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1.
In order to characterize uptake of vanadium in alfalfa grown in vanadium–cadmium (Cd)-contaminated soil, 104 soil samples
and 94 plant samples were collected from pot experiment. The results showed alfalfa had strong metal adaptability (up to 400 mg kg−1) and high accumulation (up to 3,440.14 mg kg−1) of vanadium. Root had higher contents and better absorption to vanadium than overground part. Moreover, both root and overground
part had direct correlation with vanadium in soil, especially with the sum of first three fractions and reducible fraction.
With the increasing of vanadium, higher concentration of Cd may inhibit the absorption of vanadium in alfalfa. 相似文献
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Zdenko Polák 《Biologia Plantarum》1966,8(6):431-433
Mosaic disease ofAnchusa officinalis found at a ruderal association in Prague-Hole?ovice in the close proximity of TMV infected cruciferous weedsCardaria draba andSisymbrium loeselii, was identified to be caused by the same agent—the necrotic TMV-strain. 相似文献
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Baydas G Donder E Kiliboz M Sonkaya E Tuzcu M Yasar A Nedzvetskii VS 《Biochemistry. Biokhimii?a》2004,69(9):1001-1005
Glial cells provide structural and metabolic support for neurons, and these cells become reactive to any insult to the central nervous system. The streptozotocin (STZ) rat model was used to study glial reactivity and the prevention of gliosis by alpha-lipoic acid (alpha-LA) administration. The expression of glial fibrillary acidic protein (GFAP), S100B protein, and neuron specific enolase (NSE) was determined as well as lipid peroxidation (LPO) and glutathione (GSH) levels in some brain tissues. Western blot analyses showed GFAP, S100B, and NSE levels significantly increased under STZ-induced diabetes in brain, and LPO level increased as well. Administration of alpha-LA reduced the expression both of glial and neuronal markers. In addition, alpha-LA significantly prevented the increase in LPO levels found in diabetic rats. GSH levels were increased by the administration of alpha-LA. This study suggests that alpha-LA prevents neural injury by inhibiting oxidative stress and suppressing reactive gliosis. 相似文献
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Common concepts of acoustic feature extraction within the auditory pathway of vertebrates and insects assume temporal filters tuned to particular periodicities. Crickets respond selectively to the conspecific song pattern and reveal a bandpass characteristic, which is thought to arise from a matched filter for a restricted range of periods. Unexpectedly, females of the two sibling species Teleogryllus oceanicus and T. commodus differed in fundamental filter properties. While T. oceanicus revealed a period filter, T. commodus exhibited a pulse duration filter. This finding raises the question of how so distinct properties of homologous neuronal circuits for pattern analysis have evolved during speciation. Evidence is presented that signal analysis by cross-correlation offers a simple explanation for differences in pattern selectivity as well as for the evolutionary transition. By cross-correlation the similarity of an external pattern with an internal template is determined over a certain time window. A comparison of behavioural data and cross-correlation values suggested that both species have similar templates. However, time windows were significantly different between species (T. oceanicus: 180–400 ms, T. commodus: 90–160 ms). Consequently, solely a change in the evaluation time window is required to account for the observed differences in feature extraction that serve to maintain species isolation.Dedicated to Franz Huber, who enriched neuroethology both by his pioneering studies as well as his infectious enthusiasm 相似文献
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Summary
-Lipotropin (-LPH) has been localized in hypothalamus and pituitary of sheep and ox by the immunoperoxidase technique. In both species -LPH was found in perikarya of arcuate neurons as well as in cells of the anterior and intermediate lobes of the pituitary. A large number of immunoreactive axons were found in the arcuate region; some appeared to innervate other neurons and others projected to portal capillaries. Stained fiber segments were also scattered throughout the hypothalamus. The presence of -LPH in hypothalamic neurons supports the possibility that brain -LPH may be a precursor for opiate-like or other peptides which may be involved in neuromodulation or neurohormonal activities.We thank L.A. Sternberger for peroxidase-antiperoxidase complexes, C.H. Li for ovine -LPH and -endorphin, The National Pituitary Agency for -melanocyte stimulating hormone, and S. Rosario for technical assistance. Supported by PHS grant (Teacher-Investigator Award*) NS 11008, a Parkinson's Disease Foundation grant to Columbia University, and the Lita Annenberg Hazen Charitable Trust 相似文献
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When 3 % (v/v) liquid paraffin was added to the medium, β-carotene production increased from 397 to 715 mg l?1 in mated cultures of Blakeslea trispora. Liquid paraffin also enhanced the oxygen concentration and induce high oxidative stress, as observed by the increase in activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). After 84 h of cultivation in the presence of liquid paraffin, the activities of SOD, CAT and POD in B. trispora increased 77, 52.5 and 76.6 %, respectively. 相似文献
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Acid production in milk by lactic streptococci was stimulated by added beta-galactosidase. Both glucose and galactose accumulated rapidly in the presence of this enzyme. Glucose accumulation ceased as the culture entered the most rapid period of acid production, whereas galactose accumulation continued. In cultures without added beta-galactosidase, a low concentration of galactose accumulated in the milk, whereas glucose was not detected after 2 hr of incubation. Cultures grew and produced acid faster in broth containing glucose rather than galactose or lactose. These observations suggest that the lactic streptococci do not metabolize the lactose in milk efficiently enough to permit optimum acid production and that a phenomenon such as catabolite repression functions to allow for a preferential use of glucose over either galactose or lactose. In addition to providing the culture with a more readily available energy source, it is possible that the culture produced more acidic metabolites as a result of preferentially utilizing the glucose released by the action of the beta-galactosidase. 相似文献
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Saima Charni Chaabane Alexandra Coomans de Brachène Ahmed Essaghir Amélie Velghe Sandra Lo Re Julie Stockis Sophie Lucas Levon M. Khachigian Fran?ois Huaux Jean-Baptiste Demoulin 《PloS one》2014,9(10)
Transforming growth factor-β (TGFβ) is a key mediator of fibrogenesis. TGFβ is overexpressed and activated in fibrotic diseases, regulates fibroblast differentiation into myofibroblasts and induces extracellular matrix deposition. Platelet-derived growth factor (PDGF) is also a regulator of fibrogenesis. Some studies showed a link between TGFβ and PDGF in certain fibrotic diseases. TGFβ induces PDGF receptor alpha expression in scleroderma fibroblasts. PDGF-C and -D are the most recently discovered ligands and also play a role in fibrosis. In this study, we report the first link between TGFβ and PDGF-D and -C ligands. In normal fibroblasts, TGFβ down-regulated PDGF-D expression and up-regulated PDGF-C expression at the mRNA and protein levels. This phenomenon is not limited to TGFβ since other growth factors implicated in fibrosis, such as FGF, EGF and PDGF-B, also regulated PDGF-D and PDGF-C expression. Among different kinase inhibitors, only TGFβ receptor inhibitors and the IκB kinase (IKK) inhibitor BMS-345541 blocked the effect of TGFβ. However, activation of the classical NF-κB pathway was not involved. Interestingly, in a model of lung fibrosis induced by either bleomycin or silica, PDGF-D was down-regulated, which correlates with the production of TGFβ and other fibrotic growth factors. In conclusion, the down-regulation of PDGF-D by TGFβ and other growth factors may serve as a negative feedback in the network of cytokines that control fibrosis. 相似文献
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Katerina Batsalova Kostadin Kunchev Yana Popova Annie Kozhukharova Nadezhda Kirova 《Applied microbiology and biotechnology》1987,26(3):227-230
Summary Fungal -galactosidase was immobilized in polyvinylalcohol gel formed in pores of contton material. Temperature and pH effects on the activity of free and immobilized enzymes were studied. The optimum temperatures of free and immobilized enzymes were 60° C and 55° C respectively. The pH optimum ranged from 4.5 to 5.0 for both enzymes. The thermal stability of the immobilized -galactosidase was slightly higher. The Km values for soluble and immobilized enzymes were respectively 1.9 mM and 2.5 mM. The optimization of conditions for a highly effective hydrolysis of 4% lactose solution and reusability of the immobilized enzyme resulted in 75% hydrolysis after 5–6 h. The degree of conversion decreased to 50% after 30 repeated runs. The capacity of the immobilized enzyme to hydrolyze lactose in whey was also studied. 相似文献
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《Life sciences》1995,58(5):PL87-PL96
Pycnogenol® is a commercial mixture of bioflavonoids that exhibits antioxidative activity. The effects of dietary pycnogenol on immune dysfunction in normal mice as well as those fed ethanol or infected with the LP-BM5 murine retrovirus were determined. The ethanol consumption and retrovirus infection cause abnormalities in the function and/or structure of a broad array of cells involved in humoral and cellular immunity. Pycnogenol enhanced in vitro IL-2 production by mitogen-stimulated splenocytes if its production was suppressed in ethanolfed or retrovirus-infected mice. Mitogenesis of splenocytes did not show a significant change in mice treated with pycnogenol. It reduced the elevated levels of interleukin-6 produced in vitro by cells from retrovirus infected mice and IL-10 secreted by spleen cells from mice consuming ethanol. Natural killer cell cytotoxicity was increased with pycnogenol treatment. 相似文献
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Summary Production of galacto-oligosaccharide (GO), including trisaccharide and tetrasaccharide, was performed using a -galactosidase in water-hydrophobic solvent mixtures. A maximum GO concentration of 45% (w/w) was attained in a 95% cyclohexane/5% water mixture from a 55% (w/w) of lactose at 60°C and pH 6.0, while a maximum of 38% GO in aqueous media. GO production decreased with an increase in surfactant concentration. The optimum water content for GO production showed a broad range from 2.5 to 10% (v/v). Solvent properties, such as log P and the dipole moment, had no relation to GO production. 相似文献
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Hiroyuki Nishimura Akio Asahi Kazuya Fujiwara Junya Mizutani Yataro Obata 《Bioscience, biotechnology, and biochemistry》2013,77(12):1831-1835
The effect of γ-irradiation on the flavor of Onions (Senshu Yellow) associated with sprout-inhibition has been investigated. The relative amounts of propionaldehyde, n-propyl mercaptan and di-n-propyl disulfide in onions stored for 0, 5, 10, 20 and 30 days, respectively, after irradiation were estimated by measurement of peak areas of gas chromatograms. It was observed that the lachrymatory character and the pungent flavor had been decreased by γ-irradiation (remarkably at 70 and 700 Krads). In this connection, the amounts of propionaldehyde and di-n-propyl disulfide were decreased with increasing radiation dose and storage period at room temperature (20 to 25°C) and at low temperature (4°C). Moreover, it was observed that the sweetness had been decreased by γ-irradiation, but the amount of n-propyl mercaptan was increased with radiation dose and storage period. Therefore it seems that there is no correlation between the sweetness of onion and the amount of n-propyl mercaptan. 相似文献
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Cheng C Qin Y Shao X Wang H Gao Y Cheng M Shen A 《Cellular and molecular neurobiology》2007,27(7):909-921
Mitogen-activated protein kinases (MAPKs) are important mediators of cytokine expression and are critically involved in the
immune response. The lipopolysaccharide (LPS) of gram-negative bacteria induces the expression of cytokines and proinflammatory
genes via the toll-like receptor 4 (TLR4) signaling pathway in diverse cell types. In vivo, Schwann cells (SCs) at the site
of injury may also produce tumor necrosis factor-- α (TNF-α). However, the precise mechanisms of TNF-α synthesis are still
not clear. The purpose of the present study was to elucidate the underlying molecular mechanisms in the cultured SCs for its
ability to activate the MAPKs and TNF-α gene, in response to LPS. Using enzyme-linked immunosorbent assay (ELISA), it was
confirmed that treatment with LPS stimulated the synthesis of TNF-α in a concentration- and time-dependent manner. Intracellular
location of TNF-α was detected under confocal microscope. Moreover, LPS activated extracellular signal-regulated kinase (ERK1/2),
P38 and stress activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) and induced their phosphorylation. LPS-elicited
SCs TNF-α production was also drastically suppressed by PD98059 (ERK inhibitor), SB202190 (P38 inhibitor), or SP600125 (SAPK/JNK
inhibitor). Additionally, the expression of CD14 and TLR4 was examined by RT–PCR. It was demonstrated that the expression
of CD14, TLR4 was crucial for the SCs responses to LPS. In conclusion, the results provide novel mechanisms for the response
of SCs to LPS stimulation, through MAPKs signaling pathways.
Chun Cheng and Yongwei Qin contributed equally to this work. 相似文献