Authentication email has already been sent, please check your email box: and activate it as soon as possible.
You can login to My Profile and manage your email alerts.
If you haven’t received the email, please:
|
|
There are 493 papers published in subject: since this site started. |
Select Subject |
Select/Unselect all | For Selected Papers |
Saved Papers
Please enter a name for this paper to be shown in your personalized Saved Papers list
|
1. Early chronic blockade of NR2B subunits and transient activation of NMDA receptors modulates LTP in mouse auditory cortex | |||
Yuting Mao,Shaoyun Zang,Jiping Zhang,Xinde Sun | |||
Biology 31 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:In the auditory cortex, the properties of NMDA receptors depend primarily on the ratio of NR2A and NR2B subunits. NR2B subunit expression is high at the beginning of critical period and lower in adulthood. Because NMDA receptors are crucial intriggering long-term potentiation (LTP) and long-term depression, developmental or experience-dependent modification of NMDAR subunit composition is likely to influence synaptic plasticity. To examine how NMDA subunit change duing postnatal development affect the adult synaptic plasticity, we employed chronic ifenprodil blockade of NR2B subunits and analyzed evoked field potentials in adult C57BL/6 mice auditory cortex (AC). We found that chronic loss of NR2B activity led to adecline in LTP magnitude in the AC of adult mice. Adding NMDA to the artificial cerebrospinal fluid (ACSF) in blocked mice had the opposite effect, producing LTP magnitudes at or exceeding those found in treated or untreated animals. These results suggest that even in adulthood when NR2B expression is downregulated, these receptor subunits play an important role in experience-dependent plasticity of mouse auditory cortex. Blockade from P60 did not result in any decrease of LTP amplitude,suggesting that chronic block in postnatal period may permanently affect cortical circuits so that they cannot produce significant LTP in adulthood. | |||
TO cite this article:Yuting Mao,Shaoyun Zang,Jiping Zhang, et al. Early chronic blockade of NR2B subunits and transient activation of NMDA receptors modulates LTP in mouse auditory cortex[OL].[31 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4820 |
2. A Threonine(27)-to-Proline(27) substitution in the signal peptide of Iron oxidase of Acidithiobacillus ferrooxidans decreases iron oxidation capacity | |||
penghong,yangyu,qiuguanzhou,Yuehua HU | |||
Biology 30 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:Two wild type strains of Acidithiobacillus ferrooxidans, which were called CMS and YTW respectively, were isolated from low-grade copper ores in China. The data of iron oxidation and growth rates shows that strain YTW was much lower iron oxidation capacity and longer generation time than strain CMS. To reveal these heterogeneous phenotypic characters, the iro gene encoding Iron oxidase, which catalyzed the first step of iron oxidation metabolism system, was amplified by PCR and sequenced for both strains. Sequence alignment showed that there was a Threonine(27) -to- Proline(27) substitution in the signal peptide of Iron oxidase for strain YTW. The protein secondary structure predicted that the substitution made a loop among the residue 26, 27 and 28. This substitution may affect the location and interaction of Iron oxidase in cellular membrane. The results implied that Proline(27) substitution in the signal peptide of Iron oxidase may be an important factor for heterogeneous iron oxidation capacity of iron oxidation metabolism system. Key words: Acidithiobacillus ferrooxidans; Iron oxidase; Signal peptide; Proline | |||
TO cite this article:penghong,yangyu,qiuguanzhou, et al. A Threonine(27)-to-Proline(27) substitution in the signal peptide of Iron oxidase of Acidithiobacillus ferrooxidans decreases iron oxidation capacity[OL].[30 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4803 |
3. Identification of diurnal and circadian candidate genes in rice by using cDNA array | |||
Feng Zhang,Haitao Dong,Dean Jiang,Debao Li | |||
Biology 30 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:cDNA array containing 5837 rice unique genes was used to explore gene expression patterns at 4 h intervals throughout a day. It was found that there were 190 genes with diurnal changes, of which 170 genes could change in circadian manner. Analysis of those genes showed that circadian clock played a key role in coordination of many physiological processes such as glycolysis, water and mineral elements transport. By clustering diurnal change genes from cDNA data, we found 10 clusters with different expression patterns. | |||
TO cite this article:Feng Zhang,Haitao Dong,Dean Jiang, et al. Identification of diurnal and circadian candidate genes in rice by using cDNA array[OL].[30 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4787 |
4. Antisense Inhibition of Rubisco Activase Increases Rubisco Content and Alters the Proportion of Rubisco Activase in Stoma and Thylakoids in Chloroplasts of Rice Leaves | |||
Songheng Jin,Jian Hong,Xueqin Li,Dean Jiang | |||
Biology 30 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubsico) activase (RCA) is a nuclear-encoded chloroplast protein that modifies the conformation of Rubisco, releases inhibitors from the active sites, and increases enzymatic activity. It appears to have other functions, which are related to its distribution within the chloroplast. The aim of this research was to resolve uncertainty about the localization of RCA, and to determine whether the distributions of Rubisco and RCA were altered when RCA content was reduced. Gas exchange and Rubisco were measured, and the sub-cellular locations of Rubisco and RCA were determined using immunogold-labeling electron microscopy, in wild-type and antisense rca rice plants. Net photosynthetic rate and the initial Rubisco activity in the antisense rca plants decreased much less than RCA content in the antisense plants. Immunocytolocalization showed that Rubisco in wild-type and antisense plants was localized in the stroma of chloroplasts. However, the amount of Rubisco in the antisense rca plants was greater than in the wild type plants. RCA was detected in both the stroma and in the thylakoid membranes of wild-type plants. We show that the percentage of RCA labeling in the thylakoid membrane was substantially decreased, while the fraction in the stroma was increased, by the antisense rca treatment. From the changes in RCA distribution and alterations in Rubisco activity, RCA in stroma of chloroplast probably contributes to the activation of Rubisco, and RCA in thylakoids compensates for the reduction of RCA in the stroma, allowing steady-state photosynthesis to be maintained when RCA is depleted. RCA may also have a second role in protecting membranes against environmental stresses as a chaperone. | |||
TO cite this article:Songheng Jin,Jian Hong,Xueqin Li, et al. Antisense Inhibition of Rubisco Activase Increases Rubisco Content and Alters the Proportion of Rubisco Activase in Stoma and Thylakoids in Chloroplasts of Rice Leaves[OL].[30 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4775 |
5. An improved predictive assay for radiotherapy to human hepatoma measured by prematurely chromosome condensation technique | |||
Yang Jianshe | |||
Biology 28 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:To investigate the radiation response of hepatoma, SMMC-7721 cells were irradiated with 60Co γ-rays. Initial chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks. A dose-dependent increase in radiation-induced chromatid/isochromatid breaks was observed in G1 and G2 phase respectively. A good relationship was found between cell survival and chromatin breaks. This study implied that low LET radiation-induced chromatid/isochromatid breaks can be possibly used as a good predictor of radiosensitivity of SMMC-7721 hepatoma cells. | |||
TO cite this article:Yang Jianshe. An improved predictive assay for radiotherapy to human hepatoma measured by prematurely chromosome condensation technique[OL].[28 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4728 |
6. Fusion Expression and Purification of Escherichia coli Oligopeptidase B | |||
Yan Jianbin,Jiang Xue-yuan | |||
Biology 22 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:Oligopeptidase B (OpdB) of Escherichia coli, previously called protease Ⅱ, has a trypsin-like specificity, cleaving peptides at lysine and arginine residues and belongs to the prolyl oligopeptidase family of new serine peptidases. In this study, we report the fusion expression of E. coli oligopeptidase B with an N-terminal histidine tag using pET28a as the expression vector. The homogeneity and activity of the purified OpdB were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzymatic activity assay, respectively. We also compared the substrate specificity of the purified OpdB for some synthetic trypsin substrates with those of OpdA, another trypsin-like protease in E. coli. The availability of large amount of the recombinant OpdB will facilitate the biological functional study of this enzyme. | |||
TO cite this article:Yan Jianbin,Jiang Xue-yuan. Fusion Expression and Purification of Escherichia coli Oligopeptidase B[OL].[22 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4573 |
7. Visualization of dynamic correlation among neuron population | |||
Yi Zhou,Ai-hua Chen,Xin Jin,Pei-Ji Liang | |||
Biology 21 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:A method for visualization of dynamic correlations among multi-neurons is introduced here. Dynamic correlations of multi neurons can be displayed in a simple and clear manner. The correlation histogram and the conventional gravity transform are presented to compare with this approved method. Simulated spike trains based on an I-F model were used for evaluation. | |||
TO cite this article:Yi Zhou,Ai-hua Chen,Xin Jin, et al. Visualization of dynamic correlation among neuron population[OL].[21 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4526 |
8. Transgenic rice plants expressing rice dwarf virus outer coat protein gene (S8) are moderately resistant to virus infection | |||
Zheng Honghong,Wei Chunhong,Chen Shengxiang,Chen Zhangliang,Y. Li | |||
Biology 19 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:We have previously obtained transgenic rice plants (Oryza sativa L.) containing S8 gene which encodes the outer coat protein of the rice dwarf virus (RDV) by particle bombardment. In this study, it was confirmed that the S8 gene has been stably inherited and expressed in the selfed T1 and T2 progenies of the primary trangenic rice plant line T0-2. Virus resistance assays revealed that both T1 and T2 transgenic plants exhibited resistance to RDV infection, indicating stable transmission of the trait of resistance. This study is the first report about the Pathogen-derived resistance in rice dwarf virus, a member of phytoreovirus. | |||
TO cite this article:Zheng Honghong,Wei Chunhong,Chen Shengxiang, et al. Transgenic rice plants expressing rice dwarf virus outer coat protein gene (S8) are moderately resistant to virus infection[OL].[19 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4449 |
9. Probability model for the postflight fecundity | |||
Ming-Guang Feng,Chun Chen | |||
Biology 12 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:Flight dispersal enables aphids not only to locate suitable plants but disseminate obligate aphid-pathogenic fungi among hosts. To quantify postflight colonization and fecundity potential of pathogen-infected alates, several hundreds of Myzus persicae and Sitobion avenae alates were infected preflight by a common aphid pathogen Pandora neoaphidis, flown for 0.01-10.2 km in a flight mill system, and individually reared for their performance under laboratory conditions. Cumulative probabilities [P(m凾N)] for the counts of infected alates producing m nymphs per capita (m凾N) before they became mycosed and of those uninfected ones of each aphid species during the same period of colonization fit very well to the logistic model P(m凾N) =1/[1+exp(a+rm)] (r2刣0.98), yielding a solution to the probability of the alates with a specific fecundity, pm=P(m凾N) | |||
TO cite this article:Ming-Guang Feng,Chun Chen. Probability model for the postflight fecundity [OL].[12 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4291 |
10. Reparatory Effects of Nicotine on NMDA Receptor-mediated Synaptic Plasticity in the Hippocampal CA1 Region of Chronically Lead-exposed Rats | |||
Wang Huili,Ruan Di-yun | |||
Biology 05 December 2005 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:Activation of neuronal nicotinic acetylcholine receptors (nAChRs) modulates the induction of long-term potentiation (LTP), one of the possible cellular mechanisms for learning. To investigate the effect of nicotine on synaptic plasticity in chronically lead-exposed rats, field excitatory postsynaptic potentials (fEPSPs) and paired-pulse facilitation (PPF) were recorded in the CA1 area of hippocampal slices from chronically lead-exposed rats of 23-30 days old. The results showed that: (1) 1μM nicotine facilitated the induction of LTP in CA1 area of the hippocampus by a weak tetanic stimulation (100 Hz, 20 Pulses), which does not by itself produce LTP in lead-exposed rats. This effect was significantly suppressed by mecamylamine (MEC), a nonselective nicotinic antagonist, suggesting that the facilitation of LTP was through nAChRs. (2) The nicotine-mediated LTP was blocked by dihydro-β-erythroidine (DhβE), a non-α7 nAChR antagonist, while long-term depression (LTD) produced by the combination of nicotine and methyllycaconitine (MLA), a α7-nAChR antagonist and neither LTP nor LTD observed by the combination of nicotine, MLA and DHβE. It implied that several nAChRs subtypes were involved in the nicotine-mediated synaptic plasticity. (3) Nicotine enhanced PPF in hippocampal CA1 region, and the nicotine-mediated LTP in lead-exposed rats was blocked by either D-(-)-2-amino-5-phosphonopentanoic acid (D-AP5), the NMDAs receptor antagonist, or picrotoxin (PTX), an antagonist of γ-aminobutyric acid (GABA)A receptor. It suggested that nicotine-mediated synaptic plasticity was due to the activation of NMDARs by disinhibition of pyramidal cells through presynaptic nAChRs. This may represent the cellular basis of nicotine-mediated cognitive enhancement observed in chronically lead-exposed rats. | |||
TO cite this article:Wang Huili,Ruan Di-yun. Reparatory Effects of Nicotine on NMDA Receptor-mediated Synaptic Plasticity in the Hippocampal CA1 Region of Chronically Lead-exposed Rats[OL].[ 5 December 2005] http://en.paper.edu.cn/en_releasepaper/content/4077 |
Select/Unselect all | For Selected Papers |
Saved Papers
Please enter a name for this paper to be shown in your personalized Saved Papers list
|
|
About Sciencepaper Online | Privacy Policy | Terms & Conditions | Contact Us
© 2003-2012 Sciencepaper Online. unless otherwise stated