropathy (specificity=99%). Intra-cartilaginous hyperechoic spots were detected in at least one knee of 33 out of 48 (68.7%) patients with pyrophosphate arthropathy and in two disease controls one with OA and the second with RA (specificity=97.6%). The results of the present study indicate that US may play a relevant role in distinguishing cartilage involvement in patients with crystal-related arthropathy. The selected US findings were found to be highly specific.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Characterization of single crystal chemical vapor deposition diamond detectors for neutron spectrometry.

    PubMed

    Gagnon-Moisan, F; Zimbal, A; Nolte, R; Reginatto, M; Schuhmacher, H

    2012-10-01

    Detectors made from artificial chemical vapor deposition single crystal diamond have shown great potential for fast neutron spectrometry. In this paper, we present the results of measurements made at the Physikalisch-Technische Bundesanstalt accelerator using neutron fields in the energy range from 7 MeV to 16 MeV. This study presents the first results of the characterization of the detector in this energy range.

  14. Correlation between energy deposition and AlN crystal growth induced by ion bombardment

    NASA Astrophysics Data System (ADS)

    Kenzo, Kobayashi; Masaya, Iwaki; Takanobu, Fujihana

    1991-07-01

    A study has been made of the effects of ion (He, O, N and Ne) bombardment on the crystallization of AlN. AlN 0.8 thin films 100 nm thick were deposited on Si (111) wafers by an activated reactive evaporation method in a nitrogen atmosphere. He, O, N and Ne ions were bombarded onto films at room temperature to a dose of 5 × 10 17 ions/cm 2, using an energy of 150 keV. This energy was chosen to place the average projected range of the ions in the substrate interior. XRD measurements were carried out using CuK α radiation (40 keV, 30 mA). The quantities of energy deposited in the films, through ionization and by recoil atoms, were calculated using TRIM-88. It is concluded that ion bombardment of AlN 0.8 thin films causes crystal growth of AlN, with the c-axis oriented perpendicular to the substrate plane, near to room temperature without any thermal annealing. Energy deposition through the ionization plays an essential role in the crystallization of AlN in AlN x thin films.

  15. Crystal deposition patterns from evaporating sessile drops on superhydrophobic and liquid impregnated surfaces

    NASA Astrophysics Data System (ADS)

    McBride, Samantha; Dash, Susmita; Varanasi, Kripa; Varanasi Group Team

    2016-11-01

    Accelerated corrosion and scale buildup near oceans is partially due to deposition of salty sea mist onto ships, cars, and building structures. Many corrosion preventative measures are expensive, time intensive, and/or have negative impacts on the environment. One solution is the use of specific surfaces that are engineered for scale resistance. In this work, we show that we can delay crystallization and reduce scale adhesion on specifically engineered liquid impregnated surfaces (LIS). The low contact angle hysteresis of the LIS results in a sliding contact line of the saline droplet during evaporation, and the elevated energy barrier of the smooth liquid interface delays crystallization. Experiments conducted on surfaces with different wettability also demonstrate the corresponding influence in controlling salt crystal polymorphism.

  16. Systematic comparison of crystal and NMR protein structures deposited in the protein data bank.

    PubMed

    Sikic, Kresimir; Tomic, Sanja; Carugo, Oliviero

    2010-09-03

    Nearly all the macromolecular three-dimensional structures deposited in Protein Data Bank were determined by either crystallographic (X-ray) or Nuclear Magnetic Resonance (NMR) spectroscopic methods. This paper reports a systematic comparison of the crystallographic and NMR results deposited in the files of the Protein Data Bank, in order to find out to which extent these information can be aggregated in bioinformatics. A non-redundant data set containing 109 NMR - X-ray structure pairs of nearly identical proteins was derived from the Protein Data Bank. A series of comparisons were performed by focusing the attention towards both global features and local details. It was observed that: (1) the RMDS values between NMR and crystal structures range from about 1.5 Å to about 2.5 Å; (2) the correlation between conformational deviations and residue type reveals that hydrophobic amino acids are more similar in crystal and NMR structures than hydrophilic amino acids; (3) the correlation between solvent accessibility of the residues and their conformational variability in solid state and in solution is relatively modest (correlation coefficient = 0.462); (4) beta strands on average match better between NMR and crystal structures than helices and loops; (5) conformational differences between loops are independent of crystal packing interactions in the solid state; (6) very seldom, side chains buried in the protein interior are observed to adopt different orientations in the solid state and in solution.

  17. [Light chain deposition disease as a cause of renal failure].

    PubMed

    Wohl, P; Chadimová, M; Englis, M; Táborský, P; Rossmann, P; Matl, I

    1998-11-30

    The objective of the paper is to draw attention to a rare cause of rapidly progressing renal failure which developed in the course of four months as a result of light chain deposition disease. The authors submit two case-histories of the disease assessed by renal biopsy after previous clinical and laboratory suspicion of monoclonal gammapathy. In one patient in the sternal punctate plasmacytoma was diagnosed and in the second case it was not possible to detect any type of monoclonal gammapathy or another possible cause of disease. Renal failure was in both cases irreversible and both patients were enlisted in regular haemodialyzation treatment.

  18. Combined optical second harmonic generation/quartz crystal microbalance study of underpotential deposition processes: copper electrodeposition on polycrystalline gold.

    PubMed

    Lakkaraju, S; Bennahmias, M J; Borges, G L; Gordon Ii, J G; Lazaga, M; Stone, B M; Ashley, K

    1990-11-20

    Optical second harmonic generation and quartz crystal microbalance techniques are used as in situ probes of copper underpotential deposition on polycrystalline gold surfaces in sulfuric acid electrolyte. The second harmonic signal from a polished bulk gold substrate is observed to decrease by >60% as a result of copper underpotential deposition on gold. Also, the mass of an underpotentially deposited copper adlayer is monitored in situ by an oscillating quartz crystal microbalance, yielding an estimated coverage of ~8.0 x 10(-10) mol cm(-2) and an electrosorption valency of 1.5 for a copper adlayer on the surface of vapor-deposited polycrystalline gold.

  19. Solution processed deposition of electron transport layers on perovskite crystal surface-A modeling based study

    NASA Astrophysics Data System (ADS)

    Mortuza, S. M.; Taufique, M. F. N.; Banerjee, Soumik

    2017-02-01

    The power conversion efficiency (PCE) of planar perovskite solar cells (PSCs) has reached up to ∼20%. However, structural and chemicals defects that lead to hysteresis in the perovskite based thin film pose challenges. Recent work has shown that thin films of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) deposited on the photo absorption layer, using solution processing techniques, minimize surface pin holes and defects thereby increasing the PCE. We developed and employed a multiscale model based on molecular dynamics (MD) and kinetic Monte Carlo (kMC) to establish a relationship between deposition rate and surface coverage on perovskite surface. The MD simulations of PCBMs dispersed in chlorobenzene, sandwiched between (110) perovskite substrates, indicate that PCBMs are deposited through anchoring of the oxygen atom of carbonyl group to the exposed lead (Pb) atom of (110) perovskite surface. Based on rates of distinct deposition events calculated from MD, kMC simulations were run to determine surface coverage at much larger time and length scales than accessible by MD alone. Based on the model, a generic relationship is established between deposition rate of PCBMs and surface coverage on perovskite crystal. The study also provides detailed insights into the morphology of the deposited film.

  20. Liquid crystal colloidal structures for increased silicone deposition efficiency on colour-treated hair.

    PubMed

    Brown, M A; Hutchins, T A; Gamsky, C J; Wagner, M S; Page, S H; Marsh, J M

    2010-06-01

    An approach is described to increase the deposition efficiency of silicone conditioning actives from a shampoo on colour-treated hair via liquid crystal (LC) colloidal structures, created with a high charge density cationic polymer, poly(diallyldimethyl ammonium chloride) and negatively charged surfactants. LCs are materials existing structurally between the solid crystalline and liquid phases, and several techniques, including polarized light microscopy, small angle X-Ray analysis, and differential scanning calorimetry, were used to confirm the presence of the LC structures in the shampoo formula. Silicone deposition from the LC-containing shampoo and a control shampoo was measured on a range of hair substrates, and data from inductively coupled plasma optical emission spectroscopy analysis and ToF-SIMS imaging illustrate the enhancement in silicone deposition for the LC shampoo on all hair types tested, with the most pronounced enhancement occurring on hair that had undergone oxidative treatments, such as colouring. A model is proposed in which the LC structure deposits from the shampoo onto the hair to: (i) provide 'slip planes' along the hair surface for wet conditioning purposes and (ii) form a hydrophobic layer which changes the surface energy of the fibres. This increase in hydrophobicity of the hair surface thereby increases the deposition efficiency of silicone conditioning ingredients. Zeta potential measurements, dynamic absorbency testing analysis and ToF-SIMS imaging were used to better understand the mechanisms of action. This approach to increasing silicone deposition is an improvement relative to conventional conditioning shampoos, especially for colour-treated hair.

  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.

    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. Antibacterial activity of TiO2 nanotubes: Influence of crystal phase, morphology and Ag deposition

    NASA Astrophysics Data System (ADS)

    Li, Huirong; Cui, Qiang; Feng, Bo; Wang, Jianxin; Lu, Xiong; Weng, Jie

    2013-11-01

    TiO2 nanotubes on Ti substrate were fabricated by electrochemical anodization. Ag nanoparticles were deposited on the TiO2 nanotubes by a silver mirror reaction. Antibacterial activity of the nanotubes with different structural features was evaluated by a culture test with Escherichia coli bacteria. The anatase nanotubes showed the highest antibacterial activity among three crystal phases including anatase, rutile and amorphous titania. The diameters of the nanotubes affected the antibacterial activity. The two nanotubes with 200 nm and 50 nm diameters had higher antibacterial rate than those with other diameters. The antibacterial activity of the nanotubes was independent on their lengths. Ag-deposited nanotubes exhibited excellent antibacterial activity and its antibacterial rate was up to approximately 100%. TiO2 nanotubes and Ag-deposited nanotubes on titanium should be potential for antibacterial applications in clinics and industry, especially regarding with their reusability.

  3. Non-classical crystallization of silicon thin films during hot wire chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Jung, Jae-Soo; Lee, Sang-Hoon; Kim, Da-Seul; Kim, Kun-Su; Park, Soon-Won; Hwang, Nong-Moon

    2017-01-01

    The deposition behavior of silicon films by hot wire chemical vapor deposition (HWCVD) was approached by non-classical crystallization, where the building block of deposition is a nanoparticle generated in the gas phase of the reactor. The puzzling phenomenon of the formation of an amorphous incubation layer on glass could be explained by the liquid-like property of small charged nanoparticles (CNPs), which are generated in the initial stage of the HWCVD process. Using the liquid-like property of small CNPs, homo-epitaxial growth as thick as 150 nm could be successfully grown on a silicon wafer at 600 °C under the processing condition where CNPs as small as possible could be supplied steadily by a cyclic process which periodically resets the process. The size of CNPs turned out to be an important parameter in the microstructure evolution of thin films.

  4. Deposition and characterization of silicon thin-films by aluminum-induced crystallization

    NASA Astrophysics Data System (ADS)

    Ebil, Ozgenc

    Polycrystalline silicon (poly-Si) as a thin-film solar cell material could have major advantages compared to non-silicon thin-film technologies. In theory, thin-film poly-Si may retain the performance and stability of c-Si while taking advantage of established manufacturing techniques. However, poly-Si films deposited onto foreign substrates at low temperatures typically have an average grain size of 10--50 nm. Such a grain structure presents a potential problem for device performance since it introduces an excessive number of grain boundaries which, if left unpassivated, lead to poor solar cell properties. Therefore, for optimum device performance, the grain size of the poly-Si film should be at least comparable to the thickness of the films. For this project, the objectives were the deposition of poly-Si thin-films with 2--5 mum grain size on glass substrates using in-situ and conventional aluminum-induced crystallization (AIC) and the development of a model for AIC process. In-situ AIC experiments were performed using Hot-Wire Chemical Vapor Deposition (HWCVD) both above and below the eutectic temperature (577°C) of Si-Al binary system. Conventional AIC experiments were performed using a-Si layers deposited on aluminum coated glass substrates by Electron-beam deposition, Plasma Enhanced Chemical Vapor Deposition (PECVD) and HWCVD. Continuous poly-Si films with an average grain size of 10 mum on glass substrates were achieved by both in-situ and conventional aluminum-induced crystallization of Si below eutectic temperature. The grain size was determined by three factors; the grain structure of Al layer, the nature of the interfacial oxide, and crystallization temperature. The interface oxide was found to be crucial for AIC process but not necessary for crystallization itself. The characterization of interfacial oxide layer formed on Al films revealed a bilayer structure containing Al2O3 and Al(OH)3 . The effective activation energy for AIC process was determined

  5. 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

  6. Limitations of the Current Standards of Care for Treating Gout and Crystal Deposition in the Primary Care Setting: A Review.

    PubMed

    Keenan, Robert T

    2017-02-01

    This article outlines several important issues regarding the management of patients with gout. The topics discussed include best practices for gout based on the most current guidelines, opportunities for improving gout management, and current and emerging therapies for gout. [PubMed and Google Scholar databases] were search for all articles and trials published before 2016, using the key terms [hyperuricemia, gout, tophi, joint erosion, joint damage, treatment guidelines, American College of Rheumatology (ACR), European League Against Rheumatism (EULAR), flare, comorbidity, epidemiology, adherence, serum uric acid (sUA), monosodium urate (MSU), <6 mg/dL, MSU crystal formation, as well as individual drug names and classes of treatments of interest (allopurinol, febuxostat, colchicine, non-steroidal anti-inflammatories (NSAIDs)]. Studies were selected that presented data on gout treatment, including drugs under development, and on the management of gout from both the physician and patient perspectives. The reference lists of identified articles were searched manually for additional publications. Gout, a progressive debilitating form of inflammatory arthritis, is caused by factors that elevate serum uric acid (sUA) levels, leading to hyperuricemia. Continued elevated sUA can result in monosodium urate crystal deposition in joints and soft tissues, causing acute and chronic inflammation. Crystal deposition can lead to chronic gout, with an increased number of flares, tophi development, and structural joint damage. The aims of gout treatment are to reduce the sUA level to <6 mg/dL, to inhibit the formation of new crystals, and to promote the dissolution of existing crystals. Gout is often poorly managed for several reasons, including a lack of adherence to treatment guidelines by health care providers, patients' poor adherence to therapy, and differences between a provider's and patient's perspectives regarding treatment. Patients need to be educated about their

  7. Edge-controlled growth and kinetics of single-crystal graphene domains by chemical vapor deposition.

    PubMed

    Ma, Teng; Ren, Wencai; Zhang, Xiuyun; Liu, Zhibo; Gao, Yang; Yin, Li-Chang; Ma, Xiu-Liang; Ding, Feng; Cheng, Hui-Ming

    2013-12-17

    The controlled growth of large-area, high-quality, single-crystal graphene is highly desired for applications in electronics and optoelectronics; however, the production of this material remains challenging because the atomistic mechanism that governs graphene growth is not well understood. The edges of graphene, which are the sites at which carbon accumulates in the two-dimensional honeycomb lattice, influence many properties, including the electronic properties and chemical reactivity of graphene, and they are expected to significantly influence its growth. We demonstrate the growth of single-crystal graphene domains with controlled edges that range from zigzag to armchair orientations via growth-etching-regrowth in a chemical vapor deposition process. We have observed that both the growth and the etching rates of a single-crystal graphene domain increase linearly with the slanted angle of its edges from 0° to ∼19° and that the rates for an armchair edge are faster than those for a zigzag edge. Such edge-structure-dependent growth/etching kinetics of graphene can be well explained at the atomic level based on the concentrations of the kinks on various edges and allow the evolution and control of the edge and morphology in single-crystal graphene following the classical kinetic Wulff construction theory. Using these findings, we propose several strategies for the fabrication of wafer-sized, high-quality, single-crystal graphene.

  8. 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.

  9. 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

  10. Nigral iron deposition occurs across motor phenotypes of Parkinson's disease.

    PubMed

    Jin, L; Wang, J; Jin, H; Fei, G; Zhang, Y; Chen, W; Zhao, L; Zhao, N; Sun, X; Zeng, M; Zhong, C

    2012-07-01

      To investigate whether brain iron deposition correlates with motor phenotypic expressions of Parkinson's disease.   We subtyped patients with Parkinson's disease according to their main motor symptoms (tremor, rigidity/bradykinesia) into three subgroups: tremor-dominant subgroup, akinetic/rigid-dominant subgroup, or mixed subgroup. The iron levels in bilateral substantia nigra, globus pallidus, putamen, the head of caudate, and red nucleus of 87 patients and 50 control subjects were assayed by measuring phase values using susceptibility-weighted phase imaging in a 3-tesla magnetic resonance system. The serum ceruloplasmin levels of all subjects were determined.   The bilateral average phase values of the substantia nigra and all other brain regions examined did not correlate with the main motor symptoms of Parkinson's disease in the total patient group or when patients were grouped according to serum ceruloplasmin levels. Significant correlations between serum ceruloplasmin levels and nigral bilateral average phase values were observed in the tremor and akinetic/rigid-dominant subgroups. Analysis of patients without prior dopaminergic medication exhibited similar results. Increased nigral iron content correlated with disease severity as assayed by the Unified Parkinson's Disease Rating Scale motor scores in the PD(AR) subgroup.   These findings suggest that nigral iron deposition, correlating with decreased serum ceruloplasmin levels, is a risk factor in Parkinson's disease across multiple motor phenotypic expressions. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  11. 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.

  12. 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.

  13. Intramuscular migration of calcium hydroxyapatite crystal deposits involving the rotator cuff tendons of the shoulder: report of 11 patients.

    PubMed

    Pereira, Bruno P G; Chang, Eric Y; Resnick, Donald L; Pathria, Mini N

    2016-01-01

    The intent of the study is to describe an unusual pattern of intramuscular migration of calcific deposits related to hydroxyapatite deposition disease (HADD) involving the rotator cuff, to illustrate the characteristic imaging features of this phenomenon, and to discuss the clinical significance of such migration. A series of cases of intramuscular accumulation of calcium hydroxyapatite crystals collected over a 7-year period at multiple hospitals within the same academic institution were retrospectively reviewed. The patient group was composed of seven men and four women, ranging in age from 51 to 79 years, with a mean age of 63 years. All subjects presented with acute shoulder pain. The majority of subjects reported the spontaneous onset of the symptoms (64%), while others reported weight lifting (27%) and a fall on the arm (9%) as the mechanisms of injury. The right shoulder was affected in 73% of the subjects. The supraspinatus was the most commonly affected muscle (82%), followed by the infraspinatus muscle (36%). Knowledge of the imaging features of intramuscular migration of hydroxyapatite deposits is important in order to avoid the erroneous diagnosis of other causes of muscle edema and inflammation such as myotendinous injury, myositis, subacute denervation, and neoplasm.

  14. 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.

  15. 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

  16. Optimization of periodic column growth in glancing angle deposition for photonic crystal fabrication

    NASA Astrophysics Data System (ADS)

    Summers, M. A.; Brett, M. J.

    2008-10-01

    We investigate the growth of periodically aligned silicon microstructures for the fabrication of square spiral photonic crystals using the glancing angle deposition phi-sweep process. We report the optimization of the phi-sweep offset angle for fabrication of microstructures with more precise geometry. The effects of varying the sweep offset angle of the phi-sweep process are studied for films deposited onto a square lattice array of growth seeds. To represent one growth segment of the phi-sweep process, we fabricate 15 nm silicon thin films using several azimuthal substrate offsets from 0° to 45° at a vapor incidence angle of 85°. We also deposit silicon square spirals on square lattice arrays with the phi-sweep method, using various sweep offset angles from γ = 0° to 45°. We find that using an offset angle of γ = 26.5° optimizes the shadowing geometry, which minimizes anisotropic broadening, producing greater quality photonic crystal structures. From normal incidence reflection spectroscopy, a maximum full width at half-maximum of 273 ± 3 nm and a relative peak width (Δλ/λ) of 16.1 ± 0.1% were found for a sweep offset angle of γ = 26.5°.

  17. Calcium pyrophosphate dihydrate deposition disease (CPPD)/Pseudogout of the temporomandibular joint – FNA findings and microanalysis

    PubMed Central

    Naqvi, Asghar H; Abraham, Jerrold L; Kellman, Robert M; Khurana, Kamal K

    2008-01-01

    We report a case of a Calcium pyrophosphate dihydrate deposition disease (CPPD) presenting as a mass in the parotid and temporomandibular joint (TMJ) that simulated a parotid tumor. A 35 year-old man presented with pain in the left ear area. A CT Scan of the area showed a large, calcified mass surrounding the left condylar head, and extending into the infratemporal fossa. FNA of the mass showed birefringent crystals, most of which were rhomboid with occasional ones being needle shaped, embedded in an amorphous pink substance. Scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) of these crystals showed peaks corresponding to calcium and phosphorus. SEM/EDS is a rapid method of diagnosing calcium pyrophosphate dihydrate deposition disease (CPPD) and an alternative to more commonly used method of special staining of cell block sections coupled with polarizing microscopy. PMID:18426573

  18. 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

  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. Evolution of the calcium hydroxyapatite crystal structure under plasma deposition and subsequent reducing treatment

    NASA Astrophysics Data System (ADS)

    Shamrai, V. F.; Karpikhin, A. E.; Sirotinkin, V. P.; Kalita, V. I.; Komlev, D. I.

    2014-03-01

    The structure of hydroxyapatite plasma coatings on a titanium substrate has been investigated by the X-ray Rietveld method. The hydroxyapatite crystal structure in plasma-deposited samples is characterized by strong distortions of its main element (tetrahedral PO4 cluster) and coordination calcium polyhedra, as well as calcium deficit in the Ca2 site; however, these features do not change the main motif of the hydroxyapatite structure. The bond distortions in PO4 clusters are estimated by the Bauer method. It is shown that hydrothermal treatment leads to the almost complete recovery of the hydroxyapatite structure.

  2. High-quality colloidal photonic crystals obtained by optimizing growth parameters in a vertical deposition technique

    NASA Astrophysics Data System (ADS)

    Kuai, Su-Lan; Hu, Xing-Fang; Haché, Alain; Truong, Vo-Van

    2004-06-01

    High-quality polystyrene colloidal crystals were fabricated from aqueous solutions with a vertical deposition technique. The role of sphere size, volume fraction, relative humidity (RH), evaporation temperature and the final drying conditions on the film quality were investigated. We found that all those parameters must be taken into account in order to achieve highest quality for a given particle size. With particles of 300 nm in diameter, the optimal conditions were found to be a 0.1-0.2% volume fraction, an RH between 80% and 90%, an evaporation temperature near 60°C and a quasi-equilibrium drying process.

  3. 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.

  4. Metal-induced crystallization of amorphous Si thin films assisted by atomic layer deposition of nickel oxide layers.

    PubMed

    So, Byung-Soo; Bae, Seung-Muk; You, Yil-Hwan; Jo, DaiHui; Lee, Sun Sook; Chung, Taek-Mo; Kim, Chang Gyoun; An, Ki-Seok; Hwang, Jin-Ha

    2011-08-01

    Atomic layer deposition (ALD) of nickel oxide was applied to the nickel-induced crystallization of amorphous Si thin films. The nickel-induced crystallization was monitored as a function of annealing temperature and time using Raman spectroscopy. Since Raman spectroscopy allows for the numerical quantification of structural components, the incubation time and the crystallization rates were estimated as functions of the annealing temperature. The spatial locations of a nickel-based species, probably NiSi2, were investigated using X-ray photoelectron spectrometry. The formed NiSi2 seeds appeared to accelerate the crystallization kinetics in amorphous Si thin films deposited onto glass substrates. The ramifications of the atomic layer deposition are discussed with regard to large-panel displays, with special emphasis on the sophisticated control of the catalytic elements, especially nickel.

  5. 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

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

    NASA Astrophysics Data System (ADS)

    Klein, K. L.; Randolph, S. J.; Fowlkes, J. D.; Allard, L. F.; Meyer, H. M., III; Simpson, M. L.; Rack, P. D.

    2008-08-01

    Electron-beam-induced deposition (EBID) is a useful technique for direct-writing of three-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 work, 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 β-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.

  7. Electrospray deposition device used to precisely control the matrix crystal to improve the performance of MALDI MSI

    PubMed Central

    Li, Shilei; Zhang, Yangyang; Liu, Jian’an; Han, Juanjuan; Guan, Ming; Yang, Hui; Lin, Yu; Xiong, Shaoxiang; Zhao, Zhenwen

    2016-01-01

    MALDI MSI has been recently applied as an innovative tool for detection of molecular distribution within a specific tissue. MALDI MSI requires deposition of an organic compound, known as matrix, on the tissue of interest to assist analyte desorption and ionization, in which the matrix crystal homogeneity and size greatly influence the imaging reproducibility and spatial resolution in MALDI MSI. In this work, a homemade electrospray deposition device was developed for deposition of matrix in MALDI MSI. The device could be used to achieve 1 μm homogeneous matrix crystals in MALDI MSI analysis. Moreover, it was found, for the first time, that the electrospray deposition device could be used to precisely control the matrix crystal size, and the imaging spatial resolution was increased greatly as the matrix crystals size becoming smaller. In addition, the easily-built electrospray deposition device was durable for acid, base or organic solvent, and even could be used for deposition of nanoparticles matrix, which made it unparalleled for MALDI MSI analysis. The feasibility of the electrospray deposition device was investigated by combination with MALDI FTICR MSI to analyze the distributions of lipids in mouse brain and liver cancer tissue section. PMID:27885266

  8. Electrospray deposition device used to precisely control the matrix crystal to improve the performance of MALDI MSI.

    PubMed

    Li, Shilei; Zhang, Yangyang; Liu, Jian'an; Han, Juanjuan; Guan, Ming; Yang, Hui; Lin, Yu; Xiong, Shaoxiang; Zhao, Zhenwen

    2016-11-25

    MALDI MSI has been recently applied as an innovative tool for detection of molecular distribution within a specific tissue. MALDI MSI requires deposition of an organic compound, known as matrix, on the tissue of interest to assist analyte desorption and ionization, in which the matrix crystal homogeneity and size greatly influence the imaging reproducibility and spatial resolution in MALDI MSI. In this work, a homemade electrospray deposition device was developed for deposition of matrix in MALDI MSI. The device could be used to achieve 1 μm homogeneous matrix crystals in MALDI MSI analysis. Moreover, it was found, for the first time, that the electrospray deposition device could be used to precisely control the matrix crystal size, and the imaging spatial resolution was increased greatly as the matrix crystals size becoming smaller. In addition, the easily-built electrospray deposition device was durable for acid, base or organic solvent, and even could be used for deposition of nanoparticles matrix, which made it unparalleled for MALDI MSI analysis. The feasibility of the electrospray deposition device was investigated by combination with MALDI FTICR MSI to analyze the distributions of lipids in mouse brain and liver cancer tissue section.

  9. 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.

  10. Chemical vapor deposition of high-quality large-sized MoS2 crystals on silicon dioxide substrates

    DOE PAGES

    Chen, Jianyi; Tang, Wei; Tian, Bingbing; ...

    2016-03-31

    Large-sized MoS2 crystals can be grown on SiO2/Si substrates via a two-stage chemical vapor deposition method. The maximum size of MoS2 crystals can be up to about 305 μm. The growth method can be used to grow other transition metal dichalcogenide crystals and lateral heterojunctions. Additionally, the electron mobility of the MoS2 crystals can reach ≈30 cm2 V–1 s–1, which is comparable to those of exfoliated flakes.

  11. Tumoral calcinosis form of hydroxyapatite deposition disease in related red-bellied short-necked turtles, Emydura subglobosa.

    PubMed

    Burns, R E; Bicknese, E J; Westropp, J L; Shiraki, R; Stalis, I H

    2013-05-01

    Ten of 12 red-bellied short-necked turtles from a single clutch presented at 9 months of age with multiple white to tan nodules on their feet. Histologically, the nodules were composed of large periarticular deposits of mineralized crystalline material that extended into the joint spaces of interphalangeal joints and was surrounded by granulomatous inflammation and fibrosis. Crystallographic analysis determined the material to be apatite (calcium phosphate hydroxide) consistent with the tumoral calcinosis form of hydroxyapatite deposition disease (HADD). HADD has previously been described in aquatic turtles and rarely lizards and must be differentiated from gout in reptiles. A cause for the tumoral calcinosis lesions in these turtles could not be determined; however, based on previous reports in this species, a species-specific predilection, in conjunction with unknown environmental factors, is suspected. The use of the terms HADD, pseudogout (calcium pyrophosphate crystal deposition disease), and calcinosis circumscripta has been inconsistent, creating confusion in the literature.

  12. CW laser induced crystallization of thin amorphous silicon films deposited by EBE and PECVD

    NASA Astrophysics Data System (ADS)

    Said-Bacar, Z.; Prathap, P.; Cayron, C.; Mermet, F.; Leroy, Y.; Antoni, F.; Slaoui, A.; Fogarassy, E.

    2012-09-01

    This work presents the Continuous Wave (CW) laser crystallization of thin amorphous silicon (a-Si) films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) and by Electron Beam Evaporation (EBE) on low cost glass substrate. The films are characterized by Elastic Recoil Detection Analysis (ERDA) and by Fourier-Transform Infrared (FTIR) spectroscopy to evaluate the hydrogen content. Analysis shows that the PECVD films contain a high hydrogen concentration (˜10 at.%) while the EBE films are almost hydrogen-free. It is found that the hydrogen is in a bonding configuration with the a-Si network and in a free form, requiring a long thermal annealing for exodiffusion before the laser treatment to avoid explosive effusion. The CW laser crystallization process of the amorphous silicon films was operated in liquid phase regime. We show by Electron Backscatter Diffraction (EBSD) that polysilicon films with large grains can be obtained with EBE as well as for the PECVD amorphous silicon provided that for the latest the hydrogen content is lower than 2 at.%.

  13. Dense Deposit Disease in Korean Children: A Multicenter Clinicopathologic Study

    PubMed Central

    Park, Se Jin; Kim, Yong-Jin; Ha, Tae-Sun; Lim, Beom Jin; Jeong, Hyeon Joo; Park, Yong Hoon; Lee, Dae Yeol; Kim, Pyung Kil; Kim, Kyo Sun; Chung, Woo Yeong

    2012-01-01

    The purpose of this study was to investigate the clinical, laboratory, and pathologic characteristics of dense deposit disease (DDD) in Korean children and to determine whether these characteristics differ between Korean and American children with DDD. In 2010, we sent a structured protocol about DDD to pediatric nephrologists throughout Korea. The data collected were compared with previously published data on 14 American children with DDD. Korean children had lower 24-hr urine protein excretion and higher serum albumin levels than American children. The light microscopic findings revealed that a higher percentage of Korean children had membranoproliferative glomerulonephritis patterns (Korean, 77.8%; American, 28.6%, P = 0.036), whereas a higher percentage of American children had crescents (Korean, 0%; American, 78.6%, P < 0.001). The findings from the electron microscopy revealed that Korean children were more likely to have segmental electron dense deposits in the lamina densa of the glomerular basement membrane (Korean, 100%; American, 28.6%, P = 0.002); mesangial deposit was more frequent in American children (Korean, 66.7%; American, 100%, P = 0.047). The histological findings revealed that Korean children with DDD were more likely to show membranoproliferative glomerulonephritis patterns than American children. The degree of proteinuria and hypoalbuminemia was milder in Korean children than American children. PMID:23091320

  14. 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

  15. Chemical vapor deposition growth of large grapheme single crystal from ethanol

    NASA Astrophysics Data System (ADS)

    Chen, Xiao; Zhao, Pei; Chiashi, Shohei; Maruyama, Shigeo

    2014-03-01

    Ethanol as a precursor has proven effective in the chemical vapor deposition (CVD) synthesis of graphene on both Ni foils and Cu capsule substrates. For applications of graphene in field effect transistors or as transparent conducting electrodes, larger singe-crystal graphene without any grain boundaries shows superior electrical performance and has attracted enormous interests. Here we report a protocol to synthesize large graphene single crystals (up to 600 μm) using ethanol as precursor on commercially-available polycrystalline Cu foils. We explored the mechanism by studying the influences of different growth parameters such as pressure, flow rate and temperature. Low partial pressure and low flow rate of ethanol is essential in achieving low nucleation density over the metal surface and therefore large graphene grains can be obtained. We found that growth temperature dramatically affects the crystallinity and the growth rate of graphene grains. Moreover, this CVD growth of large graphene single crystals involves no electro-polishing or annealing treatments to the metal surface, presenting a significant simplification to the current graphene synthesis process.

  16. Retinal pigment epitheliopathy, macular telangiectasis, and intraretinal crystal deposits in HIV-positive patients receiving ritonavir.

    PubMed

    Roe, Richard H; Jumper, J Michael; Gualino, Vincent; Wender, Jon; McDonald, H Richard; Johnson, Robert N; Fu, Arthur D; Cunningham, Emmett T

    2011-03-01

    The purpose of this study was to describe the occurrence of a retinal pigment epitheliopathy associated with macular telangiectasis and intraretinal crystal deposits in three human immunodeficiency virus-positive patients receiving long-term ritonavir as part of highly active antiretroviral therapy. The patient's records were reviewed. The CD4 T-cell counts at presentation were 163 cells per microliter, 464 cells per microliter, and 349 cells per microliter, and viral loads were undetectable in all patients. None of the patients had a concurrent AIDS-defining illness. Other significant medical history included hyperlipidemia in one patient and a remote history of lymphoma and tuberculosis in a second patient. Initial visual acuity ranged from 20/32 to 20/400, with a median of 20/150. Anterior segment examination and intraocular pressures were normal in all eyes. Posterior segment examination revealed bilateral macular retinal pigment epitheliopathy with intraretinal crystalline deposits. No hemorrhage or cotton wool spots were seen consistent with human immunodeficiency virus retinopathy, and there was no evidence of previous or active cystomegalovirus retinitis. Fluorescein angiography revealed parafoveal telangiectasis with late leakage in two of the three patients. Optical coherence tomography showed thickening of the macula in three eyes and inner foveal cysts in two eyes. Autofluorescence performed on one patient revealed complete loss of normal retinal pigment epithelium autofluorescence corresponding to the area of retinal pigment epitheliopathy bilaterally. The only medicine common to all 3 patients was ritonavir, and the duration of ritonavir therapy before presentation was 19 months in one patient, 30 months in the second patient, and 5 years in the third patient. Retinal changes characterized by retinal pigment epitheliopathy, parafoveal telangiectasias, and intraretinal crystal deposits occurred in three human immunodeficiency virus-positive patients on

  17. Allelic Variants of Complement Genes Associated with Dense Deposit Disease

    PubMed Central

    Abrera-Abeleda, Maria Asuncion; Nishimura, Carla; Frees, Kathy; Jones, Michael; Maga, Tara; Katz, Louis M.; Zhang, Yuzhou

    2011-01-01

    The alternative pathway of the complement cascade plays a role in the pathogenesis of dense deposit disease (DDD). Deficiency of complement factor H and mutations in CFH associate with the development of DDD, but it is unknown whether allelic variants in other complement genes also associate with this disease. We studied patients with DDD and identified previously unreported sequence alterations in several genes in addition to allelic variants and haplotypes common to patients with DDD. We found that the likelihood of developing DDD increases with the presence of two or more risk alleles in CFH and C3. To determine the functional consequence of this finding, we measured the activity of the alternative pathway in serum samples from phenotypically normal controls genotyped for variants in CFH and C3. Alternative pathway activity was higher in the presence of variants associated with DDD. Taken together, these data confirm that DDD is a complex genetic disease and may provide targets for the development of disease-specific therapies. PMID:21784901

  18. 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

  19. Near-equilibrium chemical vapor deposition of high-quality single-crystal graphene directly on various dielectric substrates.

    PubMed

    Chen, Jianyi; Guo, Yunlong; Jiang, Lili; Xu, Zhiping; Huang, Liping; Xue, Yunzhou; Geng, Dechao; Wu, Bin; Hu, Wenping; Yu, Gui; Liu, Yunqi

    2014-03-05

    By using near-equilibrium chemical vapor deposition, it is demonstrated that high-quality single-crystal graphene can be grown on dielectric substrates. The maximum size is about 11 μm. The carrier mobility can reach about 5650 cm(2) V(-1) s(-1) , which is comparable to those of some metal-catalyzed graphene crystals, reflecting the good quality of the graphene lattice.

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

    PubMed

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

    2014-11-01

    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.

  1. 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

  2. Calcium hydroxyapatite crystal deposition with intraosseous penetration involving the posterior aspect of the cervical spine: a previously unreported cause of neck pain.

    PubMed

    Urrutia, Julio; Contreras, Oscar

    2017-05-01

    Calcific tendinitis is a frequent disorder caused by hydroxyapatite crystal deposition; however, bone erosions from calcific tendinitis are unusual. The spinal manifestation of this disease is calcific tendinitis of the longus colli muscle; this disease has never been described in the posterior aspect of the spine. We report a case of calcium hydroxyapatite crystal deposition involving the posterior cervical spine eroding the bone cortex. A 57-year-old woman presented with a 5-month history of left-sided neck pain. Radiographs showed C4-C5 interspinous calcification with lytic compromise of the posterior arch of C4. Magnetic resonance imaging confirmed a lytic lesion of the posterior arch of C4, with a soft tissue mass extending to the C4-C5 interspinous space; calcifications were observed as very low signal intensity areas on T1 and T2 sequences, surrounded by gadolinium-enhanced soft tissues. A computed tomography (CT) scan confirmed the bone erosions and the soft tissue calcifications. A CT-guided needle biopsy was performed; it showed vascularized connective tissue with inflammatory histiocytic infiltration and multinucleated giant cells; Alizarin Red stain confirmed the presence of hydroxyapatite crystals. The patient was treated with anti-inflammatories for 2 weeks. She has been asymptomatic in a 6-month follow-up; a CT scan at the last follow-up revealed reparative remodeling of bone erosions. This is the first report of calcium hydroxyapatite crystal deposition with intraosseous penetration involving the posterior aspect of the cervical spine. Considering that this unusual lesion can be misinterpreted as a tumor or infection, high suspicion is required to avoid unnecessary surgical procedures.

  3. A mechanism for crystal twinning in the growth of diamond by chemical vapour deposition.

    PubMed

    Butler, James E; Oleynik, Ivan

    2008-01-28

    A model for the formation of crystal twins in chemical vapour deposited diamond materials is presented. The twinning mechanism originates from the formation of a hydrogen-terminated four carbon atom cluster on a local {111} surface morphology, which also serves as a nucleus to the next layer of growth. Subsequent growth proceeds by reaction at the step edges with one and two carbon atom-containing species. The model also provides an explanation for the high defect concentration observed in 111 growth sectors, the formation of penetration and contact twins, and the dramatic enhancement in polycrystalline diamond growth rates and morphology changes when small amounts of nitrogen are added to the plasma-assisted growth environments.

  4. 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.

  5. Protective effects of boron and vitamin E on ethylene glycol-induced renal crystal calcium deposition in rat.

    PubMed

    Bahadoran, H; Naghii, M R; Mofid, M; Asadi, M H; Ahmadi, K; Sarveazad, A

    2016-10-01

    Kidney stone disease is a common form of renal disease. Antioxidants, such as vitamin E (Vit E) and boron, are substances that reduce the damage caused by oxidation. Adult male rats were divided into 5 groups (n=6). In group 1, rats received standard food and water for 28 days (control group); in group 2, standard rodent food and water with 0.75% ethylene glycol/d (dissolved in drinking water) (EG Group); in group 3, similar to group 2, with 3 mg of boron/d (dissolved in water) (EG+B Group); in group 4, similar to group 2, with 200 IU of vitamin E injected intraperitoneally on the first day and the 14th day, (EG+Vit E Group); in group 5, mix of groups 3 and 4, respectively (EG+B+Vit E Group). Kidney sections showed that crystals in the EG group increased significantly in comparison with the control group. Crystal calcium deposition score in groups of EG+B (160), EG+Vit E, and EG+B+Vit E showed a significant decrease compared to EG group. Measurement of the renal tubules area and renal tubular epithelial histological score showed the highest significant dilation in the EG group. Tubular dilation in the EG+B+Vit E group decreased compared to the EG+B and EG+Vit E groups. Efficient effect of boron and Vit E supplements, separately and in combination, has a complimentary effect in protection against the formation of kidney stones, probably by decreasing oxidative stress.

  6. Molecular mechanisms of crystal-related kidney inflammation and injury. Implications for cholesterol embolism, crystalline nephropathies and kidney stone disease.

    PubMed

    Mulay, Shrikant R; Evan, Andrew; Anders, Hans-Joachim

    2014-03-01

    Crystals are particles of endogenous inorganic or organic composition that can trigger kidney injury when deposited or formed inside the kidney. While decades of research have focused on the molecular mechanisms of solute supersaturation and crystal formation, the pathomechanisms of crystal-induced renal inflammation remain largely unknown. The recent discovery of the intracellular NLRP3 inflammasome as a pattern recognition platform that translates crystal uptake into innate immune activation via secretion of IL-1β and IL-18 revised the pathogenesis of gout, silicosis, asbestosis, atherosclerosis and other crystal-related disorders. As a proof of concept, the NLRP3 inflammasome was now shown to trigger inflammation and acute kidney injury (AKI) in oxalate nephropathy. It seems likely that this and potentially other innate immunity mechanisms drive crystalline nephropathies (CNs) that are associated with crystals of calcium phosphate, uric acid, cysteine, adenine, certain drugs or contrast media, and potentially of myoglobin during rhabdomyolysis and of light chains in myeloma. Here, we discuss the proven and potential mechanisms of renal inflammation and kidney injury in crystal-related kidney disorders. In addition, we list topics for further research in that field. This perspective may also provide novel therapeutic options that can help to avoid progressive tissue remodeling and chronic kidney disease in patients with kidney stone disease or other CNs.

  7. Comparison in Schemes for Simulating Depositional Growth of Ice Crystal between Theoretical and Laboratory Data

    NASA Astrophysics Data System (ADS)

    Zhai, Guoqing; Li, Xiaofan

    2015-04-01

    The Bergeron-Findeisen process has been simulated using the parameterization scheme for the depositional growth of ice crystal with the temperature-dependent theoretically predicted parameters in the past decades. Recently, Westbrook and Heymsfield (2011) calculated these parameters using the laboratory data from Takahashi and Fukuta (1988) and Takahashi et al. (1991) and found significant differences between the two parameter sets. There are two schemes that parameterize the depositional growth of ice crystal: Hsie et al. (1980), Krueger et al. (1995) and Zeng et al. (2008). In this study, we conducted three pairs of sensitivity experiments using three parameterization schemes and the two parameter sets. The pre-summer torrential rainfall event is chosen as the simulated rainfall case in this study. The analysis of root-mean-squared difference and correlation coefficient between the simulation and observation of surface rain rate shows that the experiment with the Krueger scheme and the Takahashi laboratory-derived parameters produces the best rain-rate simulation. The mean simulated rain rates are higher than the mean observational rain rate. The calculations of 5-day and model domain mean rain rates reveal that the three schemes with Takahashi laboratory-derived parameters tend to reduce the mean rain rate. The Krueger scheme together with the Takahashi laboratory-derived parameters generate the closest mean rain rate to the mean observational rain rate. The decrease in the mean rain rate caused by the Takahashi laboratory-derived parameters in the experiment with the Krueger scheme is associated with the reductions in the mean net condensation and the mean hydrometeor loss. These reductions correspond to the suppressed mean infrared radiative cooling due to the enhanced cloud ice and snow in the upper troposphere.

  8. New Approaches to the Treatment of Dense Deposit Disease

    PubMed Central

    Smith, Richard J.H.; Alexander, Jessy; Barlow, Paul N.; Botto, Marina; Cassavant, Thomas L.; Cook, H. Terence; de Córdoba, Santiago Rodriguez; Hageman, Gregory S.; Jokiranta, T. Sakari; Kimberling, William J.; Lambris, John D.; Lanning, Lynne D.; Levidiotis, Vicki; Licht, Christoph; Lutz, Hans U.; Meri, Seppo; Pickering, Matthew C.; Quigg, Richard J.; Rops, Angelique L.; Salant, David J.; Sethi, Sanjeev; Thurman, Joshua M.; Tully, Hope F.; Tully, Sean P.; van der Vlag, Johan; Walker, Patrick D.; Würzner, Reinhard; Zipfel, Peter F.

    2014-01-01

    The development of clinical treatment protocols usually relies on evidence-based guidelines that focus on randomized, controlled trials. For rare renal diseases, such stringent requirements can represent a significant challenge. Dense deposit disease (DDD; also known as membranoproliferative glomerulonephritis type II) is a prototypical rare disease. It affects only two to three people per million and leads to renal failure within 10 yr in 50% of affected children. On the basis of pathophysiology, this article presents a diagnostic and treatment algorithm for patients with DDD. Diagnostic tests should assess the alternative pathway of complement for abnormalities. Treatment options include aggressive BP control and reduction of proteinuria, and on the basis of pathophysiology, animal data, and human studies, plasma infusion or exchange, rituximab, sulodexide, and eculizumab are additional options. Criteria for treatment success should be prevention of progression as determined by maintenance or improvement in renal function. A secondary criterion should be normalization of activity levels of the alternative complement pathway as measured by C3/C3d ratios and C3NeF levels. Outcomes should be reported to a central repository that is now accessible to all clinicians. As the understanding of DDD increases, novel therapies should be integrated into existing protocols for DDD and evaluated using an open-label Bayesian study design. PMID:17675665

  9. New approaches to the treatment of dense deposit disease.

    PubMed

    Smith, Richard J H; Alexander, Jessy; Barlow, Paul N; Botto, Marina; Cassavant, Thomas L; Cook, H Terence; de Córdoba, Santiago Rodriguez; Hageman, Gregory S; Jokiranta, T Sakari; Kimberling, William J; Lambris, John D; Lanning, Lynne D; Levidiotis, Vicki; Licht, Christoph; Lutz, Hans U; Meri, Seppo; Pickering, Matthew C; Quigg, Richard J; Rops, Angelique L; Salant, David J; Sethi, Sanjeev; Thurman, Joshua M; Tully, Hope F; Tully, Sean P; van der Vlag, Johan; Walker, Patrick D; Würzner, Reinhard; Zipfel, Peter F

    2007-09-01

    The development of clinical treatment protocols usually relies on evidence-based guidelines that focus on randomized, controlled trials. For rare renal diseases, such stringent requirements can represent a significant challenge. Dense deposit disease (DDD; also known as membranoproliferative glomerulonephritis type II) is a prototypical rare disease. It affects only two to three people per million and leads to renal failure within 10 yr in 50% of affected children. On the basis of pathophysiology, this article presents a diagnostic and treatment algorithm for patients with DDD. Diagnostic tests should assess the alternative pathway of complement for abnormalities. Treatment options include aggressive BP control and reduction of proteinuria, and on the basis of pathophysiology, animal data, and human studies, plasma infusion or exchange, rituximab, sulodexide, and eculizumab are additional options. Criteria for treatment success should be prevention of progression as determined by maintenance or improvement in renal function. A secondary criterion should be normalization of activity levels of the alternative complement pathway as measured by C3/C3d ratios and C3NeF levels. Outcomes should be reported to a central repository that is now accessible to all clinicians. As the understanding of DDD increases, novel therapies should be integrated into existing protocols for DDD and evaluated using an open-label Bayesian study design.

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

    DOE PAGES

    Hemawan, Kadek W.; Hemley, Russell J.

    2015-08-03

    Here, 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, C2, and H (Balmer series) important for diamond growth were found to be more depndent on operating pressure than on microwave power. Plasma gas temperatures were calculated frommore » measurements of the C2 Swan band (d3Π → a3Π 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 CH4 + H2 plasma input gas mixture has little influence on the Hα, Hβ, and Hγ intensities and single-crystal diamond growth rates.« less

  11. 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.

  12. Morphology and crystal phase evolution of GeO 2 in liquid phase deposition process

    NASA Astrophysics Data System (ADS)

    Jing, Chengbin; Sun, Wei; Wang, Wei; Li, Yi; Chu, Junhao

    2012-01-01

    Morphology and crystal phase evolution of GeO 2 in liquid phase deposition (LPD) process is investigated. Rod-like solid phases precipitate out of solution ahead of truncated cube-like phases. SEM, XRD and TEM analyses reveal that the two sorts of solid phases are tetragonal GeO 2 and hexagonal GeO 2, respectively. The tetragonal GeO 2 phases start to experience a re-dissolving process as soon as the hexagonal phases come into being. The prior precipitation of the rod-like phase arises from a relatively low solute saturation of tetragonal GeO 2. Fast growth of a tetragonal GeO 2 phase along [111] direction leads to development of a rod-like shape. The re-dissolving phenomenon does not agree with the classic growth kinetics of crystals but is strongly favored by our calculations based on thermodynamics. The GeO 2 solutes are released in a fluctuant way by germanate ions, which promotes the occurrence of the re-dissolution phenomenon. The current researches open a door for room-temperature LPD growth of not only the hexagonal GeO 2 particles and film but also the one-dimensional tetragonal GeO 2 product.

  13. 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.

  14. Electrical conductivity and crystallization of amorphous bismuth ruthenate thin films deposited by spray pyrolysis.

    PubMed

    Ryll, Thomas; Brunner, Andreas; Ellenbroek, Stefan; Bieberle-Hutter, Anja; Rupp, Jennifer L M; Gauckler, Ludwig J

    2010-11-14

    Amorphous oxide thin films with tailored functionality will be crucial for the next generation of micro-electro-mechanical-systems (MEMS). Due to potentially favorable electronic and catalytic properties, amorphous bismuth ruthenate thin films might be applied in this regard. We report on the deposition of amorphous bismuth ruthenate thin films by spray pyrolysis, their crystallization behavior and electrical conductivity. At room temperature the 200 nm thin amorphous films exhibit a high electrical conductivity of 7.7 × 10(4) S m(-1), which was found to be slightly thermally activated (E(a) = 4.1 × 10(-3) eV). It follows that a long-range order of the RuO(6) octahedra is no precondition for the electrical conductivity of Bi(3)Ru(3)O(11). Upon heating to the temperature range between 490 °C and 580 °C the initially amorphous films crystallize rapidly. Simultaneously, a transition from a dense and continuous film to isolated Bi(3)Ru(3)O(11) particles on the substrate takes place. Solid-state agglomeration is proposed as the mechanism responsible for disintegration. The area specific resistance of Bi(3)Ru(3)O(11) particles contacted by Pt paste on gadolinia doped ceria electrolyte pellets was found to be 7 Ω cm(2) at 607 °C in air. Amorphous bismuth ruthenate thin films are proposed for application in electrochemical devices operating at low temperatures, where a high electrical conductivity is required.

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

    SciTech Connect

    Hemawan, Kadek W.; Hemley, Russell J.

    2015-08-03

    Here, 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, C2, and H (Balmer series) important for diamond growth were found to be more depndent on operating pressure than on microwave power. Plasma gas temperatures were calculated from measurements of the C2 Swan band (d3Π → a3Π 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 CH4 + H2 plasma input gas mixture has little influence on the Hα, Hβ, and Hγ intensities and single-crystal diamond growth rates.

  16. 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).

  17. 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.

  18. 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.

  19. Texture and Crystal Orientation in Ti-6Al-4V Builds Fabricated by Shaped Metal Deposition

    NASA Astrophysics Data System (ADS)

    Baufeld, Bernd; van der Biest, Omer; Dillien, Steven

    2010-08-01

    The texture and crystal orientation of Ti-6Al-4V components, manufactured by shaped metal deposition (SMD), is investigated. SMD is a novel rapid prototyping tungsten inert gas (TIG) welding technique leading to near-net-shape components. This involves sequential layer by layer deposition with repeated partial melting and heat treatment, which results in epitaxial growth of large elongated prior β grains. This leads to a directionally solidified texture, where the prior β grains exhibit only a small misorientation with each other. The β grains grow in left< { 100} rightrangle direction with a second left< { 100} rightrangle direction perpendicular to the wall surface. During cooling, the α phase transformation follows the Burgers orientation relationship leading to a Widmanstätten structure, with orientation relations between most of the α lamellae and also of the residual β phase. The directionally solidification and the transformation into the α phase following the Burgers relationship results in a texture, where the hcp pole figures look similar to bcc pole figures.

  20. Application of a single crystal chemical vapor deposition diamond detector for deuteron plasma neutron measurement

    NASA Astrophysics Data System (ADS)

    Xie, Xufei; Yuan, Xi; Zhang, Xing; Chen, Zhongjing; Peng, Xingyu; Du, Tengfei; Li, Tao; Hu, Zhimeng; Cui, Zhiqiang; Chen, Jinxiang; Li, Xiangqing; Zhang, Guohui; Fan, Tieshuan; Yuan, Guoliang; Yang, Jinwei; Yang, Qingwei

    2014-10-01

    A single crystal chemical vapor deposition (scCVD) diamond detector has been characterized and employed for the neutron measurement at the HL-2A tokamak device. The scCVD diamond detector has been deposited with 5 μm of lithium fluoride (LiF) layer to enhance the sensitivity to thermal neutrons. Time stability of the detector has been studied with α-source and good performance has been found for more than 12 h. Neutron irradiations have been performed in four quasi-monoenergetic neutron fields in the energy range from 2.50 MeV to 16.03 MeV. The measured response function of the scCVD diamond detector to 14.13 MeV neutrons shows a narrow 12C (n, α)9Be reaction peak which is well isolated from other structures by about 1 MeV in energy, indicating the great potential as a fast neutron spectrometer. Neutron measurement of deuterium plasma discharge was established at the HL-2A tokamak device, and good consistence has been revealed among this detector signal and other related signals.

  1. Hollow hematite single crystals deposited with ultra-thin Al2O3 by atom layer deposition for improved photoelectrochemical performance.

    PubMed

    Jiao, Wei; Wu, Jingrui; Cui, Siwen; Wei, Ning; Rahman, Zia Ur; Yu, Meiyan; Chen, Shougang; Zhou, Yangtao; Wang, Daoai

    2017-08-15

    Hematite (α-Fe2O3) is a red material with a band gap of about 2.0 eV, which indicates that it can absorb more solar light. It is a promising photocatalyst applied in many fields. In this paper, α-Fe2O3 single crystal hollow hexagonal bipyramids were synthesized by a simple one-pot hydrothermal method. The morphology and structure of the prepared α-Fe2O3 hollow hexagonal bipyramids were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The hollow single crystals show a good light absorption and performance in photodegradation of methylene blue (MB). Due to the strategy of depositing ultra-thin layers of Al2O3 by atomic layer deposition (ALD), the photoelectrochemical (PEC) performance of α-Fe2O3 under the simulated solar light irradiation is also improved.

  2. Control of crystalline volume and nano crystal grain size in nanocrystalline silicon thin film deposited by PECVD

    NASA Astrophysics Data System (ADS)

    Bui, Thanh Tung; Chien Dang, Mau

    2014-11-01

    Application of the radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) technique was studied to fabricate amorphous and nanocrystalline silicon (a-Si and nc-Si) thin films for photovoltaic devices at substrate temperature of 200 °C. Amorphous-crystalline transition of silicon thin films in working conditions of PECVD system was shown as a function of deposition parameters, i.e., dilution ratio of silane (SiH4) in hydrogen, total gas pressure during deposition and RF excitation power density. The crystalline volume as well as grain size of nanocrystalline silicon films could be successfully controlled by tuning those deposition parameters. Micro Raman scattering spectroscopy and spectroscopic ellipsometry (SE) methods were used to characterize the structure and crystallization of the deposited silicon thin films. We could make nc-Si thin films with various crystalline volumes. Nc-Si grain size was also controlled and was in the range of 3-5 nm.

  3. [Non-amyloidotic glomerular disease caused by light-chain deposits: a case report].

    PubMed

    Cantillo, Jorge de Jesús; López, Rocío del Pilar; Andrade, Rafael Enrique

    2009-12-01

    The nephropathy of monoclonal gammopathies is principally caused by light chain deposits of fragmented immunoglobins. Paraprotein-related renal diseases are associated with such deposits of intact (heavy chain) or fragmentary (light chain) immunoglobins. A condition of pathological light chain deposits is rare and characterized by deposits of fragments of monoclonal immunoglobulins in many organs. Renal deposits occur primarily in glomeruli and tubular basement membranes. This disease is frequently associated with lymphoproliferative disorders. The majority of cases are caused by deposits of kappa light chains. Whereas this disease is most frequently associated with hematologic malignancies, occasionally a case occurs without detectable hematological pathologies; these cases are called idiopathic or primary. They usually manifest themselves as severe renal insufficiencies with nephrotic-range proteinuria. No treatment regime has been clearly established and the prognosis is poor. Herein, the clinical and histological characteristics are described regarding the first case in Colombia of light chain deposit disease without symptoms of malignancy.

  4. Definition and Reliability Assessment of Elementary Ultrasonographic Findings in Calcium Pyrophosphate Deposition Disease: A Study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force.

    PubMed

    Filippou, Georgios; Scirè, Carlo A; Damjanov, Nemanja; Adinolfi, Antonella; Carrara, Greta; Picerno, Valentina; Toscano, Carmela; Bruyn, George A; D'Agostino, Maria Antonietta; Delle Sedie, Andrea; Filippucci, Emilio; Gutierrez, Marwin; Micu, Mihaela; Möller, Ingrid; Naredo, Esperanza; Pineda, Carlos; Porta, Francesco; Schmidt, Wolfgang A; Terslev, Lene; Vlad, Violeta; Zufferey, Pascal; Iagnocco, Annamaria

    2017-03-01

    To define the ultrasonographic characteristics of calcium pyrophosphate crystal (CPP) deposits in joints and periarticular tissues and to evaluate the intra- and interobserver reliability of expert ultrasonographers in the assessment of CPP deposition disease (CPPD) according to the new definitions. After a systematic literature review, a Delphi survey was circulated among a group of expert ultrasonographers, who were members of the CPPD Ultrasound (US) Outcome Measures in Rheumatology (OMERACT) subtask force, to obtain definitions of the US characteristics of CPPD at the level of fibrocartilage (FC), hyaline cartilage (HC), tendon, and synovial fluid (SF). Subsequently, the reliability of US in assessing CPPD at knee and wrist levels according to the agreed definitions was tested in static images and in patients with CPPD. Cohen's κ was used for statistical analysis. HC and FC of the knee yielded the highest interobserver κ values among all the structures examined, in both the Web-based (0.73 for HC and 0.58 for FC) and patient-based exercises (0.55 for the HC and 0.64 for the FC). Kappa values for the other structures were lower, ranging from 0.28 in tendons to 0.50 in SF in the static exercise and from 0.09 (proximal patellar tendon) to 0.27 (triangular FC of the wrist) in the patient-based exercise. The new OMERACT definitions for the US identification of CPPD proved to be reliable at the level of the HC and FC of the knee. Further studies are needed to better define the US characteristics of CPPD and optimize the scanning technique in other anatomical sites.

  5. Ionic liquid-assisted growth of DBTTF-TCNQ complex organic crystals by vacuum co-deposition

    NASA Astrophysics Data System (ADS)

    Kuroishi, Kohei; Maruyama, Shingo; Ohashi, Noboru; Watanabe, Mio; Naito, Kenta; Matsumoto, Yuji

    2016-11-01

    High-crystalline DBTTF-TCNQ charge-transfer complex crystals with larger grains visible even by an optical microscope have been successfully grown, assisted by ionic liquid (IL) in vacuum co-deposition. Although the charge transfer reaction between the DBTTF and TCNQ molecules was ready to occur to form the complex regardless of the presence or absence of the IL even at room temperature, the subsequent crystal growth of the DBTTF-TCNQ complexes was enhanced by the IL, especially much more at temperatures higher than room temperature, leading to a significant improvement in the crystallinity of the complexes. The crystal growth mechanism of the DBTTF-TCNQ complexes in the IL was discussed based on the results of in situ optical microscope observation during the deposition of the DBTTF and TCNQ molecules into the IL.

  6. 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.

  7. Development of compact CW-IR laser deposition system for high-throughput growth of organic single crystals.

    PubMed

    Takeyama, Yoko; Maruyama, Shingo; Matsumoto, Yuji

    2011-10-01

    We developed a compact continuous-wave infrared (CW-IR) laser deposition system for the high-throughput growth of organic single crystals. In this system, two CW-IR lasers are used for the sample heating and thermal evaporation of materials. The CW-IR laser heating is simple and allows good control of the deposition rate and growth temperature, in response to the on/off laser switching. Six samples can be loaded simultaneously in a chamber, which allows one-by-one sequential deposition for high-throughput experiments, without breaking the vacuum. Using this setup, we studied the effect of ionic liquids on the growth of C60 crystals in vacuum.

  8. Prevention of renal crystal deposition by an extract of Ammi visnaga L. and its constituents khellin and visnagin in hyperoxaluric rats.

    PubMed

    Vanachayangkul, P; Chow, N; Khan, S R; Butterweck, Veronika

    2011-06-01

    In Egypt, teas prepared from the fruits of Ammi visnaga L. (syn. "Khella") are traditionally used by patients with urolithiasis. The aim of this study was to evaluate whether oral administration of an aqueous extract prepared from the fruits of A. visnaga as well as two major constituents khellin and visnagin could prevent crystal deposition in stone-forming rats. Hyperoxaluria was induced in male Sprague-Dawley rats by giving 0.75% ethylene glycol and 1% ammonium chloride via the drinking water. The Khella extract (KE; 125, 250 or 500 mg/kg) was orally administered for 14 days. The histopathological examination of the kidneys revealed that KE significantly reduced the incidence of calcium oxalate (CaOx) crystal deposition. In addition, KE significantly increased urinary excretion of citrate along with a decrease of oxalate excretion. Comparable to the extract, khellin and visnagin significantly reduced the incidence of CaOx deposition in the kidneys. However, both compounds did not affect urinary citrate or oxalate excretion indicating a mechanism of action that differs from that of the extract. For KE, a reasonably good correlation was observed between the incidence of crystal deposition, the increase in citrate excretion and urine pH suggesting a mechanisms that may interfere with citrate reabsorption. In conclusion, our data suggest that KE and its compounds, khellin and visnagin, may be beneficial in the management of kidney stone disease caused by hyperoxaluria but that it is likely that different mechanism of action are involved in mediating these effects.

  9. CT Imaging for Evaluation of Calcium Crystal Deposition in the Knee: Initial Experience from The Multicenter Osteoarthritis (MOST) Study

    PubMed Central

    Misra, Devyani; Guermazi, Ali; Sieren, Jered P.; Lynch, John; Torner, James; Neogi, Tuhina; Felson, David T.

    2014-01-01

    Objective Role of intra-articular calcium crystals in osteoarthritis (OA) is unclear. Imaging modalities used to date for its evaluation have limitations in their ability to fully characterize intra-articular crystal deposition. Since Computed Tomography (CT) imaging provides excellent visualization of bones and calcified tissue, in this pilot project we evaluated the utility of CT scan in describing intra-articular calcium crystal deposition in the knees. Method We included 12 subjects with and 4 subjects without radiographic chondrocalcinosis in the most recent visit from the Multicenter Osteoarthritis (MOST) study, which is a longitudinal cohort of community-dwelling older adults with or at risk for knee OA. All subjects underwent CT scans of bilateral knees. Each knee was divided into 25 subregions and each subregion was read for presence of calcium crystals by a musculoskeletal radiologist. To assess reliability, readings were repeated 4 weeks later. Results CT images permitted visualization of 25 subregions with calcification within and around the tibio-femoral and patello-femoral joints in all 24 knees with radiographic chondrocalcinosis. Intra-articular calcification was seen universally including meniscal cartilage (most common site involved in 21/24 knees), hyaline cartilage, cruciate ligaments, medial collateral ligament and joint capsule. Readings showed good agreement for specific tissues involved with calcium deposition (kappa: 0.70, 95% CI 0.62–0.80). Conclusion We found CT scan to be a useful and reliable tool for describing calcium crystal deposition in the knee and therefore potentially for studying role of calcium crystals in OA. We also confirmed that “chondrocalcinosis” is a misnomer because calcification is present ubiquitously. PMID:25451303

  10. On the solid phase crystallization of In2O3:H transparent conductive oxide films prepared by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Macco, Bart; Verheijen, Marcel A.; Black, Lachlan E.; Barcones, Beatriz; Melskens, J.; Kessels, Wilhelmus M. M.

    2016-08-01

    Hydrogen-doped indium oxide (In2O3:H) has emerged as a highly transparent and conductive oxide, finding its application in a multitude of optoelectronic devices. Recently, we have reported on an atomic layer deposition (ALD) process to prepare high quality In2O3:H. This process consists of ALD of In2O3:H films at 100 °C, followed by a solid phase crystallization step at 150-200 °C. In this work, we report on a detailed electron microscopy study of this crystallization process which reveals new insights into the crucial aspects for achieving the large grain size and associated excellent properties of the material. The key finding is that the best optoelectronic properties are obtained by preparing the films at the lowest possible temperature prior to post-deposition annealing. Electron microscopy imaging shows that such films are mostly amorphous, but feature a very low density of embedded crystallites. Upon post-deposition annealing, crystallization proceeds merely from isotropic crystal grain growth of these embedded crystallites rather than by the formation of additional crystallites. The relatively high hydrogen content of 4.2 at. % in these films is thought to cause the absence of additional nucleation, thereby rendering the final grain size and optoelectronic properties solely dependent on the density of embedded crystallites. The temperature-dependent grain growth rate has been determined, from which an activation energy of (1.39 ± 0.04) eV has been extracted. Finally, on the basis of the observed crystallization mechanism, a simple model to fully describe the crystallization process has been developed. This model has been validated with a numerical implementation thereof, which accurately predicts the observed temperature-dependent crystallization behaviour.

  11. COMORBIDITIES IN PATIENTS WITH CRYSTAL DISEASES AND HYPERURICEMIA

    PubMed Central

    Sattui, Sebastian E; Singh, Jasvinder A

    2014-01-01

    Summary Crystal arthropathies are among the most common causes of painful inflammatory arthritis. Gout, the most common example, has been associated with cardiovascular and renal disease. In the last years, evidence on these associations and those involving other comorbidities, such as the metabolic syndrome, have emerged and established the importance of asymptomatic hyperuricemia. This review article presents an update on evidence, both experimental and clinical, describing associations between hyperuricemia, gout, and several comorbidities. Causality on calcium pyrophosphate arthropathy and associated comorbidities is also briefly reviewed. PMID:24703346

  12. In situ Spectroscopy of Solid-State Chemical Reaction in PbBr2-Deposited CsBr Crystals

    NASA Astrophysics Data System (ADS)

    Kondo, Shin-ichi; Matsunaga, Toshihiro; Saito, Tadaaki; Asada, Hiroshi

    2003-09-01

    It is possible to measure the fundamental optical absorption spectra of CsPbBr3 and Cs4PbBr6, whose stability is predicted by the study of phase diagram in the binary system CsBr-PbBr2, by means of in situ optical absorption and reflection spectroscopy of thermally induced solid-state chemical reaction in PbBr2-deposited CsBr crystals. On heavy annealing of the crystals, the Pb2+ ions are uniformly dispersed in the crystal matrix. The present experiment provides a novel method for measuring intrinsic optical absorption of ternary metal halides and also for in situ monitoring of doping metal halide crystal with impurities (metal ions or halogen ions).

  13. Notch1 hallmarks fibrillary depositions in sporadic Alzheimer's disease.

    PubMed

    Brai, Emanuele; Alina Raio, Noemi; Alberi, Lavinia

    2016-07-01

    Notch1 signaling is a cellular cascade with a fundamental role from brain development to adult brain function. Reduction in Notch1 affects synaptic plasticity, memory and olfaction. On the other hand, Notch1 overactivation after brain injury is detrimental for neuronal survival. Some familial Alzheimer's disease (FAD) mutations in Presenilins can affect Notch1 processing/activation. Others report that Notch1 is overexpressed in sporadic Alzheimer's disease (AD). These works indicate that imbalances in Notch1 may be implicated in AD pathophysiology. In this study, we addressed whether Notch1 alteration can be considered a hallmark of AD. Immunohistochemical analysis of Notch1 on cortical and hippocampal tissue from post-mortem patients indicates an accumulation of Notch1 in plaque-like structures in the brain parenchyma of subjects with sporadic AD. Further analysis shows that displaced Notch1 is associated with fibrillary tangles/plaques. Biochemical validation confirms an accumulation of Notch1 in cytosolic brain fractions. This increase in protein is not accompanied with a raise in the Notch1 targets Hes1 and Hey1. Examination of the cerebrospinal fluid (CSF) indicates that the full length and truncations of the Notch1 protein are reduced in AD patients hinting at an accumulation in the brain parenchyma. Our research indicates that Notch1 is significantly displaced and accumulated in fibrillary structures in the susceptible hippocampal and cortical regions of sporadic AD patients. The dominant deposition of Notch1 in the brain parenchyma and its general signal reduction in neurons is consistent in all the AD patients analyzed and suggests that Notch1 may potentially be considered a novel hallmark of AD.

  14. Ultrasonography shows disappearance of monosodium urate crystal deposition on hyaline cartilage after sustained normouricemia is achieved.

    PubMed

    Thiele, Ralf G; Schlesinger, Naomi

    2010-02-01

    This study aimed at determining whether lowering serum urate (SU) to less than 6 mg/dl in patients with gout affects ultrasonographic findings. Seven joints in five patients with monosodium urate (MSU) crystal proven gout and hyperuricemia were examined over time with serial ultrasonography. Four of the five patients were treated with urate lowering drugs (ULDs) (allopurinol, n = 3; probenecid, n = 1). One patient was treated with colchicine alone. Attention was given to changes in a hyperechoic, irregular coating of the hyaline cartilage in the examined joints (double contour sign or "urate icing"). This coating was considered to represent precipitate of MSU crystals. Index joints included metacarpophalangeal (MCP) joints (n = 2), knee joints (n = 3), and first metatarsophalangeal (MTP) joints (n = 2). The interval between baseline and follow-up images ranged from 7 to 18 months. Serial SU levels were obtained during the follow-up period. During the follow-up period, three patients treated with ULD (allopurinol, n = 2; probenecid, n = 1) achieved a SU level of <6 mg/dl. In two patients, SU levels remained above 6 mg/dl (treated with allopurinol, n = 1; treated with colchicine, n = 1). At baseline, the double contour sign was seen in all patients. In those patients who achieved SU levels of <6 ml/dl, this sign had disappeared at follow-up. Disappearance of the double contour sign was seen in two knee joints, two first MTP joints, and one MCP joint. In contrast, disappearance of the double contour sign was not seen in patients who maintained a SU level > or =7 mg/dl. In one patient treated with allopurinol, SU levels improved from 13 to 7 mg/dl during the follow-up period. Decrease, but not resolution of the hyperechoic coating was seen in this patient. In the patient treated with colchicine alone, SU levels remained >8 mg/dl, and no sonographic change was observed. In our patients, sonographic signs of deposition of MSU crystals on the surface of hyaline cartilage

  15. Optical properties of electrochemically deposited ZnO thin films on colloidal crystal film of SiO2 microspheres.

    PubMed

    Oh, Yong Taeg; Choi, Bum Ho; Shin, Dong Chan

    2012-02-01

    The optical properties of electrochemically deposited ZnO thin films on colloidal crystal film of SiO2 microspheres structures were studied. Colloidal crystal film of SiO2 microspheres were self-assembled by evaporation using SiO2 in solution at a constant 0.1 wt%. ZnO in thin films was then electrochemically deposited on to colloidal crystal film of SiO2 microspheres. During electrochemical deposition, the content of Zn(NO3)2 x 6H2O in solution was 5 wt%, and the process's conditions were varied between of 2-4 V and 30-120 s at room temperature, with subsequent heat-treatment between 200 and 400 degrees C. A smooth surface and uniform thickness of 1.8 microm were obtained at 3 V for 90 s. The highest PL peak intensity was obtained in the ZnO thin film heat-treated at 400 degrees C. The double layered ZnO/SiO2 colloidal crystals showed clearly better emission properties than the SiO2/ZnO and ZnO structures.

  16. Crystal chemistry of pyrochlore from the Mesozoic Panda Hill carbonatite deposit, western Tanzania

    NASA Astrophysics Data System (ADS)

    Boniface, Nelson

    2017-02-01

    The Mesozoic Panda Hill carbonatite deposit in western Tanzania hosts pyrochlore, an ore and source of niobium. This study was conducted to establish the contents of radioactive elements (uranium and thorium) in pyrochlore along with the concentration of niobium in the ore. The pyrochlore is mainly hosted in sövite and is structurally controlled by NW-SE (SW dipping) or NE-SW (NW dipping) magmatic flow bands with dip angles of between 60° and 90°. Higher concentrations of pyrochlore are associated with magnetite, apatite and/or phlogopite rich flow bands. Electron microprobe analyses on single crystals of pyrochlore yield very low UO2 concentrations that range between 0 and 0.09 wt% (equivalent to 0 atoms per formula unit: a.p.f.u.) and ThO2 between 0.55 and 1.05 wt% (equivalent to 0.1 a.p.f.u.). The analyses reveal high concentrations of Nb2O5 (ranging between 57.13 and 65.50 wt%, equivalent to a.p.f.u. ranging between 1.33 and 1.43) and therefore the Panda Hill Nb-oxide is classified as pyrochlore sensu stricto. These data point to a non radioactive pyrochlore and a deposit rich in Nb at Panda Hill. The Panda Hill pyrochlore has low concentrations of REEs as displayed by La2O3 that range between 0.10 and 0.49 wt% (equivalent to a.p.f.u. ranging between 0 and 0.01) and Ce2O3 ranging between 0.86 and 1.80 wt% (equivalent to a.p.f.u. ranging between 0.02 and 0.03), Pr2O3 concentrations range between 0 and 0.23 wt% (equivalent to 0 a.p.f.u.), and Y2O3 is 0 wt% (equivalent to 0 a.p.f.u.). The abundance of the REEs in pyroclore at the Panda Hill Carbonatite deposit is of no economic significance.

  17. Highly organized smectic-like packing in vapor-deposited glasses of a liquid crystal

    DOE PAGES

    Gujral, Ankit; Gomez, Jaritza; Jiang, Jing; ...

    2016-12-26

    Glasses of a model smectic liquid crystal-forming molecule, itraconazole, were prepared by vapor deposition onto substrates with temperatures ranging from Tsubstrate = 0.78Tg to 1.02Tg, where Tg (=330 K) is the glass transition temperature. The films were characterized using X-ray scattering techniques. For Tsubstrate near and below Tg, glasses with layered smectic-like structures can be prepared and the layer spacing can be tuned by 16% through the choice of Tsubstrate. Remarkably, glasses prepared with Tsubstrate values above Tg exhibit levels of structural organization much higher than that of a thermally annealed film. These results are explained by a mechanism basedmore » upon a preferred molecular orientation and enhanced molecular motion at the free surface, indicating that molecular organization in the glass is independent of the anchoring preferred at the substrate. Furthermore, these results suggest new strategies for optimizing molecular packing within active layers of organic electronic and optoelectronic devices.« less

  18. Highly organized smectic-like packing in vapor-deposited glasses of a liquid crystal

    SciTech Connect

    Gujral, Ankit; Gomez, Jaritza; Jiang, Jing; Huang, Chengbin; O’Hara, Kathryn A.; Toney, Michael F.; Chabinyc, Michael L.; Yu, Lian; Ediger, M. D.

    2016-12-26

    Glasses of a model smectic liquid crystal-forming molecule, itraconazole, were prepared by vapor deposition onto substrates with temperatures ranging from Tsubstrate = 0.78Tg to 1.02Tg, where Tg (=330 K) is the glass transition temperature. The films were characterized using X-ray scattering techniques. For Tsubstrate near and below Tg, glasses with layered smectic-like structures can be prepared and the layer spacing can be tuned by 16% through the choice of Tsubstrate. Remarkably, glasses prepared with Tsubstrate values above Tg exhibit levels of structural organization much higher than that of a thermally annealed film. These results are explained by a mechanism based upon a preferred molecular orientation and enhanced molecular motion at the free surface, indicating that molecular organization in the glass is independent of the anchoring preferred at the substrate. Furthermore, these results suggest new strategies for optimizing molecular packing within active layers of organic electronic and optoelectronic devices.

  19. Crystal Growth and Dissolution of Methylammonium Lead Iodide Perovskite in Sequential Deposition: Correlation between Morphology Evolution and Photovoltaic Performance.

    PubMed

    Hsieh, Tsung-Yu; Huang, Chi-Kai; Su, Tzu-Sen; Hong, Cheng-You; Wei, Tzu-Chien

    2017-03-15

    Crystal morphology and structure are important for improving the organic-inorganic lead halide perovskite semiconductor property in optoelectronic, electronic, and photovoltaic devices. In particular, crystal growth and dissolution are two major phenomena in determining the morphology of methylammonium lead iodide perovskite in the sequential deposition method for fabricating a perovskite solar cell. In this report, the effect of immersion time in the second step, i.e., methlyammonium iodide immersion in the morphological, structural, optical, and photovoltaic evolution, is extensively investigated. Supported by experimental evidence, a five-staged, time-dependent evolution of the morphology of methylammonium lead iodide perovskite crystals is established and is well connected to the photovoltaic performance. This result is beneficial for engineering optimal time for methylammonium iodide immersion and converging the solar cell performance in the sequential deposition route. Meanwhile, our result suggests that large, well-faceted methylammonium lead iodide perovskite single crystal may be incubated by solution process. This offers a low cost route for synthesizing perovskite single crystal.

  20. Deposits from Creams Containing 20% (w/w) Urea and Suppression of Crystallization (Part 1): Rate of Crystallization from Cream Containing 20% (w/w) Urea and Evaluation of the Properties of the Deposit.

    PubMed

    Goto, Norio; Morita, Yutaka; Terada, Katsuhide

    2016-01-01

    Two creams containing 20% (w/w) urea and various emulsifiers, a nonionic surfactant (NS) and lecithin (LEC), were prepared, and the rate of crystallization following application of the cream and differences in the properties of the deposits were investigated. Post-application crystallization was slower with the LEC formulation. Differences in the crystals obtained from the two formulations and from a 20% aqueous solution of urea were evaluated by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), powder X-ray-DSC (PXRD-DSC) and Fourier transform infrared spectrophotometry (FT-IR). PXRD and PXRD-DSC measurements showed that the diffraction patterns of both formulations differed from that of urea. The NS formulation provided diffraction peaks for urea and a urea composite, whereas only the urea composite was evident in the LEC formulation. DSC scans of urea showed an endotherm at around 134°C, whereas the deposits from both formulations provided an endotherm 23-25°C below that of urea; the NS formulation also showed a peak at around 140°C. These results indicate a tendency for urea crystallization in the NS formulation. FT-IR measurements showed that both deposits have a urea-based structure. The effects of the LEC formulation components on the physical properties of urea were investigated by PXRD and showed that all diffraction peaks were evenly weakened, suggesting that urea tends to be amorphous and that the formulation impacts post-application urea crystallization. Consequently, the amorphous state of urea can be maintained post-application by optimizing the formulation, thereby increasing the clinical efficacy of the cream.

  1. Study of CdS epitaxial films chemically deposited from aqueous solutions on InP single crystals

    SciTech Connect

    Froment, M.; Bernard, M.C.; Cortes, R.; Mokili, B.; Lincot, D.

    1995-08-01

    Epitaxial growth of cadmium sulfide on InP single crystals is achieved by chemical bath deposition (CBD) in ammonia solutions at near room temperature. A better understanding of the correlations between the deposition parameters (temperature, bath composition) and the epitaxial quality is obtained by using electron diffraction and transmission techniques, x-ray diffraction, in combination with Raman spectroscopy. They are supplemented by electrochemical impedance and photocurrent experiments which give information on energetic structures between InP and CBD-CdS. Direct relations between the substrate properties and the growth habits of the CdS film (hexagonal vs. cubic, epitaxial vs. polycrystalline) are found.

  2. Anion Dependent Potential Pre-Cycling Effects on Lithium Deposition/Dissolution Reaction Studied by Electrochemical Quartz Crystal Microbalance.

    PubMed

    Smaran, Kumar Sai; Shibata, Sae; Omachi, Asami; Ohama, Ayano; Tomizawa, Eika; Kondo, Toshihiro

    2017-10-05

    The electrochemical quartz crystal microbalance technique was employed to study the initial stage of the electrodeposition and dissolution of lithium utilizing three kinds of electrolyte solutions such as LiPF6, LiTFSI, or LiFSI in tetraglyme. The native-SEI (solid electrolyte interphase) formed by potential pre-scan before the lithium deposition/dissolution in all three solutions. Simultaneous additional SEI (add-SEI) deposition and its dissolution with lithium deposition and dissolution, respectively, were observed in LiPF6 and LiTFSI. Conversely, the add-SEI dissolution with lithium deposition and its deposition with lithium dissolution were observed in LiFSI. With the pre-SEI, only lithium deposition/dissolution were significantly observed in LiTFSI and LiFSI. Based on the potential dependences of the mass and resistance changes, the anion dependent effects of such a pre-SEI layer presence/absence on the lithium deposition/dissolution processes were discussed.

  3. 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.

  4. Causes of alternative pathway dysregulation in dense deposit disease.

    PubMed

    Zhang, Yuzhou; Meyer, Nicole C; Wang, Kai; Nishimura, Carla; Frees, Kathy; Jones, Michael; Katz, Louis M; Sethi, Sanjeev; Smith, Richard J H

    2012-02-01

    This study was designed to investigate the causes of alternative pathway dysregulation in a cohort of patients with dense deposit disease (DDD). Thirty-two patients with biopsy-proven DDD underwent screening for C3 nephritic factors (C3Nefs), factor H autoantibodies (FHAAs), factor B autoantibodies (FBAAs), and genetic variants in CFH. C3Nefs were detected by: ELISA, C3 convertase surface assay (C3CSA), C3CSA with properdin (C3CSAP), two-dimensional immunoelectrophoresis (2DIEP), and immunofixation electrophoresis (IFE). FHAAs and FBAAs were detected by ELISA, and CFH variants were identified by Sanger sequencing. Twenty-five patients (78%) were positive for C3Nefs. Three C3Nef-positive patients were also positive for FBAAs and one of these patients additionally carried two novel missense variants in CFH. Of the seven C3Nef-negative patients, one patient was positive for FHAAs and two patients carried CFH variants that may be causally related to their DDD phenotype. C3CASP was the most sensitive C3Nef-detection assay. C3CASP and IFE are complementary because C3CSAP measures the stabilizing properties of C3Nefs, whereas IFE measures their expected consequence-breakdown of C3b. A test panel that includes C3CSAP, IFE, FHAAs, FBAAs, and genetic testing for CFH variants will identify a probable cause for alternative pathway dysregulation in approximately 90% of DDD patients. Dysregulation is most frequently due to C3Nefs, although some patients test positive for FHAAs, FBAAs, and CFH mutations. Defining the pathophysiology of DDD should facilitate the development of mechanism-directed therapies.

  5. Synthesis of uniformly dispersed anatase nanoparticles inside mesoporous silica thin films via controlled breakup and crystallization of amorphous TiO2 deposited using atomic layer deposition.

    PubMed

    Sree, Sreeprasanth Pulinthanathu; Dendooven, Jolien; Masschaele, Kasper; Hamed, Heidari M; Deng, Shaoren; Bals, Sara; Detavernier, Christophe; Martens, Johan A

    2013-06-07

    Amorphous titanium dioxide was introduced into the pores of mesoporous silica thin films with 75% porosity and 12 nm average pore diameter via Atomic Layer Deposition (ALD) using alternating pulses of tetrakis(dimethylamino)titanium and water. Calcination provoked fragmentation of the deposited amorphous TiO2 phase and its crystallization into anatase nanoparticles inside the nanoporous film. The narrow particle size distribution of 4 ± 2 nm and the uniform dispersion of the particles over the mesoporous silica support were uniquely revealed using electron tomography. These anatase nanoparticle bearing films showed photocatalytic activity in methylene blue degradation. This new synthesis procedure of the anatase nanophase in mesoporous silica films using ALD is a convenient fabrication method of photocatalytic coatings amenable to application on very small as well as very large surfaces.

  6. Synthesis of uniformly dispersed anatase nanoparticles inside mesoporous silica thin films via controlled breakup and crystallization of amorphous TiO2 deposited using atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Sree, Sreeprasanth Pulinthanathu; Dendooven, Jolien; Masschaele, Kasper; Hamed, Heidari M.; Deng, Shaoren; Bals, Sara; Detavernier, Christophe; Martens, Johan A.

    2013-05-01

    Amorphous titanium dioxide was introduced into the pores of mesoporous silica thin films with 75% porosity and 12 nm average pore diameter via Atomic Layer Deposition (ALD) using alternating pulses of tetrakis(dimethylamino)titanium and water. Calcination provoked fragmentation of the deposited amorphous TiO2 phase and its crystallization into anatase nanoparticles inside the nanoporous film. The narrow particle size distribution of 4 +/- 2 nm and the uniform dispersion of the particles over the mesoporous silica support were uniquely revealed using electron tomography. These anatase nanoparticle bearing films showed photocatalytic activity in methylene blue degradation. This new synthesis procedure of the anatase nanophase in mesoporous silica films using ALD is a convenient fabrication method of photocatalytic coatings amenable to application on very small as well as very large surfaces.

  7. Limitation of apoptotic changes and crystal deposition by Tutukon following hyperoxaluria-induced tubular cell injury in rat model.

    PubMed

    Sahin, Cahit; Sarikaya, Sukran; Basak, Kayhan; Cetinel, Cihangir Ali; Narter, Fehmi; Eryildirim, Bilal; Saglam, Erkin; Sarica, Kemal

    2015-08-01

    This study aimed at evaluating the protective effects of a herbal medication (Tutukon) on the hyperoxaluria induced apoptotic changes and crystal deposition in renal tubular epithelium in rat model. 60 male wistar rats were divided into three different groups (each group n: 20). In Group I severe hyperoxaluria was induced by ethylene glycol (EG) (0.75%) administration for 28 days. In Group II, in addition to hyperoxaluria induction, animals were treated with Tutukon for 28 days. Group III animals constituted the controls without any specific medication and/or intervention. While the presence and degree of crystal deposition in the tubular lumen were examined histopathologically under light microscopy, tubular apoptotic changes were evaluated using immunohistochemical staining for cysteine-aspartic acid protease-3 (Caspase-3) and tumor necrosis factor alpha (TNF-α) positivity on days 14 and 28, respectively. Evaluation of apoptotic changes by Caspase-3 positivity showed that while the majority of animals undergoing EG only showed evident apoptotic changes (n: 9), Tutukon application demonstrated a significant limitation with limited or no apoptosis (n: 7) in these animals. Similar data were noted for TNF alpha expression; while apoptotic changes were evident in 8 (80%) in Group I animals, limited changes were noted in Tutukon Group (n: 2). Regarding crystal deposition despite evident changes in Group I (9 animals), like apoptotic alterations, it was again significantly limited in animals receiving Tutukon (4 animals). Renal tubular crystal deposition and apoptotic changes induced by hyperoxaluria play a role in the pathogenesis of urolithiasis and the limitation of these changes might be instituted by Tutukon as a result of its antioxidant and antiinflammatory effects.

  8. Synthesis of Large-Sized Single-Crystal Hexagonal Boron Nitride Domains on Nickel Foils by Ion Beam Sputtering Deposition.

    PubMed

    Wang, Haolin; Zhang, Xingwang; Liu, Heng; Yin, Zhigang; Meng, Junhua; Xia, Jing; Meng, Xiang-Min; Wu, Jinliang; You, Jingbi

    2015-12-22

    Large-sized single-crystal h-BN domains with a lateral size up to 100 μm are synthesized on Ni foils by ion-beam sputtering deposition. The nucleation density of h-BN is dramatically decreased by reducing the concentrations of both active sites and species on the Ni surface through a brief in situ pretreatment of the substrate and optimization of the growth parameters, enabling the growth of large-sized domains.

  9. Structural and optical properties of ε-phase tris(8-hydroxyquinoline) aluminum crystals prepared by using physical vapor deposition method

    NASA Astrophysics Data System (ADS)

    Xie, Wanfeng; Pang, Zhiyong; Zhao, Yu; Jiang, Feng; Yuan, Huimin; Song, Hui; Han, Shenghao

    2014-10-01

    Crystals of ε-phase tris(8-hydroxyquinoline) aluminum (ε-Alq3) were prepared by using physical vapor deposition (PVD) method in a double zone tube furnace. The structural properties of the ε-Alq3 crystals were investigated by using an X-ray single crystal diffractometer (XSCD) and a high resolution scanning electron microscope (SEM). Large straight steps were observed from the side face of the pine needle-like crystals. The straight steps are parallel with each other like terraces and the widths of the steps are fixed, indicating that the ε-Alq3 crystals may have layered structures. The photoluminescence (PL) spectra at different temperatures (7 K, 66 K, 220 K, 300 K and 350 K) and the absorption spectrum were also investigated. The optical band gap of the ε-Alq3 crystals was calculated to be about 2.82 eV. This value is a little larger than that of amorphous mer-Alq3 (about 2.7 eV), indicating a minimizing of impurities, grain boundaries and defects.

  10. Urate crystal deposition and bone erosion in gout: 'inside-out' or 'outside-in'? A dual-energy computed tomography study.

    PubMed

    Towiwat, Patapong; Doyle, Anthony J; Gamble, Gregory D; Tan, Paul; Aati, Opetaia; Horne, Anne; Stamp, Lisa K; Dalbeth, Nicola

    2016-09-15

    It is currently unknown whether bone erosion in gout occurs through an 'inside-out' mechanism due to direct intra-osseous crystal deposition or through an 'outside-in' mechanism from the surface of bone. The aim of this study was to examine the mechanism ('outside-in' vs. 'inside-out') of monosodium urate (MSU) crystal deposition in bone erosion in gout. Specifically, we used three-dimensional dual-energy computed tomography (DECT) to analyse the positional relationship between bone and MSU crystal deposition in tophaceous gout, and to determine whether intra-osseous crystal deposition occurs in the absence of erosion. One hundred forty-four participants with gout and at least one palpable tophus had a DECT scan of both feet. Two readers independently scored all metatarsal heads (1433 bones available for scoring). For bones in contact with urate, the bone was scored for whether urate was present within an erosion, on the surface of bone or within bone only (true intra-osseous deposit). Data were analysed using generalised estimating equations. Urate in contact with bone was present in 370 (54.3 %) of 681 joints with urate deposition. For those bones in contact with urate, deposition was present on the surface of bone in 143 (38.6 %) of 370 joints and within erosion in 227 (61.4 %) of 370. True intra-osseous urate deposition was not observed at any site (p < 0.0001). For all bones with apparent intra-osseous deposition in one plane, examination in other planes revealed urate deposition within an en face erosion. In tophaceous gout, MSU crystal deposition is present within the joint, on the bone surface and within bone erosion, but it is not observed within bone in the absence of a cortical break. These data support the concept that MSU crystals deposit outside bone and contribute to bone erosion through an 'outside-in' mechanism.

  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. The clinicopathologic characteristics of kidney diseases related to monotypic IgA deposits.

    PubMed

    Vignon, Marguerite; Cohen, Camille; Faguer, Stanislas; Noel, Laure-Hélène; Guilbeau, Celine; Rabant, Marion; Higgins, Sarah; Hummel, Aurélie; Hertig, Alexandre; Francois, Hélène; Lequintrec, Moglie; Vilaine, Eve; Knebelmann, Bertrand; Pourrat, Jacques; Chauveau, Dominique; Goujon, Jean-Michel; Javaugue, Vincent; Touchard, Guy; El Karoui, Khalil; Bridoux, Frank

    2017-03-01

    Monoclonal gammopathy of renal significance (MGRS) regroups renal disorders caused by a monoclonal immunoglobulin without overt hematological malignancy. MGRS includes tubular disorders, glomerular disorders with organized deposits, and glomerular disorders with non-organized deposits, such as proliferative glomerulonephritis with monoclonal IgG deposits. Since glomerular involvement related to monotypic IgA deposits is poorly described we performed retrospective analysis and defined clinico-biological characteristics, renal pathology, and outcome in 19 referred patients. This analysis allowed distinction between 2 types of glomerulopathies, α-heavy chain deposition disease (5 patients) and glomerulonephritis with monotypic IgA deposits (14 patients) suggestive of IgA-proliferative glomerulonephritis with monoclonal immunoglobulin deposits in 12 cases. Clinicopathologic characteristics of α-heavy chain deposition disease resemble those of the γ-heavy chain disease, except for a higher frequency of extra-capillary proliferation and extra-renal involvement. IgA-proliferative glomerulonephritis with monoclonal immunoglobulin deposits should be differentiated from diseases with polytypic IgA deposits, given distinct clinical, histological, and pathophysiological features. Similarly to IgG-proliferative glomerulonephritis with monoclonal immunoglobulin deposits, overt hematological malignancy was infrequent, but sensitive serum and bone marrow studies revealed a subtle plasma cell proliferation in most patients with IgA-proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Anti-myeloma agents appeared to favorably influence renal prognosis. Thus, potential progression towards symptomatic IgA multiple myeloma suggests that careful hematological follow-up is mandatory. This series expands the spectrum of renal disease in MGRS.

  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. Reduced-Pressure Chemical Vapor Deposition Growth of Isolated Ge Crystals and Suspended Layers on Micrometric Si Pillars.

    PubMed

    Skibitzki, Oliver; Capellini, Giovanni; Yamamoto, Yuji; Zaumseil, Peter; Schubert, Markus Andreas; Schroeder, Thomas; Ballabio, Andrea; Bergamaschini, Roberto; Salvalaglio, Marco; Miglio, Leo; Montalenti, Francesco

    2016-10-05

    In this work, we demonstrate the growth of Ge crystals and suspended continuous layers on Si(001) substrates deeply patterned in high aspect-ratio pillars. The material deposition was carried out in a commercial reduced-pressure chemical vapor deposition reactor, thus extending the "vertical-heteroepitaxy" technique developed by using the peculiar low-energy plasma-enhanced chemical vapor deposition reactor, to widely available epitaxial tools. The growth process was thoroughly analyzed, from the formation of small initial seeds to the final coalescence into a continuous suspended layer, by means of scanning and transmission electron microscopy, X-ray diffraction, and μ-Raman spectroscopy. The preoxidation of the Si pillar sidewalls and the addition of hydrochloric gas in the reactants proved to be key to achieve highly selective Ge growth on the pillars top only, which, in turn, is needed to promote the formation of a continuous Ge layer. Thanks to continuum growth models, we were able to single out the different roles played by thermodynamics and kinetics in the deposition dynamics. We believe that our findings will open the way to the low-cost realization of tens of micrometers thick heteroepitaxial layer (e.g., Ge, SiC, and GaAs) on Si having high crystal quality.

  16. Mineralogical characteristics of unusual “Anatolian” diaspore (zultanite) crystals from the İlbirdağı diasporite deposit, Turkey

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Helvacı, Cahit; Chamberlain, Steven C.; Babalık, Hakkı

    2010-07-01

    The İlbirdağı diasporic metabauxite (diasporite) deposit of the Milas (Muğla) region of Turkey is a unique deposit including both metamorphic (primary) and hydrothermal-remobilized (secondary) diaspore that formed during different geological periods. Microscopic diaspore crystals with a metamorphic origin are common and are the main constituent of the metabauxite ore, which was metamorphosed during from the Late Cretaceous to Late Paleocene Periods. However, secondary macroscopic diaspore crystals filling fracture zones that crosscut the metabauxite ore formed during the Late Paleocene, Eocene and Oligocene Periods as the result of later hydrothermal solutions that remobilized constituents of the metabauxite. The macroscopic diaspore crystals can be distinguished from the metamorphosed microscopic diaspore crystals, based on size, appearance, occurrence, and origin. Approximately 60% of the macroscopic diaspore crystals have an opaque appearance and pale green coloration and are not considered attractive. By contrast, the other 40% are gem quality and exhibit a marked change in color under different types of illumination. The crystals are mostly olive-green and soil-brown in daylight. A small number of the crystals display color-change, such as green in daylight or equivalent illumination and carmine in low-wattage tungsten lights. X-ray diffraction (XRD) study, using a comparative matching technique, reveals that these Anatolian diaspore (zultanite) crystals [AlO(OH)] are polycrystalline and that their X-ray spectrum includes the overlapped XRD peaks of some mineral inclusions consisting of donbassite [Al 5.33Si 3O 10(OH) 8] (di-di-octahedral sheeted Al-rich chlorite), corundum (Al 2O 3), boehmite [AlO(OH)], quartz (SiO 2), ilmenite (FeTiO 3), goethite [FeO(OH)] and chloritoid [(Fe, Mg, Mn) 2Al 4Si 2O 10(OH) 4]. We label these unusual inclusions as sub-microscopic inclusions, because they cannot be seen with a polarizing microscope. Polarizing microscope (PM

  17. Observations of growth process of chemically vapor deposited diamond single crystal

    NASA Astrophysics Data System (ADS)

    Itoh, Hideaki; Nakamura, Tadashi; Iwahara, Hiroyasu; Sakamoto, Hiromichi

    1991-02-01

    The growth process and morphological variations of diamond single crystals obtained by microwave plasma CVD of the CO-H 2 reactant system were observed using scanning electron microscopy. The optimum conditions for spontaneous nucleation and growth of diamond on a (100) Si wafer were microwave power of 550 W, total pressure of 30-60 Torr, total flow rate of 200 ml/min and CO concentration of 5-10 vol%. Cubo-octahedral single crystals of diamond composed of {111} and {100} planes were grown epitaxially for 50 h by treating the coarse seed crystals of natural diamonds under the above growth conditions. Concave and terrace parts of the growing crystal surface were preferentially grown, resulting in the formation of symmetric single crystals. Typical trigonal pit patterns were formed on {111} planes of the developing crystal surface, while pyramidal shaped growth steps were observed on the {100} planes.

  18. IgD heavy-chain deposition disease: detection by laser microdissection and mass spectrometry.

    PubMed

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

    2015-04-01

    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.

  19. Unusual cause of glomerular deposition disease: Collagenofibrotic glomerulopathy

    PubMed Central

    Nimmagadda, S.; Mukku, K.; Devaraju, S. R.; Uppin, M. S.

    2017-01-01

    Collagenofibrotic glomerulopathy is a rare condition characterized by deposition of Type III collagen fibers in the subendothelial space and mesangium of the glomerulus. Only 17 cases have been reported from India. A definite diagnosis can only be established when typical histological findings are supported by electron microscopy. It is characterized by indolent progression and has no definitive therapy. PMID:28182050

  20. Cutaneous Light Chain Deposition Disease: A Report of 2 Cases and Review of the Literature.

    PubMed

    Hendricks, Carlo; Fernández Figueras, Maite T; Liersch, Julia; Martin-Urdà, Maria-Teresa; López, Dolores; Brochhausen, Christoph; Röcken, Christoph; Schaller, Jörg

    2017-09-20

    Light chain deposition disease (LCDD) is a rare systemic disorder with deposition of mostly monoclonal amorphous nonamyloid light chains in multiple organs. Renal involvement with rapidly progressing renal failure presents the dominant manifestation of LCDD. Approximately 20%-30% of patients show symptomatic cardiac or liver involvement. Cutaneous manifestations are extremely rare with only a few published cases. We report 2 additional cases of cutaneous LCDD without detectable systemic disease.

  1. A modified scheme that parameterizes depositional growth of ice crystal: A modeling study of pre-summer torrential rainfall case over Southern China

    NASA Astrophysics Data System (ADS)

    Shen, Xinyong; Huang, Wei; Qing, Tao; Huang, Wenyan; Li, Xiaofan

    2014-03-01

    Depositional growth of cloud ice is estimated and its parameterization schemes are compared through the two-dimensional cloud-resolving modeling analysis of pre-summer heavy rainfall over southern China. Hsie et al. (1980) and Krueger et al. (1995) developed parameterization schemes to calculate depositional growth of cloud ice by estimating the growth timescale under the assumption that the ice crystal concentration is independent of crystal size. A new scheme is proposed by Zeng et al. (2008) under the assumption that the ice crystal concentration is proportional to the mass of ice crystal. Hsie's and Krueger's schemes produce small amount of cloud ice similar to what Zeng's scheme with low ice crystal concentration does. When ice crystal concentration is increased to a high value in Zeng's scheme, the simulation generates anomalous depositional growth of cloud ice and thus anomalous area expansion of stratiform rainfall. Zeng's scheme is modified by changing radius of base ice crystal from 0 to 40 μm in the calculation of depositional growth of cloud ice. The modified scheme with high ice crystal concentration greatly reduces growth of cloud ice and thus fractional coverage of stratiform rainfall.

  2. 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.

  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

    2015-08-05

    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).

  4. Improvement of radiation stability of semi-insulating gallium arsenide crystals by deposition of diamond-like carbon films

    NASA Astrophysics Data System (ADS)

    Klyui, N. I.; Lozinskii, V. B.; Liptuga, A. I.; Izotov, V. Yu.; Han, Wei; Liu, Bingbing

    2016-12-01

    We studied the properties of optical elements for the IR spectral range based on semi-insulating gallium arsenide (SI-GaAs) and antireflecting diamond-like carbon films (DLCF). Particular attention has been paid to the effect of penetrating γ-radiation on transmission of the developed optical elements. A Co60 source and step-by-step gaining of γ-irradiation dose were used for treatment of both an initial SI-GaAs crystal and DLCF/SI-GaAs structures. It was shown that DLCF deposition essentially increases degradation resistance of the SI-GaAs-based optical elements to γ-radiation. Particularly, the transmittance of the DLCF/SI-GaAs structure after γ-irradiation with a dose 9ṡ104 Gy even exceeds that of initial structures. The possible mechanism that explains the effect of γ-radiation on the SI-GaAs crystals and the DLCF/SI-GaAs structures at different irradiation doses was proposed. The effect of small doses is responsible for non-monotonic transmission changes in both SI-GaAs crystals and DLCF/SI-GaAs structures. At further increasing the γ-irradiation dose, the variation of properties of both DLCF and SI-GaAs crystal influences on the transmission of DLCF/SI-GaAs system. At high γ-irradiation dose 1.4ṡ105 Gy, passivation of radiation defects in the SI-GaAs bulk by hydrogen diffused from DLCF leads to increasing the degradation resistance of the SI-GaAs crystals coated with DLCF as compared with the crystals without DLCF.

  5. Enhanced optical properties of chemical vapor deposited single crystal diamond by low-pressure/high-temperature annealing.

    PubMed

    Meng, Yu-fei; Yan, Chih-shiue; Lai, Joseph; Krasnicki, Szczesny; Shu, Haiyun; Yu, Thomas; Liang, Qi; Mao, Ho-kwang; Hemley, Russell J

    2008-11-18

    Single crystal diamond produced by chemical vapor deposition (CVD) at very high growth rates (up to 150 microm/h) has been successfully annealed without graphitization at temperatures up to 2200 degrees 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.

  6. 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.

  7. Photonic crystal waveguide-based biosensor for detection of diseases

    NASA Astrophysics Data System (ADS)

    Chopra, Harshita; Kaler, Rajinder S.; Painam, Balveer

    2016-07-01

    A biosensor is a device that is used to detect the analytes or molecules of a sample by means of a binding mechanism. A two-dimensional photonic crystal waveguide-based biosensor is designed with a diamond-shaped ring resonator and two waveguides: a bus waveguide and a drop waveguide. The sensing mechanism is based on change in refractive index of the analytes, leading to a shift in the peak resonant wavelength. This mechanism can be used in the field of biomedical treatment where different body fluids such as blood, tears, saliva, or urine can be used as the analyte in which different components of the fluid can be detected. It can also be used to differentiate between the cell lines of a normal and an unhealthy human being. Average value of quality factor for this device comes out to be 1082.2063. For different analytes used, the device exhibits enhanced sensitivity and, hence, it is useful for the detection of diseases.

  8. ATYPICAL MACULOPATHY IN A PATIENT WITH LIGHT CHAIN DEPOSITION DISEASE MIMICKING ADVANCED GEOGRAPHIC ATROPHY

    PubMed Central

    Oshry, Lauren J.; Reichel, Elias

    2017-01-01

    Purpose: To report a previously unreported presentation of advanced geographic atrophy of the macula mimicking nonneovascular (dry) age-related macular degeneration in a patient with light chain deposition disease. Methods: Ocular examination included dilated fundus examination, fundus autofluorescence, full-field electroretinography, and spectral domain optical coherence tomography. Patients: Single-patient case report. Results: Dilated fundus examination demonstrated diffuse loss of the retinal pigment epithelium in a geographic atrophy pattern in the macula and drusenlike deposits localized to the outer retina and retinal pigment epithelium. There were no signs of choroidal neovascularization or retinal pigment epithelium detachments. Fundus autofluorescence demonstrated wide areas of retinal pigment epithelium loss. Full-field electroretinography was normal. Spectral domain optical coherence tomography displayed atrophy of the outer retinal layers. Discussion: This is the first documented case of drusenlike deposits and maculopathy in a patient with light chain deposition disease that mimics advanced geographic atrophy that is typically observed in nonneovascular age-related macular degeneration. Physicians should be aware of the macular changes that can be associated with light chain deposition disease, and patients with light chain deposition disease should be regularly evaluated for associated macular disease. PMID:26934302

  9. Estrogen Intake and Copper Depositions: Implications for Alzheimer's Disease?

    PubMed Central

    Amtage, Florian; Birnbaum, Dzelila; Reinhard, Thomas; Niesen, Wolf-Dirk; Weiller, Cornelius; Mader, Irina; Meyer, Philipp T.; Rijntjes, Michel

    2014-01-01

    We present a patient with chronic postmenopausal estrogen intake with presence of Kayser-Fleischer ring in the cornea and Alzheimer's disease and discuss the pathophysiological mechanisms of estrogen intake and copper accumulation in various tissues, including the central nervous system. Sonography was compatible with copper accumulation in the basal ganglia, but the patient showed no clinical signs of Wilson's disease. Magnetic resonance imaging and positron emission tomography revealed a typical pattern for Alzheimer's disease. We propose increased copper levels as a direct effect of estrogen intake due to an augmented ATP7A-mRNA in the intestine. Moreover, we discuss the impact of elevated free serum copper on accompanying Alzheimer's disease, knowing that copper plays a crucial role in the formation of amyloid plaques and tau aggregation. This might offer a partial explanation for the observation that postmenopausal estrogen therapy is associated with a higher risk of mild cognitive impairment and Alzheimer's disease. PMID:25076894

  10. Effect of growth rate on crystallization of HfO{sub 2} thin films deposited by RF magnetron sputtering

    SciTech Connect

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

    2016-05-23

    Hafnium oxide (HfO{sub 2}) is the potentially useful dielectric material in both; electronics to replace the conventional SiO{sub 2} as gate dielectric and in Optics as anti-reflection coating material. In this present work we have synthesized polycrystalline HfO{sub 2} 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.

  11. Crystallization of In2Se3 semiconductor thin films by post-deposition heat treatment. Thickness and substrate effects

    NASA Astrophysics Data System (ADS)

    Emziane, M.; LeNy, R.

    1999-06-01

    Polycrystalline thin films of icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-In2Se3 were grown on various substrates by sequential thermal evaporation of In and Se. The crystallization was achieved by annealing the as-deposited films in flowing nitrogen. The depositions were carried out for different atomic ratios (1.5icons/Journals/Common/le" ALT="le" ALIGN="TOP"/> R = [Se]/[In]icons/Journals/Common/le" ALT="le" ALIGN="TOP"/>5) and the annealings performed at 400 °C for 0.5 h. X-ray diffraction, energy dispersive x-ray analysis, scanning electron microscopy, x-ray photoelectron spectroscopy and Raman scattering have shown that thin films of high crystalline quality were obtained. The influence of the substrate nature as well as the film thickness on the crystallite preferential orientation and size is studied.

  12. Chemical vapor deposition of thin crystals of layered semiconductor SnS2 for fast photodetection application.

    PubMed

    Su, Guoxiong; Hadjiev, Viktor G; Loya, Phillip E; Zhang, Jing; Lei, Sidong; Maharjan, Surendra; Dong, Pei; M Ajayan, Pulickel; Lou, Jun; Peng, Haibing

    2015-01-14

    Layered two-dimensional (2D) semiconductors, such as MoS(2) and SnS(2), have been receiving intensive attention due to their technological importance for the next-generation electronic/photonic applications. We report a novel approach to the controlled synthesis of thin crystal arrays of SnS(2) at predefined locations on chip by chemical vapor deposition with seed engineering and have demonstrated their application as fast photodetectors with photocurrent response time ∼ 5 μs. This opens a pathway for the large-scale production of layered 2D semiconductor devices, important for applications in integrated nanoelectronic/photonic systems.

  13. Case Report of a Fatal Antifreeze Ingestion with a Record High Level and Impressive Renal Crystal Deposition

    PubMed Central

    2016-01-01

    Ethylene glycol, methanol, and diethylene glycol are readily available in many household and commercially available products. While these alcohols are relatively nontoxic themselves, their acidic metabolites are toxic and can result in significant morbidity and mortality. Herein we report a lethal case of massive ethylene glycol ingestion in a suicide with a record high level (1254 mg/dL) and images of the histologic examination of the kidneys revealing impressive calcium oxalate crystal deposition. Autopsy findings also showed evidence of mild cerebral edema. PMID:27747109

  14. Case Report of a Fatal Antifreeze Ingestion with a Record High Level and Impressive Renal Crystal Deposition.

    PubMed

    Erickson, Heidi L

    2016-01-01

    Ethylene glycol, methanol, and diethylene glycol are readily available in many household and commercially available products. While these alcohols are relatively nontoxic themselves, their acidic metabolites are toxic and can result in significant morbidity and mortality. Herein we report a lethal case of massive ethylene glycol ingestion in a suicide with a record high level (1254 mg/dL) and images of the histologic examination of the kidneys revealing impressive calcium oxalate crystal deposition. Autopsy findings also showed evidence of mild cerebral edema.

  15. 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.

  16. 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.

  17. Chemical vapor deposition of high-quality large-sized MoS2 crystals on silicon dioxide substrates

    SciTech Connect

    Chen, Jianyi; Tang, Wei; Tian, Bingbing; Liu, Bo; Zhao, Xiaoxu; Liu, Yanpeng; Ren, Tianhua; Liu, Wei; Geng, Dechao; Jeong, Hu Young; Shin, Hyeon Suk; Zhou, Wu; Loh, Kian Ping

    2016-03-31

    Large-sized MoS2 crystals can be grown on SiO2/Si substrates via a two-stage chemical vapor deposition method. The maximum size of MoS2 crystals can be up to about 305 μm. The growth method can be used to grow other transition metal dichalcogenide crystals and lateral heterojunctions. Additionally, the electron mobility of the MoS2 crystals can reach ≈30 cm2 V–1 s–1, which is comparable to those of exfoliated flakes.

  18. 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.

  19. Crystallization of sputter-deposited amorphous Ge films by electron irradiation: Effect of low-flux pre-irradiation

    NASA Astrophysics Data System (ADS)

    Okugawa, M.; Nakamura, R.; Ishimaru, M.; Yasuda, H.; Numakura, H.

    2016-10-01

    We investigated the effect of low-flux electron irradiation with 125 keV to sputter-deposited amorphous germanium on the amorphous structure and electron-induced crystallization microstructure by TEM following our previous study on the effect of aging at room temperature. In samples aged for 3 days, coarse, spherical particles about 100 nm in diameter appear dominantly. By low-flux pre-irradiation to the samples, a reduction in the size and number of coarse particles, embedded in the matrix with fine nanograins of the diamond cubic structure, was noted with the increase in fluence. The crystal structure of these coarse particles was found to be not cubic but hexagonal. In samples aged for 4 months, a similar tendency was observed. In samples aged for 7 months, on the other hand, the homogeneous diamond cubic structured nanograins were unchanged by pre-irradiation. These results indicate that pre-irradiation as well as aging modifies the amorphous structure, preventing the appearance of a hexagonal phase. The elimination of a certain amount of medium-range ordered clusters by pre-irradiation, included in as-deposited samples and the samples aged for 4 months, apparently gives rise to a reduction in the size and number of coarse particles with a metastable hexagonal structure.

  20. Effect of IgA deposits on the glomerular mesangium in Berger's disease.

    PubMed

    Sinniah, R; Churg, J

    1983-01-01

    In mesangial IgA glomerulonephritis (Berger's disease), the immunoproteins appeared to gain access from the capillary lumen to the mesangium via endothelial fenestrae or via channels between the endothelial cells. The deposits are transported into the deeper mesangium by a process of inhibition or diffusion, with the matrix acting as the head. There are no true channels or grooves in the mesangial matrix for the transport of the immunoproteins. The contractility of the glomerular myoid fibrils may account for the movement of deposits to the hilus for possible removal. There was partial dissolution of the deposits in the mesangial matrix accompanied by loosening of the matrix. No evidence was found for any significant intracellular phagocytosis and digestion. The mesangial deposits directly or indirectly stimulated the cellular hypertrophy and hyperplasia and increased deposition of mesangial matrix. This was accompanied by formation of collagen fibrils within the thickened matrix and led to atrophy of the mesangial cells and sclerosis of the glomeruli.

  1. Chemical Vapor Deposition of Large-Size Monolayer MoSe2 Crystals on Molten Glass

    DOE PAGES

    Chen, Jianyi; Zhao, Xiaoxu; Tan, Sherman Jun Rong; ...

    2017-01-04

    We report the fast growth of high-quality millimeter-size monolayer MoSe2 crystals on molten glass using an ambient pressure CVD system. We found that the isotropic surface of molten glass suppresses nucleation events and greatly improves the growth of large crystalline domains. Triangular monolayer MoSe2 crystals with sizes reaching ~2.5 mm, and with a room-temperature carrier mobility up to ~95 cm2/(V·s), can be synthesized in 5 min. The method can also be used to synthesize millimeter-size monolayer MoS2 crystals. Our results demonstrate that “liquid-state” glass is a highly promising substrate for the low-cost growth of high-quality large-size 2D transition metal dichalcogenidesmore » (TMDs).« less

  2. Chemical Vapor Deposition of Large-Size Monolayer MoSe2 Crystals on Molten Glass.

    PubMed

    Chen, Jianyi; Zhao, Xiaoxu; Tan, Sherman J R; Xu, Hai; Wu, Bo; Liu, Bo; Fu, Deyi; Fu, Wei; Geng, Dechao; Liu, Yanpeng; Liu, Wei; Tang, Wei; Li, Linjun; Zhou, Wu; Sum, Tze Chien; Loh, Kian Ping

    2017-01-25

    We report the fast growth of high-quality millimeter-size monolayer MoSe2 crystals on molten glass using an ambient pressure CVD system. We found that the isotropic surface of molten glass suppresses nucleation events and greatly improves the growth of large crystalline domains. Triangular monolayer MoSe2 crystals with sizes reaching ∼2.5 mm, and with a room-temperature carrier mobility up to ∼95 cm(2)/(V·s), can be synthesized in 5 min. The method can also be used to synthesize millimeter-size monolayer MoS2 crystals. Our results demonstrate that "liquid-state" glass is a highly promising substrate for the low-cost growth of high-quality large-size 2D transition metal dichalcogenides (TMDs).

  3. Fat deposition in the cavernous sinus in Cushing disease

    SciTech Connect

    Bachow, T.B.; Hesselink, J.R.; Aaron, J.O.; Davis, K.R.; Taveras, J.M.

    1984-10-01

    Fat density in the cavernous sinus on computed tomography (CT) is described in 6 out of 16 (37.5%) patients with Cushing disease. This finding may aid in making a specific diagnosis in patients with a pituitary mass. It was not seen in 30 random CT studies of the sella; however, supra seller fat was incidentally noted in the patient with acromegaly.

  4. Effect of Mo concentration on shape and size of monolayer MoS2 crystals by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Wang, Wenzhao; Zeng, Xiangbin; Wu, Shaoxiong; Zeng, Yang; Hu, Yishuo; Ding, Jia; Xu, Sue

    2017-10-01

    Monolayer molybdenum disulfide (MoS2), a new two-dimensional direct-bandgap semiconductor, has attracted research interests into applications in atomically thin electronics and optoelectronics. Growing monolayer MoS2 film by chemical vapor deposition is the most commonly used approach. Little is known, however, about the cause of the shape and size evolution. Here, we explore how the precursor’s concentration affects the MoS2 crystals’ shape and size. When S concentration is stable, the shape of the MoS2 domain evolves from triangle to hexagon and then truncated triangle, finally back to a triangle as the concentration of Mo elevates. Regulating the concentration of Mo leads to the controllable growth of MoS2 crystal. By controlling the concentration of Mo, we eventually synthesized over 100 µm monolayer MoS2 crystals. Our results are a significant step forward in realizing the ultimate promise of large atomic MoS2 monolayer crystals for flexible, electronic, optoelectronic devices.

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

    DOE PAGES

    Boichot, R.; Tian, L.; Richard, M. -I.; ...

    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.

  6. 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

  7. Magnetism of Amorphous and Nano-Crystallized Dc-Sputter-Deposited MgO Thin Films

    PubMed Central

    Mahadeva, Sreekanth K.; Fan, Jincheng; Biswas, Anis; Sreelatha, K.S.; Belova, Lyubov; Rao, K.V.

    2013-01-01

    We report a systematic study of room-temperature ferromagnetism (RTFM) in pristine MgO thin films in their amorphous and nano-crystalline states. The as deposited dc-sputtered films of pristine MgO on Si substrates using a metallic Mg target in an O2 containing working gas atmosphere of (N2 + O2) are found to be X-ray amorphous. All these films obtained with oxygen partial pressure (PO2) ~10% to 80% while maintaining the same total pressure of the working gas are found to be ferromagnetic at room temperature. The room temperature saturation magnetization (MS) value of 2.68 emu/cm3 obtained for the MgO film deposited in PO2 of 10% increases to 9.62 emu/cm3 for film deposited at PO2 of 40%. However, the MS values decrease steadily for further increase of oxygen partial pressure during deposition. On thermal annealing at temperatures in the range 600 to 800 °C, the films become nanocrystalline and as the crystallite size grows with longer annealing times and higher temperature, MS decreases. Our study clearly points out that it is possible to tailor the magnetic properties of thin films of MgO. The room temperature ferromagnetism in MgO films is attributed to the presence of Mg cation vacancies.

  8. Primary cerebral low-grade B-cell lymphoma, monoclonal immunoglobulin deposition disease, cerebral light chain deposition disease and “aggregoma”: an update on classification and diagnosis

    PubMed Central

    2013-01-01

    Background This work aims to add evidence and provide an update on the classification and diagnosis of monoclonal immunoglobulin deposition disease (MIDD) and primary central nervous system low-grade lymphomas. MIDD is characterized by the deposition of light and heavy chain proteins. Depending on the spatial arrangement of the secreted proteins, light chain-derived amyloidosis (AL) can be distinguished from non-amyloid light chain deposition disease (LCDD). We present a case of an extremely rare tumoral presentation of LCDD (aggregoma) and review the 3 previously published LCDD cases and discuss their presentation with respect to AL. Case presentation A 61-year-old woman presented with a 3½-year history of neurologic symptoms due to a progressive white matter lesion of the left subcortical parieto-insular lobe and basal ganglia. 2 former stereotactic biopsies conducted at different hospitals revealed no evidence of malignancy or inflammation; thus, no therapy had been initiated. After performing physiological and functional magnetic resonance imaging (MRI), the tumor was removed under intraoperative monitoring at our department. Histological analysis revealed large amorphous deposits and small islands of lymphoid cells. Conclusion LCCD is a very rare and obscure manifestation of primary central nervous system low-grade lymphomas that can be easily misdiagnosed by stereotactic biopsy sampling. If stereotactic biopsy does not reveal a definite result, a “wait-and-see” strategy can delay possible therapy for this disease. The impact of surgical removal, radiotherapy and chemotherapy in LCDD obviously remains controversial because of the low number of relevant cases. PMID:23947787

  9. Quartz Crystal Microbalance Measurements of Protein Deposition onto Cross-linked polyHEMA Hydrogel

    NASA Astrophysics Data System (ADS)

    Teichroeb, Jonathan; Forrest, James; Jones, Lyndon

    2006-03-01

    The adsorption of various concentrations of several opthalmologically relevant proteins was measured using Quartz Crystal Microbalance (QCM). Hen egg white lysozyme HEWL, bovine serum albumin BSA, and lactoferrin were measured both individually and in various combinations as they adsorbed onto cross-linked polyHEMA substrate. Results are discussed in terms of the concentration and time dependence of total adhered protein, as well as the amount of desorbable protein. Variations seen during competitive adsorption are also presented.

  10. Renal monoclonal immunoglobulin deposition disease: a report of 64 patients from a single institution.

    PubMed

    Nasr, Samih H; Valeri, Anthony M; Cornell, Lynn D; Fidler, Mary E; Sethi, Sanjeev; D'Agati, Vivette D; Leung, Nelson

    2012-02-01

    To better define the clinical-pathologic spectrum and prognosis of monoclonal immunoglobulin deposition disease (MIDD), this study reports the largest series. Characteristics of 64 MIDD patients who were seen at Mayo Clinic are provided. Of 64 patients with MIDD, 51 had light chain deposition disease, 7 had heavy chain deposition disease, and 6 had light and heavy chain deposition disease. The mean age at diagnosis was 56 years, and 23 patients (36%) were ≤50 years of age. Clinical evidence of dysproteinemia was present in 62 patients (97%), including multiple myeloma in 38 (59%). M-spike was detected on serum protein electrophoresis in 47 (73%). Serum free light chain ratio was abnormal in all 51 patients tested. Presentation included renal insufficiency, proteinuria, hematuria, and hypertension. Nodular mesangial sclerosis was seen in 39 patients (61%). During a median of 25 months of follow-up (range, 1-140) in 56 patients, 32 (57%) had stable/improved renal function, 2 (4%) had worsening renal function, and 22 (39%) progressed to ESRD. The mean renal and patient survivals were 64 and 90 months, respectively. The disease recurred in three of four patients who received a kidney transplant. Patients with MIDD generally present at a younger age than those with light chain amyloidosis or light chain cast nephropathy. Serum free light chain ratio is abnormal in all MIDD patients, whereas only three-quarters have abnormal serum protein electrophoresis. The prognosis for MIDD is improving compared with historical controls, likely reflecting earlier detection and improved therapies.

  11. 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.

  12. Chemical vapour deposition growth of large single crystals of monolayer and bilayer graphene.

    PubMed

    Zhou, Hailong; Yu, Woo Jong; Liu, Lixin; Cheng, Rui; Chen, Yu; Huang, Xiaoqing; Liu, Yuan; Wang, Yang; Huang, Yu; Duan, Xiangfeng

    2013-01-01

    The growth of large-domain single crystalline graphene with the controllable number of layers is of central importance for large-scale integration of graphene devices. Here we report a new pathway to greatly reduce the graphene nucleation density from ~10(6) to 4 nuclei cm(-2), enabling the growth of giant single crystals of monolayer graphene with a lateral size up to 5 mm and Bernal-stacked bilayer graphene with the lateral size up to 300 μm, both the largest reported to date. The formation of the giant graphene single crystals eliminates the grain boundary scattering to ensure excellent device-to-device uniformity and remarkable electronic properties with the expected quantum Hall effect and the highest carrier mobility up to 16,000 cm(2) V(-1) s(-1). The availability of the ultra large graphene single crystals can allow for high-yield fabrication of integrated graphene devices, paving a pathway to scalable electronic and photonic devices based on graphene materials.

  13. Chemical vapour deposition growth of large single crystals of monolayer and bilayer graphene

    NASA Astrophysics Data System (ADS)

    Zhou, Hailong; Yu, Woo Jong; Liu, Lixin; Cheng, Rui; Chen, Yu; Huang, Xiaoqing; Liu, Yuan; Wang, Yang; Huang, Yu; Duan, Xiangfeng

    2013-06-01

    The growth of large-domain single crystalline graphene with the controllable number of layers is of central importance for large-scale integration of graphene devices. Here we report a new pathway to greatly reduce the graphene nucleation density from ~106 to 4 nuclei cm-2, enabling the growth of giant single crystals of monolayer graphene with a lateral size up to 5 mm and Bernal-stacked bilayer graphene with the lateral size up to 300 μm, both the largest reported to date. The formation of the giant graphene single crystals eliminates the grain boundary scattering to ensure excellent device-to-device uniformity and remarkable electronic properties with the expected quantum Hall effect and the highest carrier mobility up to 16,000 cm2 V-1 s-1. The availability of the ultra large graphene single crystals can allow for high-yield fabrication of integrated graphene devices, paving a pathway to scalable electronic and photonic devices based on graphene materials.

  14. Cystine growth inhibition through molecular mimicry: a new paradigm for the prevention of crystal diseases.

    PubMed

    Lee, Michael H; Sahota, Amrik; Ward, Michael D; Goldfarb, David S

    2015-05-01

    Cystinuria is a genetic disease marked by recurrent kidney stone formation, usually at a young age. It frequently leads to chronic kidney disease. Treatment options for cystinuria have been limited despite comprehensive understanding of its genetic pathophysiology. Currently available therapies suffer from either poor clinical adherence to the regimen or potentially serious adverse effects. Recently, we employed atomic force miscopy (AFM) to identify L-cystine dimethylester (CDME) as an effective molecular imposter of L-cystine, capable of inhibiting crystal growth in vitro. More recently, we demonstrated CDME's efficacy in inhibiting L-cystine crystal growth in vivo utilizing a murine model of cystinuria. The application of AFM to discover inhibitors of crystal growth through structural mimicry suggests a novel approach to preventing and treating crystal diseases.

  15. Electron microscopic investigation of the kinetics of the layer and island crystallization of amorphous V2O3 films deposited by pulsed laser evaporation

    NASA Astrophysics Data System (ADS)

    Bagmut, A. G.

    2017-06-01

    An electron microscopic investigation was performed on the kinetics of the layer and island crystallization of amorphous V2O3 films deposited by pulsed laser evaporation of vanadium in an oxygen atmosphere. The crystallization was initiated by the action of an electron beam on an amorphous film in the column of a transmission electron microscope. The kinetic curves were plotted on the basis of a frame-by-frame analysis of the video recorded during the crystallization of the film. It was found that the layer crystallization of amorphous films is characterized by a quadratic dependence of the fraction of the crystalline phase x on the time t, whereas the island crystallization is described by an exponential dependence of x on t. The kinetic curves of island crystallization of amorphous films were analyzed on the basis of the α-version of the Kolmogorov model. For each type of crystallization, there are specific values of the dimensionless relative length unit δ0, which is equal to the ratio of the characteristic length unit to the parameter characterizing the unit cell of the crystal. It was established that, for the layer crystallization, the relative length unit lies in the range δ0 4300-4700, whereas for the fine-grained island crystallization, it amounts to δ0 110.

  16. Ultrastructural histochemical investigations of "dense deposit disease". Pathogenetic approach to a special type of mesangiocapillary glomerulonephritis.

    PubMed

    Muda, A O; Barsotti, P; Marinozzi, V

    1988-01-01

    Dense deposit disease is characterized by the presence of intramembranous dense deposits; their constituents are unknown but immunological and biochemical studies have demonstrated that they contain no gamma-globulins or any other plasma protein. In order to clarify the nature of the dense deposits better, we investigated their most distinctive character, (marked electron-density) by means of ultrastructural histochemistry techniques using thin sections from Formaldehyde fixed, OsO4 postfixed and Epon embedded specimens collected for diagnostic electron microscopy. The dense deposits have a higher osmium affinity than the lamina densa of normal basement membranes, and the electron-density is strictly osmium-dependent suggesting the presence of a lipid component. Further data, obtained using an extraction method for lipids, seems to confirm our hypothesis.

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

    SciTech Connect

    Boichot, R.; Tian, L.; Richard, M. -I.; Crisci, A.; Chaker, A.; Cantelli, V.; Coindeau, S.; Lay, S.; Ouled, T.; Blanquet, E.; Deschanvres, J. -L.; Renevier, H.; Chu, M. H.; Aubert, N.; Ciatto, G.; Thomas, O.

    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.

  18. In situ crystal chemical study of solid diamond inclusions from Quaternary alluvial deposit in the Siberian craton

    NASA Astrophysics Data System (ADS)

    Dera, P. K.; Manghnani, M. H.; Hushur, A.; Sobolev, N. V.; Logvinova, A. M.; Newville, M.; Lanzirotti, A.

    2013-12-01

    Kimberlites belong to rare rock type available only within the Earth's cratonic areas and have been a subject of detailed studies because of the great depth of their origin in the mantle. Kimberlitic diamonds often contain pristine inclusions derived from significant depths with different histories of their origins. Many of kimberlitic diamonds were formed in ultramafic (peridotitic) and mafic (eclogitic) environments of the upper mantle. Thus far only a handful of comprehensive in situ studies including single-crystal X-ray diffraction characterization of pristine diamond solid inclusions have been reported (e.g. Kunz et al. 2001, Nestola et al. 2011). In this study five single-crystal solid inclusions from diamonds found in the Quaternary alluvial deposit in NW of the Siberian craton have been investigated using a combination of in situ single-crystal X-ray diffraction, Raman spectroscopy, synchrotron X-ray microfluorescence and X-ray Absorption Near Edge Spectroscopy (XANES). The grains were identified to be a suite of major upper mantle minerals including olivine, enstatite orthopyroxene (opx), C2/c omphacite clinopyroxene (cpx) and majoritic garnet (two grains), indicating eclogitic origin. All five inclusions are chemically homogeneous, do not show compositional zoning, and exhibit very similar major element chemistry, with significant amounts of Mn2+, Ni2+ and Cr3+ incorporated into the crystal structures, suggesting common geologic origin. All samples were studied in situ, while still embedded in the diamond crystals. High quality single-crystal X-ray diffraction data was collected at the Advanced Photon Source, Argonne National Laboratory to reveal details of the crystal structures and provide crystal chemical information. Some of the structural characteristics of the solid inclusions were found to be fairly uncommon, e.g. the orthoenstatite exhibits an unusually high Ca2+ content (Carlson et al. 1988), and omphacite occurs as the less common C2/c

  19. 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.

  20. Primary CNS Nonamyloidogenic Light Chain Deposition Disease: Case Report and Brief Review.

    PubMed

    Mercado, Juan Jose; Markert, James M; Meador, William; Chapman, Philip; Perry, Arie; Hackney, James R

    2017-06-01

    The true incidence of light chain deposition disease (LCDD) restricted to the central nervous system (CNS) is unknown. To our knowledge only 7 cases of LCDD restricted to the brain have been previously reported. We herein describe an unusual example. A 44-year-old man presented with a history of ischemic retinopathy in 2004 and left lower extremity hypoesthesia in 2007 that progressed gradually to left-sided weakness and numbness in the 2 years prior to his hospitalization in 2015. A stereotactic brain biopsy was performed, displaying nonspecific hyaline deposits of amorphous "amyloid-like" material involving deep brain white matter and vessels. These were Congo red negative and were accompanied by a sparse lymphoplasmacytic infiltrate. Plasma cells demonstrated kappa light chain class restriction by chromogenic in situ hybridization (CISH). There was patchy reactivity with kappa immunohistochemistry in the amorphous deposits. A diagnosis of light chain deposition disease was made. Subsequent systemic myeloma and lymphoma workups were negative. Previously reported cases have included men and women, spanning the ages of 19 and 72 years, often presenting with hemiparesis, hypoesthesia, or seizures. Deposits have been reported in the cerebrum and cerebellum. T2/FLAIR (fluid attenuation inversion recovery) changes are usual, but lesions may or may not produce contrast enhancement. The light chain deposition may be of kappa or lambda class. Most lesions have been accompanied by local lymphoid and/or plasma cell infiltrates exhibiting light chain restriction of the same class as the deposits. In summary, LCDD limited to the CNS is a rare lesion consisting of deposition of amyloid-like, but Congo red-negative monotypic light chain usually produced by local lymphoplasmacytic infiltrates.

  1. 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.

  2. 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.

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

    PubMed

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

    2008-10-01

    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.

  4. 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

  5. The Nokomis Cu-Ni-PGE Deposit, Duluth Complex: A sulfide-bearing, crystal-laden magmatic slurry

    NASA Astrophysics Data System (ADS)

    Peterson, D. M.

    2009-12-01

    deposit. A fundamental aspect of the ever-developing ore deposit model is an understanding of the initial conditions of the magmatic system - its crystallinity, sulfur capacity, geochemistry, and geometry - and how the sulfur saturated SKI magma lived, worked, and died. Such understanding includes the realization that the magma was a crystal-liquid (silicate and sulfide liquids) slurry and the identification of magma channelways and sub-channels and their associated thermal anomalies. In addition, the SKI magmas locally melted the footwall granitoid rocks, and such melts have been incorporated into the sulfide-bearing troctolitic melts of the SKI. In the end, hard work (>16,000 outcrops mapped, ~20,000 geochemical analyses completed, and >155,000 meters of core drilled) and intellectual geologic thought has been used to identify one of the world’s largest resources of Cu-Ni-PGEs.

  6. Different iron deposition patterns in early- and middle-late-onset Parkinson's disease.

    PubMed

    Xuan, Min; Guan, Xiaojun; Gu, Quanquan; Shen, Zhujing; Yu, Xinfeng; Qiu, Tiantian; Luo, Xiao; Song, Ruirui; Jiaerken, Yerfan; Xu, Xiaojun; Huang, Peiyu; Luo, Wei; Zhang, Minming

    2017-08-10

    Iron deposition may contribute to the clinical symptoms in Parkinson's disease (PD). With partial different clinical manifestations, the iron deposition patterns between patients with early-onset Parkinson's disease (EOPD) and middle-late-onset Parkinson's disease (M-LOPD) are still unclear. This study was designed to investigate the patterns of iron deposition and their clinical relevance in EOPD and M-LOPD patients, using quantitative susceptibility mapping technique. Thirty-five EOPD patients and 24 matched young controls, 33 M-LOPD patients and 22 matched older controls were recruited in the study. The iron content in the deep grey matter nuclei in the basal ganglia and midbrain were measured, and compared between patients and their corresponding controls. The correlations of regional iron content and clinical features were explored in patient groups. Both M-LOPD and EOPD patients showed increased iron content in the substantia nigra (SN) pars compacta and SN pars reticulata. Increased iron content in the putamen was only observed in M-LOPD patients. The relationship between the increased iron content and disease severity (H&Y stages, UPDRS II scores and UPDRS III scores) was observed in M-LOPD patients, but not in EOPD patients. Our study suggested that the iron deposition pattern was greatly influenced by the age of PD onset, which increases our understanding of the different pathological underpinnings of EOPD and M-LOPD patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Diamond photonic crystal slab: leaky modes and modified photoluminescence emission of surface-deposited quantum dots.

    PubMed

    Ondič, Lukáš; Babchenko, Oleg; Varga, Marián; Kromka, Alexander; Ctyroký, Jiří; Pelant, Ivan

    2012-01-01

    Detailed analysis of a band diagram of a photonic crystal (PhC) slab prepared on a nano-diamond layer is presented. Even though the PhC is structurally imperfect, the existence of leaky modes, determined both theoretically and experimentally in the broad spectral region, implies that an efficient light interaction with a material periodicity occurs in the sample. It is shown that the luminescence emission spectrum of a light source placed directly on the PhC surface can be modified by employing the optical modes of the studied structure. We stress also the impact of intrinsic optical losses of the nano-diamond on this modification.

  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

    2016-06-23

    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.

  10. Crystal Engineering for Low Defect Density and High Efficiency Hybrid Chemical Vapor Deposition Grown Perovskite Solar Cells.

    PubMed

    Ng, Annie; Ren, Zhiwei; Shen, Qian; Cheung, Sin Hang; Gokkaya, Huseyin Cem; So, Shu Kong; Djurišić, Aleksandra B; Wan, Yangyang; Wu, Xiaojun; Surya, Charles

    2016-12-07

    Synthesis of high quality perovskite absorber is a key factor in determining the performance of the solar cells. We demonstrate that hybrid chemical vapor deposition (HCVD) growth technique can provide high level of versatility and repeatability to ensure the optimal conditions for the growth of the perovskite films as well as potential for batch processing. It is found that the growth ambient and degree of crystallization of CH3NH3PbI3 (MAPI) have strong impact on the defect density of MAPI. We demonstrate that HCVD process with slow postdeposition cooling rate can significantly reduce the density of shallow and deep traps in the MAPI due to enhanced material crystallization, while a mixed O2/N2 carrier gas is effective in passivating both shallow and deep traps. By careful control of the perovskite growth process, a champion device with power conversion efficiency of 17.6% is achieved. Our work complements the existing theoretical studies on different types of trap states in MAPI and fills the gap on the theoretical analysis of the interaction between deep levels and oxygen. The experimental results are consistent with the theoretical predictions.

  11. Targeting cholesterol crystal-induced inflammation for the secondary prevention of cardiovascular disease.

    PubMed

    Nidorf, Stefan M; Eikelboom, John W; Thompson, Peter L

    2014-01-01

    Cholesterol crystals are present in nascent and advanced atherosclerotic plaque. Under some conditions, they may enlarge and cause direct plaque trauma or trigger an inflammatory cascade that promotes the growth and instability of atherosclerotic plaque. Therapies that reduce the risk of cholesterol crystal formation or prevent the associated inflammatory response have the potential to improve the clinical outcome of patients with cardiovascular disease. Statins have pleiotropic effects that can reduce the size of the free cholesterol pool contained within atherosclerotic plaques and prevent the formation of cholesterol crystals. Colchicine prevents crystal-induced inflammation by virtue of its ability to inhibit macrophage and neutrophil function. Both statins and colchicine have been demonstrated to reduce the risk of cardiovascular events in patients with stable coronary disease. The efficacy of statins and colchicine for cardiovascular prevention supports the hypothesis that crystal-induced inflammation plays an integral role in the progression and instability of coronary disease. Inhibition of cholesterol crystal-induced inflammation offers a promising new target for the secondary prevention of cardiovascular disease.

  12. Inhibition of Crystal Growth during Plasma Enhanced Atomic Layer Deposition by Applying BIAS

    PubMed Central

    Ratzsch, Stephan; Kley, Ernst-Bernhard; Tünnermann, Andreas; Szeghalmi, Adriana

    2015-01-01

    In this study, the influence of direct current (DC) biasing on the growth of titanium dioxide (TiO2) layers and their nucleation behavior has been investigated. Titania films were prepared by plasma enhanced atomic layer deposition (PEALD) using Ti(OiPr)4 as metal organic precursor. Oxygen plasma, provided by remote inductively coupled plasma, was used as an oxygen source. The TiO2 films were deposited with and without DC biasing. A strong dependence of the applied voltage on the formation of crystallites in the TiO2 layer is shown. These crystallites form spherical hillocks on the surface which causes high surface roughness. By applying a higher voltage than the plasma potential no hillock appears on the surface. Based on these results, it seems likely, that ions are responsible for the nucleation and hillock growth. Hence, the hillock formation can be controlled by controlling the ion energy and ion flux. The growth per cycle remains unchanged, whereas the refractive index slightly decreases in the absence of energetic oxygen ions. PMID:28793679

  13. Phase-coherent transport in catalyst-free vapor phase deposited Bi2Se3 crystals

    NASA Astrophysics Data System (ADS)

    Ockelmann, R.; Müller, A.; Hwang, J. H.; Jafarpisheh, S.; Drögeler, M.; Beschoten, B.; Stampfer, C.

    2015-08-01

    Freestanding Bi2Se3 single-crystal flakes of variable thicknesses are grown using a catalyst-free vapor-solid synthesis and are subsequently transferred onto a clean Si++/SiO2 substrate where the flakes are contacted in Hall bar geometry. Low-temperature magnetoresistance measurements are presented which show a linear magnetoresistance for high magnetic fields and weak antilocalization (WAL) at low fields. Despite an overall strong charge-carrier tunability for thinner devices, we find that electron transport is dominated by bulk contributions for all devices. Phase-coherence lengths lϕ as extracted from WAL measurements increase linearly with increasing electron density exceeding 1 μ m at 1.7 K. Although lϕ is in qualitative agreement with electron-electron interaction-induced dephasing, we find that spin-flip scattering processes limit lϕ at low temperatures.

  14. Pulsed Laser Deposition of VO2 Single Crystal Thin Films on Sapphire Substrates

    NASA Astrophysics Data System (ADS)

    Zhu, Pei-ran; S, Yamamoto; A, Miyashita; H, Naramoto

    1998-12-01

    Thin films of VO2 single-crystalline on (0001) sapphire substrates have been prepared by visible pulsed laser ablation technique. The crystal quality and properties of the films are evaluated through electrical resistance measurement, x-ray diffraction (XRD), and Rutherford-backscattering spectroscopy/channeling (RBS/C) analysis. The dependence of the surface electrical resistance of the films on the temperature shows semiconductor-to-metal transitions with the resistance change of 7 × 103-2 × 104. The hysteresis widths are from less than 1 to 3 K. XRD and RBS/C data reveal that the films prepared in particular conditions are single-crystalline VO2 with the (010) planes parallel to the surface of the sapphire substrate.

  15. 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.

  16. Chronic sleep fragmentation exacerbates amyloid β deposition in Alzheimer's disease model mice.

    PubMed

    Minakawa, Eiko N; Miyazaki, Koyomi; Maruo, Kazushi; Yagihara, Hiroko; Fujita, Hiromi; Wada, Keiji; Nagai, Yoshitaka

    2017-07-13

    Sleep fragmentation due to intermittent nocturnal arousal resulting in a reduction of total sleep time and sleep efficiency is a common symptom among people with Alzheimer's disease (AD) and elderly people with normal cognitive function. Although epidemiological studies have indicated an association between sleep fragmentation and elevated risk of AD, a relevant disease model to elucidate the underlying mechanisms was lacking owing to technical limitations. Here we successfully induced chronic sleep fragmentation in AD model mice using a recently developed running-wheel-based device and demonstrate that chronic sleep fragmentation increases amyloid β deposition. Notably, the severity of amyloid β deposition exhibited a significant positive correlation with the extent of sleep fragmentation. These findings provide a useful contribution to the development of novel treatments that decelerate the disease course of AD in the patients, or decrease the risk of developing AD in healthy elderly people through the improvement of sleep quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. FTIR imaging of brain tissue reveals crystalline creatine deposits are an ex vivo marker of localized ischemia during murine cerebral malaria: general implications for disease neurochemistry.

    PubMed

    Hackett, Mark J; Lee, Joonsup; El-Assaad, Fatima; McQuillan, James A; Carter, Elizabeth A; Grau, Georges E; Hunt, Nicholas H; Lay, Peter A

    2012-12-19

    Phosphocreatine is a major cellular source of high energy phosphates, which is crucial to maintain cell viability under conditions of impaired metabolic states, such as decreased oxygen and energy availability (i.e., ischemia). Many methods exist for the bulk analysis of phosphocreatine and its dephosphorylated product creatine; however, no method exists to image the distribution of creatine or phosphocreatine at the cellular level. In this study, Fourier transform infrared (FTIR) spectroscopic imaging has revealed the ex vivo development of creatine microdeposits in situ in the brain region most affected by the disease, the cerebellum of cerebral malaria (CM) diseased mice; however, such deposits were also observed at significantly lower levels in the brains of control mice and mice with severe malaria. In addition, the number of deposits was observed to increase in a time-dependent manner during dehydration post tissue cutting. This challenges the hypotheses in recent reports of FTIR spectroscopic imaging where creatine microdeposits found in situ within thin sections from epileptic, Alzheimer's (AD), and amlyoid lateral sclerosis (ALS) diseased brains were proposed to be disease specific markers and/or postulated to contribute to the brain pathogenesis. As such, a detailed investigation was undertaken, which has established that the creatine microdeposits exist as the highly soluble HCl salt or zwitterion and are an ex-vivo tissue processing artifact and, hence, have no effect on disease pathogenesis. They occur as a result of creatine crystallization during dehydration (i.e., air-drying) of thin sections of brain tissue. As ischemia and decreased aerobic (oxidative metabolism) are common to many brain disorders, regions of elevated creatine-to-phosphocreatine ratio are likely to promote crystal formation during tissue dehydration (due to the lower water solubility of creatine relative to phosphocreatine). The results of this study have demonstrated that

  18. FTIR Imaging of Brain Tissue Reveals Crystalline Creatine Deposits Are an ex Vivo Marker of Localized Ischemia during Murine Cerebral Malaria: General Implications for Disease Neurochemistry

    PubMed Central

    2012-01-01

    Phosphocreatine is a major cellular source of high energy phosphates, which is crucial to maintain cell viability under conditions of impaired metabolic states, such as decreased oxygen and energy availability (i.e., ischemia). Many methods exist for the bulk analysis of phosphocreatine and its dephosphorylated product creatine; however, no method exists to image the distribution of creatine or phosphocreatine at the cellular level. In this study, Fourier transform infrared (FTIR) spectroscopic imaging has revealed the ex vivo development of creatine microdeposits in situ in the brain region most affected by the disease, the cerebellum of cerebral malaria (CM) diseased mice; however, such deposits were also observed at significantly lower levels in the brains of control mice and mice with severe malaria. In addition, the number of deposits was observed to increase in a time-dependent manner during dehydration post tissue cutting. This challenges the hypotheses in recent reports of FTIR spectroscopic imaging where creatine microdeposits found in situ within thin sections from epileptic, Alzheimer’s (AD), and amlyoid lateral sclerosis (ALS) diseased brains were proposed to be disease specific markers and/or postulated to contribute to the brain pathogenesis. As such, a detailed investigation was undertaken, which has established that the creatine microdeposits exist as the highly soluble HCl salt or zwitterion and are an ex-vivo tissue processing artifact and, hence, have no effect on disease pathogenesis. They occur as a result of creatine crystallization during dehydration (i.e., air-drying) of thin sections of brain tissue. As ischemia and decreased aerobic (oxidative metabolism) are common to many brain disorders, regions of elevated creatine-to-phosphocreatine ratio are likely to promote crystal formation during tissue dehydration (due to the lower water solubility of creatine relative to phosphocreatine). The results of this study have demonstrated that

  19. A de novo monoclonal immunoglobulin deposition disease in a kidney transplant recipient: a case report.

    PubMed

    Savenkoff, Benjamin; Aubertin, Perrine; Ladriere, Marc; Hulin, Cyril; Champigneulle, Jacqueline; Frimat, Luc

    2014-06-18

    Myeloma following kidney transplantation is a rare entity. It can be divided into two groups: relapse of a previous myeloma and de novo myeloma. Some of these myelomas can be complicated by a monoclonal immunoglobulin deposition disease, which is even less common. Less than ten cases of monoclonal immunoglobulin deposition disease after renal graft have been reported in the literature. The treatment of these patients is not well codified. We report the case of a 43-year-old white European man who received a renal transplant for a nephropathy of unknown etiology and developed a nephrotic syndrome with kidney failure at 2-years follow-up. We diagnosed a de novo monoclonal immunoglobulin deposition disease associated with a kappa light chain multiple myeloma, which is a very uncommon presentation for this disease. Three risk factors were identified in this patient: Epstein-Barr virus reactivation with cytomegalovirus co-infection; intensified immunosuppressive therapy during two previous rejection episodes; and human leukocyte antigen-B mismatches. Chemotherapy treatment and decrease in the immunosuppressive therapy were followed by remission and slight improvement of renal function. A relapse occurred 8 months later and his renal function worsened rapidly requiring hemodialysis. He died from septic shock 4 years after the diagnosis of monoclonal immunoglobulin deposition disease. This rare case of post-transplant lymphoproliferative disorder with an uncommon presentation illustrates the fact that treatment in such a situation is very difficult to manage because of a small number of patients reported and a lack of information on this disease. There are no guidelines, especially concerning the immunosuppressive therapy management.

  20. A de novo monoclonal immunoglobulin deposition disease in a kidney transplant recipient: a case report

    PubMed Central

    2014-01-01

    Introduction Myeloma following kidney transplantation is a rare entity. It can be divided into two groups: relapse of a previous myeloma and de novo myeloma. Some of these myelomas can be complicated by a monoclonal immunoglobulin deposition disease, which is even less common. Less than ten cases of monoclonal immunoglobulin deposition disease after renal graft have been reported in the literature. The treatment of these patients is not well codified. Case presentation We report the case of a 43-year-old white European man who received a renal transplant for a nephropathy of unknown etiology and developed a nephrotic syndrome with kidney failure at 2-years follow-up. We diagnosed a de novo monoclonal immunoglobulin deposition disease associated with a kappa light chain multiple myeloma, which is a very uncommon presentation for this disease. Three risk factors were identified in this patient: Epstein–Barr virus reactivation with cytomegalovirus co-infection; intensified immunosuppressive therapy during two previous rejection episodes; and human leukocyte antigen-B mismatches. Chemotherapy treatment and decrease in the immunosuppressive therapy were followed by remission and slight improvement of renal function. A relapse occurred 8 months later and his renal function worsened rapidly requiring hemodialysis. He died from septic shock 4 years after the diagnosis of monoclonal immunoglobulin deposition disease. Conclusions This rare case of post-transplant lymphoproliferative disorder with an uncommon presentation illustrates the fact that treatment in such a situation is very difficult to manage because of a small number of patients reported and a lack of information on this disease. There are no guidelines, especially concerning the immunosuppressive therapy management. PMID:24942882

  1. 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

  2. Antimony-based ligand exchange to promote crystallization in spray-deposited Cu2ZnSnSe4 solar cells.

    PubMed

    Carrete, Alex; Shavel, Alexey; Fontané, Xavier; Montserrat, Joana; Fan, Jiandong; Ibáñez, Maria; Saucedo, Edgardo; Pérez-Rodríguez, Alejandro; Cabot, Andreu

    2013-10-30

    A multistrategy approach to overcome the main challenges of nanoparticle-based solution-processed Cu2ZnSnSe4 thin film solar cells is presented. We developed an efficient ligand exchange strategy, using an antimony salt, to displace organic ligands from the surface of Cu2ZnSnS4 nanoparticles. An automated pulsed spray-deposition system was used to deposit the nanoparticles into homogeneous and crack-free films with controlled thickness. After annealing the film in a Se-rich atmosphere, carbon-free and crystalline Cu2ZnSnSe4 absorber layers were obtained. Not only was crystallization promoted by the complete removal of organics, but also Sb itself played a critical role. The Sb-assisted crystal growth is associated with the formation of a Sb-based compound at the grain boundaries, which locally reduces the melting point, thus promoting the film diffusion-limited crystallization.

  3. Hyperoxaluria Requires TNF Receptors to Initiate Crystal Adhesion and Kidney Stone Disease.

    PubMed

    Mulay, Shrikant R; Eberhard, Jonathan N; Desai, Jyaysi; Marschner, Julian A; Kumar, Santhosh V R; Weidenbusch, Marc; Grigorescu, Melissa; Lech, Maciej; Eltrich, Nuru; Müller, Lisa; Hans, Wolfgang; Hrabě de Angelis, Martin; Vielhauer, Volker; Hoppe, Bernd; Asplin, John; Burzlaff, Nicolai; Herrmann, Martin; Evan, Andrew; Anders, Hans-Joachim

    2017-03-01

    Intrarenal crystals trigger inflammation and renal cell necroptosis, processes that involve TNF receptor (TNFR) signaling. Here, we tested the hypothesis that TNFRs also have a direct role in tubular crystal deposition and progression of hyperoxaluria-related CKD. Immunohistochemical analysis revealed upregulated tubular expression of TNFR1 and TNFR2 in human and murine kidneys with calcium oxalate (CaOx) nephrocalcinosis-related CKD compared with controls. Western blot and mRNA expression analyses in mice yielded consistent data. When fed an oxalate-rich diet, wild-type mice developed progressive CKD, whereas Tnfr1-, Tnfr2-, and Tnfr1/2-deficient mice did not. Despite identical levels of hyperoxaluria, Tnfr1-, Tnfr2-, and Tnfr1/2-deficient mice also lacked the intrarenal CaOx deposition and tubular damage observed in wild-type mice. Inhibition of TNFR signaling prevented the induced expression of the crystal adhesion molecules, CD44 and annexin II, in tubular epithelial cells in vitro and in vivo, and treatment with the small molecule TNFR inhibitor R-7050 partially protected hyperoxaluric mice from nephrocalcinosis and CKD. We conclude that TNFR signaling is essential for CaOx crystal adhesion to the luminal membrane of renal tubules as a fundamental initiating mechanism of oxalate nephropathy. Furthermore, therapeutic blockade of TNFR might delay progressive forms of nephrocalcinosis in oxalate nephropathy, such as primary hyperoxaluria.

  4. 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.

  5. 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

    SciTech Connect

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

    2016-04-15

    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.

  6. IgA glomerulonephritis. Mesangial IgA deposition without systemic signs (Berger's disease).

    PubMed

    Nagy, J; Brasch, H; Süle, T; Hámori, A; Deák, G; Ambrus, M

    1979-01-01

    Renal biopsy specimens from 204 patients with glomerulonephritis or nephrotic syndrome have been studied. In ten of the patients not suffering from acute poststreptococcal glomerulonephritis, systemic lupus erythematosus or Schönlein-Henoch syndrome, diffuse, selective mesangial IgA deposition was observed. Clinically, persistent microscopic haematuria, mild proteinuria and, except in one patient, normal renal function were found. Light microscopically the histological picture was dominated by a diffuse or focal increase in volume of the mesangial matrix, and mild mesangial cell proliferation. Exceptionally, there was also crescent formation. Immunofluorescence revealed large IgA, IgG and C3 deposits, as well as small IgM and fibrinogen deposits in the mesangial glomeruli. The authors' assumption that immunocomplexes containing a secretory component might be implicated in the pathomechanism of Berger's disease, could not be proved.

  7. Decreased serum ceruloplasmin levels characteristically aggravate nigral iron deposition in Parkinson's disease.

    PubMed

    Jin, Lirong; Wang, Jian; Zhao, Lei; Jin, Hang; Fei, Guoqiang; Zhang, Yuwen; Zeng, Mengsu; Zhong, Chunjiu

    2011-01-01

    In vivo and post-mortem studies have demonstrated that increased nigral iron content in patients with Parkinson's disease is a prominent pathophysiological feature. However, the mechanism and risk factors associated with nigral iron deposition in patients with Parkinson's disease have not been identified and represent a key challenge in understanding its pathogenesis and for its diagnosis. In this study, we assessed iron levels in patients with Parkinson's disease and in age- and gender-matched control subjects by measuring phase values using magnetic resonance based susceptibility-weighted phase imaging in a 3T magnetic resonance system. Phase values were measured from brain regions including bilateral substantia nigra, globus pallidus, putamen, caudate, thalamus, red nucleus and frontal white matter of 45 patients with Parkinson's disease with decreased or normal serum ceruloplasmin levels, together with age- and gender-matched control subjects. Correlative analyses between phase values, serum ceruloplasmin levels and disease severity showed that the nigral bilateral average phase values in patients with Parkinson's disease were significantly lower than in control subjects and correlated with disease severity according to the Hoehn and Yahr Scale. The Unified Parkinson's Disease Rating Scale motor scores from the clinically most affected side were significantly correlated with the phase values of the contralateral substantia nigra. Furthermore, nigral bilateral average phase values correlated highly with the level of serum ceruloplasmin. Specifically, in the subset of patients with Parkinson's disease exhibiting reduced levels of serum ceruloplasmin, we found lowered nigral bilateral average phase values, suggesting increased nigral iron content, while those patients with normal levels of serum ceruloplasmin exhibited no changes as compared with control subjects. These findings suggest that decreased levels of serum ceruloplasmin may specifically exacerbate

  8. Molecular mechanisms of the co-deposition of multiple pathological proteins in neurodegenerative diseases.

    PubMed

    Nonaka, Takashi; Masuda-Suzukake, Masami; Hasegawa, Masato

    2017-09-25

    Intracellular inclusions composed of abnormal protein aggregates are one of the neuropathological features of neurodegenerative diseases, and the formation of intracellular aggregates is believed to be associated with neurodegeneration leading to the onset of these diseases. In typical or pure cases, characteristic pathologies with one particular protein, such as tau, alpha-synuclein or trans-activation response DNA protein 43 (TDP-43), can be observed in brains of patients. On the other hand, multiple protein pathologies co-exist in many cases, raising the possibility that they may influence each other reciprocally in the pathogenesis and progression of the diseases. However, the molecular mechanisms through which these proteins interact with each other and through which they are co-deposited in brains of patients remain poorly understood. In this review, we focus on the mechanisms of deposition of multiple pathological proteins, such as tau, alpha-synuclein and/or TDP-43, and on co-deposition models of these proteins in vitro and in vivo intended to recapitulate the multiple pathologies found in diseased brains. © 2017 Japanese Society of Neuropathology.

  9. Renal involvement of monoclonal immunoglobulin deposition disease associated with an unusual monoclonal immunoglobulin A glycan profile.

    PubMed

    Kaneko, Syuzou; Usui, Joichi; Narimatsu, Yoshiki; Ito, Hiromi; Narimatsu, Hisashi; Hagiwara, Masahiro; Tsuruoka, Shuichi; Nagata, Michio; Yamagata, Kunihiro

    2010-08-01

    A 38-year-old man was admitted to the hospital for the evaluation of proteinuria, microscopic hematuria, and monoclonal IgA-kappa gammopathy. The initial renal pathological findings showed mesangial proliferative glomerulonephritis with endocapillary proliferation, a necrotizing lesion, and cellular crescent formation accompanied by IgA1-kappa deposition in the mesangium. Neither typical immune-complex deposits nor organized-structure deposits were detected. We diagnosed the patient with monoclonal immunoglobulin deposition disease (MIDD) associated with monoclonal IgA (mIgA). After the initiation of a monthly treatment with melphalan and predonisolone (MP therapy), the patient's serum IgA levels declined, and clinical remission was ultimately achieved. The follow-up renal biopsy showed reduced IgA-kappa staining, and both the endocapillary proliferation and the necrotizing lesion had disappeared. To elucidate the mechanism of IgA deposition, we investigated the glycan profile of the patient's serum mIgA using a mass spectrometry technique. The results revealed an unusual N-glycan profile compared to that of another patient with circulating mIgA lacking renal involvement and that of a healthy control. mIgA deposition in the mesangial area is a rare disease, and the glycan profiling of MIDD with renal involvement has not been reported previously. Thus, the present case suggests that any variation in Ig glycosylation may be a step in the pathogenesis of MIDD with renal involvement and/or contribute to some cases of IgA nephropathy.

  10. On the solid phase crystallization of In{sub 2}O{sub 3}:H transparent conductive oxide films prepared by atomic layer deposition

    SciTech Connect

    Macco, Bart; Verheijen, Marcel A.; Black, Lachlan E.; Melskens, J.; Barcones, Beatriz

    2016-08-28

    Hydrogen-doped indium oxide (In{sub 2}O{sub 3}:H) has emerged as a highly transparent and conductive oxide, finding its application in a multitude of optoelectronic devices. Recently, we have reported on an atomic layer deposition (ALD) process to prepare high quality In{sub 2}O{sub 3}:H. This process consists of ALD of In{sub 2}O{sub 3}:H films at 100 °C, followed by a solid phase crystallization step at 150–200 °C. In this work, we report on a detailed electron microscopy study of this crystallization process which reveals new insights into the crucial aspects for achieving the large grain size and associated excellent properties of the material. The key finding is that the best optoelectronic properties are obtained by preparing the films at the lowest possible temperature prior to post-deposition annealing. Electron microscopy imaging shows that such films are mostly amorphous, but feature a very low density of embedded crystallites. Upon post-deposition annealing, crystallization proceeds merely from isotropic crystal grain growth of these embedded crystallites rather than by the formation of additional crystallites. The relatively high hydrogen content of 4.2 at. % in these films is thought to cause the absence of additional nucleation, thereby rendering the final grain size and optoelectronic properties solely dependent on the density of embedded crystallites. The temperature-dependent grain growth rate has been determined, from which an activation energy of (1.39 ± 0.04) eV has been extracted. Finally, on the basis of the observed crystallization mechanism, a simple model to fully describe the crystallization process has been developed. This model has been validated with a numerical implementation thereof, which accurately predicts the observed temperature-dependent crystallization behaviour.

  11. 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

  12. Minimally Invasive Treatment of Pilonidal Disease: Crystallized Phenol and Laser Depilation

    PubMed Central

    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

  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.

  14. Ilmenite composition in the Tellnes Fe-Ti deposit, SW Norway: fractional crystallization, postcumulus evolution and ilmenite-zircon relation

    NASA Astrophysics Data System (ADS)

    Charlier, Bernard; Skår, Øyvind; Korneliussen, Are; Duchesne, Jean-Clair; Vander Auwera, Jacqueline

    2007-08-01

    Major and trace element XRF and in situ LA-ICP-MS analyses of ilmenite in the Tellnes ilmenite deposit, Rogaland Anorthosite Province, SW Norway, constrains a two stage fractional crystallization model of a ferrodioritic Fe-Ti-P rich melt. Stage 1 is characterized by ilmenite-plagioclase cumulates, partly stored in the lower part of the ore body (Lower Central Zone, LCZ), and stage 2 by ilmenite-plagioclase-orthopyroxene-olivine cumulates (Upper Central Zone, UCZ). The concentration of V and Cr in ilmenite, corrected for the trapped liquid effect, (1) defines the cotectic proportion of ilmenite to be 17.5 wt% during stage 1, and (2) implies an increase of D {V/Ilm} during stage 2, most likely related to a shift in fO2. The proportion of 17.5 wt% is lower than the modal proportion of ilmenite (ca. 50 wt%) in the ore body, implying accumulation of ilmenite and flotation of plagioclase. The fraction of residual liquid left after crystallization of Tellnes cumulates is estimated at 0.6 and the flotation of plagioclase at 26 wt% of the initial melt mass. The increasing content of intercumulus magnetite with stratigraphic height, from 0 to ca. 3 wt%, results from differentiation of the trapped liquid towards magnetite saturation. The MgO content of ilmenite (1.4-4.4 wt%) is much lower than the expected cumulus composition. It shows extensive postcumulus re-equilibration with trapped liquid and ferromagnesian silicates, correlated with distance to the host anorthosite. The Zr content of ilmenite, provided by in situ analyses, is low (<114 ppm) and uncorrelated with stratigraphy or Cr content. The data demonstrate that zircon coronas observed around ilmenite formed by subsolidus exsolution of ZrO2 from ilmenite. The U-Pb zircon age of 920 ± 3 Ma probably records this exsolution process.

  15. Humeral Lateral Epicondylitis Complicated by Hydroxyapatite Dihydrite Deposition Disease: A Case Report

    PubMed Central

    Marchand, Andrée-Anne; O’Shaughnessy, Julie; Descarreaux, Martin

    2014-01-01

    Objective The aim of this case report is to differentiate the recovery timeline expected for patients with simple lateral epicondylitis from an abnormal recovery period, in which case an underlying condition should be suspected. Clinical features A 49-year-old woman presented to a chiropractic clinic with posterolateral right elbow pain. The history included chronic recurrent lateral elbow pain, followed by a traumatic event leading to sustained pain and disability. Intervention and outcomes Following a trial of conservative therapy including activity restrictions, soft tissue therapy, joint mobilizations, and therapeutic ultrasonography that led to no significant improvement, the patient was referred for diagnostic imaging that revealed hydroxyapatite dihydrite deposition disease. Conclusion This report describes a case for which lateral epicondylitis symptoms failed to resolve because of an underlying condition (hydroxyapatite dihydrite deposition disease). This case emphasizes that primary care practitioners treating lateral epicondylitis should consider referral for further investigations when positive results are not achieved. PMID:24711788

  16. 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.

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

    SciTech Connect

    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 {sup 6}LiF converting layer. Fast neutrons are directly detected in the CVD diamond bulk, since they have enough energy to produce the {sup 12}C(n,{alpha}){sup 9}Be reaction in diamond. Thermal neutrons are instead converted into charged particles in the {sup 6}LiF layer through the {sup 6}Li(n,{alpha})T nuclear reaction. These charged particles are then detected in the diamond layer. The thickness of the {sup 6}LiF 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 {sup 6}Li(n,{alpha})T and the {sup 12}C(n,{alpha}){sup 9}Be 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 {sup 6}LiF 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.

  18. Geochemistry of the Topuk Pluton associated with the Kozbudaklar W-skarn deposit (Western Anatolia, Turkey): Implication for crystallization conditions

    NASA Astrophysics Data System (ADS)

    Orhan, Ayşe; Demirbilek, Mehmet; Mutlu, Halim

    2017-06-01

    The Kozbudaklar scheelite-bearing skarn deposit in the Tavşanlı Zone, western Turkey, occurs at the contact between Eocene Topuk pluton and Triassic İnönü marble of calcic character. The Topuk pluton is medium-coarse grained, granodiorite in composition and has a hypidiomorphic equigranular texture. The host rock contains mafic microgranular enclaves (MME) of monzodiorite-monzogabbro composition and is interrupted by porphyritic granodiorite and granite-aplite vein rocks. The pluton is calk-alkaline, metaluminous and composed of I-type melt character. δ18O and δD compositions of silicate minerals from granodioritic host rock are 5.9-10.6‰ and -77.0 to -71.4‰ and conformable with the range of unaltered I-type granites. Trace element contents indicate that pluton is crystallized from mantle-derived magma interacted with continental crust in a volcanic arc or subduction related setting. Major and trace element concentrations of Topuk pluton are quite consistent with geochemical patterns of Cu-skarn granitoids. Results of mineral chemistry analysis of the pluton yield that plagioclases are of oligoclase-andesine, amphiboles are of magnesio-hornblende and biotites are of ferro-magnesian composition. Amphiboles and biotites of granodioritic host rock are represented by calc-alkaline, I-type melt composition evolved in a subduction environment. Based on the results of plagioclase-Al in hornblende and amphibole chemistry data from the pluton, two different stages are proposed for the magma crystallization. The first stage was developed in a relatively deeper environment (>15 km) under high pressure (>4 kbar) and low log ƒO2 (>-17.6) conditions which reflect fractional crystallization and magma-mixing depth of basaltic magma and these conditions are not correlated with scheelite mineralization. The second crystallization stage of magma which proceeded at shallow depths (<6 km) was also developed in two separate phases with respect to P-T conditions. The first

  19. Crystal-Structure-Based Modeling Study of Temperature-Dependent Fracture Toughness for Brittle Coating Deposited on Ductile Substrate

    NASA Astrophysics Data System (ADS)

    Gu, Yichen; Chen, Kuiying; Liu, Rong; Yao, Matthew X.; Collier, Rachel

    2016-10-01

    The temperature-dependent fracture toughness of a brittle coating/ductile substrate system, WC-10Co4Cr deposited on 1018 low carbon steel, is evaluated at microscopic level using an indentation-based model in terms of the Arrhenius-type equation and rate-controlling theory. The formulation of the model utilizes the parameters of crystal structures of each phase in the coating material. The slip systems of hard hexagonal δ-WC phase and soft FCC α-Co phase are analyzed. The fracture toughness of the two-phase coating is obtained by integrating the fracture toughness of single δ-WC phase coating and that of single α-Co phase coating using either the basic mixture method or the unconstrained mixture method. The results suggest that the fracture toughness of WC-10Co4Cr coating/1018 low carbon steel substrate system may remain constant until the temperature reaches a critical value, about 200 K, and ranges from 2.16 to 10.82 {{MPa}}{{m}}^{1/2} , with temperature increasing from room temperature (298 K) to 1000 K.

  20. 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.

  1. Superconductivity of oxide film electrolytically deposited on surface of B(1-x)Sb(x) single crystal

    NASA Astrophysics Data System (ADS)

    Alfeyev, V. N.; Aminov, B. A.; Brandt, N. B.; Vasina, S. Ya.; Damaskin, B. B.; Zigel, M.; Kuznetsov, V. P.; Petriy, O. A.; Ponomarev, Ya. G.; Sudakova, M. V.

    1990-10-01

    An experimental study was made of thin oxide films electrolytically deposited on the surface of Bi(1-x)Sb(x) single crystals (x from 0.1 to 0.3) at room temperature, the electrolyte consisting of acetonitrile as solvent with salicylic acid as conductive additive and containing copper ions. The current-voltage characteristics of point junctions produced by mechanical pressure on oxidized surfaces were measured at temperatures ranging from 1.7 K to above 20 K. They were found in most cases to be characteristic of Josephson junctions, with a critical current in the milliampere range at 4.2 K, with Mersero constant-period oscillations of the differential electrical conductance dI/dV near zero voltage in a magnetic field, and with Shapiro plateaus in a microwave field. The critical temperature of superconducting transition corresponding to maximum differential electrical conductance near zero voltage was found to be within 6 to 8 K in most cases and 20 K or higher in some cases.

  2. 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.

  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.

  4. Age-related iron deposition in the basal ganglia of controls and Alzheimer disease patients quantified using susceptibility weighted imaging.

    PubMed

    Wang, Dan; Li, Yan-Ying; Luo, Jian-Hua; Li, Yue-Hua

    2014-01-01

    This study aimed to investigate age-related iron deposition changes in healthy subjects and Alzheimer disease patients using susceptibility weighted imaging. The study recruited 182 people, including 143 healthy volunteers and 39 Alzheimer disease patients. All underwent conventional magnetic resonance imaging and susceptibility weighted imaging sequences. The groups were divided according to age. Phase images were used to investigate iron deposition in the bilateral head of the caudate nucleus, globus pallidus and putamen, and the angle radian value was calculated. We hypothesized that age-related iron deposition changes may be different between Alzheimer disease patients and controls of the same age, and that susceptibility weighted imaging would be a more sensitive method of iron deposition quantification. The results revealed that iron deposition in the globus pallidus increased with age, up to 40 years. In the head of the caudate nucleus, iron deposition peaked at 60 years. There was a general increasing trend with age in the putamen, up to 50-70 years old. There was significant difference between the control and Alzheimer disease groups in the bilateral globus pallidus in both the 60-70 and 70-80 year old group comparisons. In conclusion, iron deposition increased with age in the globus pallidus, the head of the caudate nucleus and putamen, reaching a plateau at different ages. Furthermore, comparisons between the control and Alzheimer disease group revealed that iron deposition changes were more easily detected in the globus pallidus.

  5. Crystal nephropathies: mechanisms of crystal-induced kidney injury.

    PubMed

    Mulay, Shrikant R; Anders, Hans-Joachim

    2017-04-01

    Crystals can trigger a wide range of kidney injuries that can lead to acute kidney injury, chronic kidney disease, renal colic or nephrocalcinosis, depending on the localization and dynamics of crystal deposition. Studies of the biology of crystal handling by the kidney have shown that the formation of different crystals and other microparticles and the associated mechanisms of renal damage share molecular mechanisms, such as stimulation of the NLRP3 inflammasome or direct cytotoxicity through activation of the necroptosis signalling pathway. By contrast, crystal granuloma formation is limited to chronic crystallopathies that lead to chronic kidney disease and renal fibrosis. Here, we discuss current understanding of the pathomechanisms underlying the different types of crystal-induced kidney injury and propose a classification of crystal nephropathies based on the localization of crystal deposits in the renal vasculature (type 1), the nephron (type 2), or the draining urinary tract (type 3). Further exploration of the molecular mechanisms of crystal-induced kidney injury and renal remodelling might aid the development of innovative cures for these diseases.

  6. CONTRASTING HISTOPATHOLOGY AND CRYSTAL DEPOSITS IN KIDNEYS OF IDIOPATHIC STONE FORMERS WHO PRODUCE HYDROXY APATITE, BRUSHITE, OR CALCIUM OXALATE STONES

    PubMed Central

    Evan, Andrew P; Lingeman, James E; Worcester, Elaine M; Sommer, Andre J; Phillips, Carrie L; Williams, James C; Coe, Fredric L

    2014-01-01

    Our previous work has shown that stone formers who form calcium phosphate (CaP) stones that contain any brushite (BRSF) have a distinctive renal histopathology and surgical anatomy when compared to idiopathic calcium oxalate stone formers (ICSF). Here we report on another group of idiopathic CaP stone formers, those forming stone containing primarily hydroxyapatite, in order to clarify in what ways their pathology differs from BRSF and ICSF. Eleven hydroxyapatite stone formers (HASF) (2 males, 9 females) were studied using intra-operative digital photography and biopsy of papillary and cortical regions to measure tissue changes associated with stone formation. Our main finding is that HASF and BRSF differ significantly from each other and that both differ greatly from ICSF. Both BRSF and ICSF patients have significant levels of Randall’s plaque compared to HASF. Intra-tubular deposit number is greater in HASF than BRSF and non-existent in ICSF while deposit size is smaller in HASF than BRSF. Cortical pathology is distinctly greater in BRSF than HASF. Four attached stones were observed in HASF, three in 25 BRSF and 5–10 per ICSF patient. HASF and BRSF differ clinically in that both have higher average urine pH, supersaturation of CaP, and calcium excretion than ICSF. Our work suggests that HASF and BRSF are two distinct and separate diseases and both differ greatly from ICSF. PMID:24478243

  7. Glomeruli of Dense Deposit Disease contain components of the alternative and terminal complement pathway

    PubMed Central

    Sethi, Sanjeev; Gamez, Jeffrey D.; Vrana, Julie A.; Theis, Jason D.; Bergen, H. Robert; Zipfel, Peter F.; Dogan, Ahmet; Smith, Richard J. H.

    2009-01-01

    Dense Deposit Disease (DDD), or membranoproliferative glomerulonephritis type II, is a rare renal disease characterized by dense deposits in the mesangium and along the glomerular basement membranes that can be seen by electron microscopy. Although these deposits contain complement factor C3, as determined by immunofluorescence microscopy, their precise composition remains unknown. To address this question, we used mass spectrometry to identify the proteins in laser microdissected glomeruli isolated from paraffin-embedded tissue of eight confirmed cases of DDD. Compared to glomeruli from five control patients, we found that all of the glomeruli from patients with DDD contain components of the alternative pathway and terminal complement complex. Factor C9 was uniformly present as well as the two fluid-phase regulators of terminal complement complex clusterin and vitronectin. In contrast, in nine patients with immune complex–mediated membranoproliferative glomerulonephritis, glomerular samples contained mainly immunoglobulins and complement factors C3 and C4. Our study shows that in addition to fluid-phase dysregulation of the alternative pathway, soluble components of the terminal complement complex contribute to glomerular lesions found in DDD. PMID:19177158

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

    PubMed

    Löndahl, Jakob; Swietlicki, Erik; Rissler, Jenny; Bengtsson, Agneta; Boman, Christoffer; Blomberg, Anders; Sandström, Thomas

    2012-07-28

    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. To determine respiratory tract deposition of diesel combustion particles in patients with COPD during spontaneous breathing. 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. 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. 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.

  9. 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

  10. Amyloid deposition in Parkinson's disease and cognitive impairment: a systematic review.

    PubMed

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

    2015-06-01

    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 among patients with Parkinson's disease with dementia (PDD), Parkinson's disease with mild cognitive impairment (PD-MCI) and dementia with Lewy bodies (DLB). We included amyloid positron emission tomography (PET) imaging studies using Pittsburgh Compound B (PiB). 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, that is, patients showing AD range cortical Aβ-amyloid deposition. Heterogeneity was assessed. A scatterplot was used to assess publication bias. Overall pooled prevalence of "PiB-positive" studies across all three entities along the spectrum of Parkinson's disease and impaired cognition (specifically PDD, PD-MCI, and DLB) was 0.41 (95% confidence interval [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. Substantial variability occurs 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. The PD-MCI subjects showed overall lower prevalence of PiB-positive studies than reported findings in non-PD-related MCI. © 2015 International Parkinson and Movement Disorder Society. © 2015 International Parkinson and Movement Disorder Society.

  11. 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

  12. Five Sequential Evaluations of Renal Histology in a Patient with Light Chain Deposition Disease

    PubMed Central

    Ueno, Toshiharu; Kikuchi, Koichi; Hazue, Ryo; Mise, Koki; Sumida, Keiichi; Hayami, Noriko; Suwabe, Tatsuya; Hoshino, Junichi; Sawa, Naoki; Arizono, Kenji; Hara, Shigeko; Takaichi, Kenmei; Fujii, Takeshi; Ohashi, Kenichi; Ubara, Yoshifumi

    2016-01-01

    A 58-year-old man was referred to our institution for an evaluation of nephrotic range proteinuria. Renal biopsy showed a marked expansion of the mesangial matrix and thickening of glomerular basement membrane (GBM) in periodic acid-silver methenamine (PAM). Immunofluorescence (IF) revealed strong staining for the monoclonal kappa light chain. EM demonstrated massive subendothelial and mesangial dense deposits. As a result, light chain deposition disease (LCDD) was diagnosed. Melphalan and prednisolone (MP) therapy was started, which was continued for 10 years with minimal complications. Serial evaluations of renal histology revealed the resolution of nodular lesions and the glomeruli became nearly normal. MP therapy can therefore be an effective therapeutic option for LCDD if it is continued over the long term. PMID:27746438

  13. Light-chain deposition disease of the kidney: a case report.

    PubMed

    Darouich, Sihem; Goucha, Rym; Jaafoura, Mohamed Habib; Zekri, Semy; Kheder, Adel; Maiz, Hedi Ben

    2012-04-01

    A 41-year-old man was admitted for evaluation of nephrotic syndrome associated with microhematuria, hypertension, and moderate renal failure. In serum and urine samples, monoclonal IgG-lambda was detected. Bone marrow examination showed normal representation of all cell lines with normal range of plasma cells. Renal biopsy demonstrated diabetes-like nodular glomerulosclerosis. Immunofluorescence failed to demonstrate the presence of kappa or lambda light chains in the kidney. Electron microcopy showed granular electron-dense deposits along the glomerular basement membranes and in the mesangial nodules. The patient was diagnosed as having light-chain deposition disease (LCDD) without evidence of plasma cell dyscrasia. This report was designed to stress the significant challenges that remain in the diagnosis of LCDD-related glomerulopathy. The salient morphological features that help in making an accurate diagnosis are discussed.

  14. [Alcohol consumption and glomerulonephritis caused by IgA mesangial deposits. (Berger's disease)].

    PubMed

    García, R; Silva, R; Silva, D

    1995-01-01

    Alcohol ingestion is considered as a possible pathogenic agent for Berger's disease, since Iga mesangial deposits have been described in liver cirrhosis. Aiming to assess this issue, 28 patients with Berger's disease (BD) and 40 patients with other glomerulopathies (NBD) were subjected to an enquiry about alcohol ingestion. Data was corroborated with 21 close relatives of BD patients and 34 relatives of NBD patients. No differences were observed in reported alcohol intake between BD patients and their relatives, however relatives of NBD patients underestimated their alcohol intake. No differences in alcohol intake, either self-reported or reported by relatives, were observed between BD and NBD patients. It is concluded that no differences in alcohol intake were observed between patients with Berger's disease and subjects with other glomerulopathies.

  15. Relationship between the pattern of hepatic iron deposition and histological severity in nonalcoholic fatty liver disease.

    PubMed

    Nelson, James E; Wilson, Laura; Brunt, Elizabeth M; Yeh, Matthew M; Kleiner, David E; Unalp-Arida, Aynur; Kowdley, Kris V

    2011-02-01

    Previous studies examining the relationship between hepatic iron deposition and histological severity in nonalcoholic fatty liver disease (NAFLD) have been inconclusive. The goal of this study was to examine the relationship between hepatic iron deposition and liver histology in 849 patients enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network. Hepatic iron staining was performed in a central laboratory, and the stains were scored for grade and cellular and parenchymal localization by a central pathology committee; the relationship between the grade and pattern of iron deposition and the clinical, laboratory, and histological variables was examined with univariate and multivariate analyses. Stainable hepatic iron was present in 293 of 849 patients (34.5%) in one of three histological patterns: a hepatocellular (HC) pattern [63/849 (7.4%)], a reticuloendothelial system (RES) cell pattern [91/849 (10.7%)], or a mixed RES/HC pattern [139/849 (16.4%)]. Patients with the RES iron-staining pattern were more likely to have advanced fibrosis compared to those with those with HC iron (P = 0.01). Patients with RES iron were also more likely to have advanced histological features such as fibrosis (P = 0.049), portal inflammation (P = 0.002), HC ballooning (P = 0.006), and definite nonalcoholic steatohepatitis (P = 0.007) compared to those with patients with HC or mixed iron patterns. The presence of RES iron (odds ratio = 1.60, 95% confidence interval = 1.10-2.33, P = 0.015) was independently associated with advanced hepatic fibrosis on multiple regression analysis after adjustments for age, gender, diabetes status, and body mass index. The presence and pattern of hepatic iron deposition are associated with distinct histological features in patients with NAFLD and may have implications for pathophysiology and therapy. Copyright © 2010 American Association for the Study of Liver Diseases.

  16. The effect of crystal structure of TiO2 nanotubes on the formation of calcium phosphate coatings during biomimetic deposition

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Kim, Sun; McLeod, John A.; Li, Jun; Guo, Xiaoxuan; Sham, Tsun-Kong; Liu, Lijia

    2017-02-01

    The crystallization process of bioactive calcium phosphate (CaP) species via biomimetic deposition onto anodic TiO2 nanotubes is investigated. The porous surface of nanostructured TiO2 provides an ideal substrate for CaP crystallization. The compositions of CaP coatings are studied using X-ray absorption near-edge structures (XANES) at the Ca K-edge. Using detection modes with different probing depths, both the surface of the CaP coating and the CaP-TiO2 interface are simultaneously analyzed. Calcium phosphate (CaP) species, such as hydroxyapatite (HAp), octacalcium phosphate (Ca8(HPO4)2(PO4)4·5H2O, OCP), brushite (CaHPO4·2H2O, DCPD), and amorphous calcium phosphate (ACP), are found in the CaP coatings. TiO2 nanotubes of amorphous and anatase phases are comparatively studied to determine their effect on the efficiency of CaP formation and the phase transformation among CaP species in prolonged deposition time. It is found the composition of CaP coating has a strong dependency on the crystal structure of TiO2 substrate and the kinetics (deposition time).

  17. Quartz crystal microbalance studies of Al2O3 atomic layer deposition using trimethylaluminum and water at 125 degrees C.

    PubMed

    Wind, R A; George, S M

    2010-01-28

    Al(2)O(3) atomic layer deposition (ALD) growth with Al(CH(3))(3) (trimethylaluminum (TMA)) and H(2)O as the reactants was examined at the relatively low temperature of 125 degrees C using quartz crystal microbalance (QCM) measurements. The total Al(2)O(3) ALD mass gain per cycle (MGPC) and MGPCs during the individual TMA and H(2)O reactions were measured versus TMA and H(2)O exposures. The Al(2)O(3) MGPC increased with increasing H(2)O and TMA exposures at fixed TMA and H(2)O exposures, respectively. However, the TMA and H(2)O reactions were not completely self-limiting. The slower surface reaction kinetics at lower temperature may require very long exposures for the reactions to reach completion. The Al(2)O(3) MGPCs increased quickly versus H(2)O exposure and slowly reached limiting values that were only weakly dependent on the TMA doses. Small TMA exposures were also sufficient for the Al(2)O(3) MGPCs to reach different limiting values for different H(2)O doses. The TMA MGPCs increased for higher TMA exposures at all H(2)O exposures. In contrast, the H(2)O MGPCs decreased for higher TMA exposures at all H(2)O exposures. This decrease may occur from more dehydroxylation at larger hydroxyl coverages after the H(2)O exposures. The hydroxyl coverage after the H(2)O exposure was dependent only on the H(2)O exposure. The Al(2)O(3) MGPC was also linearly dependent on the hydroxyl coverage after the H(2)O dose. Both the observed hydroxyl coverage versus H(2)O exposure and the Al(2)O(3) ALD growth versus H(2)O and TMA exposures were fit using modified Langmuir adsorption isotherm expressions where the pressures are replaced with exposures. These results should be useful for understanding low-temperature Al(2)O(3) ALD, which is important for coating organic, polymeric, and biological substrates.

  18. Mesangial IgA deposits indicate pathogenesis of anti-glomerular basement membrane disease.

    PubMed

    Wang, Aifeng; Wang, Yongping; Wang, Guobao; Zhou, Zhanmei; Xun, Zhang; Tan, Xiaohui

    2012-05-01

    Anti-glomerular basement membrane (anti-GBM) disease is characterized by crescentic glomerulonephritis with immunoglobulin G (IgG) autoantibodies to the non-collagenous (NC1) domain of α3(IV) collagen presenting along the GBM. The patient clinically manifests with rapidly progressive glomerulonephritis (RPGN) with pulmonary hemorrhage (Goodpasture syndrome). In rare cases, other immunocomplexes of IgA or IgM are involved, but their specificities have not been determined. We report a rare case of a 31-year-old female who was diagnosed as having anti-GBM disease with extensive IgA deposits in the mesangium. This patient presented heavy hematuria, proteinuria with increasing creatinine, but no lung hemorrhage. Renal biopsy showed crescentic glomerulonephritis (type Ⅰ) with strong IgA (3+) as lump and branch shape. Therapies with pulse methylprednisolone, plasmapheresis and cyclophosphamide administration were less effective. This case is different from the present type Ⅰ crescentic glomerulonephritis and the specificity of IgA deposits may implicate the pathogenesis of anti-GBM disease.

  19. Fibrin deposited in the Alzheimer’s disease brain promotes neuronal degeneration

    PubMed Central

    Cortes-Canteli, Marta; Mattei, Larissa; Richards, Allison T.; Norris, Erin H.; Strickland, Sidney

    2014-01-01

    Alzheimer’s disease (AD) is the most common form of dementia and has no effective treatment. Besides the well-known pathological characteristics, this disease also has a vascular component, and substantial evidence shows increased thrombosis as well as a critical role for fibrin(ogen) in AD. This molecule has been implicated in neuroinflammation, neurovascular damage, blood brain barrier permeability, vascular amyloid deposition, and memory deficits that are observed in AD. Here we present evidence demonstrating that fibrin deposition increases in the AD brain and correlates with the degree of pathology. Moreover, we show that fibrin(ogen) is present in areas of dystrophic neurites and that a modest decrease in fibrinogen levels improves neuronal health and ameliorates amyloid pathology in the subiculum of AD mice. Our results further characterize the important role of fibrin(ogen) in this disease and support the design of therapeutic strategies aimed at blocking the interaction between fibrinogen and Aβ and/or normalizing the increased thrombosis present in AD. PMID:25475538

  20. [Formation of IgA deposits in Berger's disease: what we learned from animal models].

    PubMed

    Berthelot, Laureline; Monteiro, Renato C

    2013-01-01

    Immunoglobulin A (IgA) nephropathy (N) is the most common form of primary glomerulonephritis in the world and one of the first cause of end-stage renal failure. IgAN is characterized by the accumulation in mesangial areas of immune complexes containing IgA1. While epidemiology and clinical studies of IgAN are well-established, the mechanism(s) underlying disease development is poorly understood. The pathogenesis of this disease involves the deposition of polymeric and undergalactosylated IgA1 in the mesangium. Quantitative and structural changes of IgA1 play a key role in the development of the disease, due to functional abnormalities of two IgA receptors: the FcαR (CD89) expressed by blood myeloid cells and the transferrin receptor (TfR1) on mesangial cells. Abnormal IgA induces release of soluble CD89, responsible for the formation of circulating IgA complexes. These complexes are trapped by the TfR1 that is overexpressed on mesangial cells in IgAN patients, inducing the expression of transglutaminase 2. This enzyme stabilises IgA deposits at the surface of mesangial cells. These cells are then activated, proliferate and produce proinflammatory cytokines, leading to the loss of renal function.

  1. Hepatic Reticuloendothelial System Cell Iron Deposition is Associated with Increased Apoptosis in Nonalcoholic Fatty Liver Disease

    PubMed Central

    Maliken, Bryan D.; Nelson, James E.; Klintworth, Heather M.; Beauchamp, Mary; Yeh, Matthew M.; Kowdley, Kris V.

    2013-01-01

    The goal of this study was to examine the relationship between presence of hepatic iron deposition, apoptosis, histologic features and serum markers of oxidative stress and cell death in nonalcoholic fatty liver disease. Clinical, biochemical, metabolic and independent histopathologic assessment was conducted in 83 unselected patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD)from a single center. Apoptosis and necrosis in serum was quantified using serum cytokeratin-18(CK18) M30 and M65ELISAsand in liver by TUNEL stainingin situ. Serum malondialdehyde(MDA) and thioredoxin-1 (Trx-1) levels were measured to evaluate oxidative stress. Presence of reticuloendothelial system cell (RES) iron in the liver was associated with nonalcoholic steatohepatitis (p<0.05) and increased hepatic TUNEL staining (p=0.02),as well as increased serum levels of apoptosis-specific (M30, p=0.013) and total (M65, p=0.006) CK-18 fragments, higher MDA (p=0.002) and lower antioxidant Trx-1 levels (p=0.012) compared to patients without stainable hepatic iron. NAFLD patients with a hepatocellular iron staining pattern also had increased serum MDA (p=0.006) but not M30 CK-18 levels or TUNEL staining compared to subjects without stainable hepatic iron. Patients with iron deposition limited to hepatocytes had a lower proportion of apoptosis-specific M30 fragments relative to total M65 CK-18 levels (37% vs. ≤ 25%, p<0.05). Conclusions Presence of iron in liver RES cells is associated with NASH, increased apoptosis and increased oxidative stress. Hepatocellular iron deposition in NAFLD is also associated with oxidative stress and may promote hepatocyte necrosis in this disease. PMID:23325576

  2. Hepatic reticuloendothelial system cell iron deposition is associated with increased apoptosis in nonalcoholic fatty liver disease.

    PubMed

    Maliken, Bryan D; Nelson, James E; Klintworth, Heather M; Beauchamp, Mary; Yeh, Matthew M; Kowdley, Kris V

    2013-05-01

    The aim of this study was to examine the relationship between the presence of hepatic iron deposition, apoptosis, histologic features, and serum markers of oxidative stress (OS) and cell death in nonalcoholic fatty liver disease (NAFLD). Clinical, biochemical, metabolic, and independent histopathologic assessment was conducted in 83 unselected patients with biopsy-proven NAFLD from a single center. Apoptosis and necrosis in serum was quantified using serum cytokeratin 18 (CK18) M30 and M65 enzyme-linked immunosorbent assays and in liver by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining in situ. Serum malondialdehyde (MDA) and thioredoxin-1 (Trx1) levels were measured to evaluate OS. Presence of reticuloendothelial system (RES) cell iron in the liver was associated with nonalcoholic steatohepatitis (P < 0.05) and increased hepatic TUNEL staining (P = 0.02), as well as increased serum levels of apoptosis-specific (M30; P = 0.013) and total (M65; P = 0.006) CK18 fragments, higher MDA (P = 0.002) and lower antioxidant Trx1 levels (P = 0.012), compared to patients without stainable hepatic iron. NAFLD patients with a hepatocellular (HC) iron staining pattern also had increased serum MDA (P = 0.006), but not M30 CK18 levels or TUNEL staining, compared to subjects without stainable hepatic iron. Patients with iron deposition limited to hepatocytes had a lower proportion of apoptosis-specific M30 fragments relative to total M65 CK18 levels (37% versus ≤25%; P < 0.05). Presence of iron in liver RES cells is associated with NASH, increased apoptosis, and increased OS. HC iron deposition in NAFLD is also associated with OS and may promote hepatocyte necrosis in this disease. Copyright © 2013 American Association for the Study of Liver Diseases.

  3. 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.

  4. Combination of a Knudsen effusion cell with a quartz crystal microbalance: in situ measurement of molecular evaporation rates with a fully functional deposition source.

    PubMed

    Gutzler, Rico; Heckl, Wolfgang M; Lackinger, Markus

    2010-01-01

    We describe a straightforward, reliable, and inexpensive design of a Knudsen type molecular effusion cell capable of measuring molecular evaporation rates in situ. This is accomplished by means of a quartz crystal microbalance integrated into the shutter of the effusion cell. The presented layout facilitates both the measurement of effusion rates under ultrahigh vacuum conditions without the need for a separate experimental setup and the growth of surface supported molecular layers and nanostructures. As an important prerequisite for reproducible deposition of molecular films with defined coverages ranging from submonolayers up to multilayers, the Knudsen cell features a stable deposition rate for crucible temperatures between 50 and 500 degrees C. Experimental determination of deposition rates for different crucible temperatures allows to approximate sublimation enthalpies of the evaporant based on the Clausius-Clapeyron equation.

  5. Combination of a Knudsen effusion cell with a quartz crystal microbalance: In situ measurement of molecular evaporation rates with a fully functional deposition source

    NASA Astrophysics Data System (ADS)

    Gutzler, Rico; Heckl, Wolfgang M.; Lackinger, Markus

    2010-01-01

    We describe a straightforward, reliable, and inexpensive design of a Knudsen type molecular effusion cell capable of measuring molecular evaporation rates in situ. This is accomplished by means of a quartz crystal microbalance integrated into the shutter of the effusion cell. The presented layout facilitates both the measurement of effusion rates under ultrahigh vacuum conditions without the need for a separate experimental setup and the growth of surface supported molecular layers and nanostructures. As an important prerequisite for reproducible deposition of molecular films with defined coverages ranging from submonolayers up to multilayers, the Knudsen cell features a stable deposition rate for crucible temperatures between 50 and 500 °C. Experimental determination of deposition rates for different crucible temperatures allows to approximate sublimation enthalpies of the evaporant based on the Clausius-Clapeyron equation.

  6. 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

  7. 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

  8. Clinical features and outcomes of 98 children and adults with dense deposit disease

    PubMed Central

    Moon, Mikyung; Lanning, Lynne D.; McCarthy, Ann Marie; Smith, Richard J. H.

    2015-01-01

    Background Dense deposit disease (DDD) is an ultra-rare renal disease. Methods In the study reported here, 98 patients and their families participated in a descriptive patient-centered survey using an online research format. Reports were completed by patients (38%) or their parents (62%). Age at diagnosis ranged from 1.9 to 38.9 years (mean 14 years). Results The majority of patients presented with proteinuria and hematuria; 50% had hypertension and edema. Steroids were commonly prescribed, although their use was not evidence-based. One-half of the patients with DDD for 10 years progressed to end-stage renal disease (ESRD), with young females having the greatest risk for renal failure. Of first allografts, 45% failed within 5 years, most frequently due to recurrent disease (70%). Type 1 diabetes (T1D) was present in over 16% of families, which represents a 116-fold increase in incidence compared with the general population (p<0.001). Conclusions Based on these findings, we suggest that initiatives are needed to explore the high incidence of T1D in family members of DDD patients and the greater risk for progression to ESRD in young females with DDD. These efforts must be supported by sufficient numbers of patients to establish evidence-based practice guidelines for disease management. An international collaborative research survey should be implemented to encourage broad access and participation. PMID:22105967

  9. 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

  10. [Primary nephropathy due to mesangial deposits of IgA (Berger's disease)].

    PubMed

    Rosenberg, H

    1990-02-01

    We describe findings in 188 patients with Berger's disease, the most frequent primary glomerulopathy in our renal biopsy material (25%). Diagnosis was made by finding IgA and dense mesangial deposits with immunofluorescence and electronmicroscopy, respectively. Patient's age ranged from 3 to 64 years (mean 27), 72 were females. Five degrees of the disease were recognized: I, minimal changes, 29 patients (15%); II, minor lesions, 37 (20%); III, focal and segmental lesions, 92 (49%); IV, diffuse proliferation of mesangial cells and/or glomerulo-capsular adhesions, 22 (12%), and V, diffuse sclerosing glomerulonephritis, 8 (4%). Clinical findings at the time of renal biopsy included isolated hematuria in 61%, nephrotic syndrome or proteinuria 11%, hypertension 16%, chronic renal failure 7%, acute renal failure or nephritic syndrome 3% and rapidly progressive glomerulonephritis 2%. Berger's disease was found in 10 clinically healthy donors (13% of living-related donors). Progression of lesions was shown by serial biopsy in 12 patients. Progressive Berger's disease was demonstrated in 5 transplanted patients, requiring dialysis in one. Thus, Berger's disease leads to varying degrees of renal damage, severe extramembranous nephropathy and crescentic glomerulopathy being less frequent.

  11. Spine Topographical Distribution of Skin α-Synuclein Deposits in Idiopathic Parkinson Disease.

    PubMed

    Donadio, Vincenzo; Incensi, Alex; Rizzo, Giovanni; Scaglione, Cesa; Capellari, Sabina; Fileccia, Enrico; Avoni, Patrizia; Liguori, Rocco

    2017-05-01

    Phosphorylated α-synuclein (p-syn) in skin nerves mainly in the proximal sites is a promising neurodegenerative biomarker for idiopathic Parkinson disease (IPD). However, the p-syn spine distribution particularly in patients with unilateral motor dysfunctions remains undefined. This study aimed to investigate in IPD p-syn differences between left and right cervical spine sites in patients with prevalent unilateral motor symptoms, and cervical and thoracic spine sites in patients with bilateral motor symptoms. We enrolled 28 IPD patients fulfilling clinical diagnostic criteria associated with abnormal nigro-striatal DatScan and cardiac MIBG: 15 with prevalently unilateral motor symptoms demonstrated by DatScan; 13 with bilateral motor symptoms and DatScan abnormalities. Patients underwent skin biopsy searching for intraneural p-syn deposits: skin samples were taken from C7 paravertebral left and right sites in unilateral patients and from cervical (C7) and thoracic (Th12) paravertebral spine regions in bilateral patients. Unilateral patients displayed 20% of abnormal p-syn deposits in the affected motor site, 60% in both sites and 20% only in the non-affected site. P-syn was found in all patients in C7 but in only 62% of patients in Th12. Our data showed that cervical p-syn deposits displayed a uniform distribution between both sides not following the motor dysfunction in unilateral patients, and skin nerve p-syn deposits demonstrated a spine gradient with the cervical site expressing the highest positivity. © 2017 American Association of Neuropathologists, Inc. All rights reserved.

  12. RELATIONSHIP BETWEEN PATTERN OF HEPATIC IRON DEPOSITION AND HISTOLOGIC SEVERITY IN NONALCOHOLIC FATTY LIVER DISEASE

    PubMed Central

    Nelson, James E.; Wilson, Laura; Brunt, Elizabeth M.; Yeh, Matthew M.; Kleiner, David E.; Unalp-Arida, Aynur; Kowdley, Kris V.

    2010-01-01

    Previous studies examining the relationship between hepatic iron deposition and histological severity in nonalcoholic fatty liver disease (NAFLD) have been inconclusive. The goal of this study was to examine the relationship between hepatic iron deposition and liver histology in 849 patients enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network. Hepatic iron stains were performed in a central lab and scored for grade, cellular and parenchymal localization by a central pathology committee; the relationship between grade and pattern of iron deposition to clinical, laboratory and histological variables was examined using univariate and multivariate analyses. Stainable hepatic iron was present in 293 of 849 patients (34.5%) in one of three histological patterns: hepatocellular (HC) (63/849, {7.4%}), reticuloendothelial system cells (RES) (91/ 849, {10.7%}), or a mixed RES/HC pattern (139/849 {16.4%}). Patients with the RES iron staining pattern were more likely to have advanced fibrosis compared to those with HC iron (p=0.01). Patients with RES iron were also more likely to have advanced histologic features including: fibrosis (p=0.049), portal inflammation (p=0.002), hepatocellular ballooning (p=0.006) and definite NASH (p=0.007) compared to patients with HC or mixed iron patterns. Presence of RES iron (OR, 1.60, 95% CI, 1.10–2.33, p=0.015) was independently associated with advanced hepatic fibrosis on multiple regression analysis after adjustment for age, gender, diabetes status and BMI. Conclusion: The presence and pattern of hepatic iron deposition is associated with distinct histologic features among patients with NAFLD and may have implications for pathophysiology and therapy. PMID:21274866

  13. Biochemistry of Amyloid β-Protein and Amyloid Deposits in Alzheimer Disease

    PubMed Central

    Masters, Colin L.; Selkoe, Dennis J.

    2012-01-01

    Progressive cerebral deposition of the amyloid β-protein (Aβ) in brain regions serving memory and cognition is an invariant and defining feature of Alzheimer disease. A highly similar but less robust process accompanies brain aging in many nondemented humans, lower primates, and some other mammals. The discovery of Aβ as the subunit of the amyloid fibrils in meningocerebral blood vessels and parenchymal plaques has led to innumerable studies of its biochemistry and potential cytotoxic properties. Here we will review the discovery of Aβ, numerous aspects of its complex biochemistry, and current attempts to understand how a range of Aβ assemblies, including soluble oligomers and insoluble fibrils, may precipitate and promote neuronal and glial alterations that underlie the development of dementia. Although the role of Aβ as a key molecular factor in the etiology of Alzheimer disease remains controversial, clinical trials of amyloid-lowering agents, reviewed elsewhere in this book, are poised to resolve the question of its pathogenic primacy. PMID:22675658

  14. The risk of renal disease is increased in lambda myeloma with bone marrow amyloid deposits

    PubMed Central

    Kozlowski, Piotr; Montgomery, Scott; Befekadu, Rahel; Hahn-Strömberg, Victoria

    2017-01-01

    Background Light chain amyloidosis (AL) is a rare deposition disease and is present in 10–15% of patients with myeloma (MM). In contrast to symptomatic AL in MM, presence of bone marrow (BM) amyloid deposits (AD) in MM is not connected to kidney damage. Renal AD but not BM-AD occur mostly in MM with lambda paraprotein (lambda MM). Methods We investigated amyloid presence in BM clots taken at diagnosis in 84 patients with symptomatic MM and compared disease characteristics in MM with kappa paraprotein (kappa MM)/lambda MM with and without BM-AD. Results Lambda MM with BM-AD was compared with kappa MM without BM-AD, kappa MM with BM-AD, and lambda MM without BM-AD: lambda MM with BM-AD patients had a significantly higher mean creatinine level (4.23 mg/dL vs 1.69, 1.14, and 1.28 mg/dL, respectively) and a higher proportion presented with severe kidney failure (6/11 [55%] vs 6/32 [19%], 1/22 [5%], and 3/19 [16%], respectively). Proteinuria was more common in lambda MM with BM-AD patients compared with kappa MM without BM-AD patients (8/11 [73%] vs 5/32 [16%], respectively). Conclusion Kidney damage was more common in lambda MM with BM-AD indicating presence of renal AD. PMID:28293126

  15. 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

  16. Neuronal and microglial involvement in beta-amyloid protein deposition in Alzheimer's disease.

    PubMed Central

    Cras, P.; Kawai, M.; Siedlak, S.; Mulvihill, P.; Gambetti, P.; Lowery, D.; Gonzalez-DeWhitt, P.; Greenberg, B.; Perry, G.

    1990-01-01

    This study was undertaken to localize amyloid precursor protein (APP) and to determine how APP might be released and proteolyzed to yield the beta-amyloid protein deposits found in senile plaques in the brains of Alzheimer's disease patients. We found that antibodies to recombinantly expressed APP labeled many normal neurons and neurites. In addition, dystrophic neurites in different types of senile plaques and degenerating neurons in the temporal cortex and hippocampus of Alzheimer's disease patients were immunostained. We also detected small clusters of dystrophic APP immunoreactive neurites that were not associated with beta-amyloid protein deposits. Microglia was involved in different types of senile plaques and often were associated closely with APP immunoreactive neurites and neurons. The greatest concurrence of APP immunoreactivity and reactive microglia was seen in the subiculum and area CA1, regions with a high density of congophilic plaques and subject to intense Alzheimer's pathology. Our findings suggest that neuronally derived APP is the source for senile plaque beta-amyloid protein, while microglia may act as processing cells. Images Figure 1 Figure 2 PMID:2117395

  17. Discontinuation of dialysis with eculizumab therapy in a pediatric patient with dense deposit disease.

    PubMed

    Tran, Cheryl L; Sethi, Sanjeev; Murray, David; Cramer, Carl H; Sas, David J; Willrich, Maria; Smith, Richard J; Fervenza, Fernando C

    2016-04-01

    Dense deposit disease (DDD) is a rare glomerular disease caused by an uncontrolled activation of the alternative complement pathway leading to end-stage renal disease in 50 % of patients. As such, DDD has been classified within the spectrum of complement component 3 (C3) glomerulopathies due to its pathogenesis from alternative pathway dysregulation. Conventional immunosuppressive therapies have no proven effectiveness. Eculizumab, a terminal complement inhibitor, has been reported to mitigate disease in some cases. We report on the efficacy of eculizumab in a pediatric patient who failed to respond to cyclophosphamide, corticosteroids, and plasma exchange. Complement biomarker profiling was remarkable for low serum C3, low properdin, and elevated soluble C5b-9. Consistent with these findings, the alternative pathway functional assay was abnormally low, indicative of alternative pathway activity, although neither C3-nephritic factors nor Factor H autoantibodies were detected. Eculizumab therapy was associated with significant improvement in proteinuria and renal function allowing discontinuation of hemodialysis (HD). Repeat C3 and soluble C5b-9 levels normalized, showing that terminal complement pathway activity was successfully blocked while the patient was receiving eculizumab therapy. Repeat testing for alternative pathway activation allowed for a successful decrease in eculizumab dosing. The case reported here demonstrates the successful recovery of renal function in a pediatric patient on HD following the use of eculizumab.

  18. 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.

  19. 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.

  20. 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

  1. Overexpression of ABCA1 reduces amyloid deposition in the PDAPP mouse model of Alzheimer disease

    PubMed Central

    Wahrle, Suzanne E.; Jiang, Hong; Parsadanian, Maia; Kim, Jungsu; Li, Aimin; Knoten, Amanda; Jain, Sanjay; Hirsch-Reinshagen, Veronica; Wellington, Cheryl L.; Bales, Kelly R.; Paul, Steven M.; Holtzman, David M.

    2008-01-01

    APOE genotype is a major genetic risk factor for late-onset Alzheimer disease (AD). ABCA1, a member of the ATP-binding cassette family of active transporters, lipidates apoE in the CNS. Abca1–/– mice have decreased lipid associated with apoE and increased amyloid deposition in several AD mouse models. We hypothesized that mice overexpressing ABCA1 in the brain would have increased lipidation of apoE-containing lipoproteins and decreased amyloid deposition. To address these hypotheses, we created PrP-mAbca1 Tg mice that overexpress mouse Abca1 throughout the brain under the control of the mouse prion promoter. We bred the PrP-mAbca1 mice to the PDAPP AD mouse model, a transgenic line overexpressing a mutant human amyloid precursor protein. PDAPP/Abca1 Tg mice developed a phenotype remarkably similar to that seen in PDAPP/Apoe–/– mice: there was significantly less amyloid β-peptide (Aβ) deposition, a redistribution of Aβ to the hilus of the dentate gyrus in the hippocampus, and an almost complete absence of thioflavine S–positive amyloid plaques. Analyses of CSF from PrP-mAbca1 Tg mice and media conditioned by PrP-mAbca1 Tg primary astrocytes demonstrated increased lipidation of apoE-containing particles. These data support the conclusions that increased ABCA1-mediated lipidation of apoE in the CNS can reduce amyloid burden and that increasing ABCA1 function may have a therapeutic effect on AD. PMID:18202749

  2. High-speed growth of YBa2Cu3O7 - δ film with high critical temperature on MgO single crystal substrate by laser chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Zhao, Pei; Ito, Akihiko; Tu, Rong; Goto, Takashi

    2010-12-01

    a-axis- and c-axis-oriented YBa2Cu3O7 - δ films were prepared on a (100) MgO single crystal substrate by chemical vapor deposition enhanced by a continuous wave Nd:YAG laser. A c-axis-oriented YBCO film with a critical temperature of 89 K was prepared at a high deposition rate of 57 µm h - 1, about 2-600 times higher than that of conventional chemical vapor deposition.

  3. Serum uric acid and nigral iron deposition in Parkinson's disease: a pilot study.

    PubMed

    Kim, Tae-Hyoung; Lee, Jae-Hyeok

    2014-01-01

    Uric acid (UA) is an endogenous antioxidant which is known to reduce oxidative stress and also chelate iron ion. Recent studies have provided evidence that UA may play a neuroprotective role in Parkinson's disease (PD). However, it is unknown whether UA relates to nigral iron deposition, which is a characteristic pathophysiological alteration in PD. The aim of this study was to determine the potential relationship of these two markers in patients with PD. A total of 30 patients of PD and 25 age- and gender- matched healthy controls underwent 3-Tesla MRI and laboratory tests including serum UA levels. We assessed iron levels by measuring phase shift values using susceptibility-weighted image. Mean phase shift values of the substantia nigra (SN), red nucleus, head of the caudate nucleus, globus pallidus, putamen, thalamus, and frontal white matter were calculated and correlated with serum UA levels. Serum UA levels were significantly decreased in the PD patients than in the controls. Phase shift values in bilateral SN were significantly increased in the PD patients than in the controls. There was no significant correlation between serum UA levels and nigral phase shift values. As previous studies, low serum UA level and increased nigral iron content in the PD was reconfirmed in this study. However, we failed to find the relationship between these two markers. Our data suggest that serum UA may not be important determinant of nigral iron deposition in PD.

  4. Ligand co-crystallization of aminoacyl-tRNA synthetases from infectious disease organisms.

    PubMed

    Moen, Spencer O; Edwards, Thomas E; Dranow, David M; Clifton, Matthew C; Sankaran, Banumathi; Van Voorhis, Wesley C; Sharma, Amit; Manoil, Colin; Staker, Bart L; Myler, Peter J; Lorimer, Donald D

    2017-03-16

    Aminoacyl-tRNA synthetases (aaRSs) charge tRNAs with their cognate amino acid, an essential precursor step to loading of charged tRNAs onto the ribosome and addition of the amino acid to the growing polypeptide chain during protein synthesis. Because of this important biological function, aminoacyl-tRNA synthetases have been the focus of anti-infective drug development efforts and two aaRS inhibitors have been approved as drugs. Several researchers in the scientific community requested aminoacyl-tRNA synthetases to be targeted in the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure determination pipeline. Here we investigate thirty-one aminoacyl-tRNA synthetases from infectious disease organisms by co-crystallization in the presence of their cognate amino acid, ATP, and/or inhibitors. Crystal structures were determined for a CysRS from Borrelia burgdorferi bound to AMP, GluRS from Borrelia burgdorferi and Burkholderia thailandensis bound to glutamic acid, a TrpRS from the eukaryotic pathogen Encephalitozoon cuniculi bound to tryptophan, a HisRS from Burkholderia thailandensis bound to histidine, and a LysRS from Burkholderia thailandensis bound to lysine. Thus, the presence of ligands may promote aaRS crystallization and structure determination. Comparison with homologous structures shows conformational flexibility that appears to be a recurring theme with this enzyme class.

  5. Fabrication and laser performance of Yb3+/Al3+ co-doped photonic crystal fiber synthesized by plasma nonchemical vapor deposition method

    NASA Astrophysics Data System (ADS)

    Xia, Changming; Zhou, Guiyao; Liu, Jiantao; Wang, Chao; Han, Ying; Zhang, Wei; Yuan, Jinhui

    2015-10-01

    In this paper, the bulk Yb3+/Al3+ co-doped silica glass with 1.3 Yb2O3-2.5Al2O3-96.2SiO2 (wt%) are synthesized by plasma nonchemical vapor deposition method combining solution doping technology, where the inductively coupled plasma is used as the heat source. The influence of different O2/N2 ratios on the fluorescence properties of Yb3+/Al3+ co-doped silica glass are investigated. The large mode area photonic crystal fiber (PCF) is fabricated by using the bulk Yb3+/Al3+ co-doped silica glass as fiber core. The laser performance of Yb3+/Al3+ co-doped photonic crystal fiber is studied.

  6. [Hippocampal and cognitive alterations precede amyloid deposition in a mouse model for Alzheimer's disease].

    PubMed

    Beauquis, Juan; Vinuesa, Angeles; Pomilio, Carlos; Pavía, Patricio; Saravia, Flavia

    2014-01-01

    Although there is strong evidence about neuronal and glial disturbances at advanced stages of Alzheimer's disease, less attention has been directed to early, preamyloid changes that could contribute to the progression of the disease. We evaluated neuronal and glial morphological changes and behavioral disturbances in PDAPP-J20 transgenic (Tg) mice, carrying mutated human APP gene (amyloid precursor protein), at 5 months of age, before brain amyloid deposition occurs. Using NeuN immunohistochemistry we found decreased numbers of pyramidal and granular neurons in the hippocampus associated with a reduction of hippocampal volume in Tg mice compared with controls. Neurogenesis was impaired, evidenced by means of DCX immunohistochemistry in the dentate gyrus. In the CA3 region we found a decreased density of synaptophysin, suggesting synaptic disturbance, but no changes were found in CA1 synaptic spine density. Using confocal microscopy we observed decreased number and cell complexity of GFAP+ astrocytes, indicating potential glial atrophy. Cognitive impairment (novel location recognition test) and increased anxiety (open field) were detected in Tg mice, associated with more c-Fos+ nuclei in the amygdala, possibly indicating a role for emotionality in early stages of the disease. The study of early alterations in the course of amyloid pathology could contribute to the development of diagnostic and preventive strategies.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. CH3NH3PbI3 films prepared by combining 1- and 2-step deposition: how crystal growth conditions affect properties.

    PubMed

    Mokhtar, Muhamad Z; Chen, Mu; Whittaker, Eric; Hamilton, Bruce; Aristidou, Nicholas; Ramadan, Simko; Gholinia, Ali; Haque, Saif A; O'Brien, Paul; Saunders, Brian R

    2017-02-24

    Perovskite solar cells continue to attract strong attention because of their unprecedented rate of power conversion efficiency increase. CH3NH3PbI3 (MAPbI3) is the most widely studied perovskite. Typically one-step (1-s) or two-step (2-s) deposition methods are used to prepare MAPbI3 films. Here, we investigate a new MAPbI3 film formation method that combines 1-s and 2-s deposition (termed 1 & 2-s) and uses systematic variation of the stoichiometric mole ratio (x) for the PbI2 + xMAI solutions employed. The PbI2 + xMAI solutions were used to deposit precursor films that were subsequently dipped in MAI solution as a second step to produce the final MAPbI3 films. The morphologies of the 1 & 2-s MAPbI3 films consisted of three crystal types: tree-like microcrystals (≫1 μm), cuboid meso-crystals (∼0.1-1 μm) and nanocrystals (∼50-80 nm). Each crystal type and their proportions were controlled by the value for x. The new 1 & 2-s deposition method produced MAPbI3 films with tuneable optoelectronic properties that were related to those for the conventional 1-s and 2-s films. However, the 1 & 2-s film properties were not simply a combination of those for the 1-s and 2-s films. The 1 & 2-s films showed enhanced light scattering and the photoluminescence spectra displayed a morphologically-dependent red-shift. The unique morphologies for the 1 & 2-s films also strongly influenced PbI2 conversion, power conversion efficiency, hysteresis and recombination. The trends for the performance parameters and hysteresis were compared for devices constructed using spiro-MeOTAD and P3HT and were similar. The 1 & 2-s method should apply to other perovskite formulations and the new insights concerning MAPbI3 crystal growth conditions, morphology and material properties established in this study should also be transferable.

  13. 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. © The Author(s) 2015.

  14. 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. (c) 2010 Elsevier B.V. All rights reserved.

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

    PubMed Central

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

    2016-01-01

    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 18F-florbetapir (AV-45). 18F-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

  16. 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.

  17. Anisotropic growth of single-crystal graphite plates by nickel-assisted microwave-plasma chemical-vapor deposition

    NASA Astrophysics Data System (ADS)

    Badzian, Teresa; Badzian, Andrzej; Roy, Rustum; Cheng, Shang-Cong

    2000-02-01

    Growth of single-crystal graphite free-standing plates has been achieved by a microwavehydrogen-plasma etching of graphite powder and nickel mesh. The plates resemble a knife blade and grow in the <11¯00> direction with long crystals exceeding 100 μm. Hexagonal growth features at the edges and electron diffraction patterns confirm the single-crystal nature of these ultrathin plates. Electron microprobe and Raman spectroscopy indicate the presence of graphite. Diamond crystals nucleate on these plates and they grow simultaneously. We suggest that the paradoxical growth of graphite in a hydrogen plasma, under conditions in which graphite is usually etched away, is possible because of a protective coating by a Ni-C-H phase. This thin coating allows for transport of carbon atoms from the gas phase to the growing graphite surface.

  18. Plasma complement and vascular complement deposition in patients with coronary artery disease with and without inflammatory rheumatic diseases.

    PubMed

    Shields, Kelly J; Mollnes, Tom Eirik; Eidet, Jon Roger; Mikkelsen, Knut; Almdahl, Sven M; Bottazzi, Barbara; Lyberg, Torstein; Manzi, Susan; Ahearn, Joseph M; Hollan, Ivana

    2017-01-01

    Inflammatory rheumatic diseases (IRD) are associated with accelerated coronary artery disease (CAD), which may result from both systemic and vascular wall inflammation. There are indications that complement may be involved in the pathogenesis of CAD in Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA). This study aimed to evaluate the associations between circulating complement and complement activation products with mononuclear cell infiltrates (MCI, surrogate marker of vascular inflammation) in the aortic media and adventitia in IRDCAD and non-IRDCAD patients undergoing coronary artery bypass grafting (CABG). Furthermore, we compared complement activation product deposition patterns in rare aorta adventitial and medial biopsies from SLE, RA and non-IRD patients. We examined plasma C3 (p-C3) and terminal complement complexes (p-TCC) in 28 IRDCAD (SLE = 3; RA = 25), 52 non-IRDCAD patients, and 32 IRDNo CAD (RA = 32) from the Feiring Heart Biopsy Study. Aortic biopsies taken from the CAD only patients during CABG were previously evaluated for adventitial MCIs. The rare aortic biopsies from 3 SLE, 3 RA and 3 non-IRDCAD were assessed for the presence of C3 and C3d using immunohistochemistry. IRDCAD patients had higher p-TCC than non-IRDCAD or IRDNo CAD patients (p<0.0001), but a similar p-C3 level (p = 0.42). Circulating C3 was associated with IRD duration (ρ, p-value: 0.46, 0.03). In multiple logistic regression analysis, IRD remained significantly related to the presence and size of MCI (p<0.05). C3 was present in all tissue samples. C3d was detected in the media of all patients and only in the adventitia of IRD patients (diffuse in all SLE and focal in one RA). The independent association of IRD status with MCI and the observed C3d deposition supports the unique relationship between rheumatic disease, and, in particular, SLE with the complement system. Exaggerated systemic and vascular complement activation may accelerate CVD, serve as a CVD

  19. Plasma complement and vascular complement deposition in patients with coronary artery disease with and without inflammatory rheumatic diseases

    PubMed Central

    2017-01-01

    Purpose Inflammatory rheumatic diseases (IRD) are associated with accelerated coronary artery disease (CAD), which may result from both systemic and vascular wall inflammation. There are indications that complement may be involved in the pathogenesis of CAD in Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA). This study aimed to evaluate the associations between circulating complement and complement activation products with mononuclear cell infiltrates (MCI, surrogate marker of vascular inflammation) in the aortic media and adventitia in IRDCAD and non-IRDCAD patients undergoing coronary artery bypass grafting (CABG). Furthermore, we compared complement activation product deposition patterns in rare aorta adventitial and medial biopsies from SLE, RA and non-IRD patients. Methods We examined plasma C3 (p-C3) and terminal complement complexes (p-TCC) in 28 IRDCAD (SLE = 3; RA = 25), 52 non-IRDCAD patients, and 32 IRDNo CAD (RA = 32) from the Feiring Heart Biopsy Study. Aortic biopsies taken from the CAD only patients during CABG were previously evaluated for adventitial MCIs. The rare aortic biopsies from 3 SLE, 3 RA and 3 non-IRDCAD were assessed for the presence of C3 and C3d using immunohistochemistry. Results IRDCAD patients had higher p-TCC than non-IRDCAD or IRDNo CAD patients (p<0.0001), but a similar p-C3 level (p = 0.42). Circulating C3 was associated with IRD duration (ρ, p-value: 0.46, 0.03). In multiple logistic regression analysis, IRD remained significantly related to the presence and size of MCI (p<0.05). C3 was present in all tissue samples. C3d was detected in the media of all patients and only in the adventitia of IRD patients (diffuse in all SLE and focal in one RA). Conclusion The independent association of IRD status with MCI and the observed C3d deposition supports the unique relationship between rheumatic disease, and, in particular, SLE with the complement system. Exaggerated systemic and vascular complement activation may

  20. CFD coupled kinetic modeling and simulation of hot wall vertical tubular reactor for deposition of SiC crystal from MTS

    NASA Astrophysics Data System (ADS)

    Mollick, P. K.; Venugopalan, R.; Srivastava, D.

    2017-10-01

    Chemical Vapor Deposition (CVD) process is generally carried out in a hot wall reactor of vertical or horizontal type keeping the substrate inside the chamber on which deposition is targeted. Present study is focused to explain the role of hydrodynamics and temperature conditions on the overall coating rates inside a hot wall vertical tubular reactor. Deposition of β-Silicon Carbide crystals from Methytricholorosilane catalyzed by hydrogen is modeled here considering growth kinetics which can be successfully described - using only two steps. Finite Element Method based simulation is performed to obtain the flow and temperature profiles inside the hot wall reactor. Model equations for kinetics are derived in differential form based on mass balance considering transport of species. Kinetic parameters were approximated comparing the experimentally found coating rates as reported earlier. Present model is seen to fit reasonably well for the wide variation of gas flow rates as well as temperature. Apart from the flow rates of total fluid at inlet and initial wall temperature of reactor, sample position and the inlet diameter of the reactor are found to be key important parameters for the desired coating to take place. Model prediction thus can provide better knowledge in order to carefully choose process parameters in designing the reactor for achieving optimized deposition rates by CVD with desired properties.

  1. 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

  2. Prevalence of monosodium urate deposits in a population of rheumatoid arthritis patients with hyperuricemia.

    PubMed

    Petsch, Christina; Araujo, Elizabeth G; Englbrecht, Matthias; Bayat, Sara; Cavallaro, Alexander; Hueber, Axel J; Lell, Michael; Schett, Georg; Manger, Bernhard; Rech, Juergen

    2016-06-01

    To investigate the prevalence of monosodium urate (MSU) crystal deposits, indicative for gout, in a population of rheumatoid arthritis (RA) patients with concomitant hyperuricemia and to analyze the clinical and disease-specific characteristics of RA patients who exhibit MSU crystal deposits. Overall, 100 consecutive patients with the diagnosis of RA and a serum urate level above 6mg/dl underwent dual energy computed tomography (DECT) of both feet and hands to search for MSU crystals in a prospective study between October 2011 and July 2013. Presence and extent of MSU crystal deposits on DECT was assessed by automated volume measurement. Demographic and disease-specific characteristics were recorded and included into two logistic regression models to test for the factors associated with MSU crystal deposits in RA. Hyperuricemic RA patients were mostly male (55%), over 60 years of age (63 ± 11 years), had established disease (8.7 ± 10.5 years) and a mean disease activity score 28 (DAS 28) of 3.2. In total, 20 out of 100 patients displayed MSU crystal deposits in DECT. Interestingly, the majority (70%) of the RA patients positive for MSU crystal deposits were seronegative RA patients. Hence, every third seronegative RA patient had MSU crystal deposits. According to logistic regression model analysis, seronegative status correlated positively with presence of urate deposits (p = 0.019). These data show that a considerable number of RA patients display periarticular MSU crystal deposits. Seronegative patients were shown to be predominantly affected with every third patient being positive for urate deposits. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Assessing THK523 selectivity for tau deposits in Alzheimer’s disease and non–Alzheimer’s disease tauopathies

    PubMed Central

    2014-01-01

    Introduction The introduction of tau imaging agents such as 18F-THK523 offers new hope for the in vivo assessment of tau deposition in tauopathies such as Alzheimer’s disease (AD), where preliminary 18F-THK523-PET studies have demonstrated significantly higher cortical retention of 18F-THK523 in AD compared to age-matched healthy individuals. In addition to AD, tau imaging with PET may also be of value in assessing non-AD tauopathies, such as corticobasal degeneration (CBD), progressive supranuclear palsy (PSP) and Pick’s disease (PiD). Methods To further investigate the ability of THK523 to recognize tau lesions, we undertook immunohistochemical and fluorescence studies in serial brain sections taken from individuals with AD (n = 3), CBD (n = 2), PSP (n = 1), PiD (n = 2) and Parkinson’s disease (PD; n = 2). In addition to the neuropathological analysis, one PSP patient had undergone a 18F-THK523 PET scan 5 months before death. Results Although THK523 labelled tau-containing lesions such as neurofibrillary tangles and neuropil threads in the hippocampus and frontal regions of AD brains, it failed to label tau-containing lesions in non-AD tauopathies. Furthermore, though THK523 faintly labelled dense-cored amyloid-β plaques in the AD frontal cortex, it failed to label α-synuclein-containing Lewy bodies in PD brain sections. Conclusion The results of this study suggest that 18F-THK523 selectively binds to paired helical filament tau in AD brains but does not bind to tau lesions in non-AD tauopathies, or to α-synuclein in PD brains. PMID:24572336

  4. Growth and physical properties of amorphous and single crystal ZnGeAs 2 layers deposited on (100)GaAs by sputter deposition in excess Zn and As 4

    NASA Astrophysics Data System (ADS)

    Shah, S. I.; Greene, J. E.

    1984-09-01

    Amorphous and single crystal ZnGeAs 2 layers, typically 1 μm thick, have been grown by RF sputtering from a single-phase polycrystalline ZnGeAs 2 wafer target. The amorphous layers were deposited at room temperature on Corning 7059 glass while the single crystals were grown on (100)GaAs at temperatures between 450 and 520°C using an overpressure of Zn and As 4 supplied by evaporation from effusion cells. X-ray diffraction analyses of amorphous films sealed with ZrO 2 cap layers and annealed at 400°C for ⩾ 4 h showed well-defined polycrystalline chalcopyrite-structure ZnGeAs 2 peaks with no strong preferred orientation. The enthalpy for the amorphous to crystalline phase transition was determined from differential scanning calorimetry to be 126 meV / atom. The single crystal films exhibited the highest mobility yet reported for ZnGeAs 2, 51 cm 2 /V ṡ s at room temperature, with a corresponding net hole concentration of 9 × 10 18 cm -3, very close to that of the target. The optical bandgap was determined to be 1.1±0.05 eV at room temperature.

  5. Hematologic and renal improvement of monoclonal immunoglobulin deposition disease after treatment with bortezomib-based regimens.

    PubMed

    Ziogas, Dimitrios C; Kastritis, Efstathios; Terpos, Evangelos; Roussou, Maria; Migkou, Magdalini; Gavriatopoulou, Maria; Spanomichou, Despoina; Eleutherakis-Papaiakovou, Evangelos; Fotiou, Despoina; Panagiotidis, Ioannis; Kafantari, Eftychia; Psimenou, Erasmia; Boletis, Ioannis; Vlahakos, Demetrios V; Gakiopoulou, Hariklia; Matsouka, Charis; Dimopoulos, Meletios A

    2017-08-01

    Monoclonal immunoglobulin deposition disease (MIDD) is characterized by non-organized immunoglobulin-fragments along renal basement membranes with subsequent organ deterioration. Treatment is directed against the immunoglobulin-producing clone. We treated 18 MIDD patients with bortezomib-based regimens (12 received bortezomib-dexamethasone, 6 bortezomib-dexamethasone with cyclophosphamide). Eleven (61%) patients achieved a hematologic response, but only 6 (33.3%) reached to a complete (CR) or very good partial response (VGPR). Regarding renal outcomes 77.8 and 55.6% had ≥30 and ≥50% reduction of proteinuria, respectively, but 33.3% ended up in end-stage renal disease (ESRD). Among patients with CR or VGPR, median eGFR improvement was 7.7 ml/min/1.73 m(2) and none progressed to ESRD, but no significant renal recovery was observed in patients achieving a partial response or less, with 50% progressing to dialysis. Pretreatment eGFR seems to influence renal prognosis. Bortezomib-based treatment is considered an effective approach in MIDD and reaching to a deep hematologic response (≥VGPR) conditionally controls further renal declining.

  6. Aktashite Cu6Hg3As4S12 from the Aktash deposit, Altai, Russia: Refinement and crystal chemical analysis of the structure

    NASA Astrophysics Data System (ADS)

    Vasil'Ev, V. I.; Pervukhina, N. V.; Borisov, S. V.; Magarill, S. A.; Naumov, D. Yu.; Kurat'eva, N. V.

    2010-12-01

    The composition and structure of aktashite from the Aktash deposit, Gorny Altai, Russia, have been studied by electron microprobe and X-ray structural analysis. On the basis of close compositions and crystal structures, the identity of aktashite from the Gal-Khaya and Aktash deposits has been demonstrated. Crystals of aktashite are of trigonal symmetry; the unit-cell dimensions are: a = 13.7500(4), c = 9.3600(3) Å, V = 532.54(8) Å3, space group R3, Z = 3 for the composition of Cu6Hg3As4S12, R = 0.043. The structure of aktashite as a framework of vertex-shared HgS4- and CuS4- tetrahedrons of the same orientation is intimately related to the sphalerite-type structure. The earlier identified uncommon cluster group [As4] has been verified and its parameters have been refined. It is shown that the structure may be represented as construction blocks (As4S12)12- packed according to the law of the distorted cubic I-cell.

  7. Photonic band gap and defect mode of one-dimensional photonic crystal coated from a mixture of (HMDSO, N2) layers deposited by PECVD

    NASA Astrophysics Data System (ADS)

    Amri, R.; Sahel, S.; Gamra, D.; Lejeune, M.; Clin, M.; Zellama, K.; Bouchriha, H.

    2017-04-01

    One dimensional photonic crystal based on a mixture of an organic compound HMDSO and nitrogen N2, is elaborated by radiofrequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) at different radiofrequency powers. The variation of the radiofrequency power for a flow of N2/HMDSO ratio equal to 0.4, leads to obtain two kinds of layers A and B with refractive index nA = 2 and nB = 1.55 corresponding to RF power of 200 W and 20 W, respectively. The analysis of the infrared results shows that these layers have the same chemical composition element with different structure. These layers, which exhibit a good indexes difference (nA - nB) contrast, allowed then the elaboration of a one-photonic crystal from the same initial gas mixture, which is the aim of this work. After the optimization of the layers thickness, we have measured transmission and reflection spectra and we found that the photonic band gap (PBG) appears after 15 periods of alternating A and B deposited layers. The introduction of defect in the structure leads to obtain a localized mode in the center of the PBG corresponding to the telecommunication wave length 1.55 μm. Finally, we have successfully interpreted our experimental results by using a theoretical model based on transfer matrix method.

  8. Immunolocalization of Kisspeptin Associated with Amyloid-β Deposits in the Pons of an Alzheimer's Disease Patient

    PubMed Central

    Ashioti, Maria; Nercessian, Amanda N.; Milton, Nathaniel G. N.

    2013-01-01

    The pons region of the Alzheimer's disease (AD) brain is one of the last to show amyloid-β (Aβ) deposits and has been suggested to contain neuroprotective compounds. Kisspeptin (KP) is a hormone that activates the hypothalamic-pituitary-gonadal axis and has been suggested to be neuroprotective against Aβ toxicity. The localization of KP, plus the established endogenous neuroprotective compounds corticotropin releasing hormone (CRH) and catalase, in tissue sections from the pons region of a male AD subject has been determined in relation to Aβ deposits. Results showed Aβ deposits also stained with KP, CRH, and catalase antibodies. At high magnification the staining of deposits was either KP or catalase positive, and there was only a limited area of the deposits with KP-catalase colocalization. The CRH does not bind Aβ, whilst both KP and catalase can bind Aβ, suggesting that colocalization in Aβ deposits is not restricted to compounds that directly bind Aβ. The neuroprotective actions of KP, CRH, and catalase were confirmed in vitro, and fibrillar Aβ preparations were shown to stimulate the release of KP in vitro. In conclusion, neuroprotective KP, CRH, and catalase all colocalize with Aβ plaque-like deposits in the pons region from a male AD subject. PMID:26317001

  9. A prolonged course of Group A streptococcus-associated nephritis: a mild case of dense deposit disease (DDD)?

    PubMed

    Sawanobori, E; Umino, A; Kanai, H; Matsushita, K; Iwasa, S; Kitamura, H; Oda, T; Yoshizawa, N; Sugita, K; Higashida, K

    2009-06-01

    We herein report the case of a 12-year-old boy with dense deposit disease (DDD) evoked by streptococcal infection. He had been diagnosed to have asymptomatic hematuria syndrome at the age of 6 during school screening. At 12 years of age, he was found to have macrohematuria and overt proteinuria with hypocomplementemia 2 months after streptococcal pharyngitis. Renal biopsy showed endocapillary proliferative glomerulonephritis with double contours of the glomerular basement membrane. Hypocomplementemia and proteinuria were sustained for over 8 weeks. He was suspected to have dense deposit disease due to intramembranous deposits in the first and the second biopsies. 1 month after treatment with methylprednisolone pulse therapy, proteinuria decreased to a normal level. Microscopic hematuria disappeared 2 years later, but mild hypocomplementemia persisted for more than 7 years. Nephritis-associated plasmin receptor (NAPlr), a nephritic antigen for acute poststreptococcal glomerulonephritis, was found to be positive in the glomeruli for more than 8 weeks. DDD is suggested to be caused by dysgeneration of the alternative pathway due to C3NeF and impaired Factor H activity. A persistent deposition of NAPlr might be one of the factors which lead to complement dysgeneration. A close relationship was suggested to exist between the streptococcal infection and dense deposit disease in this case.

  10. Discordant American College of Physicians and international rheumatology guidelines for gout management: consensus statement of the Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN).

    PubMed

    Dalbeth, Nicola; Bardin, Thomas; Doherty, Michael; Lioté, Frédéric; Richette, Pascal; Saag, Kenneth G; So, Alexander K; Stamp, Lisa K; Choi, Hyon K; Terkeltaub, Robert

    2017-09-01

    In November 2016, the American College of Physicians (ACP) published a clinical practice guideline on the management of acute and recurrent gout. This guideline differs substantially from the latest guidelines generated by the American College of Rheumatology (ACR), European League Against Rheumatism (EULAR) and 3e (Evidence, Expertise, Exchange) Initiative, despite reviewing largely the same body of evidence. The Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) convened an expert panel to review the methodology and conclusions of these four sets of guidelines and examine possible reasons for discordance between them. The G-CAN position, presented here, is that the fundamental pathophysiological knowledge underlying gout care, and evidence from clinical experience and clinical trials, supports a treat-to-target approach for gout aimed at lowering serum urate levels to below the saturation threshold at which monosodium urate crystals form. This practice, which is truly evidence-based and promotes the steady reduction in tissue urate crystal deposits, is promoted by the ACR, EULAR and 3e Initiative recommendations. By contrast, the ACP does not provide a clear recommendation for urate-lowering therapy (ULT) for patients with frequent, recurrent flares or those with tophi, nor does it recommend monitoring serum urate levels of patients prescribed ULT. Results from emerging clinical trials that have gout symptoms as the primary end point are expected to resolve this debate for all clinicians in the near term future.

  11. Plasma polymerization and deposition of linear, cyclic and aromatic fluorocarbons on (100)-oriented single crystal silicon substrates

    NASA Astrophysics Data System (ADS)

    Yang, G. H.; Oh, S. W.; Kang, E. T.; Neoh, K. G.

    2002-11-01

    Fluoropolymer films were deposited on the Ar plasma-pretreated Si(100) surfaces by plasma polymerization of perfluorohexane (PFH, a linear fluorocarbon), perfluoro(methylcyclohexane) (MCH, a cyclic fluorocarbon), and hexafluorobenzene (HFB, an aromatic fluorocarbon) under different glow discharge conditions. The effects of the radio-frequency plasma power on the chemical composition and structure of the plasma-polymerized fluoropolymer films were studied by x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, time-of-flight secondary ion mass spectrometry, and water contact angle measurements. The changes in structure and composition of the three types of the plasma-deposited films from those of the respective fluorocarbons were compared. Under similar glow discharge conditions: (i) the extent of defluorination was highest for the PFH polymer, (ii) the deposition rate was highest for the HFB polymer, (iii) the cyclic structure of MCH was less well preserved than the aromatic structure of HFB, (iv) aliphatic structures appeared in the plasma-deposited MCH polymer, and (v) the plasma-polymerized HFB has the highest thermal stability due to the preservation of the aromatic rings. The adhesive tape peel test results revealed that the plasma-polymerized and deposited fluoropolymer layers were strongly bonded to the Ar plasma-pretreated Si(100) surfaces.

  12. 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…

  13. 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…

  14. Dermal phospho-alpha-synuclein deposits confirm REM sleep behaviour disorder as prodromal Parkinson's disease.

    PubMed

    Doppler, Kathrin; Jentschke, Hanna-Maria; Schulmeyer, Lena; Vadasz, David; Janzen, Annette; Luster, Markus; Höffken, Helmut; Mayer, Geert; Brumberg, Joachim; Booij, Jan; Musacchio, Thomas; Klebe, Stephan; Sittig-Wiegand, Elisabeth; Volkmann, Jens; Sommer, Claudia; Oertel, Wolfgang H

    2017-04-01

    Phosphorylated alpha-synuclein (p-alpha-syn) deposits, one of the neuropathological hallmarks of Parkinson's disease (PD), have recently been detected in dermal nerve fibres in PD patients with good specificity and sensitivity. Here, we studied whether p-alpha-syn may serve as a biomarker in patients with a high risk of developing PD, such as those with REM sleep behaviour disorder (RBD). We compared the presence and distribution of p-alpha-syn deposits in dermal nerve fibres in 18 patients with RBD, 25 patients with early PD and 20 normal controls. Skin biopsy was taken at C7, Th10, and the upper and lower leg. Presynaptic dopamine transporter imaging using FP-CIT-SPECT was performed in all patients with RBD and in 11 patients with PD. All RBD patients underwent olfactory function testing. The likelihood ratio (LR) for prodromal PD was calculated for each patient based on published research criteria. Skin serial sections were assessed by double-immunofluorescence labelling with antibodies to pSer129-alpha-syn under blinded conditions. P-alpha-syn was visualized in 10/18 patients with RBD (sensitivity of 55.6%) and in 20/25 early PD patients (sensitivity of 80%) but in none of the controls (specificity of 100%). The percentage of dermal structures innervated by p-alpha-syn-positive fibres was negatively correlated with dopamine transporter binding in the FP-CIT-SPECT (ρ = -0.377, p = 0.048), with olfactory function (ρ = -0.668, p = 0.002), and positively correlated with the total LR for RBD to present prodromal PD (ρ = 0.531, p = 0.023). Dermal p-alpha-syn can be considered a peripheral histopathological marker of synucleinopathy and can be detected in a subgroup of RBD patients presumably representing prodromal PD. Dermal p-alpha-syn is detectable in RBD patients without PD motor symptoms, thereby stratifying a patient group that is of great interest for clinical trials testing disease-modifying drugs.

  15. Evolution of Texture from a Single Crystal Ti-6Al-4V Substrate During Electron Beam Directed Energy Deposition

    NASA Astrophysics Data System (ADS)

    Butler, Todd M.; Brice, Craig A.; Tayon, Wesley A.; Semiatin, S. Lee; Pilchak, Adam L.

    2017-07-01

    Additive manufacturing of Ti-6Al-4V commonly produces <001> β -fiber textures aligned with the build direction. We have performed wire-feed electron beam directed energy deposition on the {112} β plane of a single prior β-grain. The build initially grew epitaxially from the substrate with the preferred <001> growth direction significantly angled away from the build direction. However, continued layer deposition drove the formation of a <001> β -fiber texture aligned with the build direction and the direction of the strongest thermal gradient.

  16. Evolution of Texture from a Single Crystal Ti-6Al-4V Substrate During Electron Beam Directed Energy Deposition

    NASA Astrophysics Data System (ADS)

    Butler, Todd M.; Brice, Craig A.; Tayon, Wesley A.; Semiatin, S. Lee; Pilchak, Adam L.

    2017-10-01

    Additive manufacturing of Ti-6Al-4V commonly produces 〈001〉 β -fiber textures aligned with the build direction. We have performed wire-feed electron beam directed energy deposition on the {112} β plane of a single prior β-grain. The build initially grew epitaxially from the substrate with the preferred 〈001〉 growth direction significantly angled away from the build direction. However, continued layer deposition drove the formation of a 〈001〉 β -fiber texture aligned with the build direction and the direction of the strongest thermal gradient.

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

    PubMed

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

    2016-01-01

    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. 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. 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. 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.

  18. 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

  19. Hydroxyapatite deposition disease around the hip: outcomes of CT-guided treatment

    PubMed Central

    Klontzas, Michail E.; Vassalou, Evangelia E.; Zibis, Aristeidis H.; Karantanas, Apostolos H.

    2016-01-01

    PURPOSE Hydroxyapatite deposition disease (HADD) around the hip joint is a self-limiting condition usually treated conservatively. The aim of the present study is to directly compare the outcomes of CT-guided and conservative treatments in cases of refractory hip HADD. METHODS Two groups of patients with refractory hip HADD were prospectively constructed from a pool of 484 patients referred for greater trochanter pain syndrome, based on the presence of calcifications around the hip and the failure of conservative treatment. Study group included 22 hips, which underwent CT-guided barbotage and steroid injection treatment, whereas control group consisted of 28 hips that were treated conservatively. Evaluation of the outcome of both groups was performed over a one-year follow-up period with the use of a score measuring clinical improvement in terms of pain and functional impairment. RESULTS Three weeks after the initiation of treatment, study group exhibited significantly higher scores compared with the control group (P < 0.001). Improvement scores of the control group were similar to the study group after three months of treatment (P > 0.1). CONCLUSION CT-guided treatment provides relief of debilitating symptoms in the acute phase. PMID:27537854

  20. Differential cerebral deposition of IDE and NEP in sporadic and familial Alzheimer’s disease

    PubMed Central

    Dorfman, Verónica Berta; Pasquini, Laura; Riudavets, Miguel; López-Costa, Juan José; Villegas, Andrés; Troncoso, Juan Carlos; Lopera, Francisco; Castaño, Eduardo Miguel; Morelli, Laura

    2011-01-01

    Alzheimer’s disease (AD) is characterized by amyloid β (Aβ) accumulation in the brain and is classified as familial early-onset (FAD) or sporadic late-onset (SAD). Evidences suggest that deficits in the brain expression of insulin degrading enzyme (IDE) and neprilysin (NEP), both proteases involved in amyloid degradation, may promote Aβ deposition in SAD. We studied by immunohistochemistry IDE and NEP cortical expression in SAD and FAD samples carrying the E280A presenilin-1 missense mutation. We showed that IDE, a soluble peptidase, is linked with aggregated Aβ40 isoform while NEP, a membrane-bound protease, negatively correlates with amyloid angiopathy and its expression in the senile plaques is independent of aggregated amyloid and restricted to SAD cases. NEP, but not IDE, is over-expressed in dystrophic neurites, both proteases are immunoreactive in activated astrocytes but not in microglia and IDE was the only one detected in astrocytes of white matter from FAD cases. Collectively, our results support the notion that gross conformational changes involved in the modification from “natively folded-active” to “aggregated-inactive” IDE and NEP may be a relevant pathogenic mechanism in SAD. PMID:19019493

  1. Differential relationships of reactive astrocytes and microglia to fibrillar amyloid deposits in Alzheimer disease.

    PubMed

    Serrano-Pozo, Alberto; Muzikansky, Alona; Gómez-Isla, Teresa; Growdon, John H; Betensky, Rebecca A; Frosch, Matthew P; Hyman, Bradley T

    2013-06-01

    Although it is clear that astrocytes and microglia cluster around dense-core amyloid plaques in Alzheimer disease (AD), whether they are primarily attracted to amyloid deposits or are just reacting to plaque-associated neuritic damage remains elusive. We postulate that astrocytes and microglia may differentially respond to fibrillar amyloid β. Therefore, we quantified the size distribution of dense-core thioflavin-S (ThioS)-positive plaques in the temporal neocortex of 40 AD patients and the microglial and astrocyte responses in their vicinity (≤50 μm) and performed correlations between both measures. As expected, both astrocytes and microglia were clearly spatially associated with ThioS-positive plaques (p = 0.0001, ≤50 μm vs. >50 μm from their edge), but their relationship to ThioS-positive plaque size differed: larger ThioS-positive plaques were associated with more surrounding activated microglia (p = 0.0026), but this effect was not observed with reactive astrocytes. Microglial response to dense-core plaques seems to be proportional to their size, which we postulate reflects a chemotactic effect of amyloid β. By contrast, plaque-associated astrocytic response does not correlate with plaque size and seems to parallel the behavior of plaque-associated neuritic damage.

  2. Clinical and prognostic differences among patients with light chain deposition disease, myeloma cast nephropathy and both.

    PubMed

    Zand, Ladan; Nasr, Samih H; Gertz, Morie A; Dispenzieri, Angela; Lacy, Martha Q; Buadi, Francis K; Kumar, Shaji; Kyle, Robert A; Fervenza, Fernando C; Sethi, Sanjeev; Dingli, David; Rajkumar, S Vincent; Kapoor, Prashant; McCurdy, Arleigh; Leung, Nelson

    2015-01-01

    In some patients with light chain deposition disease (LCDD) there is also evidence of myeloma cast nephropathy (MCN) on renal biopsy. The purpose of this study was to evaluate the renal and survival outcome of patients with concomitant diagnosis of MCN and LCDD to LCDD and MCN alone. Eighty seven patients were identified and divided into LCDD (n=45), MCN (n=29), and LCDD+ MCN (n=13). Patients with LCDD+ MCN had a worse overall survival (OS) compared to patients with LCDD (p=0.03), but similar to patients with MCN (p=0.4). Death-censored renal survival was no different amongst the groups. Presenting with acute renal failure at time of renal biopsy (HR 7.2, p=0.0002) was an independent poor renal prognostic factor while older age (HR 1.06, p=0.0002), presence of osteolytic lesions (HR 4.4, p<0.0001), and requirement for dialysis or creatinine≥5 mg/dL (HR 3.2, p=0.0006) at time of renal biopsy were independent poor prognostic factors for OS.

  3. Differential Relationships of Reactive Astrocytes and Microglia to Fibrillar Amyloid Deposits in Alzheimer Disease

    PubMed Central

    Serrano-Pozo, Alberto; Muzikansky, Alona; Gómez-Isla, Teresa; Growdon, John H.; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.

    2013-01-01

    While it is clear that astrocytes and microglia cluster around dense-core amyloid plaques in Alzheimer disease (AD), whether they are primarily attracted to amyloid deposits or are just reacting to plaque-associated neuritic damage remains elusive. We postulate that astrocytes and microglia may differentially respond to fibrillar amyloid β (Aβ). Therefore, we quantified the size distribution of dense-core Thioflavin-S (ThioS)-positive plaques in the temporal neocortex of 40 AD patients and the microglial and astrocyte responses in their vicinity (≤50 μm), and performed correlations between both measures. As expected, both astrocytes and microglia were clearly spatially associated with ThioS-positive plaques (p = 0.0001, ≤50 μm vs. >50 μm from their edge), but their relationship to ThioS-positive plaque size differed; larger ThioS-positive plaques were associated with more surrounding activated microglia (p = 0.0026), but this effect was not observed with reactive astrocytes. Microglial response to dense-core plaques appears to be proportional to their size, which we postulate reflects a chemotactic effect of Aβ. By contrast, plaque-associated astrocytic response does not correlate with plaque size and seems to parallel the behavior of plaque-associated neuritic damage. PMID:23656989

  4. Hydrogen Assisted Nano-crystallization in TiO2 Thin Film Prepared by Hot-Wire Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Iida, Tamio; Koie, Ryousuke; Masuda, Toshiro; Ueno, Hiroyuki; Nonomura, Shuichi

    2009-03-01

    Preparations and structural studies of TiO2 thin films using hot-wire chemical vapor deposition (CVD) (hot-filament CVD) are reported for the first time. Titanium tetra-isopropoxide [Ti(OC3H7)4] was used as a source gas and decomposed on a heated rhenium filament. The film deposited at the filament temperature (Tf) of 1300 °C shows amorphous structure with the substrate temperature (Ts) of 300 °C, and X-ray diffraction (XRD) peaks originated from nano-crystalline with anatase structure appeared over Ts of 400-700 °C. The optical band gap energies of the nano-crystalline TiO2 films with anatase structure were ˜3.4 eV. An increase of Ts from 400 to 700 °C enhanced the XRD peak intensity of (112) orientation. Meanwhile, an increase of Tf up to 1500 °C induces nano-crystalline TiO2 with rutile structure. Furthermore, the hydrogen dilution realizes the nano-crystallite growth of rutile structure even in the deposition at Tf = 1300 °C. During this deposition, the actual substrate surface temperature (Tsuf) was 305 °C. In bulk TiO2 materials, the anatase structure changes to the rutile structure by thermal annealing up to about 800 °C. We propose for the first time that atomic hydrogen contributes to the low temperature nucleation of rutile structure in the deposition of oxide system, TiO2 films.

  5. 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

    2016-03-31

    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

  6. Amyloid misfolding, aggregation, and the early onset of protein deposition diseases: insights from AFM experiments and computational analyses.

    PubMed

    Lyubchenko, Yuri L

    2015-01-01

    The development of Alzheimer's disease is believed to be caused by the assembly of amyloid β proteins into aggregates and the formation of extracellular senile plaques. Similar models suggest that structural misfolding and aggregation of proteins are associated with the early onset of diseases such as Parkinson's, Huntington's, and other protein deposition diseases. Initially, the aggregates were structurally characterized by traditional techniques such as x-ray crystallography, NMR, electron microscopy, and AFM. However, data regarding the structures formed during the early stages of the aggregation process were unknown. Experimental models of protein deposition diseases have demonstrated that the small oligomeric species have significant neurotoxicity. This highlights the urgent need to discover the properties of these species, to enable the development of efficient diagnostic and therapeutic strategies. The oligomers exist transiently, making it impossible to use traditional structural techniques to study their characteristics. The recent implementation of single-molecule imaging and probing techniques that are capable of probing transient states have enabled the properties of these oligomers to be characterized. Additionally, powerful computational techniques capable of structurally analyzing oligomers at the atomic level advanced our understanding of the amyloid aggregation problem. This review outlines the progress in AFM experimental studies and computational analyses with a primary focus on understanding the very first stage of the aggregation process. Experimental approaches can aid in the development of novel sensitive diagnostic and preventive strategies for protein deposition diseases, and several examples of these approaches will be discussed.

  7. Amyloid misfolding, aggregation, and the early onset of protein deposition diseases: insights from AFM experiments and computational analyses

    PubMed Central

    Lyubchenko, Yuri L.

    2016-01-01

    The development of Alzheimer’s disease is believed to be caused by the assembly of amyloid β proteins into aggregates and the formation of extracellular senile plaques. Similar models suggest that structural misfolding and aggregation of proteins are associated with the early onset of diseases such as Parkinson’s, Huntington’s, and other protein deposition diseases. Initially, the aggregates were structurally characterized by traditional techniques such as x-ray crystallography, NMR, electron microscopy, and AFM. However, data regarding the structures formed during the early stages of the aggregation process were unknown. Experimental models of protein deposition diseases have demonstrated that the small oligomeric species have significant neurotoxicity. This highlights the urgent need to discover the properties of these species, to enable the development of efficient diagnostic and therapeutic strategies. The oligomers exist transiently, making it impossible to use traditional structural techniques to study their characteristics. The recent implementation of single-molecule imaging and probing techniques that are capable of probing transient states have enabled the properties of these oligomers to be characterized. Additionally, powerful computational techniques capable of structurally analyzing oligomers at the atomic level advanced our understanding of the amyloid aggregation problem. This review outlines the progress in AFM experimental studies and computational analyses with a primary focus on understanding the very first stage of the aggregation process. Experimental approaches can aid in the development of novel sensitive diagnostic and preventive strategies for protein deposition diseases, and several examples of these approaches will be discussed. PMID:27830177

  8. Evaluating the Effect of Surface Roughness on Titanium Dioxide Nanoparticle Deposition using a Combined Quartz Crystal Microbalance with Dissipation (QCM-D) and Generalized Ellipsometry (GE) Technique

    NASA Astrophysics Data System (ADS)

    Kananizadeh, N.; Lee, J.; Rodenhausen, K. B.; Sekora, D.; Schubert, M.; Schubert, E.; Bartelt-Hunt, S.; Li, Y.

    2016-12-01

    Quantification and characterization of nanoparticles in soils and sediments are very challenging because they will interact not only with soil-water chemistry but also with highly heterogeneous soil and sediment surfaces. In this work, we measured the interaction of Titanium dioxide nanoparticles (nTiO2), the most extensively manufactured engineered materials, with engineered rough surfaces under varied ionic strength conditions. Innovative three-dimensional Silicon nanostructured surfaces, referred to here as slanted columnar thin films (SCTFs), were used to generate surface roughness with controlled heights of 50nm, 100nm, and 200nm. Using atomic layer deposition technique (ALD), surfaces of SCTF were coated with either silicon dioxide or aluminum oxides to represent the most abundant silica aquifer materials and metal oxide impurities, respectively. The interaction between nTiO2 and model rough surfaces was measured using quartz crystal microbalance with dissipation monitoring (QCM-D). The data were analyzed using a model that couples the viscoelastic effect with the surface roughness effect. No nTiO2 deposition was observed on neither flat nor rough silicon dioxide surfaces under ionic strength ranged from 0 to 100 mM NaCl. On the other hand, the deposition of nTiO2 on the aluminum oxides coated surfaces increased as the height of roughness increased. In parallel with QCM-D, a Generalized Ellipsometry (GE) was used to measure the mass of deposited nTiO2. The combination of QCM-D and GE revealed that the properties (i.e. porosity and rigidness) of attached nTiO2 layer on the QCM-D surfaces were dependent on ionic strength and surface roughness.

  9. On the Discontinuity of Polycrystalline Silicon Thin Films Realized by Aluminum-Induced Crystallization of PECVD-Deposited Amorphous Si

    NASA Astrophysics Data System (ADS)

    Pan, Qingtao; Wang, Tao; Yan, Hui; Zhang, Ming; Mai, Yaohua

    2017-01-01

    Crystallization of glass/Aluminum (50, 100, 200 nm) /hydrogenated amorphous silicon (a-Si:H) (50, 100, 200 nm) samples by Aluminum-induced crystallization (AIC) is investigated in this article. After annealing and wet etching, we found that the continuity of the polycrystalline silicon (poly-Si) thin films was strongly dependent on the double layer thicknesses. Increasing the a-Si:H/Al layer thickness ratio would improve the film microcosmic continuity. However, too thick Si layer might cause convex or peeling off during annealing. Scanning electron microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX) are introduced to analyze the process of the peeling off. When the thickness ratio of a-Si:H/Al layer is around 1 to 1.5 and a-Si:H layer is less than 200 nm, the poly-Si film has a good continuity. Hall measurements are introduced to determine the electrical properties. Raman spectroscopy and X-ray diffraction (XRD) results show that the poly-Si film is completely crystallized and has a preferential (111) orientation.

  10. On the Discontinuity of Polycrystalline Silicon Thin Films Realized by Aluminum-Induced Crystallization of PECVD-Deposited Amorphous Si

    NASA Astrophysics Data System (ADS)

    Pan, Qingtao; Wang, Tao; Yan, Hui; Zhang, Ming; Mai, Yaohua

    2017-04-01

    Crystallization of glass/Aluminum (50, 100, 200 nm) /hydrogenated amorphous silicon (a-Si:H) (50, 100, 200 nm) samples by Aluminum-induced crystallization (AIC) is investigated in this article. After annealing and wet etching, we found that the continuity of the polycrystalline silicon (poly-Si) thin films was strongly dependent on the double layer thicknesses. Increasing the a-Si:H/Al layer thickness ratio would improve the film microcosmic continuity. However, too thick Si layer might cause convex or peeling off during annealing. Scanning electron microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX) are introduced to analyze the process of the peeling off. When the thickness ratio of a-Si:H/Al layer is around 1 to 1.5 and a-Si:H layer is less than 200 nm, the poly-Si film has a good continuity. Hall measurements are introduced to determine the electrical properties. Raman spectroscopy and X-ray diffraction (XRD) results show that the poly-Si film is completely crystallized and has a preferential (111) orientation.

  11. The formation of the Yichun Ta-Nb deposit, South China, through fractional crystallization of magma indicated by fluid and silicate melt inclusions

    NASA Astrophysics Data System (ADS)

    Li, Shenghu; Li, Jiankang; Chou, I.-Ming; Jiang, Lei; Ding, Xin

    2017-04-01

    The Yichun Ta-Nb deposit, which is located in Jiangxi Province, South China, can be divided into four lithological zones (from bottom upward): two-mica granite, muscovite granite, albite granite, and lepidolite-albite granite zones. It remains controversial whether these distinct vertical zones were formed through late magmatic-hydrothermal metasomatic alteration or fractional crystallization of magma. To investigate the evolution mechanism of rock- and ore-forming fluid in this deposit, we studied fluid and melt inclusions in quartz and lepidolite in these four granite zones. These fluid inclusions are mainly composed of H2O-NaCl, and have homogenization temperatures ranging from 160 °C to 240 °C, with densities between 0.86 and 0.94 g/cm3 and salinities between 0.5 and 6.5 wt% NaCl equivalent. Raman spectroscopic analyses showed that the daughter minerals contained in silicate melt inclusions are mainly quartz, lepidolite, albite, muscovite, microcline, topaz, and sassolite. From the lower to upper granite zones, the albite contents in silicate melt inclusions increase, while the muscovite contents decrease gradually until muscovite is substituted by lepidolite in the lepidolite-albite granite zone. Additionally, the calculated densities of the silicate melt inclusions exhibit decreasing trends from bottom upward. The total homogenization temperatures of silicate melt inclusions, which were observed under external pressures created in the sample chamber of a hydrothermal diamond-anvil cell, decreased from 860 °C in the lower lithological zone to 776 °C in the upper lithological zone, and the initial melting temperatures of solid phases were 570-710 °C. The calculated initial H2O contents of granitic magma showed an increasing trend from the lower (∼2 wt% in the two-mica granite zone) to the upper granitic zones (∼3 wt% in the albite granite zone). All of these features illustrate that the vertical granite zones in the Yichun Ta-Nb deposit formed through

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

    DOEpatents

    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.

  13. Structurization of submonolayer carbon coatings deposited in a low-pressure microwave plasma on single-crystal silicon

    SciTech Connect

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

    2011-11-15

    Features of surface structurization of submonolayer carbon coatings deposited in highly ionized ultrahigh-frequency low-pressure plasma on silicon wafers with (111) and (100) crystallographic orientations are studied. It is shown that the size and surface density of nanostructured carbon formations are controlled by the atomic microstructure of the silicon free surface of these crystallographic orientations and its modifications depending on deposition and annealing conditions. We show the fundamental possibility of fabricating integrated columnar nanostructures with surface densities to (4-5) Multiplication-Sign 10{sup 9} cm{sup -2} and higher than 400 nm by highly anisotropic etching using the obtained carbon island nanostructures as a mask coating on singlecrystal (100) silicon.

  14. Gamma G globulin subgroup composition of the glomerular deposits in human renal diseases

    PubMed Central

    Lewis, Edmund J.; Busch, George J.; Schur, Peter H.

    1970-01-01

    36 renal biopsies from patients with nephritis were studied for glomerular localization of the heavy chain subgroups of immunoglobulin G (IgG or γG). The deposition pattern of these subgroups was selective and did not reflect the normal serum concentration of these proteins. γG2, which comprises 18% of normal serum γG, was the predominant or unique subgroup deposited in five cases of lupus nephritis and four biopsies with other forms of nephritis associated with granular γG deposits. γG3, which normally makes up only 8% of the serum γG, was the dominant subgroup seen in one biopsy of lobular glomerulonephritis. Patients with linear γG deposits generally had a selective absence of γG3 and often had large amounts of γG4 (normally 3% of the serum γG) deposited. The deposition of complement components C1q, C4, and C3 was variable. One biopsy had only γG2 and no complement components in the deposits and had no neutrophile leukocyte infiltration. This latter observation correlates well with the poor ability of γG2 to fix complement in vitro. Similarly, deposits containing large amounts of γG4, which does not fix complement, also tended to have less inflammatory infiltrate than deposits devoid of this subgroup. The selective deposition of monotypic or restricted γG subgroups on the glomerulus supports the likelihood that the γG represents antibody. The nature of the subgroup involved in the deposit may represent one variable in the determination of the inflammatory and morphological picture that evolves in human glomerulonephritis. Images PMID:4987169

  15. Facile Synthesis of Single Crystal Vanadium Disulfide Nanosheets by Chemical Vapor Deposition for Efficient Hydrogen Evolution Reaction.

    PubMed

    Yuan, Jiangtan; Wu, Jingjie; Hardy, Will J; Loya, Philip; Lou, Minhan; Yang, Yingchao; Najmaei, Sina; Jiang, Menglei; Qin, Fan; Keyshar, Kunttal; Ji, Heng; Gao, Weilu; Bao, Jiming; Kono, Junichiro; Natelson, Douglas; Ajayan, Pulickel M; Lou, Jun

    2015-10-07

    A facile chemical vapor deposition method to prepare single-crystalline VS2 nanosheets for the hydrogen evolution reaction is reported. The electrocatalytic hydrogen evolution reaction (HER) activities of VS2 show an extremely low overpotential of -68 mV at 10 mA cm(-2), small Tafel slopes of ≈34 mV decade(-1), as well as high stability, demonstrating its potential as a candidate non-noble-metal catalyst for the HER.

  16. 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.

  17. Preparation and characterization of Bi2Sr2CaCu2O8+δ thin films on MgO single crystal substrates by chemical solution deposition

    NASA Astrophysics Data System (ADS)

    Grivel, J.-C.; Kępa, K.; Hlásek, T.; Andersen, N. H.; Rubešová, K.

    2013-03-01

    Bi2Sr2CaCu2O8 thin films have been deposited on MgO single crystal substrates by spin-coating a solution based on 2-ethylhexanoate precursors. Pyrolysis takes place between 200 °C and 450 °C and is accompanied by the release of 2-ethylhexanoic acid, CO2 and H2O vapour. Highly c-axis oriented Bi2Sr2CaCu2O8 films were obtained after heat treatment at 840 °C in air. The highest Tc of 81 K was measured in a 10-layer film. Subsequent post-annealing in Ar and pure O2 did not improve the superconducting properties of the films and resulted in the appearance of Bi2CaCuO5 or Bi2(Sr, Ca)2CuO6 impurities.

  18. Independent contribution of temporal beta-amyloid deposition to memory decline in the pre-dementia phase of Alzheimer's disease.

    PubMed

    Chételat, Gaël; Villemagne, Victor L; Pike, Kerryn E; Ellis, Kathryn A; Bourgeat, Pierrick; Jones, Gareth; O'Keefe, Graeme J; Salvado, Olivier; Szoeke, Cassandra; Martins, Ralph N; Ames, David; Masters, Colin L; Rowe, Christopher C

    2011-03-01

    The relationship between β-amyloid deposition and memory deficits in early Alzheimer's disease is unresolved, as past studies show conflicting findings. The present study aims to determine the relative contribution of regional β-amyloid deposition, hippocampal atrophy and white matter integrity to episodic memory deficits in non-demented older individuals harbouring one of the characteristic hallmarks of Alzheimer's disease, i.e. with β-amyloid pathology. Understanding these relationships is critical for effective therapeutic development. Brain magnetic resonance imaging and [(11)C]Pittsburgh Compound B-positron emission tomography scans were obtained in 136 non-demented individuals aged over 60 years, including 93 healthy elderly and 43 patients with mild cognitive impairment. Voxel-based correlations were computed between a memory composite score and grey matter volume, white matter volume and β-amyloid deposition imaging datasets. Hierarchical linear regression analyses were then performed using values extracted in regions of most significant correlations to determine the relative contribution of each modality to memory deficits. All analyses were conducted pooling all groups together as well as within separate subgroups of cognitively normal elderly, patients with mild cognitive impairment and individuals with high versus low neocortical β-amyloid. Brain areas of highest correlation with episodic memory deficits were the hippocampi for grey matter volume, the perforant path for white matter volume and the temporal neocortex for β-amyloid deposition. When considering these three variables together, only hippocampal volume and temporal β-amyloid deposition provided independent contributions to memory deficits. In contrast to global β-amyloid deposition, temporal β-amyloid deposition was still related to memory independently from hippocampal atrophy within subgroups of cognitively normal elderly, patients with mild cognitive impairment or cases with high

  19. Data on the purification and crystallization of the loss-of-function von Willebrand disease variant (p.Gly1324Ser) of the von Willebrand factor A1 domain.

    PubMed

    Campbell, James C; Tischer, Alexander; Machha, Venkata; Moon-Tasson, Laurie; Sankaran, Banumathi; Kim, Choel; Auton, Matthew

    2016-06-01

    von Willebrand factor׳s (VWF) primary hemostatic responsibility is to deposit platelets at sites of vascular injury to prevent bleeding. This function is mediated by the interaction between the VWF A1 domain and the constitutively active platelet receptor, GPIbα. The crystal structure of the A1 domain harboring the von Willebrand disease (vWD) type 2M mutation p.Gly1324Ser has been recently published in the Journal of Biological Chemistry describing its effect on the function and structural stability of the A1 domain of VWF, "Mutational constraints on local unfolding inhibit the rheological adaptation of von Willebrand factor" [1]. The mutation introduces a side chain that thermodynamically stabilizes the domain by reducing the overall flexibility of the A1-GPIbα binding interface resulting in loss-of-function and bleeding due to the inability of A1 to adapt to a binding competent conformation under the rheological shear stress blood flow. In this data article we describe the production, quality control and crystallization of the p.Gly1324Ser vWD variant of the A1 domain of VWF. p.Gly1324Ser A1 was expressed in Escherichia coli as insoluble inclusion bodies. After the preparation of the inclusion bodies, the protein was solubilized, refolded, purified by affinity chromatography and crystallized. The crystal structure of the p.Gly1324Ser mutant of the A1 domain is deposited at the Protein Data Bank PDB: 5BV8.

  20. 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.

  1. 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.

  2. Laminar distribution of β-amyloid (Aβ) peptide deposits in the frontal lobe in familial and sporadic Alzheimer's disease.

    PubMed

    Armstrong, R A

    2015-01-01

    To determine whether genetic factors influence frontal lobe degeneration in Alzheimer's disease (AD), the laminar distributions of diffuse, primitive, and classic β-amyloid (Aβ) peptide deposits were compared in early-onset familial AD (EO-FAD) linked to mutations of the amyloid precursor protein (APP) or presenilin 1 (PSEN1) gene, late-onset familial AD (LO-FAD), and sporadic AD (SAD). The influence of apolipoprotein E (Apo E) genotype on laminar distribution was also studied. In the majority of FAD and SAD cases, maximum density of the diffuse and primitive Aβdeposits occurred in the upper cortical layers, whereas the distribution of the classic Aβ deposits was more variable, either occurring in the lower layers, or a double-peaked (bimodal) distribution was present, density peaks occurring in upper and lower layers. The cortical layer at which maximum density of Aβ deposits occurred and maximum density were similar in EO-FAD, LO-FAD and SAD. In addition, there were no significant differences in distributions in cases expressing Apo E ε4 alleles compared with cases expressing the ε2 or ε3 alleles. These results suggest that gene expression had relatively little effect on the laminar distribution of Aβ deposits in the frontal lobe of the AD cases studied. Hence, the pattern of frontal lobe degeneration in AD is similar regardless of whether it is associated with APP and PSEN1, mutation, allelic variation in Apo E, or with SAD.

  3. High-Performance Flexible Thin-Film Transistors Based on Single-Crystal-like Silicon Epitaxially Grown on Metal Tape by Roll-to-Roll Continuous Deposition Process.

    PubMed

    Gao, Ying; Asadirad, Mojtaba; Yao, Yao; Dutta, Pavel; Galstyan, Eduard; Shervin, Shahab; Lee, Keon-Hwa; Pouladi, Sara; Sun, Sicong; Li, Yongkuan; Rathi, Monika; Ryou, Jae-Hyun; Selvamanickam, Venkat

    2016-11-02

    Single-crystal-like silicon (Si) thin films on bendable and scalable substrates via direct deposition are a promising material platform for high-performance and cost-effective devices of flexible electronics. However, due to the thick and unintentionally highly doped semiconductor layer, the operation of transistors has been hampered. We report the first demonstration of high-performance flexible thin-film transistors (TFTs) using single-crystal-like Si thin films with a field-effect mobility of ∼200 cm(2)/V·s and saturation current, I/lW > 50 μA/μm, which are orders-of-magnitude higher than the device characteristics of conventional flexible TFTs. The Si thin films with a (001) plane grown on a metal tape by a "seed and epitaxy" technique show nearly single-crystalline properties characterized by X-ray diffraction, Raman spectroscopy, reflection high-energy electron diffraction, and transmission electron microscopy. The realization of flexible and high-performance Si TFTs can establish a new pathway for extended applications of flexible electronics such as amplification and digital circuits, more than currently dominant display switches.

  4. 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.

  5. 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.

  6. Monoclonal gammopathy of renal significance with light-chain deposition disease diagnosed postrenal transplant: a diagnostic and therapeutic challenge.

    PubMed

    Nambirajan, Aruna; Bhowmik, Dipankar; Singh, Geetika; Agarwal, Sanjay Kumar; Dinda, Amit Kumar

    2015-03-01

    Patients with light-chain deposition disease (LCDD) frequently do not meet criteria for myeloma. In such cases, despite low tumor burden, the circulating monoclonal immunoglobulins cause renal damage, are responsible for post-transplant recurrence, and are rightly categorized as monoclonal gammopathy of renal significance (MGRS) requiring chemotherapy. A 65-year male with uncharacterized nodular glomerulopathy presented with proteinuria 3 years postrenal transplant. His allograft biopsies were diagnostic of light-chain deposition disease (likely recurrent), and in the absence of myeloma, he was labeled as MGRS. Based on the limited literature available, he was treated with bortezomib which resulted in normalization of serum-free light-chain ratios and resolution of proteinuria. He, however, later succumbed to complications of chemotherapy. This case highlights the diagnostic difficulties in LCDD, the importance of an accurate pretransplant diagnosis, and treatment of the malignant clone, in the absence of which post-transplant management of recurrence is challenging with poor outcomes.

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

    PubMed

    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

    2015-04-24

    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.

  8. 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.

  9. The Role of MicroRNAs in Aβ Deposition and Tau Phosphorylation in Alzheimer’s Disease

    PubMed Central

    Zhao, Juanjuan; Yue, Dongxu; Zhou, Ya; Jia, Li; Wang, Hairong; Guo, Mengmeng; Xu, Hualin; Chen, Chao; Zhang, Jidong; Xu, Lin

    2017-01-01

    Alzheimer’s disease (AD), with main clinical features of progressive impairment in cognitive and behavioral functions, is the most common degenerative disease of the central nervous system. Recent evidence showed that microRNAs (miRNAs) played important roles in the pathological progression of AD. In this article, we reviewed the promising role of miRNAs in both Aβ deposition and Tau phosphorylation, two key pathological characters in the pathological progression of AD, which might be helpful for the understanding of pathogenesis and the development of new strategies of clinical diagnosis and treatment of AD. PMID:28769871

  10. 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.

  11. In-situ STM studies of thallium underpotential deposition on Au(111) single-crystal electrode in acid solution

    NASA Astrophysics Data System (ADS)

    Polewska, Wanda; Adzic, Radoslav

    1999-04-01

    The structure of electrodeposited Tl adlayers on Au(111) in 0.1 M. HClO4 has been investigated using in-situ scanning tunneling microscopy method. Incommensurate, rotated hexagonal (RHCP) Tl adlayer was found, within a wide potential window, between Tl bulk deposition at -0.7 V and -0.4 V. This adlayer is closely packed with Tl interatomic distance of 3.4 +/- 0.2 angstroms, its rotation from the gold substrate axis is 60 +/- 10 and its coverage is 0.74. At slightly more positive potentials, between -0.45 V and -0.37 V, low coverage 2 X 2 phase of Tl was found, coexisting together with RHCP monolayer. At the potential region between -0.35 V and 0.8 V both ordered Tl phases disappeared and instead the formation of considerable amount of pits at the surface has been observed.

  12. 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

  13. Comparison of surgical Limberg flap technique and crystallized phenol application in the treatment of pilonidal sinus disease: a retrospective study

    PubMed Central

    Akan, Kaan; Tihan, Deniz; Duman, Uğur; Özgün, Yiğit; Erol, Fatih; Polat, Murat

    2013-01-01

    Objective: This study was designed to compare the efficacy of crystallized phenol method with Limberg flap in pilonidal sinus treatment. Material and Methods: Patients with a diagnosis of pilonidal sinus disease treated with surgical excision + Limberg rhomboid flap technique and crystallized phenol method between 2010–2011 in the Şevket Yılmaz Training and Research Hospital, Department of General Surgery were evaluated retrospectively. Patients’ age, sex, length of hospital stay, complications and recurrence rates were evaluated. Results: Eighty eight percent of patients were male and mean age was 26.84±6.41 in the Limberg group, and 24.72±5.00 in the crystallized phenol group. Sinus orifice locations and nature, and duration of symptoms before surgery were similar in the two groups. Length of hospital stay in the Limberg group was 1.46±0.61 days; whereas all patients in the crystallized phenol group were discharged on the same day. Infection, hematoma, wound dehiscence, and cosmetic problems were significantly higher in the Limberg group. There was no difference between the two groups in terms of recurrence and seroma formation. Conclusion: The less invasive method of crystallized phenol application may be an alternative approach to rhomboid excision and Limberg flap in patients with non-complicated pilonidal sinus disease, yielding acceptable recurrence rates. PMID:25931870

  14. [Dense deposit nephropathy: a peculiar variant of glomerulonephritis or a distinct disease entity (author's transl)].

    PubMed

    Rossmann, P; Matousovic, K; Bucek, J

    1975-01-01

    In four renal biopsies of two patients with chronic glomerulonephritis (GN), the so-called dense deposit nephropathy (NDD) was diagnosed by means of light, electron, and immunofluorescence microscopy. In routine paraffin sections the picture approached that of the membrano-proliferative GN. In semithin sections (toluidine blue, periodic acid-Ag-methenamine) and especially in the ultrastructure there appeared extensive confluent deposits of a very dense substance, infiltrating the lamina densa of glomerular capillaries, basal membranes of both Bowman's capsules and tubules, and arteriolar walls. In this localization, a non-diffuse "psdudolinear" deposition of beta1c was detected, whereas antisera to main Ig-fractions and fibrin(ogen) were not fixed. In a biopsy performed six years later, a concentration of dense depositis towards the mesangial area and a partial regeneration of basal membranes were observed. In a part of dense deposits there appeared vacuolization, primarily in tubular and arteriolar basal membranes. In glomeruli, focal IgM deposits were apparent at an advanced stage. NDD apparently is a sequel of a particular metabolic (immune?) process, afflicting solely the renal membranous system and distinctly dns known at present. The noncharacteristic clinical presentation resembles chronic. GN, is very protracted, lengthy, and relatively benigh, with a chance of functional and possible even morphological remission.

  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.

  16. 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.

  17. 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

    2015-05-19

    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.

  18. 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

  19. Growth and characterization of 7,7,8,8-tetracyano-quinodimethane crystals on chemical vapor deposition graphene

    NASA Astrophysics Data System (ADS)

    Black, Andrés; Jiménez, Fernando; Bernardo-Gavito, Ramón; Casado, Santiago; Granados, Daniel; Vázquez de Parga, Amadeo L.

    2016-11-01

    Chemical functionalization of graphene could pave the way for favorably modifying its already remarkable properties. Organic molecules have been utilized to this end as a way to alter graphene's structural, chemical, electrical, optical and even magnetic properties. One such promising organic molecule is 7,7,8,8-tetracyano-quinodimethane (TCNQ), a strong electron acceptor which has been shown to be an effective p-dopant of graphene. This study explores the thermal evaporation of TCNQ onto graphene transferred onto SiO2/Si substrates. Using two different home-made thermal evaporators, a wide range of TCNQ growth regimes are explored, from thin films to bulk crystals. The resulting graphene/TCNQ structure is characterized via optical microscopy, Raman spectroscopy and atomic force microscopy (AFM). Films are found to be comprised of TCNQ and the oxidized product of TCNQ, α,α-dicyano-p-toluoylcyanide (DCTC), which confirms the electron charge transfer from graphene to the TCNQ films. AFM measurements of these films show that after forming a rather smooth layer covering the graphene surface, small clusters start to form. For higher TCNQ coverage, the clusters agglomerate, becoming quite large in size and forming ripples or wrinkles across the surface.

  20. Direct synthesis of solid and hollow carbon nanospheres over NaCl crystals using acetylene by chemical vapour deposition

    NASA Astrophysics Data System (ADS)

    Chandra Kishore, S.; Anandhakumar, S.; Sasidharan, M.

    2017-04-01

    Carbon nanospheres (CNS) with hollow and solid morphologies have been synthesised by a simple chemical vapour deposition method using acetylene as a carbon precursor. Sodium chloride (NaCl) powder as a template was used for the direct growth of CNS via facile and low-cost approach. The effect of various temperatures (500 °C, 600 °C and 700 °C) and acetylene flow rates were investigated to study the structural evolution on the carbon products. The purified CNS thus obtained was characterized by various physicochemical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and cyclicvoltametry. The synthesised hollow nanospheres were investigated as anode materials for Li-ion batteries. After 25 cycles of repeated charge/discharge cycles, the discharge and charge capacities were found to be 574 mAh/g and 570 mAh/g, respectively which are significantly higher than the commercial graphite samples.

  1. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    SciTech Connect

    Sokolov, N. S. Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V.; Maksimova, K. Yu.; Grunin, A. I.; Tabuchi, M.

    2016-01-14

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films.

  2. Second-order susceptibility spectra for δ-BiB₃O₆ polymer nanocomposites deposited on the chalcogenide crystals.

    PubMed

    Kityk, I V; Chrunik, M; Majchrowski, A; Guidi, Mariangela Cestelli; Angelucci, Marco; Kamel, Gihan; Fedorchuk, A O; Pępczyńska, M; Jaroszewicz, L R; Parasyuk, O; Bolesta, I M; Kowerdziej, R

    2015-07-05

    The optimized conditions for the enhancement of the second harmonic generation in the composites of the orthorhombic δ-BiB3O6:Pr(3+) nanoparticles embedded in polyvinyl alcohol films and deposited on the AgGaGe2Se6, AgGaGe2.7Si0.3Se8 (90 mol.% AgGaGe3Se8 - 10 mol.% AgGaSi3Se8), and AgGaGe3Se8:Cu substrates were established. The highest second-order susceptibility was achieved during the Ag-Ga-Ge-Se crystalline substrates photo-illumination by nanosecond laser pulses of about 2900 nm wavelength. The effect was found to be completely reversible after the interruption of the photo-inducing stimulation. Complementary studies of Atomic Force Microscopy, AFM, X-ray Diffraction, XRD, and Fourier-Transform Infrared Spectroscopy, and DFT simulations of spectral dependences of the corresponding second-order nonlinear optical susceptibilities, were performed. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Characterization and modeling of illite crystal particles and growth mechanisms in a zoned hydrothermal deposit, Lake City, Colorado

    USGS Publications Warehouse

    Bove, D.J.; Eberl, D.D.; McCarty, D.K.; Meeker, G.P.

    2002-01-01

    Mean thickness measurements and crystal-thickness distributions (CTDs) of illite particles vary systematically with changes in hydrothermal alteration type, fracture density, and attendant mineralization in a large acid-sulfate/Mo-porphyry hydrothermal system at Red Mountain, near Lake City, Colorado. The hydrothermal illites characterize an extensive zone of quartz-sericite-pyrite alteration beneath two deeply rooted bodies of magmatic-related, quartz-alunite altered rock. Nineteen illites from a 3000 ft vertical drill hole were analyzed by XRD using the PVP-10 intercalation method and the computer program MudMaster (Bertaut-Warren-Averbach technique). Mean crystallite thicknesses, as determined from 001 reflections, range from 5-7 nanometers (nm) at depths from 0-1700 ft, then sharply increase to 10-16 nm at depths between 1800-2100 ft, and decrease again to 4-5 nm below this level. The interval of largest particle thickness correlates strongly with the zone of most intense quartz-sericite-pyrite alteration (QSP) and attendant high-density stockwork fracturing, and with the highest concentrations of Mo within the drill core. CTD shapes for the illite particles fall into two main categories: asymptotic and lognormal. The shapes of the CTDs are dependent on conditions of illite formation. The asymptotic CTDs correspond to a nucleation and growth mechanism, whereas surface-controlled growth was the dominant mechanism for the lognormal CTDs. Lognormal CTDs coincide with major through-going fractures or stockwork zones, whereas asymptotic CTDs are present in wallrock distal to these intense fracture zones. The increase in illite particle size and the associated zone of intense QSP alteration and stockwork veining was related by proximity to the dacitic magma(s), which supplied both reactants and heat to the hydrothermal system. However, no changes in illite polytype, which in other studies reflect temperature transitions, were observed within this interval.

  4. Eight years of follow-up after laminectomy of calcium pyrophosphate crystal deposition in the cervical yellow ligament of patient with Coffin–Lowry syndrome

    PubMed Central

    Morino, Tadao; Ogata, Tadanori; Horiuchi, Hideki; Yamaoka, Shintaro; Fukuda, Mitsumasa; Miura, Hiromasa

    2016-01-01

    Abstract Background: We report 8 years of follow-up after decompression to treat cervical myelopathy in a patient with Coffin–Lowry syndrome (CLS). CLS is a rare X-linked semidominant syndrome associated with growth and psychomotor retardation, general hypotonia, and skeletal abnormalities. In this patient, the spinal cord was compressed by calcium pyrophosphate crystal deposition in the cervical yellow ligament (YL). To date, only 1 report has described clinical features after surgery for calcified cervical YL in CLS. Methods: A 15-year-old male with tetraplegia secondary to compression of the cervical spinal cord induced by a hypoplastic posterior arch of C1 and calcification of the YL from C2 to C7 was treated surgically with laminectomy from C1 to C7. The patient's history, clinical examination, imaging findings, and treatment are reported. The patient was incapable of speech because of mental retardation, so he could not describe his symptoms. Gait disturbance worsened over the 2 months before admission to our hospital. At admission, the patient could not move his extremities, and tendon reflexes of the upper and lower extremities were significantly increased. Computed tomography of the cervical spine showed YL calcification from C2 to C7. Magnetic resonance imaging showed consecutive compression of the cervical spinal cord. We diagnosed quadriplegia secondary to cervical cord damage and performed emergency surgery. Results: During C1–C7 laminectomy, YL calcification in C2–C7 was observed. The calcification was confirmed as calcium pyrophosphate by crystal analysis. Quadriplegia gradually resolved, and almost disappeared by 2 weeks after the operation. Cervical hyperlordosis was observed in radiographs starting from 1 month after the operation, but it has not progressed and is not associated with any symptoms. Conclusions: The efficacy of decompression continued, and no postoperative complications have occurred during at least 8 years of follow-up. PMID

  5. Light Chain Deposition Disease Diagnosed with Laser Micro-dissection, Liquid Chromatography, and Tandem Mass Spectrometry of Nodular Glomerular Lesions

    PubMed Central

    Kasagi, Tomomichi; Nobata, Hironobu; Suzuki, Keisuke; Miura, Naoto; Banno, Shogo; Takami, Akiyoshi; Yamashita, Taro; Ando, Yukio; Imai, Hirokazu

    2017-01-01

    A 42-year-old man developed nephrotic syndrome and rapidly progressive renal failure. Kidney biopsy demonstrated nodular glomerulosclerosis, negative Congo red staining, and no deposition of light or heavy chains. Laser micro-dissection and liquid chromatography with tandem mass spectrometry of nodular lesions revealed the presence of a kappa chain constant region and kappa III variable region, which signified light chain deposition disease. Dexamethasone and thalidomide were effective in decreasing the serum levels of free kappa light chain from 147.0 to 38.0 mg/L, eliminating proteinuria, and halting the worsening of the kidney dysfunction, with serum creatinine levels stable around 4.0 mg/dL for 3 years. PMID:28050001

  6. Enhanced photocatalytic performance of mesoporous TiO{sub 2} coated SBA-15 nanocomposites fabricated through a novel approach: supercritical deposition aided by liquid-crystal template

    SciTech Connect

    Liu, Chen; Lin, Xiao; Li, Youji Xu, Peng; Li, Ming; Chen, Feitai

    2016-03-15

    Highlights: • Highly uniform mesoporous TiO{sub 2} nanopartices were coated SBA-15. • MT showed smaller crystallite size, higher hydroxyl content and surface area. • MT/SBA-15 show enhanced photocatalytic activity and high reused activity. • The optimum MT loading rate and calcination temperature were obtained to be 15% and 400 °C, respectively. • Photocatalytic behaviors are discussed in terms of the Langmuir–Hinshelwood model. - Abstract: Mesoporous TiO2 coated SBA-15 (MT@S) nanocomposites were fabricated through supercritical CO{sub 2} deposition aided by liquid-crystal template. The as-prepared samples were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy and so on. The results reveal that MT uniformly deposited onto silica with titania incorporated in SBA-15 channels, showed smaller crystallite size, higher hydroxyl content and surface area than nonporous TiO{sub 2} coated SBA-15 (NT@S) obtained by a similar route without template. With TiO{sub 2} loading ratio of 15 wt% and calcination temperature of 400 °C, 15%MT@S-400 showed the enhanced degradation efficiency for azo dyes (methylene blue, methyl orange, and rhodamine B) and phenol in comparsion with 15%NT@S-400, due to those improved textural and physicochemical properties. Meanwhile, the reused MT@S also showed high photoactivity. Additionally, the effects of MT content and calcination temperature have been examined as operational parameters. Photocatalytic reactions followed pseudo-first-order kinetics and are discussed in terms of the Langmuir–Hinshelwood model.

  7. PGC-1α overexpression exacerbates β-amyloid and tau deposition in a transgenic mouse model of Alzheimer's disease

    PubMed Central

    Dumont, Magali; Stack, Cliona; Elipenahli, Ceyhan; Jainuddin, Shari; Launay, Nathalie; Gerges, Meri; Starkova, Natalia; Starkov, Anatoly A.; Calingasan, Noel Y.; Tampellini, Davide; Pujol, Aurora; Beal, M. Flint

    2014-01-01

    The peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) interacts with various transcription factors involved in energy metabolism and in the regulation of mitochondrial biogenesis. PGC-1α mRNA levels are reduced in a number of neurodegenerative diseases and contribute to disease pathogenesis, since increased levels ameliorate behavioral defects and neuropathology of Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. PGC-1α and its downstream targets are reduced both in postmortem brain tissue of patients with Alzheimer's disease (AD) and in transgenic mouse models of AD. Therefore, we investigated whether increased expression of PGC-1α would exert beneficial effects in the Tg19959 transgenic mouse model of AD; Tg19959 mice express the human amyloid precursor gene (APP) with 2 familial AD mutations and develop increased β-amyloid levels, plaque deposition, and memory deficits by 2–3 mo of age. Rather than an improvement, the cross of the Tg19959 mice with mice overexpressing human PGC-1α exacerbated amyloid and tau accumulation. This was accompanied by an impairment of proteasome activity. PGC-1α overexpression induced mitochondrial abnormalities, neuronal cell death, and an exacerbation of behavioral hyperactivity in the Tg19959 mice. These findings show that PGC-1α overexpression exacerbates the neuropathological and behavioral deficits that occur in transgenic mice with mutations in APP that are associated with human AD.—Dumont, M., Stack, C., Elipenahli, C., Jainuddin, S., Launay, N., Gerges, M., Starkova, N., Starkov, A. A., Calingasan, N. Y., Tampellini, D., Pujol, A., Beal, M. F. PGC-1α overexpression exacerbates β-amyloid and tau deposition in a transgenic mouse model of Alzheimer's disease. PMID:24398293

  8. 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.

  9. AB stacked few layer graphene growth by chemical vapor deposition on single crystal Rh(1 1 1) and electronic structure characterization

    NASA Astrophysics Data System (ADS)

    Kordatos, Apostolis; Kelaidis, Nikolaos; Giamini, Sigiava Aminalragia; Marquez-Velasco, Jose; Xenogiannopoulou, Evangelia; Tsipas, Polychronis; Kordas, George; Dimoulas, Athanasios

    2016-04-01

    Graphene synthesis on single crystal Rh(1 1 1) catalytic substrates is performed by Chemical Vapor Deposition (CVD) at 1000 °C and atmospheric pressure. Raman analysis shows full substrate coverage with few layer graphene. It is found that the cool-down rate strongly affects the graphene stacking order. When lowered, the percentage of AB (Bernal) -stacked regions increases, leading to an almost full AB stacking order. When increased, the percentage of AB-stacked graphene regions decreases to a point where almost a full non AB-stacked graphene is grown. For a slow cool-down rate, graphene with AB stacking order and good epitaxial orientation with the substrate is achieved. This is indicated mainly by Raman characterization and confirmed by Reflection high-energy electron diffraction (RHEED) imaging. Additional Scanning Tunneling Microscopy (STM) topography data confirm that the grown graphene is mainly an AB-stacked structure. The electronic structure of the graphene/Rh(1 1 1) system is examined by Angle resolved Photo-Emission Spectroscopy (ARPES), where σ and π bands of graphene, are observed. Graphene's ΓK direction is aligned with the ΓK direction of the substrate, indicating no significant contribution from rotated domains.

  10. Theoretical study of the deposition and adsorption of bisphosphonates on the 001 hydroxyapatite surface: Implications in the pathological crystallization inhibition and the bone antiresorptive action

    NASA Astrophysics Data System (ADS)

    Fernández, David; Ortega-Castro, Joaquín; Frau, Juan

    2017-01-01

    The effect of different side chain groups of bisphosphonates (BPs) on the adsorption on the hydroxyapatite (HAP) is still a controversial issue. In this work, we studied the deposition and adsorption of a set of 26 BPs on the HAP (001) surface by using density functional theory (DFT) in which has been shown that the charge, the length or the presence of different functional groups at R2 side chain can modulate the adsorption energy of the BP. It was observed that negative charged groups at R2 enhanced the favourable electrostatic interactions between the BP and the HAP surface, but also that the length of R2 was important to enable the formation of the favorable electrostatic interactions between the functional group at R2 and the surface. A crossover study between the HAP/BP model (3D-QSAR/DFT) and the inhibition of the human farnesyl pyrophosphate synthase (FPPS) (3D-QSAR) pointed out that the electrostatic character of the R2 side chain provokes contrary effects in the inhibition of pathological crystallization and in the bone antiresorptive action of BPs.

  11. Direct Observation of the Thickness-Induced Crystallization and Stress Build-Up during Sputter-Deposition of Nanoscale Silicide Films.

    PubMed

    Krause, Bärbel; Abadias, Gregory; Michel, Anny; Wochner, Peter; Ibrahimkutty, Shyjumon; Baumbach, Tilo

    2016-12-21

    The kinetics of phase transitions during formation of small-scale systems are essential for many applications. However, their experimental observation remains challenging, making it difficult to elucidate the underlying fundamental mechanisms. Here, we combine in situ and real-time synchrotron X-ray diffraction (XRD) and X-ray reflectivity (XRR) experiments with substrate curvature measurements during deposition of nanoscale Mo and Mo1-xSix films on amorphous Si (a-Si). The simultaneous measurements provide direct evidence of a spontaneous, thickness-dependent amorphous-to-crystalline (a-c) phase transition, associated with tensile stress build-up and surface roughening. This phase transformation is thermodynamically driven, the metastable amorphous layer being initially stabilized by the contributions of surface and interface energies. A quantitative analysis of the XRD data, complemented by simulations of the transformation kinetics, unveils an interface-controlled crystallization process. This a-c phase transition is also dominating the stress evolution. While stress build-up can significantly limit the performance of devices based on nanostructures and thin films, it can also trigger the formation of these structures. The simultaneous in situ access to the stress signal itself, and to its microstructural origins during structure formation, opens new design routes for tailoring nanoscale devices.

  12. Low interfacial trap density and high-temperature thermal stability in atomic layer deposited single crystal Y2O3/n-GaAs(001)

    NASA Astrophysics Data System (ADS)

    Lin, Yen-Hsun; Fu, Chien-Hua; Lin, Keng-Yung; Chen, Kuan-Hsiung; Chang, Tsong-Wen; Raynien Kwo, J.; Hong, Minghwei

    2016-08-01

    A low interfacial trap density (D it) of 2.2 × 1011 eV-1 cm-2 has been achieved with an atomic layer deposited (ALD) single crystal Y2O3 epitaxially on n-GaAs(001), along with a small frequency dispersion of 10.3% (2.6%/decade) at the accumulation region in the capacitance-voltage (C-V) curves. The D it and frequency dispersion in the C-V curves in this work are the lowest among all of the reported ALD-oxides on n-type GaAs(001). The D it was measured using the conductance-voltage (G-V) and quasi-static C-V (QSCV) methods. Moreover, the heterostructure was thermally stable with rapid annealing at 900 °C under various durations in He and N2, which has not been achieved in the heterostructures of ALD-Al2O3 or HfO2 on GaAs.

  13. Nigral Tau pathology and striatal amyloid-β deposition does not correlate with striatal dopamine deficit in Alzheimer's disease.

    PubMed

    Schauer, Tabea H; Lochner, Maximilian; Kovacs, Gabor G

    2012-12-01

    Extrapyramidal symptoms may appear in Alzheimer's disease (AD). In the present study, using morphometric immunohistochemistry in 34 cases with AD-related pathology, we evaluated whether nigral burden of tau pathology or striatal burden of amyloid-β deposition correlates with dopamine transporter (DAT) expression in the striatum. Our observations show a lack of correlation between these variables and support the notion that lower striatal DAT expression in AD patients suggests concomitant nigral α-synuclein pathology. Extrapyramidal symptoms may have a complex background in AD.

  14. 'PrP systemic deposition disease': clinical and pathological characteristics of novel familial prion disease with 2-bp deletion in codon 178.

    PubMed

    Matsuzono, K; Honda, H; Sato, K; Morihara, R; Deguchi, K; Hishikawa, N; Yamashita, T; Kono, S; Ohta, Y; Iwaki, T; Abe, K

    2016-01-01

    A novel TYPE of prion disease associated mainly with autonomic-sensory polyneuropathy was reported by us previously. Here the autopsy pathology for patient 1 (the sister) and the clinical characteristics of her younger brother (patient 2) are newly reported. Polymerase chain reaction based restriction fragment length polymorphism analysis of the prion protein gene (PRNP) was performed on both patients and their father (normal control). Polymerase chain reaction based restriction fragment length polymorphism analysis revealed a 2-bp deletion (CT) in codon 178 that causes an additional variable 25 amino acids at the C terminal, from the mutation site to the premature stop codon at codon 203, in both patients 1 and 2 but not in their father. The autopsy of patient 1 showed remarkable prion protein (PrP) deposits in the sympathetic ganglion and peripheral nerves, correlated to her severe autonomic sensory failure. PrP deposits were also found in the central nervous system and peripheral organs such as the heart, lung, stomach, jejunum, ileum, colon, urinary bladder and adrenal gland. The symptoms and biopsy findings of patient 2 were nearly the same as those reported previously for patient 1. His cognitive function was well preserved, but autonomic functions were severely impaired. His biopsied samples showed PrP deposits in the sural nerve and nerve plexuses of the stomach and colon. The present unique 2-bp deletion (CT) in codon 178 induced a 'PrP systemic deposition disease' such as pan-autonomic failure, sensory neuropathy and mild cognitive impairment with a specific pathology. © 2015 EAN.

  15. Aerodynamics and deposition effects of inhaled submicron drug aerosol in airway diseases.

    PubMed

    Faiyazuddin, Md; Mujahid, Md; Hussain, Talib; Siddiqui, Hefazat H; Bhatnagar, Aseem; Khar, Roop K; Ahmad, Farhan J

    2013-01-01

    Particle engineering is the prime focus to improve pulmonary drug targeting with the splendor of nanomedicines. In recent years, submicron particles have emerged as prettyful candidate for improved fludisation and deposition. For effective deposition, the particle size must be in the range of 0.5-5 μm. Inhalers design for the purpose of efficient delivery of powders to lungs is again a crucial task for pulmonary scientists. A huge number of DPI devices exist in the market, a significant number are awaiting FDA approval, some are under development and a large number have been patented or applied for patent. Even with superior design, the delivery competence is still deprived, mostly due to fluidisation problems which cause poor aerosol generation and deposition. Because of the cohesive nature and poor flow characteristics, they are difficult to redisperse upon aerosolization with breath. These problems are illustrious in aerosol research, much of which is vastly pertinent to pulmonary therapeutics. A technical review is presented here of advances that have been utilized in production of submicron drug particles, their in vitro/in vivo evaluations, aerosol effects and pulmonary fate of inhaled submicron powders.

  16. Preferential association of serum amyloid P component with fibrillar deposits in familial British and Danish dementias: similarities with Alzheimer's disease.

    PubMed

    Rostagno, Agueda; Lashley, Tammaryn; Ng, Douglas; Meyerson, Jordana; Braendgaard, Hans; Plant, Gordon; Bojsen-Møller, Marie; Holton, Janice; Frangione, Blas; Revesz, Tamas; Ghiso, Jorge

    2007-06-15

    Two hereditary forms of cerebrovascular amyloidosis, familial British and Danish dementias (FBD and FDD), share striking similarities with Alzheimer's disease (AD) despite structural differences among their amyloid subunits (ABri in FBD, ADan in FDD, and Abeta in AD). Neuropathological lesions in these disorders include neurofibrillary tangles, parenchymal amyloid and pre-amyloid deposits and overwhelming cerebral amyloid angiopathy co-localizing with reactive microglia and multiple amyloid associated proteins including activation products of the complement cascade. Immunohistochemical analysis of FBD and FDD brain lesions unveiled the presence of serum amyloid P-component (SAP) primarily associated with thioflavin positive amyloid deposits in spite of the significant pre-amyloid burden existing in both disorders. Using affinity chromatography and ELISA binding assays we demonstrated specific, calcium-dependent, saturable, high affinity binding interactions between SAP and ABri/ADan peptides, with dissociation constant values in the sub-nanomolar range and within the same order of magnitude as those resulting from the interaction of SAP with Alzheimer's Abeta1-40 and Abeta1-42. The preferential association of SAP with fibrillar amyloid lesions and not with non-fibrillar pre-amyloid deposits is puzzling, suggesting that SAP modulates the assembly and stability of the final fibril rather than participating in the early steps of protein misfolding and oligomerization.

  17. 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

  18. PGC-1α overexpression exacerbates β-amyloid and tau deposition in a transgenic mouse model of Alzheimer's disease.

    PubMed

    Dumont, Magali; Stack, Cliona; Elipenahli, Ceyhan; Jainuddin, Shari; Launay, Nathalie; Gerges, Meri; Starkova, Natalia; Starkov, Anatoly A; Calingasan, Noel Y; Tampellini, Davide; Pujol, Aurora; Beal, M Flint

    2014-04-01

    The peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) interacts with various transcription factors involved in energy metabolism and in the regulation of mitochondrial biogenesis. PGC-1α mRNA levels are reduced in a number of neurodegenerative diseases and contribute to disease pathogenesis, since increased levels ameliorate behavioral defects and neuropathology of Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. PGC-1α and its downstream targets are reduced both in postmortem brain tissue of patients with Alzheimer's disease (AD) and in transgenic mouse models of AD. Therefore, we investigated whether increased expression of PGC-1α would exert beneficial effects in the Tg19959 transgenic mouse model of AD; Tg19959 mice express the human amyloid precursor gene (APP) with 2 familial AD mutations and develop increased β-amyloid levels, plaque deposition, and memory deficits by 2-3 mo of age. Rather than an improvement, the cross of the Tg19959 mice with mice overexpressing human PGC-1α exacerbated amyloid and tau accumulation. This was accompanied by an impairment of proteasome activity. PGC-1α overexpression induced mitochondrial abnormalities, neuronal cell death, and an exacerbation of behavioral hyperactivity in the Tg19959 mice. These findings show that PGC-1α overexpression exacerbates the neuropathological and behavioral deficits that occur in transgenic mice with mutations in APP that are associated with human AD.

  19. Using susceptibility-weighted images to quantify iron deposition differences in amnestic mild cognitive impairment and Alzheimer's disease.

    PubMed

    Wang, Dan; Zhu, Dan; Wei, Xiao-Er; Li, Yue-Hua; Li, Wen-Bin

    2013-01-01

    To quantify iron deposition in Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI), and control individuals using susceptibility weighted imaging (SWI). Sixty participants (22 aMCI, 20 AD, 18 normal controls) underwent conventional magnetic resonance imaging (MRI) and SWI using axial/oblique coronal sequences. Phase images were used to calculate bilateral iron deposition in 18 regions of interest (ROI). The radian angle value was calculated and compared between the three participant groups. The difference in radian angle value was significant between the aMCI and control groups in the left (L)-hippocampus, L-head of the caudate nucleus, R-lenticular nucleus, L-lenticular nucleus (P =0.02239, <0. 001, 0.03571, 0.00943, respectively). The difference in radian angle value was significant between the AD and aMCI groups in the R-cerebellar hemisphere, L-cerebellar hemisphere, R-hippocampus, L-hippocampus, R-red nucleus, R-thalamus, L-thalamus, and splenium of corpus callosum (P =0.02754, 0.01839, 0.00934, 0.04316, 0.02472, 0.00152, <0.001, 0.01448, respectively). Pearson correlation coefficients of the Mini-Mental State Examination score were all significant for the bilateral cerebellar hemisphere, hippocampus, red nucleus, lenticular nucleus, thalamus, R-head of the caudate nucleus, and splenium of corpus callosum. Iron deposition in the hippocampus, head of the caudate nucleuslenticular nucleus, and thalamus are significantly different between individuals with aMCI, AD, and controls. The thalamus is a particularly sensitive area. Using SWI to quantify the iron deposition is a useful tool in detecting aMCI and AD.

  20. Optogenetic Restoration of Disrupted Slow Oscillations Halts Amyloid Deposition and Restores Calcium Homeostasis in an Animal Model of Alzheimer's Disease.

    PubMed

    Kastanenka, Ksenia V; Hou, Steven S; Shakerdge, Naomi; Logan, Robert; Feng, Danielle; Wegmann, Susanne; Chopra, Vanita; Hawkes, Jonathan M; Chen, Xiqun; Bacskai, Brian J

    2017-01-01

    Slow oscillations are important for consolidation of memory during sleep, and Alzheimer's disease (AD) patients experience memory disturbances. Thus, we examined slow oscillation activity in an animal model of AD. APP mice exhibit aberrant slow oscillation activity. Aberrant inhibitory activity within the cortical circuit was responsible for slow oscillation dysfunction, since topical application of GABA restored slow oscillations in APP mice. In addition, light activation of channelrhodopsin-2 (ChR2) expressed in excitatory cortical neurons restored slow oscillations by synchronizing neuronal activity. Driving slow oscillation activity with ChR2 halted amyloid plaque deposition and prevented calcium overload associated with this pathology. Thus, targeting slow oscillatory activity in AD patients might prevent neurodegenerative phenotypes and slow disease progression.

  1. Sequence variants of IDE are associated with the extent of beta-amyloid deposition in the Alzheimer's disease brain.

    PubMed

    Blomqvist, Mia E-L; Chalmers, Katy; Andreasen, Niels; Bogdanovic, Nenad; Wilcock, Gordon K; Cairns, Nigel J; Feuk, Lars; Brookes, Anthony J; Love, Seth; Blennow, Kaj; Kehoe, Patrick G; Prince, Jonathan A

    2005-06-01

    Insulin degrading enzyme, encoded by IDE, plays a primary role in the degradation of amyloid beta-protein (A beta), the deposition of which in senile plaques is one of the defining hallmarks of Alzheimer's disease (AD). We recently identified haplotypes in a broad linkage disequilibrium (LD) block encompassing IDE that associate with several AD-related quantitative traits. Here, by examining 32 polymorphic markers extending across IDE and testing quantitative measures of plaque density and cognitive function in three independent Swedish AD samples, we have refined the probable position of pathogenic sequences to a 3' region of IDE, with local maximum effects in the proximity of marker rs1887922. To replicate these findings, a subset of variants were examined against measures of brain A beta load in an independent English AD sample, whereby maximum effects were again observed for rs1887922. For both Swedish and English autopsy materials, variation at rs1887922 explained approximately 10% of the total variance in the respective histopathology traits. However, across all clinical materials studied to date, this variant site does not appear to associate directly with disease, suggesting that IDE may affect AD severity rather than risk. Results indicate that alleles of IDE contribute to variability in A beta deposition in the AD brain and suggest that this relationship may have relevance for the degree of cognitive dysfunction in AD patients.

  2. Impact of composition and crystallization behavior of atomic layer deposited strontium titanate films on the resistive switching of Pt/STO/TiN devices

    SciTech Connect

    Aslam, N.; Rodenbücher, C.; Szot, K.; Waser, R.; Hoffmann-Eifert, S.; Longo, V.; Roozeboom, F.; Kessels, W. M. M.

    2014-08-14

    The resistive switching (RS) properties of strontium titanate (Sr{sub 1+x}Ti{sub 1+y}O{sub 3+(x+2y)}, STO) based metal-oxide-metal structures prepared from industrial compatible processes have been investigated focusing on the effects of composition, microstructure, and device size. Metastable perovskite STO films were prepared on Pt-coated Si substrates utilizing plasma-assisted atomic layer deposition (ALD) from cyclopentadienyl-based metal precursors and oxygen plasma at 350 °C, and a subsequent annealing at 600 °C in nitrogen. Films of 15 nm and 12 nm thickness with three different compositions [Sr]/([Sr] + [Ti]) of 0.57 (Sr-rich STO), 0.50 (stoichiometric STO), and 0.46 (Ti-rich STO) were integrated into Pt/STO/TiN crossbar structures with sizes ranging from 100 μm{sup 2} to 0.01 μm{sup 2}. Nano-structural characterizations revealed a clear effect of the composition of the as-deposited STO films on their crystallization behavior and thus on the final microstructures. Local current maps obtained by local-conductivity atomic force microscopy were in good agreement with local changes of the films' microstructures. Correspondingly, also the initial leakage currents of the Pt/STO/TiN devices were affected by the STO compositions and by the films' microstructures. An electroforming process set the Pt/STO/TiN devices into the ON-state, while the forming voltage decreased with increasing initial leakage current. After a RESET process under opposite voltage has been performed, the Pt/STO/TiN devices showed a stable bipolar RS behavior with non-linear current-voltage characteristics for the high (HRS) and the low (LRS) resistance states. The obtained switching polarity and nearly area independent LRS values agree with a filamentary character of the RS behavior according to the valence change mechanism. The devices of 0.01 μm{sup 2} size with a 12 nm polycrystalline stoichiometric STO film were switched at a current compliance of 50 μA with

  3. Biomimetic thin film deposition

    NASA Astrophysics Data System (ADS)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  4. Mixed connective tissue disease characterized by speckled epidermal nuclear IgG deposition in normal skin.

    PubMed

    Bentley-Phillips, C B; Geake, T M

    1980-05-01

    Four African female patients are described, who presented with the features of systemic sclerosis. Overlapping features of lupus erythematosus or dermatomyositis were present in three cases but were not prominent. Direct immunofluorescence of uninvolved skin revealed a particulate (or speckled) epidermal nuclear staining, with specificity for IgG. In view of the reported association between this finding and mixed connective tissue disease, these patients were treated with corticosteroids and marked improvment occurred in all cases. The usefulness of this investigation in making the distinction between systemic sclerosis and mixed connective tissue disease and in indicating a potentially effective form of therapy is discussed.

  5. [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; Galtseva, 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.

  6. Clinically different stages of Alzheimer's disease associated by amyloid deposition with [11C]-PIB PET imaging.

    PubMed

    Hatashita, Shizuo; Yamasaki, Hidetomo

    2010-01-01

    We investigated whether [11C]-PIB PET detects underlying amyloid deposition at clinically different stages of Alzheimer's disease (AD) and preclinical dementia. The Japanese cohort of 214 subjects underwent cognitive testing and 60-min dynamic [11C]-PIB PET. [11C]-PIB data were acquired from 35-60 min after injection. Regions of interest were defined on co-registered MRI. Distribution volume ratios (DVR) of PIB retention were determined using Logan graphical analysis. All 56 patients with AD showed a robust increase in PIB retention in cortical areas (typical PIB AD-pattern). A mean DVR value in 11 patients with moderate AD (CDR: 2.1 ± 0.4) showed significantly higher PIB retention (2.38 ± 0.42, p < 0.01) than amyloid-negative healthy control (HC) subjects. The DVR values in 23 patients with very mild AD (CDR: 0.5) and 22 patients with mild AD (CDR: 1.0) were 2.32 ± 0.45 and 2.34 ± 0.42, respectively, similar to moderate AD. In contrast, 28 (48%) of the 58 mild cognitive impairment (MCI) patients (MMSE: 27.3 ± 1.7) showed a typical AD-like pattern with a DVR value of 2.07 ± 0.34. Further, 17 (18%) of 91 HC subjects had a typical AD-like pattern with a DVR value of 2.06 ± 0.28. They did not significantly differ from very mild AD. The prevalence of AD among the 53 amyloid positive patients aged 75 years or older increased greatly to 74% whereas that of amyloid positive HC decreased by only 9% and amyloid positive MCI by 17%. Prodromal AD and AD dementia is identified, based on cognitive function and amyloid deposition by PIB PET imaging. Further, the cortical amyloid deposition could be detected at preclinical stage of AD.

  7. 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%.

  8. 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 %.

  9. 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%.

  10. 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 %.

  11. Change perspective to increase diagnostic accuracy of ultrasonography in calcium pyrophosphate dehydrate deposition disease! A new approach: the axial scan of the meniscus.

    PubMed

    Filippou, G; Picerno, V; Adinolfi, A; Di Sabatino, V; Bertoldi, I; Galeazzi, M; Frediani, B

    2015-03-31

    Ultrasonography (US) is a relevant tool in the study of calcium pyrophosphate dihydrate (CPP) deposition disease. However, differential diagnosis of hyperechoic deposits within the fibrocartilage can be difficult; moreover, US study is limited by the need of an adequate acoustic window. We describe a US scanning technique that offers a new viewpoint in the study of knee meniscal structure: a longitudinal scan performed according to the long axis of meniscus. This technique proves to be particularly useful for the identification of CPP deposition, but could also improve the US diagnostic utility and accuracy in other meniscal pathologies.

  12. Oxidative stress accelerates amyloid deposition and memory impairment in a double-transgenic mouse model of Alzheimer's disease.

    PubMed

    Kanamaru, Takuya; Kamimura, Naomi; Yokota, Takashi; Iuchi, Katsuya; Nishimaki, Kiyomi; Takami, Shinya; Akashiba, Hiroki; Shitaka, Yoshitsugu; Katsura, Ken-Ichiro; Kimura, Kazumi; Ohta, Shigeo

    2015-02-05

    Oxidative stress is known to play a prominent role in the onset and early stage progression of Alzheimer's disease (AD). For example, protein oxidation and lipid peroxidation levels are increased in patients with mild cognitive impairment. Here, we created a double-transgenic mouse model of AD to explore the pathological and behavioral effects of oxidative stress. Double transgenic (APP/DAL) mice were constructed by crossing Tg2576 (APP) mice, which express a mutant form of human amyloid precursor protein (APP), with DAL mice expressing a dominant-negative mutant of mitochondrial aldehyde dehydrogenase 2 (ALDH2), in which oxidative stress is enhanced. Y-maze and object recognition tests were performed at 3 and 6 months of age to evaluate learning and memory. The accumulation of amyloid plaques, deposition of phosphorylated-tau protein, and number of astrocytes in the brain were assessed histopathologically at 3, 6, 9, and 12-15 months of age. The life span of APP/DAL mice was significantly shorter than that of APP or DAL mice. In addition, they showed accelerated amyloid deposition, tau phosphorylation, and gliosis. Furthermore, these mice showed impaired performance on Y-maze and object recognition tests at 3 months of age. These data suggest that oxidative stress accelerates cognitive dysfunction and pathological insults in the brain. APP/DAL mice could be a useful model for exploring new approaches to AD treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. [The disease of beta 2-amyloid deposition in the differential diagnosis of juxta-articular subchondral geode lesions].

    PubMed

    Marri, C; Romagnoli, C; Solano, G; Caldeo, A; Emiliani, G

    1993-01-01

    Beta-2 amyloidosis deposition is a new type of amyloidosis recently observed in long-term hemodialysis patients. One of the major osteoarticular complications of this disease is the appearance of subchondral bone cysts. In this paper the radiologic features of such radiolucencies are described and the criteria are outlined of the differential diagnosis from the geodes found in other arthropathies or para-physiologic conditions. The importance of the status of the joint space is stressed: on the basis of its patterns, arthropathies may be grouped as follows: inhomogeneous space narrowing in degenerative arthritis; homogeneous space narrowing in inflammatory arthritis; normal or nearly normal joint space if there is no/not-prevalent involvement of articular cartilage.

  14. 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.

  15. Longitudinal β-Amyloid Deposition and Hippocampal Volume in Preclinical Alzheimer Disease and Suspected Non-Alzheimer Disease Pathophysiology.

    PubMed

    Gordon, Brian A; Blazey, Tyler; Su, Yi; Fagan, Anne M; Holtzman, David M; Morris, John C; Benzinger, Tammie L S

    2016-10-01

    Preclinical Alzheimer disease (AD) can be staged using a 2-factor model denoting the presence or absence of β-amyloid (Aβ+/-) and neurodegeneration (ND+/-). The association of these stages with longitudinal biomarker outcomes is unknown. To examine whether longitudinal Aβ accumulation and hippocampal atrophy differ based on initial preclinical staging. This longitudinal population-based cohort study used data collected at the Knight Alzheimer Disease Research Center, Washington University, St Louis, Missouri, from December 1, 2006, to June 31, 2015. Cognitively normal older adults (n = 174) were recruited from the longitudinal Adult Children Study and Healthy Aging and Senile Dementia Study at the Knight Alzheimer Disease Research Center. At baseline, all participants had magnetic resonance imaging (MRI) scans, positron emission tomography (PET) scans with carbon 11-labeled Pittsburgh Compound B (PiB), and cerebrospinal fluid assays of tau and phosphorylated tau (ptau) acquired within 12 months. Using the baseline biomarkers, individuals were classified into preclinical stage 0 (Aβ-/ND-), 1 (Aβ+/ND-), or 2+ (Aβ+/ND+) or suspected non-AD pathophysiology (SNAP; Aβ-/ND+). Subsequent longitudinal accumulation of Aβ assessed with PiB PET and loss of hippocampal volume assessed with MRI in each group. Among the 174 participants (81 men [46.6%]; 93 women [53.4%]; mean [SD] age, 65.7 [8.9] years), a proportion (14%-17%) of individuals with neurodegeneration alone (SNAP) later demonstrated Aβ+. The rates of Aβ accumulation and loss of hippocampal volume in individuals with SNAP were indistinguishable from those without any pathologic features at baseline (for Aβ accumulation: when hippocampal volume was used to define ND, t = 0.00 [P > .99]; when tau and ptau were used to define ND, t = -0.02 [P = .98]; for loss of hippocampal volume: when hippocampal volume was used to define ND, t = -1.34 [P = .18]; when tau and ptau were used to

  16. Longitudinal β-Amyloid Deposition and Hippocampal Volume in Preclinical Alzheimer Disease and Suspected Non–Alzheimer Disease Pathophysiology

    PubMed Central

    Gordon, Brian A.; Blazey, Tyler; Su, Yi; Fagan, Anne M.; Holtzman, David M.; Morris, John C.; Benzinger, Tammie L. S.

    2016-01-01

    Importance Preclinical Alzheimer disease (AD) can be staged using a 2-factor model denoting the presence or absence of β-amyloid (Aβ+/−) and neurodegeneration (ND+/−). The association of these stages with longitudinal biomarker outcomes is unknown. Objective To examine whether longitudinal Aβ accumulation and hippocampal atrophy differ based on initial preclinical staging. Design, Setting, and Participants This longitudinal population-based cohort study used data collected at the Knight Alzheimer Disease Research Center, Washington University, St Louis, Missouri, from December 1, 2006, to June 31, 2015. Cognitively normal older adults (n = 174) were recruited from the longitudinal Adult Children Study and Healthy Aging and Senile Dementia Study at the Knight Alzheimer Disease Research Center. At baseline, all participants had magnetic resonance imaging (MRI) scans, positron emission tomography (PET) scans with carbon 11-labeled Pittsburgh Compound B (PiB), and cerebrospinal fluid assays of tau and phosphorylated tau (ptau) acquired within 12 months. Using the baseline biomarkers, individuals were classified into preclinical stage 0 (Aβ−/ND−), 1 (Aβ+/ND−), or 2+ (Aβ+/ND+) or suspected non-AD pathophysiology (SNAP; Aβ−/ND+). Main Outcomes and Measures Subsequent longitudinal accumulation of Aβ assessed with PiB PET and loss of hippocampal volume assessed with MRI in each group. Results Among the 174 participants (81 men [46.6%]; 93 women [53.4%]; mean [SD] age, 65.7 [8.9] years), a proportion (14%-17%) of individuals with neurodegeneration alone (SNAP) later demonstrated Aβ+. The rates of Aβ accumulation and loss of hippocampal volume in individuals with SNAP were indistinguishable from those without any pathologic features at baseline (for Aβ accumulation: when hippocampal volume was used to define ND, t = 0.00 [P > .99]; when tau and ptau were used to define ND, t = −0.02 [P = .98]; for loss of hippocampal volume: when hippocampal volume

  17. Effect of Co-doping on Microstructural, Crystal Structure and Optical Properties of Ti1-xCOxO2 Thin films Deposited on Si Substrate by MOCVD Method

    NASA Astrophysics Data System (ADS)

    Supriyanto, E.; Sutanto, H.; Subagio, A.; Saragih, H.; Budiman, M.; Arifin, P.; Sukirno, Barmawi, M.

    2008-03-01

    Ti1-xCOxO2 thin films have been grown on n-type Si(100) substrates by metal organic vapor deposition (MOCVD) using titanium (IV) isopropoxide (TTIP) and tris (2,2,6,6-tetramethyl-3, 5-heptanedionato) cobalt (III) as metal organic precursors. The parameter deposition, such as: bubbler temperature of TTIP Tb(Ti) = 50 °C; substrate temperature Ts = 450 °C; bubbler pressure Pb(Ti) = 260 Torr; flow rate of Ar gas through TTIP precursor Ar(Ti) = 100 sccm (standard cubic centimeters per minute) and flow rate of oxygen gas O2 = 60 sccm were found as optimal deposition parameters. The thin films deposited were have rutile (002) crystal plane, whereas those deposited at other parameter were mixing of anatase and rutile phases. Co dopant with concentration of up to 5.77% was not changes the structure of TiO2. Increase of Co incorporated in thin films was decreasing of band-gap energy.

  18. Crystal-associated synovitis- ultrasonographic feature and clinical correlation.

    PubMed

    Fodor, Danela; Albu, Adriana; Gherman, Claudia

    2008-01-01

    The aim of this paper is to describe the ultrasonographic findings in rheumatologic pathology due to crystal deposition. There are four main types of crystals involved: monosodium urate, calcium pyrophosphate dihydrate, basic calcium phosphate (hydroxyapatite), and calcium oxalate. In gout the joint fluid is anechoic only at the first gouty attack; afterwards the synovium begins to proliferate. Double contuour sign, a focal or diffuse enhancement of the superficial margin of the articular cartilage is a specific finding. Bursitis has chronic features from the beginning. The ultrasonographic aspect of tophi depends on their age and size (at first small, hypoechoic and homogenous nodules, then echoic with hyperechoic edges and finally pseudotumoral, inhomogeneous). The depositions in the superficial layer are hyperechoic, well delimited only in the absence of inflammatory reaction. The depositions at the entheseal level are leading to the gouty enthesopathy. In knee involvement irregularities of the anterior surface of patella are found. In chondrocalcinosis the most important ultrasonographic signs are the thin hyperechoic band, parallel to the surface of the hyaline cartilage and the punctuated pattern of the fibrocartilage. In hydroxyapatite associated disease, calcifications are frequent in the shoulder or in the great trochanter of the hip, with aspects depending of the calcification phase. Milwakee shoulder is an advanced form of this pathology, associated with rotator cuff arthropathy. Oxalate crystal deposition disease is seen rarely, in patients with primary hyperoxaluria and in patients with end-stage renal disease. Therefore ultrasonography is useful in characterize the articular and juxta-articular alterations in crystal related diseases.

  19. Characterization of damage induced by heavy neutron irradiation on multilayered {sup 6}LiF-single crystal chemical vapor deposition diamond detectors

    SciTech Connect

    Almaviva, S.; Marinelli, Marco; Milani, E.; Prestopino, G.; Tucciarone, A.; Verona, C.; Verona-Rinati, G.; Angelone, M.; Pillon, M.

    2009-10-01

    High performance neutron detectors sensitive to both thermal and fast neutrons are of great interest to monitor the high neutron flux produced, e.g., by fission and fusion reactors. An obvious requirement for such an application is neutron irradiation hardness. This is why diamond based neutron detectors are currently under test in some of these facilities. In this paper the damaging effects induced in chemical vapor deposition (CVD) diamond based detectors by a neutron fluence of approx2x10{sup 16} neutrons/cm{sup 2} have been studied and significant changes in spectroscopic, electrical, and optical properties have been observed. The detectors are fabricated using high quality synthetic CVD single crystal diamond using the p-type/intrinsic/Schottky metal/{sup 6}LiF layered structure recently proposed by Marinelli et al. [Appl. Phys. Lett. 89, 143509 (2006)], which allows simultaneous detection of thermal and fast neutrons. Neutron radiation hardness up to at least 2x10{sup 14} n/cm{sup 2} fast (14 MeV) neutron fluence has been confirmed so far [see Pillon et al., (Fusion Eng. Des. 82, 1174 (2007)]. However, at the much higher neutron fluence of approx2x10{sup 16} neutrons/cm{sup 2} damage is observed. The detector response to 5.5 MeV {sup 241}Am alpha-particles still shows a well resolved alpha-peak, thus confirming the good radiation hardness of the device but a remarkable degradation and a significant instability with time of charge collection efficiency and energy resolution arise. Symmetric, nearly Ohmic I-V (current-voltage) characteristics have been recorded from the metal/intrinsic/p-doped diamond layered structure, which before neutron irradiation acted as a Schottky barrier diode with a strong rectifying behavior. The nature and the distribution of the radiation induced damage have been deeply examined by means of cathodoluminescence spectroscopy. A more heavily damaged area into the intrinsic diamond at the same position and with the same extension of

  20. Sub-band gap photo-enhanced secondary electron emission from high-purity single-crystal chemical-vapor-deposited diamond

    SciTech Connect

    Yater, J. E. Shaw, J. L.; Pate, B. B.; Feygelson, T. I.

    2016-02-07

    Secondary-electron-emission (SEE) current measured from high-purity, single-crystal (100) chemical-vapor-deposited diamond is found to increase when sub-band gap (3.06 eV) photons are incident on the hydrogenated surface. Although the light does not produce photoemission directly, the SEE current increases by more than a factor of 2 before saturating with increasing laser power. In energy distribution curves (EDCs), the emission peak shows a corresponding increase in intensity with increasing laser power. However, the emission-onset energy in the EDCs remains constant, indicating that the bands are pinned at the surface. On the other hand, changes are observed on the high-energy side of the distribution as the laser power increases, with a well-defined shoulder becoming more pronounced. From an analysis of this feature in the EDCs, it is deduced that upward band bending is present in the near-surface region during the SEE measurements and this band bending suppresses the SEE yield. However, sub-band gap photon illumination reduces the band bending and thereby increases the SEE current. Because the bands are pinned at the surface, we conclude that the changes in the band levels occur below the surface in the electron transport region. Sample heating produces similar effects as observed with sub-band gap photon illumination, namely, an increase in SEE current and a reduction in band bending. However, the upward band bending is not fully removed by either increasing laser power or temperature, and a minimum band bending of ∼0.8 eV is established in both cases. The sub-band gap photo-excitation mechanism is under further investigation, although it appears likely at present that defect or gap states play a role in the photo-enhanced SEE process. In the meantime, the study demonstrates the ability of visible light to modify the electronic properties of diamond and enhance the emission capabilities, which may have potential impact for diamond-based vacuum electron

  1. Sub-band gap photo-enhanced secondary electron emission from high-purity single-crystal chemical-vapor-deposited diamond

    NASA Astrophysics Data System (ADS)

    Yater, J. E.; Shaw, J. L.; Pate, B. B.; Feygelson, T. I.

    2016-02-01

    Secondary-electron-emission (SEE) current measured from high-purity, single-crystal (100) chemical-vapor-deposited diamond is found to increase when sub-band gap (3.06 eV) photons are incident on the hydrogenated surface. Although the light does not produce photoemission directly, the SEE current increases by more than a factor of 2 before saturating with increasing laser power. In energy distribution curves (EDCs), the emission peak shows a corresponding increase in intensity with increasing laser power. However, the emission-onset energy in the EDCs remains constant, indicating that the bands are pinned at the surface. On the other hand, changes are observed on the high-energy side of the distribution as the laser power increases, with a well-defined shoulder becoming more pronounced. From an analysis of this feature in the EDCs, it is deduced that upward band bending is present in the near-surface region during the SEE measurements and this band bending suppresses the SEE yield. However, sub-band gap photon illumination reduces the band bending and thereby increases the SEE current. Because the bands are pinned at the surface, we conclude that the changes in the band levels occur below the surface in the electron transport region. Sample heating produces similar effects as observed with sub-band gap photon illumination, namely, an increase in SEE current and a reduction in band bending. However, the upward band bending is not fully removed by either increasing laser power or temperature, and a minimum band bending of ˜0.8 eV is established in both cases. The sub-band gap photo-excitation mechanism is under further investigation, although it appears likely at present that defect or gap states play a role in the photo-enhanced SEE process. In the meantime, the study demonstrates the ability of visible light to modify the electronic properties of diamond and enhance the emission capabilities, which may have potential impact for diamond-based vacuum electron

  2. Production of calcium oxalate crystals by the basidiomycete Moniliophthora perniciosa, the causal agent of witches' broom disease of Cacao.

    PubMed

    Rio, Maria Carolina S do; de Oliveira, Bruno V; de Tomazella, Daniela P T; Silva, José A Fracassi da; Pereira, Gonçalo A G

    2008-04-01

    Oxalic acid has been shown as a virulence factor for some phytopathogenic fungi, removing calcium from pectin and favoring plant cell wall degradation. Recently, it was published that calcium oxalate accumulates in infected cacao tissues during the progression of Witches' Broom disease (WBD). In the present work we report that the hemibiotrophic basidiomycete Moniliophthora perniciosa, the causal agent of WBD, produces calcium oxalate crystals. These crystals were initially observed by polarized light microscopy of hyphae growing on a glass slide, apparently being secreted from the cells. The analysis was refined by Scanning electron microscopy and the compositon of the crystals was confirmed by energy-dispersive x-ray spectrometry. The production of oxalate by M. perniciosa was reinforced by the identification of a putative gene coding for oxaloacetate acetylhydrolase, which catalyzes the hydrolysis of oxaloacetate to oxalate and acetate. This gene was shown to be expressed in the biotrophic-like mycelia, which in planta occupy the intercellular middle-lamella space, a region filled with pectin. Taken together, our results suggest that oxalate production by M. perniciosa may play a role in the WBD pathogenesis mechanism.

  3. Determining composition of micron-scale protein deposits in neurodegenerative disease by spatially targeted optical microproteomics

    PubMed Central

    Hadley, Kevin C; Rakhit, Rishi; Guo, Hongbo; Sun, Yulong; Jonkman, James EN; McLaurin, Joanne; Hazrati, Lili-Naz; Emili, Andrew; Chakrabartty, Avijit

    2015-01-01

    Spatially targeted optical microproteomics (STOMP) is a novel proteomics technique for interrogating micron-scale regions of interest (ROIs) in mammalian tissue, with no requirement for genetic manipulation. Methanol or formalin-fixed specimens are stained with fluorescent dyes or antibodies to visualize ROIs, then soaked in solutions containing the photo-tag: 4-benzoylbenzyl-glycyl-hexahistidine. Confocal imaging along with two photon excitation are used to covalently couple photo-tags to all proteins within each ROI, to a resolution of 0.67 µm in the xy-plane and 1.48 µm axially. After tissue solubilization, photo-tagged proteins are isolated and identified by mass spectrometry. As a test case, we examined amyloid plaques in an Alzheimer's disease (AD) mouse model and a post-mortem AD case, confirming known plaque constituents and discovering new ones. STOMP can be applied to various biological samples including cell lines, primary cell cultures, ex vivo specimens, biopsy samples, and fixed post-mortem tissue. DOI: http://dx.doi.org/10.7554/eLife.09579.001 PMID:26418743

  4. Dentate nucleus iron deposition is a potential biomarker for tremor-dominant Parkinson's disease.

    PubMed

    He, Naying; Huang, Pei; Ling, Huawei; Langley, Jason; Liu, Chunlei; Ding, Bei; Huang, Juan; Xu, Hongmin; Zhang, Yong; Zhang, Zhongping; Hu, Xiaoping; Chen, Shengdi; Yan, Fuhua

    2016-05-18

    Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder with variable clinicopathologic phenotypes and underlying neuropathologic mechanisms. Each clinical phenotype has a unique set of motor symptoms. Tremor is the most frequent initial motor symptom of PD and is the most difficult symptom to treat. The dentate nucleus (DN) is a deep iron-rich nucleus in the cerebellum and may be involved in PD tremor. In this study, we test the hypothesis that DN iron may be elevated in tremor-dominant PD patients using quantitative susceptibility mapping. Forty-three patients with PD [19 tremor dominant (TD)/24 akinetic rigidity (AR) dominant] and 48 healthy gender- and age-matched controls were recruited. Multi-echo gradient echo data were collected for each subject on a 3.0-T MR system. Inter-group susceptibility differences in the bilateral DN were investigated and correlations of clinical features with susceptibility were also examined. In contrast with the AR-dominant group, the TD group was found to have increased susceptibility in the bilateral DN when compared with healthy controls. In addition, susceptibility was positively correlated with tremor score in drug-naive PD patients. These findings indicate that iron load within the DN may make an important contribution to motor phenotypes in PD. Moreover, our results suggest that TD and AR-dominant phenotypes of PD can be differentiated on the basis of the susceptibility of the DN, at least at the group level. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Human C3 mutation reveals a mechanism of dense deposit disease pathogenesis and provides insights into complement activation and regulation

    PubMed Central

    Martínez-Barricarte, Rubén; Heurich, Meike; Valdes-Cañedo, Francisco; Vazquez-Martul, Eduardo; Torreira, Eva; Montes, Tamara; Tortajada, Agustín; Pinto, Sheila; Lopez-Trascasa, Margarita; Morgan, B. Paul; Llorca, Oscar; Harris, Claire L.; Rodríguez de Córdoba, Santiago

    2010-01-01

    Dense deposit disease (DDD) is a severe renal disease characterized by accumulation of electron-dense material in the mesangium and glomerular basement membrane. Previously, DDD has been associated with deficiency of factor H (fH), a plasma regulator of the alternative pathway (AP) of complement activation, and studies in animal models have linked pathogenesis to the massive complement factor 3 (C3) activation caused by this deficiency. Here, we identified a unique DDD pedigree that associates disease with a mutation in the C3 gene. Mutant C3923ΔDG, which lacks 2 amino acids, could not be cleaved to C3b by the AP C3-convertase and was therefore the predominant circulating C3 protein in the patients. However, upon activation to C3b by proteases, or to C3(H2O) by spontaneous thioester hydrolysis, C3923ΔDG generated an active AP C3-convertase that was regulated normally by decay accelerating factor (DAF) but was resistant to decay by fH. Moreover, activated C3b923ΔDG and C3(H2O)923ΔDG were resistant to proteolysis by factor I (fI) in the presence of fH, but were efficiently inactivated in the presence of membrane cofactor protein (MCP). These characteristics cause a fluid phase–restricted AP dysregulation in the patients that continuously activated and consumed C3 produced by the normal C3 allele. These findings expose structural requirements in C3 that are critical for recognition of the substrate C3 by the AP C3-convertase and for the regulatory activities of fH, DAF, and MCP, all of which have implications for therapeutic developments. PMID:20852386

  6. Crystal structure of the amyloid-β p3 fragment provides a model for oligomer formation in Alzheimer's disease.

    PubMed

    Streltsov, Victor A; Varghese, Joseph N; Masters, Colin L; Nuttall, Stewart D

    2011-01-26

    Alzheimer's disease is a progressive neurodegenerative disorder associated with the presence of amyloid-β (Aβ) peptide fibrillar plaques in the brain. However, current evidence suggests that soluble nonfibrillar Aβ oligomers may be the major drivers of Aβ-mediated synaptic dysfunction. Structural information on these Aβ species has been very limited because of their noncrystalline and unstable nature. Here, we describe a crystal structure of amylogenic residues 18-41 of the Aβ peptide (equivalent to the p3 α/γ-secretase fragment of amyloid precursor protein) presented within the CDR3 loop region of a shark Ig new antigen receptor (IgNAR) single variable domain antibody. The predominant oligomeric species is a tightly associated Aβ dimer, with paired dimers forming a tetramer in the crystal caged within four IgNAR domains, preventing uncontrolled amyloid formation. Our structure correlates with independently observed features of small nonfibrillar Aβ oligomers and reveals conserved elements consistent with residues and motifs predicted as critical in Aβ folding and oligomerization, thus potentially providing a model system for nonfibrillar oligomer formation in Alzheimer's disease.

  7. The Interaction between Enterobacteriaceae and Calcium Oxalate Deposits

    PubMed Central

    Barr-Beare, Evan; Saxena, Vijay; Hilt, Evann E.; Thomas-White, Krystal; Schober, Megan; Li, Birong; Becknell, Brian; Hains, David S.; Wolfe, Alan J.; Schwaderer, Andrew L.

    2015-01-01

    Background The role of calcium oxalate crystals and deposits in UTI pathogenesis has not been established. The objectives of this study were to identify bacteria present in pediatric urolithiasis and, using in vitro and in vivo models, to determine the relevance of calcium oxalate deposits during experimental pyelonephritis. Methods Pediatric kidney stones and urine were collected and both cultured and sequenced for bacteria. Bacterial adhesion to calcium oxalate was compared. Murine kidney calcium oxalate deposits were induced by intraperitoneal glyoxalate injection and kidneys were transurethrally inoculated with uropathogenic Escherichia coli to induce pyelonephritis Results E. coli of the family Enterobacteriaceae was identified in patients by calcium oxalate stone culture. Additionally Enterobacteriaceae DNA was sequenced from multiple calcium oxalate kidney stones. E. coli selectively aggregated on and around calcium oxalate monohydrate crystals. Mice inoculated with glyoxalate and uropathogenic E. coli had higher bacterial burdens, increased kidney calcium oxalate deposits and an increased kidney innate immune response compared to mice with only calcium oxalate deposits or only pyelonephritis. Conclusions In a murine model, the presence of calcium oxalate deposits increases pyelonephritis risk, likely due to preferential aggregation of bacteria on and around calcium oxalate crystals. When both calcium oxalate deposits and uropathogenic bacteria were present, calcium oxalate deposit number increased along with renal gene transcription of inner stone core matrix proteins increased. Therefore renal calcium oxalate deposits may be a modifiable risk factor for infections of the kidney and urinary tract. Furthermore, bacteria may be present in calcium oxalate deposits and potentially contribute to calcium oxalate renal disease. PMID:26448465

  8. Brain iron deposition fingerprints in Parkinson's disease and progressive supranuclear palsy.

    PubMed

    Boelmans, Kai; Holst, Brigitte; Hackius, Marc; Finsterbusch, Jürgen; Gerloff, Christian; Fiehler, Jens; Münchau, Alexander

    2012-03-01

    It can be difficult to clinically distinguish between classical Parkinson's disease (PD) and progressive supranuclear palsy. Previously, there have been no biomarkers that reliably allow this distinction to be made. We report that an abnormal brain iron accumulation is a marker for ongoing neurodegeneration in both conditions, but the conditions differ with respect to the anatomical distribution of these accumulations. We analyzed quantitative T2' maps as markers of regional brain iron content from PD and progressive supranuclear palsy patients and compared them to age-matched control subjects. T2-weighted and T2*-weighted images were acquired in 30 PD patients, 12 progressive supranuclear palsy patients, and 24 control subjects at 1.5 Tesla. Mean T2' values were determined in regions-of-interest in the basal ganglia, thalamus, and white matter within each hemisphere. The main findings were shortened T2' values in the caudate nucleus, globus pallidus, and putamen in progressive supranuclear palsy compared to PD patients and controls. A stepwise linear discriminant analysis allowed progressive supranuclear palsy patients to be distinguished from PD patients and the healthy controls. All progressive supranuclear palsy patients were correctly classified. No progressive supranuclear palsy patient was classified as a healthy control, no healthy controls were incorrectly classified as having progressive supranuclear palsy, and only 6.7% of the PD patients were incorrectly classified as progressive supranuclear palsy. Regional decreases of T2' relaxation times in parts of the basal ganglia reflecting increased brain iron load in these areas are characteristic for progressive supranuclear palsy but not PD patients.

  9. Sputtering characteristics, crystal structures, and transparent conductive properties of TiOxNy films deposited on α-Al2O3(0 0 0 1) and glass substrates

    NASA Astrophysics Data System (ADS)

    Akazawa, Housei

    2012-12-01

    Adding N2 gas during reactive sputtering of a Ti target prevented the target surface from being severely poisoned by oxygen atoms and sustained a high deposition rate for titanium oxynitride films under metal-mode-like sputtering conditions. With progress in the degree of oxidization, films deposited onto a glass substrate varied from TiO1-xNx having a face-centered cubic (fcc) structure to TiO2-xNx having an anatase structure. Titanium oxynitride films deposited on an Al2O3(0 0 0 1) substrate were epitaxial with major orientations toward the (1 1 1) and (2 0 0) directions for fcc-TiO1-xNx and (1 1 2) for anatase-TiO2-xNx. Intermediately oxidized films between TiO1-xNx and TiO2-xNx were amorphous on the glass substrate but crystallized into a Magneli phase, TinO(N)2n-1, on the Al2O3(0 0 0 1) substrate. Partially substituting oxygen in TiO2 with nitrogen as well as continuously irradiating the growing film surface with a Xe plasma stream preferentially formed anatase rather than rutile. However, the occupation of anion sites with enough oxygen rather than nitrogen was the required condition for anatase crystals to form. The transparent conductive properties of epitaxial TiO2-xNx films on Al2O3(0 0 0 1) were superior to those of microcrystalline films on the glass substrate. Since resistivity and optical transmittance of TiOxNy films vary continuously with changing N2 flow rate, their transparent conductive properties can be controlled more easily than TiOx. Nb5+ ions could be doped as donors in TiO2-xNx anatase crystals.

  10. Electrical properties of thin-film structures formed by pulsed laser deposition of Au, Ag, Cu, Pd, Pt, W, Zr metals on n-6H-SiC crystal

    SciTech Connect

    Romanov, R. I.; Zuev, V. V.; Fominskii, V. Yu. Demin, M. V.; Grigoriev, V. V.

    2010-09-15

    Diode structures with ideality factors of 1.28-2.14 and potential barriers from 0.58 to 0.62 eV on the semiconductor side were formed by pulsed laser deposition of Au, Ag, Cu, Pd, Pt, W, and Zr metal films on n-6H-SiC crystal without epitaxial layer preparation. A high density of surface acceptor and donor states was formed at the metal-semiconductor interface during deposition of the laser-induced atomic flux, which violated the correlation between the potential barrier height and metal work function. The barrier heights determined from characteristic currents and capacitance measurements were in quite good agreement. For the used low-resistance semiconductor and contact elements, the sizes of majority carrier (electron) depletion regions were determined as 26-60 nm.

  11. Synthesis of alpha-aluminum oxide and hafnium-doped beta-nickel aluminide coatings on single crystal nickel-based superalloy by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    He, Limin

    Thermal barrier coatings (TBCs) are widely used for air-cooled turbine components in advanced aircraft engines and power generation systems. The dominant failure mode observed in TBCs is progressive fracture of the metal-oxide interface upon oxidation and thermal cycling. Two potential coating methods for improving TBC performance were studied: (1) preparing a high-quality alpha-Al 2O3 coating layer on the surface of a single crystal Ni-based superalloy (Rene N5) to extend the oxidative stability of the interface and (2) doping beta-NiAl bond coating with a small amount of Hf to improve the adhesion of thermally grown oxide (TGO) at the interface. In the first coating method, a novel chemical vapor deposition (CVD) procedure was developed using AlCl3, CO2 and H 2 as precursors. A critical part of this procedure was a short-time pre-oxidation step (1 min) with CO2 and H2 in the CVD chamber, prior to introducing the AlCl3, vapor. Without this pre-oxidation step, extensive whisker formation was observed on the alloy surface. Characterization results showed that the pre-oxidation step resulted in the formation of a continuous oxide layer (˜50 nm) on the alloy surface. The outer part of this layer (˜20 nm) appeared to contain mixed oxides whereas the inner part (˜30 nm) consisted of alpha-Al2O3 as a dominant major phase and theta-Al2O3 as a minor phase. It appeared that the preferential nucleation of beta-Al2O3 in the pre-oxidized layer was promoted by: (1) rapid heating (˜10 sec) of the alloy surface to the temperature region, where alpha-Al 2O3 was expected to nucleate instead of metastable Al 2O3 phases, (2) the low oxygen pressure environment of the pre-oxidation step which kept the rate of oxidation low, and (3) contamination of the CVD chamber with HfCl4. It appeared that the role of HfCl 4 was to enhance the preferential nucleation of alpha-Al2O 3 in the pre-oxidized layer. In our second coating method, we utilized the dynamic versatility of CVD as an avenue

  12. Consumption of grape seed extract prevents amyloid-beta deposition and attenuates inflammation in brain of an Alzheimer's disease mouse.

    PubMed

    Wang, Yan-Jiang; Thomas, Philip; Zhong, Jin-Hua; Bi, Fang-Fang; Kosaraju, Shantha; Pollard, Anthony; Fenech, Michael; Zhou, Xin-Fu

    2009-01-01

    Polyphenols extracted from grape seeds are able to inhibit amyloid-beta (Abeta) aggregation, reduce Abeta production and protect against Abeta neurotoxicity in vitro. We aimed to investigate the therapeutic effects of a polyphenol-rich grape seed extract (GSE) in Alzheimer's disease (AD) mice. APP(Swe)/PS1dE9 transgenic mice were fed with normal AIN-93G diet (control diet), AIN-93G diet with 0.07% curcumin or diet with 2% GSE beginning at 3 months of age for 9 months. Total phenolic content of GSE was 592.5 mg/g dry weight, including gallic acid (49 mg/g), catechin (41 mg/g), epicatechin (66 mg/g) and proanthocyanidins (436.6 mg catechin equivalents/g). Long-term feeding of GSE diet was well tolerated without fatality, behavioural abnormality, changes in food consumption, body weight or liver function. The Abeta levels in the brain and serum of the mice fed with GSE were reduced by 33% and 44%, respectively, compared with the Alzheimer's mice fed with the control diet. Amyloid plaques and microgliosis in the brain of Alzheimer's mice fed with GSE were also reduced by 49% and 70%, respectively. Curcumin also significantly reduced brain Abeta burden and microglia activation. Conclusively, polyphenol-rich GSE prevents the Abeta deposition and attenuates the inflammation in the brain of a transgenic mouse model, and this thus is promising in delaying development of AD.

  13. Lateral Asymmetry and Spatial Difference of Iron Deposition in the Substantia Nigra of Patients with Parkinson Disease Measured with Quantitative Susceptibility Mapping.

    PubMed

    Azuma, M; Hirai, T; Yamada, K; Yamashita, S; Ando, Y; Tateishi, M; Iryo, Y; Yoneda, T; Kitajima, M; Wang, Y; Yamashita, Y

    2016-05-01

    Quantitative susceptibility mapping is useful for assessing iron deposition in the substantia nigra of patients with Parkinson disease. We aimed to determine whether quantitative susceptibility mapping is useful for assessing the lateral asymmetry and spatial difference in iron deposits in the substantia nigra of patients with Parkinson disease. Our study population comprised 24 patients with Parkinson disease and 24 age- and sex-matched healthy controls. They underwent 3T MR imaging by using a 3D multiecho gradient-echo sequence. On reconstructed quantitative susceptibility mapping, we measured the susceptibility values in the anterior, middle, and posterior parts of the substantia nigra, the whole substantia nigra, and other deep gray matter structures in both hemibrains. To identify the more and less affected hemibrains in patients with Parkinson disease, we assessed the severity of movement symptoms for each hemibrain by using the Unified Parkinson's Disease Rating Scale. In the posterior substantia nigra of patients with Parkinson disease, the mean susceptibility value was significantly higher in the more than the less affected hemibrain substantia nigra (P < .05). This value was significantly higher in both the more and less affected hemibrains of patients with Parkinson disease than in controls (P < .05). Asymmetry of the mean susceptibility values was significantly greater for patients than controls (P < .05). Receiver operating characteristic analysis showed that quantitative susceptibility mapping of the posterior substantia nigra in the more affected hemibrain provided the highest power for discriminating patients with Parkinson disease from the controls. Quantitative susceptibility mapping is useful for assessing the lateral asymmetry and spatial difference of iron deposition in the substantia nigra of patients with Parkinson disease. © 2016 by American Journal of Neuroradiology.

  14. Label-free and depth resolved optical sectioning of iron-complex deposits in sickle cell disease splenic tissue by multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Vigil, Genevieve D.; Adami, Alexander J.; Ahmed, Tahsin; Khan, Aamir; Chapman, Sarah; Andemariam, Biree; Thrall, Roger S.; Howard, Scott S.

    2015-06-01

    Multiphoton microscopy (MPM) imaging of intrinsic two-photon excited fluorescence (TPEF) is performed on humanized sickle cell disease (SCD) mouse model splenic tissue. Distinct morphological and spectral features associated with SCD are identified and discussed in terms of diagnostic relevance. Specifically, spectrally unique splenic iron-complex deposits are identified by MPM; this finding is supported by TPEF spectroscopy and object size to standard histopathological methods. Further, iron deposits are found at higher concentrations in diseased tissue than in healthy tissue by all imaging methods employed here including MPM, and therefore, may provide a useful biomarker related to the disease state. These newly characterized biomarkers allow for further investigations of SCD in live animals as a means to gain insight into the mechanisms impacting immune dysregulation and organ malfunction, which are currently not well understood.

  15. Crystal Structure of Human [Beta]-Hexosaminidase B: Understanding the Molecular Basis of Sandhoff and Tay-Sachs Disease

    SciTech Connect

    Mark, Brian L.; Mahuran, Don J.; Cherney, Maia M.; Zhao, Dalian; Knapp, Spencer; James, Michael N.G.

    2010-12-01

    In humans, two major {beta}-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits {alpha} and {beta} (60% identity), whereas Hex B is a homodimer of {beta}-subunits. Interest in human {beta}-hexosaminidase stems from its association with Tay-Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of G{sub M2}-ganglioside (G{sub M2}). Hex A degrades G{sub M2} by removing a terminal N-acetyl-D-galactosamine ({beta}-GalNAc) residue, and this activity requires the G{sub M2}-activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4 {angstrom}) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2 {angstrom}) or NAG-thiazoline (2.5 {angstrom}). From these, and the known X-ray structure of the G{sub M2}-activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how {alpha} and {beta}-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease ({beta}-subunit mutations) and Tay-Sachs disease ({alpha}-subunit mutations).

  16. Crystal Structure of Human β-Hexosaminidase B: Understanding the Molecular Basis of Sandhoff and Tay–Sachs Disease

    PubMed Central

    Mark, Brian L.; Mahuran, Don J.; Cherney, Maia M.; Zhao, Dalian; Knapp, Spencer; James, Michael N. G.

    2010-01-01

    In humans, two major β-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits α and β (60% identity), whereas Hex B is a homodimer of β-subunits. Interest in human β-hexosaminidase stems from its association with Tay–Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of GM2-ganglioside (GM2). Hex A degrades GM2 by removing a terminal N-acetyl-D-galactosamine (β-GalNAc) residue, and this activity requires the GM2–activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4 Å) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2 Å) or NAG-thiazoline (2.5 Å). From these, and the known X-ray structure of the GM2–activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how α and β-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease (β-subunit mutations) and Tay–Sachs disease (α-subunit mutations). PMID:12662933

  17. Crystal structure of human beta-hexosaminidase B: understanding the molecular basis of Sandhoff and Tay-Sachs disease.

    PubMed

    Mark, Brian L; Mahuran, Don J; Cherney, Maia M; Zhao, Dalian; Knapp, Spencer; James, Michael N G

    2003-04-11

    In humans, two major beta-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits alpha and beta (60% identity), whereas Hex B is a homodimer of beta-subunits. Interest in human beta-hexosaminidase stems from its association with Tay-Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of G(M2)-ganglioside (G(M2)). Hex A degrades G(M2) by removing a terminal N-acetyl-D-galactosamine (beta-GalNAc) residue, and this activity requires the G(M2)-activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4A) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2A) or NAG-thiazoline (2.5A). From these, and the known X-ray structure of the G(M2)-activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how alpha and beta-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease (beta-subunit mutations) and Tay-Sachs disease (alpha-subunit mutations).

  18. Controlled deposition of a high-performance small-molecule organic single-crystal transistor array by direct ink-jet printing.

    PubMed

    Kim, Yong-Hoon; Yoo, Byungwook; Anthony, John E; Park, Sung Kyu

    2012-01-24

    Ink-jet printed small-molecule organic single-crystal transistors are realized by using selective surface energy modification, precise control of volume density of ink droplets on spatially patterned areas, and a co-solvent system to control solvent evaporation properties. The single-crystal formation in bottom-contact-structured transistors via direct printing is expected to permit high-density array fabrication in large-area electronics. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Neuronal and glial alterations, increased anxiety, and cognitive impairment before hippocampal amyloid deposition in PDAPP mice, model of Alzheimer's disease.

    PubMed

    Beauquis, Juan; Vinuesa, Angeles; Pomilio, Carlos; Pavía, Patricio; Galván, Verónica; Saravia, Flavia

    2014-03-01

    In the context of Alzheimer's disease (AD), hippocampal alterations have been well described in advanced stages of the pathology, when amyloid deposition, inflammation and glial activation occur, but less attention has been directed to studying early brain and behavioral changes. Using an animal model of AD, the transgenic PDAPP-J20 mouse at 5 months of age, when no amyloid plaques are present and low cerebral levels of amyloid peptides are detectable, we found structural, morphological, and cellular alterations in the hippocampus. Young transgenic mice showed a reduced hippocampal volume with less number of pyramidal and granular neurons, which additionally exhibited cell atrophy. The neurogenic capability in this zone, measured as DCX+ cells, was strongly diminished and associated to alterations in cell maturity. A decrease in presynaptic synaptophysin optical density was detected in mossy fibers reaching CA3 subfield but not in Golgi stained- CA1 dendritic spine density. Employing confocal microscopy and accurate stereological tools we also found a reduction in the number of GFAP+ cells, along with decreased astrocyte complexity, suggesting a potential detriment of neural support. According with untimely neuroglial alterations, young PDAPP mice failed in the novel location recognition test, that depends on hippocampal function. Moreover, multivariate statistical analysis of the behavioral outcome in the open-field test evidenced an elevated anxiety score in Tg mice compared with age-matched control mice. In line with this, the transgenic group showed a higher number of c-Fos+ nuclei in central and basolateral amygdala, a result that supports the early involvement of the emotionality factor in AD pathology. Applying an integrative approach, this work focuses on early structural, morphological and functional changes and provides new and compelling evidence of behavioral alterations that precede manifest AD. Copyright © 2013 Wiley Periodicals, Inc.

  20. microRNA-132/212 deficiency enhances Aβ production and senile plaque deposition in Alzheimer's disease triple transgenic mice.

    PubMed

    Hernandez-Rapp, Julia; Rainone, Sara; Goupil, Claudia; Dorval, Véronique; Smith, Pascal Y; Saint-Pierre, Martine; Vallée, Maxime; Planel, Emmanuel; Droit, Arnaud; Calon, Frédéric; Cicchetti, Francesca; Hébert, Sébastien S

    2016-08-03

    The abnormal regulation of amyloid-β (Aβ) metabolism (e.g., production, cleavage, clearance) plays a central role in Alzheimer's disease (AD). Among endogenous factors believed to participate in AD progression are the small regulatory non-coding microRNAs (miRs). In particular, the miR-132/212 cluster is severely reduced in the AD brain. In previous studies we have shown that miR-132/212 deficiency in mice leads to impaired memory and enhanced Tau pathology as seen in AD patients. Here we demonstrate that the genetic deletion of miR-132/212 promotes Aβ production and amyloid (senile) plaque formation in triple transgenic AD (3xTg-AD) mice. Using RNA-Seq and bioinformatics, we identified genes of the miR-132/212 network with documented roles in the regulation of Aβ metabolism, including Tau, Mapk, and Sirt1. Consistent with these findings, we show that the modulation of miR-132, or its target Sirt1, can directly regulate Aβ production in cells. Finally, both miR-132 and Sirt1 levels correlated with Aβ load in humans. Overall, our results support the hypothesis that the miR-132/212 network, including Sirt1 and likely other target genes, contributes to abnormal Aβ metabolism and senile plaque deposition in AD. This study strengthens the importance of miR-dependent networks in neurodegenerative disorders, and opens the door to multifactorial drug targets of AD by targeting Aβ and Tau.

  1. Increased plant sterol deposition in vascular tissue characterizes patients with severe aortic stenosis and concomitant coronary artery disease.

    PubMed

    Luister, Alexandra; Schött, Hans Frieder; Husche, Constanze; Schäfers, Hans-Joachim; Böhm, Michael; Plat, Jogchum; Gräber, Stefan; Lütjohann, Dieter; Laufs, Ulrich; Weingärtner, Oliver

    2015-07-01

    The aim of the study was to evaluate the relationship between phytosterols, oxyphytosterols, and other markers of cholesterol metabolism and concomitant coronary artery disease (CAD) in patients with severe aortic stenosis who were scheduled for elective aortic valve replacement. Markers of cholesterol metabolism (plant sterols and cholestanol as markers of cholesterol absorption and lathosterol as an indicator of cholesterol synthesis) and oxyphytosterols were determined in plasma and aortic valve tissue from 104 consecutive patients with severe aortic stenosis (n=68 statin treatment; n=36 no statin treatment) using gas chromatography-flame ionization and mass spectrometry. The extent of CAD was determined by coronary angiography prior to aortic valve replacement. Patients treated with statins were characterized by lower plasma cholesterol, cholestanol, and lathosterol concentrations. However, statin treatment did not affect the sterol concentrations in cardiovascular tissue. The ratio of campesterol-to-cholesterol was increased by 0.46±0.34μg/mg (26.0%) in plasma of patients with CAD. The absolute values for the cholesterol absorption markers sitosterol and campesterol were increased by 18.18±11.59ng/mg (38.8%) and 11.40±8.69ng/mg (30.4%) in the tissues from patients with documented CAD compared to those without concomitant CAD. Campesterol oxides were increased by 0.06±0.02ng/mg (17.1%) in the aortic valve cusps and oxidized sitosterol-to-cholesterol ratios were up-regulated by 0.35±0.2ng/mg (22.7%) in the plasma of patients with CAD. Of note, neither cholestanol nor the ratio of cholestanol-to-cholesterol was associated with CAD. Patients with concomitant CAD are characterized by increased deposition of plant sterols, but not cholestanol in aortic valve tissue. Moreover, patients with concomitant CAD were characterized by increased oxyphytosterol concentrations in plasma and aortic valve cusps.

  2. Characterizing regional correlation, laterality and symmetry of amyloid deposition in mild cognitive impairment and Alzheimer's disease with Pittsburgh Compound B.

    PubMed

    Raji, Cyrus A; Becker, James T; Tsopelas, Nicholas D; Price, Julie C; Mathis, Chester A; Saxton, Judith A; Lopresti, Brian J; Hoge, Jessica A; Ziolko, Scott K; DeKosky, Steven T; Klunk, William E

    2008-07-30

    We evaluated the region-to-region correlation, laterality and asymmetry of amyloid deposition in subjects with mild cognitive impairment (MCI) or Alzheimer's disease (AD) using the amyloid tracer, Pittsburgh Compound B (PiB). Seventeen subjects, including 7 with MCI (MMSE 26.7+/-2.4) and 10 with AD (MMSE of 24.8+/-2.7) underwent PiB imaging. Measures of laterality (i.e., group-wise predilection for right or left) and asymmetry (i.e., group-wise predilection for unequal PiB retention between the two hemispheres) were calculated for 17 Regions of Interest (ROIs). Regional correlations were calculated along with within-group and between-groups statistical analyses of laterality and asymmetry metrics. The median correlation between PiB retention across all pairs of ROIs was 0.65, with highest correlations found in areas of highest PiB retention (r=0.74). Overall, PiB retention was symmetric bilaterally, but there was PiB laterality in MCI in dorsal frontal cortex [(t(6)=3.05, p=0.02, L>R] and sensory-motor area [t(6)=3.10, p=0.02, L>R] and in AD in the occipital pole (t(9)=-2.63, p=0.03, R>L). The most significant asymmetries in PiB retention were found in sub-cortical white matter (t(6)=3.99, p=0.01) and middle precuneus [(t(6)=3.57, p=0.01] in MCI, and in lateral temporal cortex (t(9)=3.02, p=0.01) and anterior ventral striatum [t(9)=2.37, p=0.04] in AD. No group differences (AD versus MCI) were detected in laterality [F (1, 15)=0.15, p=0.7] or asymmetry [F (1, 15)=0.7, p=0.42].

  3. Crystal structure of cathepsin A, a novel target for the treatment of cardiovascular diseases

    SciTech Connect

    Schreuder, Herman A. Liesum, Alexander Kroll, Katja Böhnisch, Britta Buning, Christian Ruf, Sven Sadowski, Thorsten

    2014-03-07

    Graphical abstract: - Highlights: • The structures of active cathepsin A and the inactive precursor are very similar. • The only major difference is the absence of a 40 residue activation domain. • The termini of the active catalytic core are held together by a disulfide bond. • Compound 1 reacts with the catalytic Ser150, building a tetrahedral intermediate. • Compound 2 is cleaved by the enzyme and a fragment remained bound. - Abstract: The lysosomal serine carboxypeptidase cathepsin A is involved in the breakdown of peptide hormones like endothelin and bradykinin. Recent pharmacological studies with cathepsin A inhibitors in rodents showed a remarkable reduction in cardiac hypertrophy and atrial fibrillation, making cathepsin A a promising target for the treatment of heart failure. Here we describe the crystal structures of activated cathepsin A without inhibitor and with two compounds that mimic the tetrahedral intermediate and the reaction product, respectively. The structure of activated cathepsin A turned out to be very similar to the structure of the inactive precursor. The only difference was the removal of a 40 residue activation domain, partially due to proteolytic removal of the activation peptide, and partially by an order–disorder transition of the peptides flanking the removed activation peptide. The termini of the catalytic core are held together by the Cys253–Cys303 disulfide bond, just before and after the activation domain. One of the compounds we soaked in our crystals reacted covalently with the catalytic Ser150 and formed a tetrahedral intermediate. The other compound got cleaved by the enzyme and a fragment, resembling one of the natural reaction products, was found in the active site. These studies establish cathepsin A as a classical serine proteinase with a well-defined oxyanion hole. The carboxylate group of the cleavage product is bound by a hydrogen-bonding network involving one aspartate and two glutamate side chains

  4. Mechanisms of uric acid crystal-mediated autoinflammation.

    PubMed

    Martinon, Fabio

    2010-01-01

    Gout is an arthritis characterized by elevated uric acid in the bloodstream. In this condition, crystals of uric acid are formed and accumulate in the synovial fluids. Crystal deposition leads to acute inflammation, which is associated with the spontaneous resolution of the disease. Recent studies have led to significant advances in the understanding of the basic biology of crystal-mediated inflammation. Uric acid has been identified as a danger signal that triggers a cytosolic sensor, the inflammasome. This signaling platform is required for the activation of interleukin-1, a cytokine that is critical to the initiation of acute inflammation in gout. Importantly, both molecular and pathological evidence support the notion that gout is a prototypical member of the growing family of autoinflammatory diseases. This review discusses the role of the inflammasome in gout and the emerging new therapeutic strategies aimed at controlling inflammation in crystal arthritis.

  5. CALCIUM OXALATE STONE FRAGMENT AND CRYSTAL PHAGOCYTOSIS BY HUMAN MACROPHAGES

    PubMed Central

    Kusmartsev, Sergei; Dominguez-Gutierrez, Paul R.; Canales, Benjamin K.; Bird, Vincent G.; Vieweg, Johannes; Khan, Saeed R.

    2015-01-01

    Purpose In murine and human hyperoxaluric conditions, macrophages can be seen surrounding renal calcium oxalate (CaOx) crystal deposits. We hypothesize that macrophages play a role in degrading and destroying these deposits and investigated inflammatory response and phagocytic mechanisms when macrophages are exposed to human kidney stones and inorganic crystals. Materials and Methods Human monocytes were differentiated into resting, fully-differentiated macrophages by treating with recombinant human M-CSF or GM-CSF for 6 days. After confirming phenotype by flow cytometry, macrophages were exposed for 20 hours to fragments of sterile human CaOx stones or CaOx crystals. Crystal uptake was determined, and supernatant cytokine and chemokine profiles were analyzed using antibody arrays. qRT-PCR was used to validate mRNA profile expression. Results Under direct-vision fluorescent microscopy, activated human macrophages were noted to surround both stone fragments and synthesized crystals and destroy them in a step-by-step process that involved clathrin-mediated endocytosis and phagocytosis. An inflammatory cascade was released by macrophages, including chemokines CCL2, CCL3, interleukin-1 receptor antagonist (IL-1ra), complement component C5/C5a and IL-8. The response patterns to stone and crystal material was dependent on macrophage phenotype and activation status. Conclusions In our in vitro study, macrophages differentiated with M-CSF displayed a greater ability to phagocytize crystal deposits than those treated with GM-CSF. Following clathrin-mediated endocytosis, macrophages released a number of cytokines crucial for inflammatory immune response, suggesting that tissue macrophages play an important role in preventing kidney stone disease by removing and digesting interstitial renal crystal deposits. PMID:26626217

  6. The Growth Mechanism of Transition Metal Dichalcogenides by using Sulfurization of Pre-deposited Transition Metals and the 2D Crystal Hetero-structure Establishment

    PubMed Central

    Wu, Chong-Rong; Chang, Xiang-Rui; Wu, Chao-Hsin; Lin, Shih-Yen

    2017-01-01

    A growth model is proposed for the large-area and uniform MoS2 film grown by using sulfurization of pre-deposited Mo films on sapphire substrates. During the sulfurization procedure, the competition between the two mechanisms of the Mo oxide segregation to form small clusters and the sulfurization reaction to form planar MoS2 film is determined by the amount of background sulfur. Small Mo oxide clusters are observed under the sulfur deficient condition, while large-area and complete MoS2 films are obtained under the sulfur sufficient condition. Precise layer number controllability is also achieved by controlling the pre-deposited Mo film thicknesses. The drain currents in positive dependence on the layer numbers of the MoS2 transistors with 1-, 3- and 5- layer MoS2 have demonstrated small variation in material characteristics between each MoS2 layer prepared by using this growth technique. By sequential transition metal deposition and sulfurization procedures, a WS2/MoS2/WS2 double hetero-structure is demonstrated. Large-area growth, layer number controllability and the possibility of hetero-structure establishment by using sequential metal deposition and following sulfurization procedures have revealed the potential of this growth technique for practical applications. PMID:28176836

  7. The Growth Mechanism of Transition Metal Dichalcogenides by using Sulfurization of Pre-deposited Transition Metals and the 2D Crystal Hetero-structure Establishment

    NASA Astrophysics Data System (ADS)

    Wu, Chong-Rong; Chang, Xiang-Rui; Wu, Chao-Hsin; Lin, Shih-Yen

    2017-02-01

    A growth model is proposed for the large-area and uniform MoS2 film grown by using sulfurization of pre-deposited Mo films on sapphire substrates. During the sulfurization procedure, the competition between the two mechanisms of the Mo oxide segregation to form small clusters and the sulfurization reaction to form planar MoS2 film is determined by the amount of background sulfur. Small Mo oxide clusters are observed under the sulfur deficient condition, while large-area and complete MoS2 films are obtained under the sulfur sufficient condition. Precise layer number controllability is also achieved by controlling the pre-deposited Mo film thicknesses. The drain currents in positive dependence on the layer numbers of the MoS2 transistors with 1-, 3- and 5- layer MoS2 have demonstrated small variation in material characteristics between each MoS2 layer prepared by using this growth technique. By sequential transition metal deposition and sulfurization procedures, a WS2/MoS2/WS2 double hetero-structure is demonstrated. Large-area growth, layer number controllability and the possibility of hetero-structure establishment by using sequential metal deposition and following sulfurization procedures have revealed the potential of this growth technique for practical applications.

  8. Amyloid Angiopathy and Variability in Amyloid β Deposition Is Determined by Mutation Position in Presenilin-1-Linked Alzheimer’s Disease

    PubMed Central

    Mann, David M. A.; Pickering-Brown, Stuart M.; Takeuchi, Ayano; Iwatsubo, Takeshi

    2001-01-01

    The presenilins (PSs) are components of large molecular complexes that contain β-catenin and function as γ-secretase. We report here a striking correlation between amyloid angiopathy and the location of mutation in PS-1 linked Alzheimer’s disease. The amount of amyloid β protein, Aβ42(43), but not Aβ40, deposited in the frontal cortex of the brain is increased in 54 cases of early-onset familial Alzheimer’s disease, encompassing 25 mutations in the presenilin-1 (PS-1) gene, compared to sporadic Alzheimer’s disease. The amount of Aβ40 in PS-1 Alzheimer’s disease varied according to the copy number of ε4 alleles of the Apolipoprotein E gene. Although the amounts of Aβ40 and Aβ42(43) deposited did not correlate with the genetic location of the mutation in a strict linear sense, the histological profile did so vary. Cases with mutations between codon 1 and 200 showed, in frontal cortex, many diffuse plaques, few cored plaques, and mild or moderate amyloid angiopathy. Cases with mutations occurring after codon 200 also showed many diffuse plaques, but the number and size of cored plaques were increased (even when ε4 allele was not present) and these were often clustered around blood vessels severely affected by amyloid angiopathy. Similarly, diverging histological profiles, mainly according to the degree of amyloid angiopathy, were seen in the cerebellum. Mutations in the PS-1 gene may therefore alter the topology of the PS-1 protein so as to favor Aβ formation and deposition, generally, but also to facilitate amyloid angiopathy particularly in cases in which the mutation lies beyond codon 200. Finally we report that the amount of Aβ42(43) deposited in the brain correlated with the amount of this produced in culture by cells bearing the equivalent mutations. PMID:11395394

  9. Crystal structure of 2A proteinase from hand, foot and mouth disease virus.

    PubMed

    Mu, Zhixia; Wang, Bei; Zhang, Xiaoyu; Gao, Xiaopan; Qin, Bo; Zhao, Zhendong; Cui, Sheng

    2013-11-15

    EV71 is responsible for several epidemics worldwide; however, the effective antiviral drug is unavailable to date. The 2A proteinase (2A(pro)) of EV71 presents a promising drug target due to its multiple roles in virus replication, inhibition of host protein synthesis and evasion of innate immunity. We determined the crystal structure of EV71 2A(pro) at 1.85Å resolution, revealing that the proteinase maintains a chymotrypsin-like fold. The active site is composed of the catalytic triads C110A, H21 and D39 with the geometry similar to that in other picornaviral 2A(pro), 3C(pro) and serine proteinases. The cI-to-eI2 loop at the N-terminal domain of EV71 2A(pro) adopts a highly stable conformation and contributes to the hydrophilic surface property, which are strikingly different in HRV2 2A(pro) but are similar in CVB4 2A(pro). We identified a hydrophobic motif "LLWL" followed by an acidic motif "DEE" at the C-terminus of EV71 2A(pro). The "LLWL" motif is folded into the β-turn structure that is essential for the positioning of the acidic motif. Our structural and mutagenesis study demonstrated that both the negative charging and the correct positioning of the C-terminus are essential for EV71 replication. Deletion of the "LLWL" motif abrogated the proteolytic activity, indicating that the motif is critical for maintaining the active proteinase conformation. Our findings provide the structural and functional insights into EV71 2A(pro) and establish a framework for structure-based inhibitor design.

  10. Grow Your Own Copper Deposit

    ERIC Educational Resources Information Center

    Corcoran, Timothy John

    2009-01-01

    Crystals are beautiful structures--yet they occur naturally in dirty and remote places. In the inquiry-based activity described here, students will enjoy the process of creating their own crystals and using microscopes to examine them. It demonstrates the process of mineral concentration and deposition. Upon completing this activity, students…

  11. Grow Your Own Copper Deposit

    ERIC Educational Resources Information Center

    Corcoran, Timothy John

    2009-01-01

    Crystals are beautiful structures--yet they occur naturally in dirty and remote places. In the inquiry-based activity described here, students will enjoy the process of creating their own crystals and using microscopes to examine them. It demonstrates the process of mineral concentration and deposition. Upon completing this activity, students…

  12. Raman tensor and domain structure study of single-crystal-like epitaxial films of CaCu3Ti4O12 grown by pulsed laser deposition.

    PubMed

    Ahlawat, Anju; Mishra, Dileep K; Sathe, V G; Kumar, Ravi; Sharma, T K

    2013-01-16

    The local domain structure of a strain free, 150 nm thick, epitaxially grown single crystalline thin film of CaCu(3)Ti(4)O(12) is probed by polarized Raman spectroscopy. The polarization dependence of the Raman intensities of the observed bands as a function of varying angle between the domain axes and the polarization vector of the scattered laser photon is measured. Theoretical formulations involving the Raman tensor are presented, which enable determination of the domain structure from the observed polarized Raman spectra, and a single-crystal-like domain structure is found. The Raman tensor elements and domain orientation direction were determined by fitting the observed Raman intensities with theoretical calculations and by carrying out Raman mapping of the film. Our data show an absence of twin domain structure and twin domain boundaries in the single-crystal-like epitaxial thin films of CaCu(3)Ti(4)O(12).

  13. Confocal Laser Raman Microspectroscopy of Biomineralization Foci in UMR 106 Osteoblastic Cultures Reveals Temporally Synchronized Protein Changes Preceding and Accompanying Mineral Crystal Deposition*

    PubMed Central

    Wang, Chuanyi; Wang, Yong; Huffman, Nichole T.; Cui, Chaoying; Yao, Xiaomei; Midura, Sharon; Midura, Ronald J.; Gorski, Jeff P.

    2009-01-01

    Mineralization in UMR 106-01 osteoblastic cultures occurs within extracellular biomineralization foci (BMF) within 12 h after addition of β-glycerol phosphate to cells at 64 h after plating. BMF are identified by their enrichment with an 85-kDa glycoprotein reactive with Maackia amurensis lectin. Laser Raman microspectroscopic scans were made on individual BMF at times preceding (64–76 h) and following the appearance of mineral crystals (76–88 h). The range of variation between spectra for different BMF in the same culture was rather small. In contrast, significant differences were observed for spectral bands at 957–960, 1004, and 1660 cm-1 when normalized BMF spectra at different times were compared. Protein-dependent spectral bands at 1004 and 1660 cm-1 increased and then decreased preceding the detection of hydroxyapatite crystals via the phosphate stretching peak at 959–960 cm-1. When sodium phosphate was substituted for β-glycerol phosphate, mineralization occurred 3–6 h earlier. Irrespective of phosphate source, the Raman full peak width at half-maximum ratio for 88 h cultures was similar to that for 10-day-old marrow ablation primary bone. However, if mineralization was blocked with serine protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride, 64–88-h BMF spectra remained largely invariant. In summary, Raman spectral data demonstrate for the first time that formation of hydroxyapatite crystals within individual BMF is a multistep process. Second, changes in protein-derived signals at 1004 and 1660 cm-1 reflect events within BMFs that precede or accompany mineral crystal production because they are blocked by mineralization inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride. Finally, the low extent of spectral variability detected among different BMF at the same time point indicates that mineralization of individual BMF within a culture is synchronized. PMID:19116206

  14. Crystallization and preliminary X-ray diffraction analysis of the Fab fragment of WO2, an antibody specific for the Aβ peptides associated with Alzheimer’s disease

    SciTech Connect

    Wun, Kwok S.; Miles, Luke A.; Crespi, Gabriela A. N.; Wycherley, Kaye; Ascher, David B.; Barnham, Kevin J.; Cappai, Roberto; Beyreuther, Konrad; Masters, Colin L.; Parker, Michael W.; McKinstry, William J.

    2008-05-01

    Crystallization and X-ray diffraction data collection of the Fab fragment of the monoclonal antibody WO2 in the absence or presence of amyloid β peptides associated with Alzheimer’s disease are reported. The murine monoclonal antibody WO2 specifically binds the N-terminal region of the amyloid β peptide (Aβ) associated with Alzheimer’s disease. This region of Aβ has been shown to be the immunodominant B-cell epitope of the peptide and hence is considered to be a basis for the development of immunotherapeutic strategies against this prevalent cause of dementia. Structural studies have been undertaken in order to characterize the molecular basis for antibody recognition of this important epitope. Here, details of the crystallization and X-ray analysis of the Fab fragment of the unliganded WO2 antibody in two crystal forms and of the complexes that it forms with the truncated Aβ peptides Aβ{sub 1–16} and Aβ{sub 1–28} are presented. These crystals were all obtained using the hanging-drop vapour-diffusion method at 295 K. Crystals of WO2 Fab were grown in polyethylene glycol solutions containing ZnSO{sub 4}; they belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} and diffracted to 1.6 Å resolution. The complexes of WO2 Fab with either Aβ{sub 1–@}@{sub 16} or Aβ{sub 1–28} were cocrystallized from polyethylene glycol solutions. These two complex crystals grew in the same space group, P2{sub 1}2{sub 1}2{sub 1}, and diffracted to 1.6 Å resolution. A second crystal form of WO2 Fab was grown in the presence of the sparingly soluble Aβ{sub 1–42} in PEG 550 MME. This second form belonged to space group P2{sub 1} and diffracted to 1.9 Å resolution.

  15. Crystal structure of foot-and-mouth disease virus 3C protease. New insights into catalytic mechanism and cleavage specificity.

    PubMed

    Birtley, James R; Knox, Stephen R; Jaulent, Agnès M; Brick, Peter; Leatherbarrow, Robin J; Curry, Stephen

    2005-03-25

    Foot-and-mouth disease virus (FMDV) causes a widespread and economically devastating disease of domestic livestock. Although FMDV vaccines are available, political and technical problems associated with their use are driving a renewed search for alternative methods of disease control. The viral RNA genome is translated as a single polypeptide precursor that must be cleaved into functional proteins by virally encoded proteases. 10 of the 13 cleavages are performed by the highly conserved 3C protease (3C(pro)), making the enzyme an attractive target for antiviral drugs. We have developed a soluble, recombinant form of FMDV 3C(pro), determined the crystal structure to 1.9-angstroms resolution, and analyzed the cleavage specificity of the enzyme. The structure indicates that FMDV 3C(pro) adopts a chymotrypsin-like fold and possesses a Cys-His-Asp catalytic triad in a similar conformation to the Ser-His-Asp triad conserved in almost all serine proteases. This observation suggests that the dyad-based mechanisms proposed for this class of cysteine proteases need to be reassessed. Peptide cleavage assays revealed that the recognition sequence spans at least four residues either side of the scissile bond (P4-P4') and that FMDV 3C(pro) discriminates only weakly in favor of P1-Gln over P1-Glu, in contrast to other 3C(pro) enzymes that strongly favor P1-Gln. The relaxed specificity may be due to the unexpected absence in FMDV 3C(pro) of an extended beta-ribbon that folds over the substrate binding cleft in other picornavirus 3C(pro) structures. Collectively, these results establish a valuable framework for the development of FMDV 3C(pro) inhibitors.

  16. Characterizing Regional Correlation, Laterality and Symmetry of Amyloid Deposition in Mild Cognitive Impairment and Alzheimer's Disease with Pittsburgh Compound B

    PubMed Central

    Raji, Cyrus A.; Becker, James T.; Tsopelas, Nicholas D.; Price, Julie C.; Mathis, Chester A.; Saxton, Judith A.; Lopresti, Brian J.; Hoge, Jessica A.; Ziolko, Scott K.; DeKosky, Steven T.; Klunk, William E.

    2008-01-01

    We evaluated the region-to-region correlation, laterality and asymmetry of amyloid deposition in subjects with mild cognitive impairment (MCI) or Alzheimer's Disease (AD) using the amyloid tracer, Pittsburgh-Compound B (PiB). Seventeen subjects, including 7 with MCI (MMSE 26.7 ± 2.4) and 10 with AD (MMSE of 24.8 ± 2.7) underwent PiB imaging. Measures of laterality (i.e. group-wise predilection for right or left) and asymmetry (i.e. group-wise predilection for unequal PiB retention between the two hemispheres) were calculated for seventeen Regions of Interest (ROIs). Regional correlations were calculated along with within-group and between-groups statistical analyses of laterality and asymmetry metrics. The median correlation between PiB retention across all pairs of ROIs was 0.65, with highest correlations found in areas of highest PiB retention, (r = 0.74). Overall, PiB retention was symmetric bilaterally, but there was PiB laterality in MCI in dorsal frontal cortex [(t(6) = 3.05, p = 0.02, L>R] and sensory-motor area [t(6) = 3.10, p = 0.02, L>R] and in AD in the occipital pole (t(9) = −2.63, p = 0.03, R>L). The most significant asymmetries in PiB retention were found in sub-cortical white matter (t(6) = 3.99, p = 0.01) and middle precuneus [(t(6) = 3.57, p = 0.01] in MCI, and in lateral temporal cortex (t(9) = 3.02, p = 0.01) and anterior ventral striatum [t(9) = 2.37, p = 0.04] in AD. No group differences (AD versus MCI) were detected in laterality [F (1,15)= 0.15, p= 0.7] or asymmetry [F (1, 15) = 0.7, p = 0.42]. PMID:18582948

  17. The wrong white crystals: not salt but sugar as aetiological in hypertension and cardiometabolic disease.

    PubMed

    DiNicolantonio, James J; Lucan, Sean C

    2014-01-01

    Cardiovascular disease is the leading cause of premature mortality in the developed world, and hypertension is its most important risk factor. Controlling hypertension is a major focus of public health initiatives, and dietary approaches have historically focused on sodium. While the potential benefits of sodium-reduction strategies are debatable, one fact about which there is little debate is that the predominant sources of sodium in the diet are industrially processed foods. Processed foods also happen to be generally high in added sugars, the consumption of which might be more strongly and directly associated with hypertension and cardiometabolic risk. Evidence from epidemiological studies and experimental trials in animals and humans suggests that added sugars, particularly fructose, may increase blood pressure and blood pressure variability, increase heart rate and myocardial oxygen demand, and contribute to inflammation, insulin resistance and broader metabolic dysfunction. Thus, while there is no argument that recommendations to reduce consumption of processed foods are highly appropriate and advisable, the arguments in this review are that the benefits of such recommendations might have less to do with sodium-minimally related to blood pressure and perhaps even inversely related to cardiovascular risk-and more to do with highly-refined carbohydrates. It is time for guideline committees to shift focus away from salt and focus greater attention to the likely more-consequential food additive: sugar. A reduction in the intake of added sugars, particularly fructose, and specifically in the quantities and context of industrially-manufactured consumables, would help not only curb hypertension rates, but might also help address broader problems related to cardiometabolic disease.

  18. The wrong white crystals: not salt but sugar as aetiological in hypertension and cardiometabolic disease

    PubMed Central

    DiNicolantonio, James J; Lucan, Sean C

    2014-01-01

    Cardiovascular disease is the leading cause of premature mortality in the developed world, and hypertension is its most important risk factor. Controlling hypertension is a major focus of public health initiatives, and dietary approaches have historically focused on sodium. While the potential benefits of sodium-reduction strategies are debatable, one fact about which there is little debate is that the predominant sources of sodium in the diet are industrially processed foods. Processed foods also happen to be generally high in added sugars, the consumption of which might be more strongly and directly associated with hypertension and cardiometabolic risk. Evidence from epidemiological studies and experimental trials in animals and humans suggests that added sugars, particularly fructose, may increase blood pressure and blood pressure variability, increase heart rate and myocardial oxygen demand, and contribute to inflammation, insulin resistance and broader metabolic dysfunction. Thus, while there is no argument that recommendations to reduce consumption of processed foods are highly appropriate and advisable, the arguments in this review are that the benefits of such recommendations might have less to do with sodium—minimally related to blood pressure and perhaps even inversely related to cardiovascular risk—and more to do with highly-refined carbohydrates. It is time for guideline committees to shift focus away from salt and focus greater attention to the likely more-consequential food additive: sugar. A reduction in the intake of added sugars, particularly fructose, and specifically in the quantities and context of industrially-manufactured consumables, would help not only curb hypertension rates, but might also help address broader problems related to cardiometabolic disease. PMID:25717381

  19. Characterisation and deposition studies of engineered lactose crystals with potential for use as a carrier for aerosolised salbutamol sulfate from dry powder inhalers.

    PubMed

    Larhrib, Hassan; Martin, Gary P; Prime, David; Marriott, Christopher

    2003-07-01

    Lactose particles with different elongation ratio, roundness, polymorphic form and crystallinity were prepared by a one-step crystallisation process using varying ratios of acetone/water. The crystals were characterised using image analysis optical microscopy, scanning electron microscopy, differential scanning calorimetry and X-ray powder diffraction. The elongation ratio was found to increase with increasing acetone ratio which therefore, appears to accelerate the growth in length rather than width and/or thickness. The crystallinity and polymorphic forms were also acetone-concentration dependent. For example, the crystals formed using 65-80% v/v acetone were almost all of the alpha-form whereas at 85% v/v a small amount of beta-form was precipitated, as detected by a peak at the reflection angle 2 theta=10.4 in the X-ray diffractogram. When 90% v/v acetone was incorporated a mixture of alpha- and beta-forms were produced in almost equal quantity, whereas, with 95% v/v acetone the beta-form predominated. At high acetone concentration (90 and 95% v/v), the crystallisation proceeded rapidly leading to the creation of some amorphous content. The 63-90-microm sieve cut of either commercial grade lactose (CL) or crystallised lactose was mixed with salbutamol sulfate and dispersibility was determined using the twin stage liquid impinger. All the formulations containing carrier particles generated by crystallization from solvent showed higher dispersibility and fine particle fraction (FPF) of the drug compared to the formulation made containing CL. The carrier that showed the highest elongation ratio (produced from an 85% acetone 15% water solution), when mixed with salbutamol sulfate produced the highest dispersibility (38.5%) and highest FPF (29.24%). These parameters were six times higher than the values obtained with the formulation containing CL.

  20. Achieving omnidirectional photonic band gap in sputter deposited TiO{sub 2}/SiO{sub 2} one dimensional photonic crystal

    SciTech Connect

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

    2015-06-24

    The multilayer structure of TiO{sub 2}/SiO{sub 2} (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.

  1. Cortical laminar tau deposits and activated astrocytes in Alzheimer’s disease visualised by 3H-THK5117 and 3H-deprenyl autoradiography

    PubMed Central

    Lemoine, Laetitia; Saint-Aubert, Laure; Nennesmo, Inger; Gillberg, Per-Göran; Nordberg, Agneta

    2017-01-01

    Hyperphosphorylated tau protein deposits and, inflammatory processes are characteristic components of Alzheimer disease (AD) pathology. We here aimed to visualize in vitro the distribution of tau deposits and activated astrocytes across the cortical layers in autopsy AD brain tissue using the radiotracers 3H-THK5117 and 3H-deprenyl. 3H-THK5117 and 3H-deprenyl autoradiographies were carried out on frozen brain sections from three AD patients and one healthy control. 3H-THK5117 showed a distinct laminar cortical binding similar to 3H-deprenyl autoradiography, with an extensive binding in the superficial and deep layers of the temporal neocortices, whereas the middle frontal gyrus showed an even binding throughout the layers. Globally, eventhough some differences could be observed, AT8 (tau) and GFAP (astrocyte) immunostaining showed a laminar pattern comparable to their corresponding radiotracers within each AD case. Some variability was observed between the AD cases reflecting differences in disease phenotype. The similar laminar cortical brain distribution of tau deposits and activated astrocytes supports the hypothesis of a close pathological interconnection. The difference in regional binding patterns of 3H-THK5117 and AT8 antibody staining suggest additional tau binding sites detectable by 3H-THK5117. PMID:28374768

  2. Epitaxial single-crystal thin films of MnxTi1-xO2-δ grown on (rutile)TiO2 substrates with pulsed laser deposition: Experiment and theory

    SciTech Connect

    Ilton, Eugene S.; Droubay, Timothy C.; Chaka, Anne M.; Kovarik, Libor; Varga, Tamas; Arey, Bruce W.; Kerisit, Sebastien N.

    2015-02-01

    Epitaxial rutile-structured single-crystal MnxTi1-xO2-δ films were synthesized on rutile- (110) and -(001) substrates using pulsed laser deposition. The films were characterized by reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and aberration-corrected transmission electron microscopy (ACTEM). Under the present conditions, 400oC and PO2 = 20 mTorr, single crystal epitaxial thin films were grown for x = 0.13, where x is the nominal average mole fraction of Mn. In fact, arbitrarily thick films could be grown with near invariant Mn/Ti concentration profiles from the substrate/film interface to the film surface. In contrast, at x = 0.25, Mn became enriched towards the surface and a secondary nano-scale phase formed which appeared to maintain the basic rutile structure but with enhanced z-contrast in the tunnels, or tetrahedral interstitial sites. Ab initio thermodynamic calculations provided quantitative estimates for the destabilizing effect of expanding the β-MnO2 lattice parameters to those of TiO2-rutile, the stabilizing effect of diluting Mn with increasing Ti concentration, and competing reaction pathways.

  3. Epitaxial single-crystal thin films of MnxTi1 - xO2 - δ grown on (rutile)TiO2 substrates with pulsed laser deposition: Experiment and theory

    NASA Astrophysics Data System (ADS)

    Ilton, Eugene S.; Droubay, Timothy C.; Chaka, Anne M.; Kovarik, Libor; Varga, Tamas; Arey, Bruce W.; Kerisit, Sebastien N.

    2015-02-01

    Epitaxial rutile-structured single-crystal MnxTi1 - xO2 - δ films were synthesized on rutile- (110) and -(001) substrates using pulsed laser deposition. The films were characterized by reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and aberration-corrected transmission electron microscopy (ACTEM). Under the present conditions, 400 °C and PO2 = 20 mTorr, single crystal epitaxial thin films were grown for x = 0.13, where x is the nominal average mole fraction of Mn. In fact, arbitrarily thick films could be grown with near invariant Mn/Ti concentration profiles from the substrate/film interface to the film surface. In contrast, at x = 0.25, Mn became enriched towards the surface and a secondary nano-scale phase formed which appeared to maintain the basic rutile structure but with enhanced z-contrast in the tunnels, or interstitial sites. Ab initio thermodynamic calculations provided quantitative estimates for the destabilizing effect of expanding the β-MnO2 lattice parameters to those of TiO2-rutile, the stabilizing effect of diluting Mn with increasing Ti concentration, and competing reaction pathways for surface oxide formation.

  4. Crystal structure of the Borna disease virus matrix protein (BDV-M) reveals ssRNA binding properties

    PubMed Central

    Neumann, Piotr; Lieber, Diana; Meyer, Sylke; Dautel, Philipp; Kerth, Andreas; Kraus, Ina; Garten, Wolfgang; Stubbs, Milton T.

    2009-01-01

    Borna disease virus (BDV) is a neurotropic enveloped RNA virus that causes a noncytolytic, persistent infection of the central nervous system in mammals. BDV belongs to the order Mononegavirales, which also includes the negative-strand RNA viruses (NSVs) Ebola, Marburg, ves