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Contrasting patterns of nitrogen release from fine roots and leaves driven by microbial communities during decomposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:158809. [PMID: 36116643 DOI: 10.1016/j.scitotenv.2022.158809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/12/2022] [Accepted: 09/12/2022] [Indexed: 06/15/2023]
Abstract
Leachate from decaying root and leaf litter plays crucial roles in soil biogeochemical processes in forest ecosystems. Unlike for leaf litter, however, the chemical composition and microbial community of root litter leachate are poorly understood. We hypothesized that both leachate nitrogen (N) composition and microbial communities differ between plant organs and decomposition stages and that leachate composition affects microbial community composition. We conducted a 2.5-year laboratory incubation using root and leaf substrate from Cryptomeria japonica and Chamaecyparis obtusa. We monitored the N forms released and used metabarcoding to characterize the microbial communities. Leachate N accounted for 40 % and 30 % of net N losses from C. japonica and C. obtusa roots, respectively; the remainder was probably lost in gaseous forms. In contrast, leaves absorbed N during the incubation regardless of tree species. The predominant N form in root leachate was nitrate (NO3-); cumulative NO3- quantity was 22.6 and 25.5 times greater in root than in leaf leachate for C. japonica and C. obtusa, respectively. A nitrifying bacterium was selected as the indicator taxon in root substrates, whereas many families of N-fixing bacteria were selected in leaf substrates. At the end of the incubation period, bacterial taxonomic diversity was high in both organs from both tree species, ranging from 177 to 339 taxa and increasing with time. However, fungal diversity was low for both organs (72 to 155 taxa). Shifts in bacterial community structure were related to NO3- concentration and leachate pH, whereas shifts in fungal community structure were related to leachate pH. These results suggest that the contrasting N dynamics of root and leaf substrates are strongly affected by the characteristics of and the microbes recruited by their leachates. Understanding organ-specific litter N dynamics is indispensable for predicting N cycling for optimal management of forest ecosystems in a changing world.
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Abstract
The periodontal ligament (PDL) contains mesenchymal stem cells (MSCs) that can differentiate into osteoblasts, cementoblasts, and fibroblasts. Nevertheless, the distribution and characteristics of these cells remain uncertain. Gli1, an essential hedgehog signaling transcription factor, functions in undifferentiated cells during embryogenesis. Therefore, in the present study, the differentiation ability of Gli1+ cells was examined using Gli1-CreERT2/ROSA26-loxP-stop-loxP-tdTomato (iGli1/Tomato) mice. In 4-wk-old iGli1/Tomato mice, Gli1/Tomato+ cells were only slightly detected in the PDL, around endomucin-expressing blood vessels. These cells had proliferated over time, localizing in the PDL as well as on the bone and cementum surfaces at day 28. However, in 8-wk-old iGli1/Tomato mice, Gli1/Tomato+ cells were quiescent, as most cells were not immunoreactive for Ki-67. These cells in 8-wk-old mice exhibited high colony-forming unit fibroblast activity and were capable of osteogenic, chondrogenic, and adipogenic differentiation in vitro. In addition, after transplantation of teeth of iGli1/Tomato mice into the hypodermis of wild-type mice, Tomato fluorescence indicating the progeny of Gli1+ cells was detected in the osteoblasts and osteocytes of the regenerated bone. These results demonstrate that Gli1+ cells in the PDL were MSCs and could contribute to the alveolar bone regeneration.
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Arterial stiffness could reflect increased cardiac load and reduced pulmonary function in the general population. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.2371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Pulmonary function is known to decrease with age and reduced pulmonary function has been reported to be associated with all-cause mortality and cardiovascular death. The association between pulmonary impairment and atherosclerosis was reported previously but has not been investigated sufficiently in the general population.
Purpose
We hypothesized that arterial stiffness could reflect increase of cardiac load and reduced pulmonary function. The present study aimed to investigate whether increased cardiac load and reduced pulmonary function could affect arterial stiffness in the general population.
Methods
Subjects undergoing their health check-up were enrolled. Plasma B-type natriuretic peptide (BNP) levels and serum high-sensitivity cardiac troponin I (hs-cTnI) levels were measured to evaluate cardiac load and myocardial damage. Radial augmentation index (rAI) was measured to investigate arterial stiffness using HEM-9000AI device. Subjects with an ST-T segment abnormality on the electrocardiogram, renal insufficiency, cancer, active inflammatory disease, or a history of cardiovascular events and pulmonary disease were excluded. Pulmonary function was assessed using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in 1 second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC).
Results
A total of 1100 subjects aged 57 years were enrolled and their median values of BNP and hs-cTnI were 15.5 and 2.3 pg/ml. The levels of rAI were significantly associated with the levels of BNP after adjustment for possible confounders in multivariate regression analysis, but were not with the levels of hs-TnI. While the parameters of pulmonary function were inversely associated with the levels of rAI and hs-cTnI after adjustment for possible confounders in the multivariate regression analysis, but not with the levels of BNP. The other multivariate regression analyses where BNP, hs-cTnI, parameters of pulmonary function, and the other possible factors were simultaneously included as independent variables revealed that the BNP levels and the FVC%-predicted or FEV1%-predicted, besides age, gender, smoking status, body mass index, blood pressure, heart rate, creatinine, fasting plasma glucose, and triglyceride, were significantly associated with the levels of rAI.
Conclusions
The significant associations of rAI with BNP and pulmonary function were revealed in the general population. These findings support that arterial stiffness could reflect increased cardiac load and reduced pulmonary function, in apparently healthy individuals.
Funding Acknowledgement
Type of funding source: None
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1436Overexpression of Cytotoxic T-Lymphocyte Associated Antigen-4 suppresses aortic immunoinflammatory responses and prevents angiotensin II-induced abdominal aortic aneurysm formation in mice. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Aims
Vascular inflammation via T-cell-mediated immune responses has been shown to be critically involved in the pathogenesis of abdominal aortic aneurysm (AAA). T-cell coinhibitory molecule cytotoxic T-lymphocyte–associated antigen-4 (CTLA-4) is known to act as a potent negative regulator of immune responses. However, the role of this molecule in the development of AAA remains completely unknown. In the present study, we determined the effects of CTLA-4 overexpression on experimental AAA.
Methods and results
We continuously infused 12-week-old CTLA-4 transgenic (CTLA-4-Tg)/apolipoprotein E–deficient (Apoe−/−) mice (n=35) or control Apoe−/− mice (n=40) fed a high-cholesterol diet with angiotensin II by implanting osmotic mini-pumps and evaluated the development of AAA. Ninety percent of angiotensin II-infused mice developed AAA, with 50% mortality because of aneurysm rupture. Overexpression of CTLA-4 significantly reduced the incidence (66%), mortality (26%), and diameter (18%) of AAA (incidence: P=0.0104; mortality: P=0.031; diameter: P=0.011). These protective effects were associated with a decreased number of effector CD4+ T cells and the downregulated expression of costimulatory molecules CD80 and CD86, ligands for CTLA-4, on CD11c+ dendritic cells in lymphoid tissues. In addition, by performing in situ zymography of the abdominal aortic aneurysm lesions, we observed a trend toward a decrease in MMP activity in the aneurysmal lesion following overexpression of CTLA-4. Finally, CTLA-4-Tg/Apoe−/− mice had reduced macrophage and CD4+ T cell accumulation and MMP activity in the aneurysmal lesion, leading to attenuated aortic inflammation, preserved vessel integrity, and decreased susceptibility to AAA and aortic rupture.
Conclusion
Our findings suggest that CTLA-4 protects against AAA by suppressing immunoinflammatory responses and could be an attractive therapeutic target for AAA.
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Leachate from fine root litter is more acidic than leaf litter leachate: A 2.5-year laboratory incubation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:179-191. [PMID: 30021175 DOI: 10.1016/j.scitotenv.2018.07.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/22/2018] [Accepted: 07/03/2018] [Indexed: 06/08/2023]
Abstract
Some tree species increase fine root production under soil acidification, thus changing the balance of litter input from leaves and roots. Litter leaches a significant amount of acidic materials during its decomposition, which might facilitate soil acidification. In this context, we focused on dissolved organic matter (DOM) as the major component of acidic materials. We hypothesized that both the quality and quantity of DOM, which control its function (i.e., proton supply), differ between leaf and root litter. To test this hypothesis, we conducted a 2.5-year laboratory incubation experiment using fresh fine roots and fresh green leaves as litter of two coniferous species (Cryptomeria japonica and Chamaecyparis obtusa) and investigated the leachate pH and DOM composition based on the optical properties. After the early stage of decomposition when flash leaching of DOM converged, the amount of dissolved organic carbon (DOC) leached from roots increased again and leachate pH declined. In contrast, DOC concentrations continued to decrease in leaf leachates during the incubation period, and the pH decrease was not as striking as that of root leachates. Optical properties (ultraviolet visible absorption and fluorescence) of DOM revealed that humic-like substances in DOM played a central role in the acidic pH of root leachates. The total amount of protons released from roots of C. japonica and C. obtusa is about 13 and 18 times higher, respectively, than that from leaves. These results imply that the increase of fine root biomass may induce a positive plant-soil feedback in acidic soils, affecting soil biogeochemical functions of terrestrial ecosystems.
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Peculiar clinical features of cellulitis in peripheral lymphedema. Lymphology 2018; 51:47-53. [PMID: 30253454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Although the occurrence of cellulitis in lymphedema (LE) is believed to be an infection-related event, many findings in its clinical course seem to suggest that it is unlikely to be an infection. Therefore, we tried to clarify the specific features of cellulitis in LE. In-hospital courses of cellulitis obtained from medical charts were reviewed in the patients with leg LE (LE; 24 patients, 72admissions), chronic venous insufficiency (CVI; 28 patients, 29 admissions), and leg cellulitis secondary to wound infection without underlying disease (N; 42 patients, 42 admissions). The patients with LE complained of less local pain (peak numerical scale; LE: 1.4 ± 1.7, CVI: 4.1 ± 2.5, N: 3.2 ±2.0, p < 0.0001), showed an abnormally higher peak procalcitonin level (LE: 33.8 ± 34.8 (N = 7), CVI: 2.9 ± 5.8 (N = 8), N: 0.4 ± 0.6(N = 10), p < 0.05), and required fewer antibiotics (LE: 1.1 ± 0.3, CVI: 1.8 ± 0.9, N: 1.5 ± 0.9, p < 0.0001). These findings suggested that the occurrence of cellulitis in LE seems unlikely to be an infection-related type of cellulitis similar to that found in CVI.
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Differential effects of light-to-dark transitions on phase setting in circadian expression among clock-controlled genes in Pharbitis nil. PLANT SIGNALING & BEHAVIOR 2018; 13:e1473686. [PMID: 29944436 PMCID: PMC6110364 DOI: 10.1080/15592324.2018.1473686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 04/27/2018] [Indexed: 05/18/2023]
Abstract
The circadian clock is synchronized by the day-night cycle to allow plants to anticipate daily environmental changes and to recognize annual changes in day length enabling seasonal flowering. This clock system has been extensively studied in Arabidopsis thaliana and was found to be reset by the dark to light transition at dawn. By contrast, studies on photoperiodic flowering of Pharbitis nil revealed the presence of a clock system reset by the transition from light to dark at dusk to measure the duration of the night. However, a Pharbitis photosynthetic gene was also shown to be insensitive to this dusk transition and to be set by dawn. Thus Pharbitis appeared to have two clock systems, one set by dusk that controls photoperiodic flowering and a second controlling photosynthetic gene expression similar to that of Arabidopsis. Here, we show that circadian mRNA expression of Pharbitis homologs of a series of Arabidopsis clock or clock-controlled genes are insensitive to the dusk transition. These data further define the presence in Pharbitis of a clock system that is analogous to the Arabidopsis system, which co-exists and functions with the dusk-set system dedicated to the control of photoperiodic flowering.
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Excitonic, vibrational, and van der Waals interactions in electron energy loss spectroscopy. Ultramicroscopy 2017; 180:93-103. [DOI: 10.1016/j.ultramic.2017.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 02/21/2017] [Accepted: 03/01/2017] [Indexed: 11/16/2022]
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9
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OM-I-3Atomic-scale investigation of Glass, Liquid, and Gas using STEM, EELS, and theoretical calculation. Microscopy (Oxf) 2016. [DOI: 10.1093/jmicro/dfw077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Improvement of immunoassay detection system by using alternating current magnetic susceptibility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:035112. [PMID: 27036824 DOI: 10.1063/1.4943256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
A major goal with this research was to develop a low-cost and highly sensitive immunoassay detection system by using alternating current (AC) magnetic susceptibility. We fabricated an improved prototype of our previously developed immunoassay detection system and evaluated its performance. The prototype continuously moved sample containers by using a magnetically shielded brushless motor, which passes between two anisotropic magneto resistance (AMR) sensors. These sensors detected the magnetic signal in the direction where each sample container passed them. We used the differential signal obtained from each AMR sensor's output to improve the signal-to-noise ratio (SNR) of the magnetic signal measurement. Biotin-conjugated polymer beads with avidin-coated magnetic particles were prepared to examine the calibration curve, which represents the relation between AC magnetic susceptibility change and polymer-bead concentration. For the calibration curve measurement, we, respectively, measured the magnetic signal caused by the magnetic particles by using each AMR sensor installed near the upper or lower part in the lateral position of the passing sample containers. As a result, the SNR of the prototype was 4.5 times better than that of our previous system. Moreover, the data obtained from each AMR sensor installed near the upper part in the lateral position of the passing sample containers exhibited an accurate calibration curve that represented good correlation between AC magnetic susceptibility change and polymer-bead concentration. The conclusion drawn from these findings is that our improved immunoassay detection system will enable a low-cost and highly sensitive immunoassay.
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Comparing immunocompetent and immunodeficient mice as animal models for bone tissue engineering. Oral Dis 2015; 21:583-92. [PMID: 25648203 DOI: 10.1111/odi.12319] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/04/2015] [Accepted: 01/16/2015] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To understand the differences and similarities between immunocompetent and immunodeficient mice as ectopic transplantation animal models for bone tissue engineering. MATERIALS AND METHODS Osteogenic cells from mouse leg bones were cultured, seeded on β-TCP granules, and transplanted onto the backs of either immunocompetent or immunodeficient nude mice. At 1, 2, 4, and 8 weeks postoperatively, samples were harvested and evaluated by hematoxylin-eosin staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemical staining and quantitative PCR. RESULTS In immunocompetent mice, inflammatory cell infiltration was evident at 1 week postoperatively and relatively higher expression of TNF-α and IL-4 was observed. In immunodeficient mice, new bone area and the number of TRAP-positive cells were larger at 4 weeks than in immunocompetent mice. The volume of new bone area in immunodeficient mice was reduced by 8 weeks. CONCLUSIONS Bone regeneration was feasible in immunocompetent mice. However, some differences were observed between immunocompetent and immunodeficient mice in the bone regeneration process possibly due to different cytokine expression, which should be considered when utilizing in vivo animal models.
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Ameliorating effects of miglitol on postprandial hyperglycemia and triglyceride/HDL ratio are associated with beneficial impact on atherosclerosis in diabetic patients with coronary artery disease. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p2271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Community structures of Mesostigmata, Prostigmata and Oribatida in broad-leaved regeneration forests and conifer plantations of various ages. EXPERIMENTAL & APPLIED ACAROLOGY 2013; 59:391-408. [PMID: 23011106 DOI: 10.1007/s10493-012-9618-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 09/15/2012] [Indexed: 05/24/2023]
Abstract
The community structures of Mesostigmata, Prostigmata, and Oribatida in the soil of broad-leaved regeneration forests and conifer plantations of various ages were assessed alongside soil and plant environmental variables using three response metrics (density, species richness, and species-abundance distribution). The density and species richness of mites recovered swiftly after clear-cutting or replanting. Oribatid mites dominated the soil mite communities in terms of densities and species richness for both forest types. Soil mite communities in broad-leaved forests was related to forest age, the crown tree communities index, and forest-floor litter weight. In contrast, soil mite communities in the conifer plantation sites were related to various indices of understory plants. The development of the understory plants was synchronized with the silvicultural schedules, including a closed canopy and thinning. Such a conifer plantation management may affect indirectly the community of mites.
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Stimulation of liver functions in hierarchical co-culture of bone marrow cells and hepatocytes. Cytotechnology 2012; 26:5-12. [PMID: 22359001 DOI: 10.1023/a:1007938118602] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A hierarchial co-culture, in which rat hepatocytes and non-parenchymal liver cells (NPLCs) were separated by a collagen layer and which was designed to mimic the in vivo microenvironment, was carried out with the aim of developing a module for bio-artificial liver support. Compared with a monolayer co-culture and hepatocytes cultured alone in a monolayer, higher urea synthesis activity was maintained for 6 d in the hierarchical co-culture. When a rat hepatoma cell line H4-II-E-C3, which retains the induction of tyrosine aminotransferase (TAT), was co-cultured in a monolayer with NPLCs, dose-dependent stimulation of TAT induction was observed. In a hierarchical co-culture, NPLCs further stimulated TAT induction in H4-II-E-C3 cells. Since peritoneal macrophages could stimulate TAT induction in hepatocytes in both monolayer and hierarchical co-cultures, bone marrow cells, which can proliferate and differentiate into macrophages in vitro, were investigated as a possible substitute for NPLCs. Bone marrow cells isolated from rat femurs were cultivated in the presence of IL-3 and macrophage colony-stimulating factor (M-CSF), and co-cultured with hepatocytes. Urea synthesis and TAT induction of hepatocytes were stimulated in the co-culture. The co-culture of bone marrow and H4-II-E-C3 cells, both of which have proliferation ability in vitro, was also shown to be effective in stimulating liver functions. The hierarchical configuration, in which two cell types can communicate with the soluble factor(s) through a collagen layer, was found to be more effective than a monolayer in long-term co-culture.
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Monitoring of fluconazole in serum of patients undergoing hemodiafiltration by solid-phase extraction and high-performance liquid chromatography with ultraviolet detection. DIE PHARMAZIE 2012; 67:765-767. [PMID: 23016448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A high-performance liquid chromatographic assay for monitoring the antifungal drug fluconazole in human serum was developed using a C18 reversed-phase column with isocratic elution. The method involved sample clean-up by solid-phase column extraction, and subsequent analysis required only 14 min per sample for separation and quantitation. The assay was precise, with intra- and inter-assay relative standard deviations of < or = 1.5% and < or = 3.1%. The minimum detectable concentration of fluconazole was 0.3 nmol/ml. This assay has the advantage of minimizing the risk of interference from co-administered drugs to critically ill patients undergoing hemodiafiltration.
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The effect of vacancies on the annular dark field image contrast of grain boundaries: A SrTiO3 case study. Ultramicroscopy 2011; 111:1531-9. [DOI: 10.1016/j.ultramic.2011.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 08/24/2011] [Accepted: 08/25/2011] [Indexed: 11/16/2022]
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Abstract
Tularemia is a zoonotic disease caused by Francisella tularensis. The distribution of the pathogen in Japan has not been studied well. In this study, seroprevalence of tularemia among wild black bears and hares in Japan was determined. Blood samples collected from 431 Japanese black bears (Ursus thibetanus japonicus) and 293 Japanese hares (Lepus brachurus) between 1998 and 2009 were examined for antibodies against F. tularensis by micro-agglutination test (MA) or enzyme-linked immunosorbent assay. By subsequent confirmatory tests using western blot (WB) and indirect immunofluorescence assay (IFA), eight sera from Japanese black bears were definitely shown to be seropositive. All of these eight bears were residents of the northeastern part of main-island of Japan, where human tularemia had been reported. On the other hand, no seropositive Japanese hares were found. These results suggest that Japanese black bears can serve as sentinel for tularemia surveillance and may help understand the distribution of F. tularensis throughout the country. This is the first report on detection of antibody to F. tularensis in black bears of Japan.
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Scanning transmission electron microscopy imaging dynamics at low accelerating voltages. Ultramicroscopy 2011; 111:999-1013. [DOI: 10.1016/j.ultramic.2011.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 02/22/2011] [Accepted: 02/24/2011] [Indexed: 11/28/2022]
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Quantitative analyses of oxidation states for cubic SrMnO(3) and orthorhombic SrMnO(2.5) with electron energy loss spectroscopy. JOURNAL OF APPLIED PHYSICS 2010; 108:124903. [PMID: 21245943 PMCID: PMC3021553 DOI: 10.1063/1.3520655] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 10/25/2010] [Indexed: 05/30/2023]
Abstract
The oxidation state of Mn in cubic SrMnO(3) and orthorhombic SrMnO(2.5) was investigated by electron energy loss (EEL) spectroscopy. Change in the oxidation state of Mn produced some spectral changes in the O-K edge as well as in the Mn-L(2,3) edge EEL spectra. This study demonstrated that the oxidation state of Mn and the amount of oxygen vacancies in cubic SrMnO(3) and orthorhombic SrMnO(2.5) could be quantified by analyzing the features of the O-K edge spectrum and the Mn L(3)∕L(2) ratio in the Mn-L(2,3) edge spectrum. Our quantitative analysis showed that the spectral changes in the Mn-L(2,3) edge were mainly caused by the oxidation state of Mn, whereas those in the O-K edge could be sensitive to both the oxidation state of Mn and to lattice distortions.
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Atomic-scale imaging of individual dopant atoms in a buried interface. NATURE MATERIALS 2009; 8:654-658. [PMID: 19543277 DOI: 10.1038/nmat2486] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 05/19/2009] [Indexed: 05/27/2023]
Abstract
Determining the atomic structure of internal interfaces in materials and devices is critical to understanding their functional properties. Interfacial doping is one promising technique for controlling interfacial properties at the atomic scale, but it is still a major challenge to directly characterize individual dopant atoms within buried crystalline interfaces. Here, we demonstrate atomic-scale plan-view observation of a buried crystalline interface (an yttrium-doped alumina high-angle grain boundary) using aberration-corrected Z-contrast scanning transmission electron microscopy. The focused electron beam transmitted through the off-axis crystals clearly highlights the individual yttrium atoms located on the monoatomic layer interface plane. Not only is their unique two-dimensional ordered positioning directly revealed with atomic precision, but local disordering at the single-atom level, which has never been detected by the conventional approaches, is also uncovered. The ability to directly probe individual atoms within buried interface structures adds new dimensions to the atomic-scale characterization of internal interfaces and other defect structures in many advanced materials and devices.
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Trabeculotomy combined with phacoemulsification and implantation of intraocular lens for primary open-angle glaucoma. Semin Ophthalmol 2009; 16:162-7. [PMID: 15513436 DOI: 10.1076/soph.16.3.162.4195] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Retrospective study examined the surgical effects of lowering intraocular pressure of trabeculotomy combined with phacoemulsification and implantation of an intraocular lens. Included in the retrospective study were 96 eyes of 64 patients with primary open-angle glaucoma. Preoperative mean IOP was 25.6 mmHg. At final examination, the IOP was well-controlled at 21 mmHg or lower without medications in 32 of 96 eyes. In another 62 eyes, the IOP was well-controlled with antiglaucoma medications. The postoperative IOPs were in the high teens after surgery. The life table analysis using Kaplan-Meier methods showed that the success probability after phacoemulsification and implantation of intraocular lens, combined with trabeculotomy (PIT)-I and PIT-II, were 93.9% and 82.6% at 4 years, respectively. Postoperative visual acuity improved by more than two lines in 79 of the 96 eyes. In no case was the visual acuity decreased by more than two lines. Deterioration of the visual field was found in 4 eyes. There were no complications such as shallow anterior chamber, choroidal detachment, malignant glaucoma, hypotonic maculopathy, and endophthalmitis. This triple procedure should be performed in the early stages of glaucoma. Trabeculotomy is thought to relieve the resistance to aqueous outflow by mechanical cleavage of the trabecular meshwork and the inner layer of Schlemm's canal. This technique leads to aqueous outflow the from the opening of the internal trabecular meshwork to the collector channel. For this reason trabeculotomy was developed by a number of surgeons. Recently, however, trabeculotomy has not been selected for those patients with advanced stages of primary open-angle glaucoma because of the disadvantages such as transient intraocular pressure (IOP) elevation several days after surgery and somewhat higher levels (18 mmHg) of postoperative intraocular pressure (Fig. 1). To avoid the IOP spike (transient IOP elevation) after trabeculotomy, we reported previously that the new technique of trabeculotomy combined with outer sclerectomy was a useful surgical option. The results of our previous study indicated that the postoprative intraocular pressure levels after combined trabeculotomy and outer sclerectomy were significantly lower than that of trabeculotomy alone. On the other hand, trabeculotomy with mitomycin C is currently the standard filtration procedure for glaucoma. This technique, however causes severe postoperative complication such as hypotonic maculopathy, bleb leakage and late bleb infection. The major advantages of trabeculotomy preclude these severe complications resulting from creating progressive filtration of aqueous humor from the anterior chamber to the subconjunctival space. The recent advance of small-incision phacoemulsification procedure prompted phacoemulsification and implantation of intraocular lens and trabeculotomy. The theoretical advantages of smaller scleral, conjunctival incision, reduced stimuli to wound healing, and inflammation, could improve long-term IOP control in patients with glaucoma. Therefore several reports have been published on the surgical outcomes of combined trabeculotomy and modern phacoemulsification. These reports suggested that the combined trabeculotomy and a small-incision with intraocular lens implantation is effective in controlling IOP in patients with glaucoma.
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Advanced nonpenetrating trabeculectomy (advanced NPT) and combined surgery of advanced NPT and phacoemulsification and intraocular lens implantation. Semin Ophthalmol 2009; 16:172-6. [PMID: 15513438 DOI: 10.1076/soph.16.3.172.4201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have devised a new glaucoma surgery combining deep sclerectomy with nonpenetrating trabeculectomy (NPT); we call this surgery advanced NPT. We evaluated intraocular pressure (IOP) control, postoperative complication and visual acuity after combined advanced NPT and phacoemulsification and intraocular lens implantation (combined surgery), and advanced NPT alone. The mean preoperative IOP for the trabeculectomy only group was 22.4 +/- 6.3 mmHg(bleb+), 23.0 +/- 4.9 mmHg(bleb-), and that of the combined surgery group was 18.1 +/- 4.5 mmHg(bleb+), 18.5 +/- 2.6 mmHg(bleb-). Mean postoperative IOP for the two groups were 13.0 +/- 2.3 mmHg(bleb+), 15.0 +/- 1.5 mmHg(bleb-) and 12.9 +/- 2.7 mmHg(bleb+), 13.3 +/- 2.4 mmHg(bleb-), respectively. After 15 months, the success probability for postoperative IOP control were 63%(bleb+), 23%(bleb-) in the advanced NPT only group (<or=12 mmHg), and 60% in the advanced NPT only group, 70% in the combined surgery group (<or=14 mmHg) (Kaplan-Meier survival rate). In early complication, there were significantly fewer cases of shallow anterior chamber, hypertension, hypotension and anterior chamber inflamation in both groups than that of trabeculectomy. Nd:YAG goniopuncture was performed for purposes of better IOP control; preferred performance being within a month after surgery. Regarding visual acuity after either advanced NPT alone or combined surgery, an earlier recovery can be expected than with trabeculectomy. Advanced NPT and combined procedure is a reliable technique for glaucoma and cataract surgery.
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Abstract
It has recently become popular to use mitomycin C (MMC) with trabeculectomy. MMC helps to maintain effective filtration and long-term intraocular pressure (IOP) control, while the use of laser suture lysis has improved the safety of this procedure. We evaluated the outcome of trabeculectomy alone and of trabeculectomy plus phacoemulsification (PEA) and intraocular lens (IOL) implantation, each supplemented with MMC. The mean preoperative IOP for the trabeculectomy alone group was 22.4 +/- 3.2 mmHg(bleb+), 25.3 +/- 2.6 mmHg(bleb-), and that of the combined surgery group was 22.4 +/- 2.8 mmHg(bleb+), 21.0 +/- 3.5 mmHg(bleb-). Mean postoperative IOP for the two groups were 13.3 +/- 2.7 mmHg(bleb+), 17.1 +/- 4.4 mmHg(bleb-) and 11.9 +/- 2.7 mmHg(bleb+), 16.4 +/- 3.4 mmHg(bleb-), respectively. After 4.5 years, the success probability for postoperative IOP control was 38%(bleb+), 3%(bleb-) in the trabeculectomy alone group and 53%(bleb+), 10%(bleb-) in the combined surgery group (<or=12 mmHg) and 65%(bleb+), 3%(bleb-) and 75%(bleb+), 10%(bleb-) (<or=14 mmHg)(Kaplan-Meier survival rate). With early complications, the frequency of shallow anterior chamber and choroidal detachment were significantly fewer in the combined surgery group. The combined surgery of PEA, IOL implantation and trabeculectomy is an effective procedure that offers visual rehabilitation, fewer early complications and good IOP control in patients with advanced, medically uncontrolled glaucoma and cataract.
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Interface structures of gold nanoparticles on TiO2 (110). PHYSICAL REVIEW LETTERS 2009; 102:136105. [PMID: 19392375 DOI: 10.1103/physrevlett.102.136105] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Indexed: 05/27/2023]
Abstract
Scanning transmission electron microscopy and density functional theory are used to characterize atomic structures of nanoscale heterointerfaces between gold nanoparticles and a TiO2 (110) surface. It is found that when the gold nanoparticle size is smaller than a few nanometers, gold atoms preferentially attach to specific sites on the TiO2 surface and thus form an epitaxial and coherent heterointerface. Conversely, as the gold size becomes larger, the gold-TiO2 interface loses lattice coherency in order to accommodate the large lattice mismatch between the two dissimilar crystals.
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Fine root morphological traits determine variation in root respiration of Quercus serrata. TREE PHYSIOLOGY 2009; 29:579-585. [PMID: 19203981 DOI: 10.1093/treephys/tpn050] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Fine root respiration is a significant component of carbon cycling in forest ecosystems. Although fine roots differ functionally from coarse roots, these root types have been distinguished based on arbitrary diameter cut-offs (e.g., 2 or 5 mm). Fine root morphology is directly related to physiological function, but few attempts have been made to understand the relationships between morphology and respiration of fine roots. To examine relationships between respiration rates and morphological traits of fine roots (0.15-1.4 mm in diameter) of mature Quercus serrata Murr., we measured respiration of small fine root segments in the field with a portable closed static chamber system. We found a significant power relationship between mean root diameter and respiration rate. Respiration rates of roots<0.4 mm in mean diameter were high and variable, ranging from 3.8 to 11.3 nmol CO2 g(-1) s(-1), compared with those of larger diameter roots (0.4-1.4 mm), which ranged from 1.8 to 3.0 nmol CO2 g(-1) s(-1). Fine root respiration rate was positively correlated with specific root length (SRL) as well as with root nitrogen (N) concentration. For roots<0.4 mm in diameter, SRL had a wider range (11.3-80.4 m g(-1)) and was more strongly correlated with respiration rate than diameter. Our results indicate that a more detailed classification of fine roots<2.0 mm is needed to represent the heterogeneity of root respiration and to evaluate root biomass and root morphological traits.
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First-principles calculation of oxygen K-electron energy loss near edge structure of HfO(2). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:104212. [PMID: 21817432 DOI: 10.1088/0953-8984/21/10/104212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Oxygen K-electron energy loss near edge structures (ELNES) of monoclinic, tetragonal, and cubic HfO(2) were calculated by the first-principles full-potential augmented plane wave plus local orbitals (APW+lo) method. By considering the relativistic effect as well as the core-hole effect in the calculation, the experimental oxygen K ELNES was successfully reproduced. The first, second, third, and fourth peaks originate from oxygen p components hybridized with Hf d-e(g), d-t(2g), s, and p components, respectively. It was found that the spectral differences among the polymorphs are mainly caused by the local structure of the Hf in the crystal.
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Comprehensive resources for tomato functional genomics based on the miniature model tomato micro-tom. Curr Genomics 2008; 9:436-43. [PMID: 19506732 PMCID: PMC2691670 DOI: 10.2174/138920208786241225] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 07/23/2008] [Accepted: 07/27/2008] [Indexed: 11/22/2022] Open
Abstract
Tomato (Solanum lycopersicum L., Solanaceae) is an excellent model plant for genomic research of solanaceous plants, as well as for studying the development, ripening, and metabolism of fruit. In 2003, the International Solanaceae Project (SOL, www.sgn.cornell.edu ) was initiated by members from more than 30 countries, and the tomato genome-sequencing project is currently underway. Genome sequence of tomato obtained by this project will provide a firm foundation for forthcoming genomic studies such as the comparative analysis of genes conserved among the Solanaceae species and the elucidation of the functions of unknown tomato genes. To exploit the wealth of the genome sequence information, there is an urgent need for novel resources and analytical tools for tomato functional genomics. Here, we present an overview of the development of genetic and genomic resources of tomato in the last decade, with a special focus on the activities of Japan SOL and the National Bio-Resource Project in the development of functional genomic resources of a model cultivar, Micro-Tom.
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Multivariate data analysis approach to understand magnetic properties of perovskite manganese oxides. J SOLID STATE CHEM 2008. [DOI: 10.1016/j.jssc.2008.02.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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A case of delayed rectal stenosis from severe pelvic fracture with massive bleeding successfully treated by bilateral internal iliac TAE: report on a patient survival. Int J Colorectal Dis 2007; 22:853-4. [PMID: 16583197 DOI: 10.1007/s00384-006-0103-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/12/2006] [Indexed: 02/04/2023]
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Coordination of microtubules and the actin cytoskeleton is important in osteoclast function, but calcitonin disrupts sealing zones without affecting microtubule networks. Bone 2006; 39:684-93. [PMID: 16774853 DOI: 10.1016/j.bone.2006.04.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 03/07/2006] [Accepted: 04/04/2006] [Indexed: 01/28/2023]
Abstract
Bone-resorbing osteoclasts form sealing zones and ruffled borders toward the bone surface. The sealing zone consists of a ring-like alignment of F-actin dots and surrounds the ruffled border, from which protons are secreted into the bone surface. Vacuolar-type proton ATPase (V-ATPase) in osteoclasts is a ruffled border-associated enzyme responsible for the proton secretion. We studied the interaction between microtubules and the actin cytoskeleton in osteoclasts. Confocal microscopic observation revealed that osteoclasts on glass coverslips, dentine slices and Osteologictrade mark discs formed the ring-like structure of F-actin dots, and microtubules overlapped the top of the F-actin dots. Osteoclasts cultured on dentine formed resorption pits within 48 h. The treatment of osteoclasts with cytochalasin D, an F-actin-depolymerizing reagent, induced perturbation of the microtubules in osteoclasts on glass and inhibited their pit-forming activity on dentine in a dose-dependent and reversible manner. Conversely, nocodazole, a microtubule-depolymerizing reagent, disrupted sealing zones and inhibited pit-forming activity of osteoclasts in a dose-dependent and reversible manner. V-ATPase showed a tendency to be localized inside sealing zones in osteoclasts. Treatment of osteoclasts with calcitonin induced both disruption of sealing zones and dispersion of V-ATPase to the whole area of the cytoplasm within 60 min. The microtubule networks in osteoclasts remained unchanged for 60 min even in the presence of calcitonin. These results suggest that coordination of the actin cytoskeleton and microtubules is important in the function of osteoclasts, but calcitonin selectively affects the actin cytoskeleton and induces the dispersion of V-ATPase without causing significant changes in the microtubules.
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Effects of calcitonin on the function of human osteoclast-like cells formed from CD14-positive monocytes. Cell Mol Biol (Noisy-le-grand) 2006; 52:25-31. [PMID: 17535751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Accepted: 07/29/2005] [Indexed: 05/15/2023]
Abstract
Calcitonin inhibits bone-resorbing activity of osteoclasts. Expression of mRNA of calcitonin receptor (CTR) and its related proteins was examined in human osteoclasts and their progenitors. CD14-positive (CD14 + macrophages) in the monocytes prepared from human peripheral blood cells differentiated into macrophages (CD14 +) presence of macrophage colony-stimulating factor (M-CSF) or into osteoclast-like cells (OCLs) in the presence of M-CSF plus receptor activator of NFkappaB ligand. CD14 macrophages expressed mRNA of CTR-like receptor (CRLR), receptor activity modifying protein (RAMP) 1, RAMP2, and RAMP3, but not CTR. In contrast, OCLs expressed mRNA of CTR but not CRLR or RAMPs. Human OCLs cultured on dentine slices formed actin rings (corresponding to clear zones) and resorption pits on the slices. Calcitonin disrupted actin rings and inhibited the pit-forming activity of OCLs. CTR is known to couple to cAMP-dependent protein kinase (PKA) and protein kinase C (PKC). The effect of calcitonin on actin ring disruption was partially blocked by adding H-7, an inhibitor of both PKA and PKC. Both forskolin, an activator of PKA, and phorbol myristate, an activator of PKC, disrupted actin rings in OCLs. These results suggest that both PKA- and PKC-mediated signals are involved in calcitonin-induced inhibition of human OCL function.
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Real-time observation of anisotropic structure of aggregates in stretched rubber by 2D-USAXS. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305094778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Evaluation of sample spin-polarization from spin-polarized scanning tunneling spectroscopy experiments. Microsc Res Tech 2005; 66:93-104. [PMID: 15880517 DOI: 10.1002/jemt.20149] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Spin-polarized scanning tunneling microscopy has produced a great amount of images presenting magnetic contrast between different magnetic domains with an unsurpassed spatial resolution but getting values like the surface polarization has proven to be a difficult task. We will discuss in detail how to extract this information for the case of manganese layers grown on Fe(001) whiskers. Mn layers adopt a body-centered-tetragonal (bct) structure when they are grown on the Fe(001) surface at room temperature. The Mn layers show an antiferromagnetic coupling between the layers. Comparing our spin-polarized scanning tunneling spectra measured with Fe-coated W tips with spin-resolved band structure calculations, we are able to find the value of the sample surface polarization. Also discussed is a method to change the tip magnetization. Finally, the magnetic structure around a screw dislocation on the surface is reviewed.
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Surgically-induced astigmatism following single-site phacotrabeculectomy, phacotrabeculotomy and advanced non-penetrating phacotrabeculectomy. Semin Ophthalmol 2004; 16:158-61. [PMID: 15513435 DOI: 10.1076/soph.16.3.158.4196] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We study surgically-induced astigmatism following three kinds of glaucoma surgeries combined with cataract surgery with 6 months of follow-up. The mean surgically-induced astigmatism at 6 months postoperatively was 1.92 +/- 1.87 diopters in phacotrabeculectomy (n = 45), 0.72 +/- 0.40 diopters in advanced non-penetrating phacotrabeculectomy (n = 40) and 0.76 +/- 0.47 diopters in phacotrabeculotomy (n = 49), which appeared to be stabilized by 3 months. Each group revealed a tendency of "with the wound" induced astigmatism. Phacotrabeculectomy could induce greater surgically-induced astigmatism than advanced non-penetrating phacotrabeculectomy and phacotrabeculotomy.
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Combined procedures in glaucoma surgery. Semin Ophthalmol 2004; 16:139-43. [PMID: 15513432 DOI: 10.1076/soph.16.3.139.4204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
Polyethylene glycol is used as a non-aqueous solvent for a variety of medical agents. We believe it could also be used as a base component in root canal filling material and aimed to test the histological safety of subcutaneously injected polyethylene glycol. We injected polyethylene glycol subcutaneously into the dorsal area of 30 6-week-old anaesthetized male ddY mice. An equal number of mice were injected with propylene glycol as controls. One week, 3 weeks and 9 weeks after injection, the tissue surrounding the injection site was removed from 10 mice in each group and examined. We found no histopathological changes, degeneration, necrosis, foreign body reactions or granulation tissue proliferation in either group. Some inflammatory cell infiltration was observed in both groups. Based on these results, we believe that polyethylene glycol could be used safely as a base component of biomaterials for internal medical use, such as in root canal filling material.
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Observation of spin-polarized surface states on ultrathin bct Mn(001) films by spin-polarized scanning tunneling spectroscopy. PHYSICAL REVIEW LETTERS 2003; 90:056803. [PMID: 12633385 DOI: 10.1103/physrevlett.90.056803] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2002] [Indexed: 05/24/2023]
Abstract
We report the observation of a magnetic contrast of up to 20% in the scanning tunneling spectroscopy dI/dV maps obtained with Fe-coated tips on Mn(001) layers grown on an Fe(001) whisker at 370 K. These nanometer resolution microscopy results show that the layers couple antiferromagnetically. By normalizing the dI/dV curves by tunneling probability functions, we found a spin-dependent peak on the body-centered-tetragonal (bct) Mn(001) surface at +0.8 V, whose high spin polarization gives rise to the dI/dV map contrast. Band structure calculations allow one to identify the +0.8 V peak as due to two spin-polarized d(z(2)) surface states.
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Photochemistry of the phthalimide system. VII. Regioselective remote photocyclization. Examples of a photochemical macrocyclic synthesis with sulfide-containing phthalimides. J Am Chem Soc 2002. [DOI: 10.1021/ja00424a066] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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40
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Anodic Oxidation Studies of N,N-Dimethylaniline. I. Voltammetric and Spectroscopic Investigations at Platinum Electrodes. J Am Chem Soc 2002. [DOI: 10.1021/ja00870a009] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Time-dependent changes in the carotenoid composition and preferential binding of spirilloxanthin to the reaction center and anhydrorhodovibrin to the LH1 antenna complex in Rhodobium marinum. Photochem Photobiol 2001; 74:444-52. [PMID: 11594059 DOI: 10.1562/0031-8655(2001)074<0444:tdcitc>2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Carotenoids were isolated from the cells of Rhodobium marinum, and their structures were determined by mass spectrometry and 1H nuclear magnetic resonance spectroscopy; the carotenoids include lycopene, rhodopin, anhydrorhodovibrin, rhodovibrin and spirilloxanthin. Time-dependent changes in the carotenoid composition in the reaction center (RC) and the light-harvesting complex 1 (LH1) were traced by high-performance liquid chromatography analysis of the extracts. The carotenoid composition changed according to the spirilloxanthin biosynthetic pathway. However, spirilloxanthin having the longest conjugated chain was always preferentially bound to the RC, and anhydrorhodovibrin and other precursors to the LH1.
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Oxidative stress activates ATMPK6, an Arabidopsis homologue of MAP kinase. PLANT & CELL PHYSIOLOGY 2001; 42:1012-1016. [PMID: 11577197 DOI: 10.1093/pcp/pce123] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades function in biotic and abiotic stress responses in plants. We analysed effect of oxidative stress on the activation of ATMPK6, an Arabidopsis thaliana MAPK, in Arabidopsis T87 cultured cells and rosette leaves using anti-ATMPK6 specific antibody. ATMPK6 in T87 cells was strongly activated by reactive oxygen species (ROS) such as H(2)O(2) and KO(2). In leaves, ATMPK6 was activated by paraquat and 3-amino-1,2,4-triazole (a catalase inhibitor). These results indicate that ATMPK6 is one of the candidates for signal mediators in response to abiotic or biotic sources for ROS in Arabidopsis.
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ITER R&D: Auxiliary Systems: Introduction. FUSION ENGINEERING AND DESIGN 2001. [DOI: 10.1016/s0920-3796(01)00209-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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ITER R&D: Vacuum Vessel and In-vessel Components: Introduction. FUSION ENGINEERING AND DESIGN 2001. [DOI: 10.1016/s0920-3796(01)00207-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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ITER R&D: Remote Handling Systems: Introduction. FUSION ENGINEERING AND DESIGN 2001. [DOI: 10.1016/s0920-3796(01)00214-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Repression of starch degradation under anaerobic conditions by irregularly high levels of ATP in Chlamydomonas sp. MGA161. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2001; 160:629-634. [PMID: 11448738 DOI: 10.1016/s0168-9452(00)00438-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
It is generally known that in green algal species the acceleration of starch degradation upon transition from aerobic to anaerobic conditions is a result of the Pasteur effect in glycolysis. However, the acceleration of starch degradation did not occur in cells of Chlamydomonas sp. MGA161. In MGA161 cells, the anaerobic ATP level, which decreased to about half of the aerobic ATP level in cells of Chlamydomonas reinhardtii after fermentation for 2 h, was kept higher than its aerobic ATP level. Gramicidin D, a monovalent cation ionophore, markedly decreased the anaerobic and aerobic ATP levels due to the increase in ATP demand, accompanied by the acceleration of starch degradation in MGA161 cells. Although the anaerobic ATP level of C. reinhardtii cells was partially decreased by gramicidin D, starch degradation did not accelerate markedly when compared with the result in MGA161 cells. Therefore, starch was degraded at nearly the maximum rate in C. reinhardtii cells under anaerobic conditions; in contrast, the high level of ATP in MGA161 cells repressed starch degradation even under anaerobic conditions, resulting in the absence of the Pasteur effect.
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Abstract
Electron-energy-loss near edge structures (ELNES) at the Zn-L(2,3) edge and the O-K edge have been measured for 10 mol% ZnO-doped MgO, and were compared with spectra from reference materials. In order to interpret the spectra, first principles molecular orbital calculations were made using model clusters composed of 125 and 153 atoms. Photoabsorption cross sections (PACS) were computed at the Slater's transition state in which a half-filled core hole was included in the self-consistent calculations. The difference in the coordination numbers of Zn was found well distinguishable by the Zn-L(2,3)-edge ELNES. The experimental spectra in the first 25 eV were well reproduced by the theoretical PACS. In this energy region, the Zn-L(2,3)-edge ELNES from four-fold coordinated Zn showed four sets of peaks, whereas the six-fold coordinated Zn exhibits three sets of peaks. The origin of these peaks can be explained by the point symmetry within the first coordination unit. A small shift toward the lower energy side was observed in the O-K edge ELNES of the ZnO-doped MgO as compared with pure MgO. This can be ascribed to the lower energy of the Zn-4s orbital as compared with the Mg-3s orbital, which is the common mechanism to the difference in the band gap between MgO and ZnO.
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Abstract
A definitive method is described for the indirect assay of milligram quantities of D(+)-glucose by coulometric titration. D(+)-Glucose was aerobically oxidized by glucose oxidase in an acetate buffer solution (pH 5.1). Subsequently, the enzymatically formed hydrogen peroxide was titrated coulometrically with electrogenerated hypobromite in sodium bromide-sodium tetraborate medium of pH 8.6, with biamperometric end-point detection. Parameters affecting the enzymatically catalyzed oxidation and coulometric titration were evaluated. The optimized conditions for the oxidation of up to 20 mg of D(+)-glucose include the addition of 4500 U of glucose oxidase and stirring over a 10-min interval at 25 degrees C. Under proposed conditions, the assay values of several commercial D(+)-glucose reagents were somewhat lower than the guaranteed minimum values, with RSDs (n = 5) of 0.071 - 0.106%.
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