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91.
Relationship between river water quality and land use in a small river basin running through the urbanizing area of Central Japan 总被引:9,自引:0,他引:9
In this study, the relationship between water quality (as represented by major inorganic ion concentrations) and land use
characteristics is examined for a small river basin which runs through the urbanizing area of central Japan. Water samples
were taken from 24 sites at base flow and analyzed, and the proportions of the various land uses associated with the respective
drainage basins were calculated using a digital land-use map (scale: 1:25000). The electrical conductivity (EC) of the water
ranged from 84.5 to 600 μS cm−1. Ca2+ and Na+ were the major cations, accounting for 77% of all cations. Among the anions, HCO3
− was dominant (56%), followed by Cl− (24%), SO4
2− (13%) and NO3
− (7%). Applying principal component analysis to land use in the drainage basin yielded three principal components. The first
principal component expressed the degree of occupation by residential areas, the second indicated the degree of urban developing
area (i.e., fast-developing and industrial areas), and the third showed the degree of coverage with farmland and green space.
The residential area showed significant positive correlations with K+, Mg2+, Ca2+, NO3
−, HCO3
−, EC and TMI (total major ions). Urban developing area showed significant positive correlations with Ca2+, Cl−, HCO3
−, EC and TMI as well as weak negative correlations with NO3
− and SO4
2−. Industrial area showed weak positive correlations with Na+ and Cl− and a moderate negative correlation with NO3
−. Farmland showed significant positive correlations with NO3
− and SO4
2−; these ions are present due to fertilizers and the biological activity of plants. Forest area is inversely related to almost
all ions, indicating the need for this form of land use in order to maintain river water quality. 相似文献
92.
Matsuno Y Deguchi J Hirasawa Y Ohyama K Toyoda H Hirobe C Ekasari W Widyawaruyanti A Zaini NC Morita H 《Bioorganic & medicinal chemistry letters》2008,18(13):3774-3777
Two new cassane-type diterpenes, sucutiniranes A (1) and B (2), have been isolated from the seeds of Bowdichia nitida together with 6alpha-acetoxyvouacapane (3) and 6alpha,7beta-diacetoxyvouacapane (4), and the structures of 1 and 2 were elucidated by using 2D NMR data and chemical correlations. Sucutinirane A (1) and 3 showed a moderate cytotoxicity against human colon carcinoma COLO201 cells, and 6alpha,7beta-diacetoxyvouacapane (4) showed in vitro antiplasmodial activity against parasite Plasmodium falciparum 3D7. 相似文献
93.
Tashiro Y Nomura N Nakao R Senpuku H Kariyama R Kumon H Kosono S Watanabe H Nakajima T Uchiyama H 《Journal of bacteriology》2008,190(11):3969-3978
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that is one of the most refractory to therapy when it forms biofilms in the airways of cystic fibrosis patients. To date, studies regarding the production of an immunogenic and protective antigen to inhibit biofilm formation by P. aeruginosa have been superficial. The previously uncharacterized outer membrane protein (OMP) Opr86 (PA3648) of P. aeruginosa is a member of the Omp85 family, of which homologs have been found in all gram-negative bacteria. Here we verify the availability of Opr86 as a protective antigen to inhibit biofilm formation by P. aeruginosa PAO1 and several other isolates. A mutant was constructed in which Opr86 expression could be switched on or off through a tac promoter-controlled opr86 gene. The result, consistent with previous Omp85 studies, showed that Opr86 is essential for viability and plays a role in OMP assembly. Depletion of Opr86 resulted in streptococci-like morphological changes and liberation of excess membrane vesicles. A polyclonal antibody against Opr86 which showed reactivity to PAO1 cells was obtained. The antibody inhibited biofilm formation by PAO1 and the other clinical strains tested. Closer examination of early attachment revealed that cells treated with the antibody were unable to attach to the surface. Our data suggest that Opr86 is a critical OMP and a potential candidate as a protective antigen against biofilm formation by P. aeruginosa. 相似文献
94.
95.
Masafumi Oyadomari Hiroaki Shinohara Toru Johjima Hiroyuki Wariishi Hiroo Tanaka 《Journal of Molecular Catalysis .B, Enzymatic》2003,21(4-6):291-297
Electrochemical analysis of lignin peroxidase (LiP) was performed using a pyrolytic graphite electrode coated with peroxidase-embedded tributylmethyl phosphonium chloride membrane. The formal redox potential of ferric/ferrous couples of LiP was −126 mV (versus SHE), which was comparable with that of manganese peroxidase (MnP) and horseradish peroxidase (HRP). Yet, only LiP is capable of oxidizing non-phenolic substrates with a high redox potential. Since with decreasing pH, the redox potential increased, an incredibly low pH optimum of LiP as peroxidase at 3.0 or lower was proposed as the clue to explain LiP mechanisms. A low pH might be the key for LiP to possess a high redox potential. The pKa values for the distal His in peroxidases were calculated using redox data and the Nernst equation, to be 5.8 for LiP, 4.7 for MnP, and 3.8 for HRP. A high pKa value of the distal His might be crucial for LiP compound II to uptake a proton from the solvent. As a result, LiP is able to complete its catalytic cycle during the oxidation of non-proton-donating substrates. In compensation, LiP has diminished its reactivity toward hydrogen peroxide. 相似文献
96.
Sachiko Saino-Saito Reza Mohammad Nourani Hiroo Iwasa Hisatake Kondo Yuji Owada 《Cell and tissue research》2009,338(2):191-201
The analysis of myenteric neurons is becoming increasingly important for the assessment of enteric nervous system injury and
degeneration occurring in motor disorders of the gut. Limited information is presently available on the quantitative estimation
of myenteric neurons and glial cells in paraffin-embedded colonic sections; additional data would be useful for diagnostic
purposes. In this morphometric study, we performed immunohistochemistry to count myenteric neurons and glial cells in paraffin
sections of human colon. Serial cross sections of formalin-fixed paraffin-embedded full-thickness normal human left colon
(n = 10, age-range: 50–72 years) were examined. HuC/D and S100β antigens were found to be the best markers for the detection
of neurons and glial cells, respectively. Significant correlations were noted between the numbers of neurons/glial cells and
the respective myenteric ganglion areas. These findings suggest that HuC/D-S100β-immunostained paraffin cross sections of
human colon can be regarded as valuable tools for the quantitative estimation of myenteric neurons and glial cells. Based
on the present method, only a limited number of paraffin sections are needed for reliable quantitative assessments of myenteric
ganglion cells, thus allowing fast and simple approaches in the settings of the histopathological diagnosis of colonic motility
disorders and retrospective evaluations of pathological archival tissue specimens.
R. De Giorgio is the recipient of grants from the Fondazione Del Monte di Bologna e Ravenna and from the Fondazione Cassa
di Risparmio, Bologna, Italy. The authors declare no conflicting interests. 相似文献
97.
Hiroki Miwa Atsuko Kinoshita Hiroo Fukuda Shinichiro Sawa 《Journal of plant research》2009,122(1):31-39
The plant meristems, shoot apical meristem (SAM) and root apical meristem (RAM), are unique structures made up of a self-renewing
population of undifferentiated pluripotent stem cells. The SAM produces all aerial parts of postembryonic organs, and the
RAM promotes the continuous growth of roots. Even though the structures of the SAM and RAM differ, the signaling components
required for stem cell maintenance seem to be relatively conserved. Both meristems utilize cell-to-cell communication to maintain
proper meristematic activities and meristem organization and to coordinate new organ formation. In SAM, an essential regulatory
mechanism for meristem organization is a regulatory loop between WUSCHEL (WUS) and CLAVATA (CLV), which functions in a non-cell-autonomous manner. This intercellular signaling network coordinates the development of the
organization center, organ boundaries and distant organs. The CLAVATA3/ESR (CLE)-related genes produce signal peptides, which act non-cell-autonomously in the meristem regulation in SAM. In RAM, it has
been suggested that a similar mechanism can regulate meristem maintenance, but these functions are largely unknown. Here,
we overview the WUS–CLV signaling network for stem cell maintenance in SAM and a related mechanism in RAM maintenance. We also discuss conservation
of the regulatory system for stem cells in various plant species.
S. Sawa is the recipient of the BSJ Award for Young Scientist, 2007. 相似文献
98.
Functional Analyses of LONELY GUY Cytokinin-Activating Enzymes Reveal the Importance of the Direct Activation Pathway in Arabidopsis 总被引:1,自引:0,他引:1
Takeshi Kuroha Hiroki Tokunaga Mikiko Kojima Nanae Ueda Takashi Ishida Shingo Nagawa Hiroo Fukuda Keiko Sugimoto Hitoshi Sakakibara 《The Plant cell》2009,21(10):3152-3169
Cytokinins play crucial roles in diverse aspects of plant growth and development. Spatiotemporal distribution of bioactive cytokinins is finely regulated by metabolic enzymes. LONELY GUY (LOG) was previously identified as a cytokinin-activating enzyme that works in the direct activation pathway in rice (Oryza sativa) shoot meristems. In this work, nine Arabidopsis thaliana LOG genes (At LOG1 to LOG9) were predicted as homologs of rice LOG. Seven At LOGs, which are localized in the cytosol and nuclei, had enzymatic activities equivalent to that of rice LOG. Conditional overexpression of At LOGs in transgenic Arabidopsis reduced the content of N6-(Δ2-isopentenyl)adenine (iP) riboside 5′-phosphates and increased the levels of iP and the glucosides. Multiple mutants of At LOGs showed a lower sensitivity to iP riboside in terms of lateral root formation and altered root and shoot morphology. Analyses of At LOG promoter:β-glucuronidase fusion genes revealed differential expression of LOGs in various tissues during plant development. Ectopic overexpression showed pleiotropic phenotypes, such as promotion of cell division in embryos and leaf vascular tissues, reduced apical dominance, and a delay of leaf senescence. Our results strongly suggest that the direct activation pathway via LOGs plays a pivotal role in regulating cytokinin activity during normal growth and development in Arabidopsis. 相似文献
99.
100.
Nakaaki Kawamata Baohui Xu Hiroo Nishijima Kohji Aoyama Mayumi Kusumoto Toru Takeuchi Chuwa Tei Sara A Michie Takami Matsuyama 《Respiratory research》2009,10(1):1-11