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1.
Walter Oettmeier 《Photosynthesis research》2009,100(3):125-127
In this tribute, I offer my best wishes to Achim Trebst on his 80th birthday on June 9, 2009. At the invitation of Govindjee,
I present here a perspective of some of our joint research during 1970s through 2000s. 相似文献
2.
Shortleaf pine (n = 93) and loblolly pine (n = 112) trees representing 22 seed sources or 16 physiographic populations were sampled from Southwide Southern Pine Seed
Source Study plantings located in Oklahoma, Arkansas, and Mississippi. The sampled trees were grown from shortleaf pine and
loblolly pine seeds formed in 1951 and 1952, prior to the start of intensive forest management across their native ranges.
Amplification fragment length polymorphism (AFLP) markers were developed and used to study genetic diversity and its structure
in these pine species. After screening 48 primer pairs, 17 and 21 pairs were selected that produced 794 and 647 AFLPs in shortleaf
pine and loblolly pine, respectively. High-AFLP-based genetic diversity exists within shortleaf pine and loblolly pine, and
most (84.73% in shortleaf pine; 87.69% in loblolly pine) of this diversity is maintained within physiographic populations.
The high value of unbiased measures of genetic identity and low value of genetic distance for all pairwise comparisons indicates
that the populations have similar genetic structures. For shortleaf pine, there was no significant correlation between geographic
distance and genetic distance (r = 0.28), while for loblolly pine there was a weak but significant correlation (r = 0.51). 相似文献
3.
This research compared the binding and release of recombinant human bone morphogenetic protein 2 (rhBMP-2) with a series of
hydrophobic and hydrophilic poly-lactide-co-glycolide (PLGA) copolymers. Porous microspheres were produced via a double emulsion
process. Binding and incorporation of protein were achieved by soaking microspheres in buffered protein solutions, filtering,
and comparing protein concentration remaining to nonmicrosphere-containing samples. Protein release was determined by soaking
bound microspheres in a physiological buffer and measuring protein concentration (by reversed-phase high-performance liquid
chromatography) in solution over time. Normalized for specific surface area and paired by polymer molecular weight. microspheres
made from hydrophilic 50∶50 or 75∶25 PLGA bound significantly more protein than microspheres made from the corresponding hydrophobic
PLGA. Increased binding capacity correlated with higher polymer acid values. With certain polymers, rhBMP-2 adsorption was
decreased or inhibited at high protein concentration, but protein loading could be enhanced by increasing the protein solution:PLGA
(volume:mass) ratio or by repetitive soaking. Microspheres of various PLGAs released unbound protein in 3 days, whereas the
subsequent bound protein release corresponded to mass loss. RhBMP-2 binding to PLGA was controlled by the acid value, protein
concentration, and adsorption technique. The protein released in 2 phases: the first occurred over 3 days regardless of PLGA
used and emanated from unbound, incorporated protein, while the second was controlled by mass loss and therefore was dependent
on the polymer molecular weight. Overall, control of rhBMP-2 delivery is achievable by selection of PLGA microsphere carriers.
Published: October, 7, 2001. 相似文献
4.
5.
Wang J Ohmuraya M Hirota M Baba H Zhao G Takeya M Araki K Yamamura K 《Histochemistry and cell biology》2008,130(2):387-397
Recent evidence shows that the serine protease inhibitor Kazal type 3 (Spink3) has more diverse functions than expected. To gain insight into its function, we analyzed the spatiotemporal expression profile of Spink3, using in situ hybridization (ISH) and a Spink3 ( +/lacZ ) knock-in mouse, in which lacZ was inserted into the Spink3 locus. Spink3 ( lacZ ) expression was first observed in the foregut, midgut, hindgut and the forebrain/midbrain junction region at 9.5 days post coitus (dpc). In the pancreas, Spink3 mRNA was detected at 11.5 dpc, before formation of the typical shape of the exocrine structure of the pancreas. Acinar cell expression was clearly identified by 13.5 dpc. After differentiation of the intestinal tract, Spink3 ( lacZ ) expression was observed in the large intestine at 11.5 dpc, followed by expression in the small intestine at 13.5 dpc, before appearance of intestinal digestive enzymes. Spink3 mRNA and Spink3 ( lacZ ) activity were also detected in other tissues, including the mesonephric tubules and the urogenital ridge at 11.5 dpc, the genital swelling at 13.5 dpc, the ductus epididymis at 17.5 dpc, and the seminal vesicle at 8 weeks. These data suggest that Spink3 may play important roles in proliferation and/or differentiation of various cell types during development. 相似文献
6.
We investigated the optimal levels of growth regulators, culture media, and pH on callus growth and organogenesis of in-vitro
cultured ‘Kyoho’ grapes. Calli were induced by culturing leaf blades on an MS basal medium supplemented with 1 mg/IL BA and
0.01 mg/L 2,4-D. In addition, calli originating from the exocarp and mesocarp of grape fruits devel-oped on MS media supplemented
with 0.1 mg/L IAA, NAA, or 2,4-D, or with 0.2 mg/L BA. In testing the potential for plant regeneration from shoot tips on
various media, we found that the Nitsch medium, with I mg/L BA, was optimal for caulogenesis. The type of shoot development
depended on the pH of the medium, with vigorous multiple-shoot devel-opment occurring at pH 6.0, and single shoots forming
at pH 5.0. Finally, we were able to obtain rooted seedlings from the regenerated shoots that had been cultured on 1/4-strength
Nitsch medium supplemented with 0.03 mg/L NAA. 相似文献
7.
8.
The purpose of this study was to determine the effects of cell-specific mental imagery on neutrophil and lymphocyte cell counts. Subjects (N=30) were randomly assigned to one of two experimental groups that underwent a 6-week training program focusing on images of morphology, location, and movement of either neutrophils or lymphocytes. Music was used to enhance the imagery of the subjects. Peripheral white blood cell and differential counts were determined before and after the final 20-minute imagery session. Results indicated that neutrophils decreased significantly (p<.04) in the neutrophil-change group while lymphocytes did not. The reverse occurred in the lymphocyte-change group, with only the lymphocytes decreasing significantly (p<.03). The authors concluded that under the conditions of the present study, cell-specific imagery was associated with decreases in peripheral blood cell counts of lymphocytes and neutrophils. 相似文献
9.
GAO George Fu 《中国科学:生命科学英文版》2009,52(5):470-473
Highly pathogenic influenza A virus H5N1 has spread out worldwide and raised the public concerns. This increased the output
of influenza virus sequence data as well as the research publication and other reports. In order to fight against H5N1 avian
flu in a comprehensive way, we designed and started to set up the Website for Avian Flu Information () from 2004. Other than the influenza virus database available, the website is aiming to integrate diversified information
for both researchers and the public. From 2004 to 2009, we collected information from all aspects, i.e. reports of outbreaks,
scientific publications and editorials, policies for prevention, medicines and vaccines, clinic and diagnosis. Except for
publications, all information is in Chinese. Till April 15, 2009, the cumulative news entries had been over 2000 and research
papers were approaching 5000. By using the curated data from Influenza Virus Resource, we have set up an influenza virus sequence
database and a bioinformatic platform, providing the basic functions for the sequence analysis of influenza virus. We will
focus on the collection of experimental data and results as well as the integration of the data from the geological information
system and avian influenza epidemiology.
Contributed equally to this work
Special Project of Informatization of Chinese Academy of Sciences in “the Eleventh Five-Year Plan”, E-Science Application
of Research on Resources, Disease Monitoring and Risk Assessment of Important Wild Birds in Qinghai Lake Region (Grant No.
INFO-115-D02), China International Science and Technology Cooperation of the Ministry of Science and Technology, China (MOST)
(Grant Nos. 2006DFB32010 and 2007DFC30240), MOST Grant 2005CB523001 (Program 973), National Key Technologies Research & Development
Program (Grant 2006BAD06A01), and a grant from NIH (Grant No. 3 U19 AI051915-05S1), the China Post-doctor fellowship (Grant
No. 20070420542). 相似文献
10.
Protein-tyrosine phosphatases (PTPases) have a catalytic cysteine residue whose reduced state is integral to the reaction
mechanism. Since exposure to air can artifactually oxidize this highly reactive thiol, PTPase assays have typically used potent
reducing agents to reactivate the enzymes present; however, this approach does not allow for the measurement of the endogenous
PTPase activity directly isolated from the in vivo cellular environment. Here we provide a method for using an anaerobic chamber to preserve the activity of the total PTPase
complement in a tissue lysate or of an immunoprecipitated PTPase homolog to characterize their endogenous activation state.
Comparison with a sample treated with biochemical reducing agents allows the determination of the activatable (reducible)
fraction of the endogenous PTPase pool.
Published: June 11, 2002. 相似文献
11.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1425-1429
The protective effect of dietary l-glutamine against the hepatotoxic action of d-galactosamine (GalN) was investigated by model experiments with rats. Rats fed with 20% casein diets containing 10% free amino acids were injected with GalN, and the serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase activities and the hepatic glycogen content were assayed 20 hours after the injection. These enzyme activities in the group fed with the 10% l-glutamine diet for 8 days were lower than those in the groups fed with the control, 10% l-glutamic acid and 10% l-alanine diets for 8 days. The more prolonged the feeding period with the 10% l-glutamine diet was, the more the serum activity levels of such enzymes were decreased. Although neomycin also lowered these enzyme activities, its simultaneous ingestion with neomycin did not show any additive or synergistic effect. The hepatic glycogen content in the 10% glutamine group still remained high after the GalN treatment. It is therefore assumed that the effectiveness of glutamine intake would have been mediated by glycogen metabolism rather than by uridine metabolism. 相似文献
12.
Shangang Li Yi Guo Jianjun Shi Chunguang Yin Fengying Xing Lingyang Xu Chuanshan Zhang Tao Liu Yao Li Hongbin Li Lixin Du Xuejin Chen 《Transgenic research》2009,18(2):227-235
Live rabbits have previously been generated through nuclear transfer using adult cells as nuclear donors. We demonstrated
in this study that transfected adult rabbit fibroblasts are also capable of supporting full-term development. The fibroblasts
were transfected with a pEGFP-C1 plasmid using lipofectamine™ 2000, and the transgenic cells were derived from conditioned medium. The transgenic fibroblasts were cultured until confluent
and then serum-starved prior to be used as nuclear donors. After nuclear transfer and activation, 22% (12/55) of the transgenic
cloned embryos developed to the blastocyst stage. A total of 114 embryos at the 4- to 8-cell stage were transferred to the
oviducts of 8 pseudo-pregnant mothers; 5 of these animals became pregnant, and 3 of the 5 mother rabbits carried the pregnancy
to term. Caesarean section was performed on the 3 pregnant mothers, yielding 4 kits, one of which has survived for more than
9 months. Green fluorescence could be detected in the toenails of the living cloned rabbit and the offspring from the living
cloned rabbit under ultraviolet light. DNA analyses confirmed that all 4 cloned rabbits were genetically identical to the
transgenic donor cells, and that they all carried the EGFP gene. The present study demonstrated that transgenic rabbits can
be generated through nuclear transfer. These results may facilitate future developments in the genetic engineering of rabbits. 相似文献
13.
We have isolated a cDNA clone for the antifungal protein,CaAFP, from hot pepper,Capsicum annuum L. Its open reading frame encodes 85 amino acids, including 8 cysteine residues. CaAFP consists of three domains: a signal
peptide, a chitin-binding domain, and a C-terminal peptide domain. The deduced amino acid sequence of the chitin-binding domain
shows 92% and 85% similarity to the same domain from PnAMPs and hevein, respectively. Southern blot analysis indicated that
CaAFP is present as a single copy, while the northern blots revealed that the clone is highly expressed in the leaves and
flower buds, but not in the roots. However, wounding treatments and chemicals generally known to induce PR proteins did not
stimulate its expression.In situ hybridization also showed that CaAFP is expressed in the parenchyma cells of the floral sepals. As seen in our functional
analysis, this clone was expressed inEscherichia coli, and the fusion protein was purified using nickel-affinity column chromatography. This purified AFP fusion protein inhibited
spore germination and appressoria formation in several plant pathogenic fungi, includingFusarium oxisporum andColletotrichum gloeosporioides. Our results suggest CaAFP is an antifungal protein that defends developing seeds against pathogen invasion while also having
a specific biological role during floral development. 相似文献
14.
In proteins, some processes require conformational changes involving structural domain diffusion. Among these processes are
protein folding, unfolding and enzyme catalysis. During catalysis some enzymes undergo large conformational changes as they
progress through the catalytic cycle. According to Kramers theory, solvent viscosity results in friction against proteins
in solution, and this should result in decreased motion, inhibiting catalysis in motile enzymes. Solution viscosity was increased
by adding increasing concentrations of glycerol, sucrose and trehalose, resulting in a decrease in the reaction rate of the
H+-ATPase from the plasma membrane ofKluyveromyces lactis. A direct correlation was found between viscosity (η) and the inhibition of the maximum rate of catalysis (V
max). The protocol used to measure viscosity by means of a falling ball type viscometer is described, together with the determination
of enzyme kinetics and the application of Kramers’ equation to evaluate the effect of viscosity on the rate of ATP hydrolysis
by the H+-ATPase.
Published: May 1, 2003 相似文献
15.
B. Sorkin 《Historical Biology》2013,25(4):375-388
Giant bear-dogs of the genera Amphicyon and Ischyrocyon (Carnivora, Amphicyonidae, Amphicyoninae) were the largest carnivorans in North America during middle and late Miocene (17.5–8.8 Mya) with a dental and skeletal morphology that combined features found in living Ursidae, Canidae, and Felidae. This study tests previously proposed models of diet and hunting behaviour of these extinct carnivorans. Relative grinding area (RGA) of lower molars and wear pattern on upper molars suggest that bear-dogs were carnivorous. Amphicyon and Ischyrocyon possessed skeletal features of both ambush (short distal limb segments) and pursuit (caudally bent olecranon process of ulna) living predators. Therefore, bear-dogs probably pursued their prey (mediportal ungulates) for a longer distance but at a slower speed than do living ambush predators. Upon catching up to its prey a bear-dog probably seized it with powerfully muscled forelimbs and killed it by tearing into its ribcage or neck with canines set in a narrow rostrum. 相似文献
16.
Effect of osmotic stress on transpiration and absorption rates in triticale and its parental species
In triticale and its parental species, the application of a root osmotic stress induced either a transient increase or an
immediate decrease in transpiration rate. The response of wheat (Trticum dicoccum farrum) proved to depend on relative humidity of air. In rye (Secale cerealecv. Petkus) and triticale (T. 300) the effect of NaCl stress was less expressive, than the effect of PEG. 相似文献
17.
We have investigated the effects of cadmium on the microtubular (MT) cytoskeleton in the root tip cells of Allium sativum L. using indirect immunofluorescence microscopy. Cd affected the mechanisms controlling the organization of MT cytoskeleton,
as well as tubulin assembly/disassembly processes. Cd induced the formation of abnormal MT arrays, consisting of discontinuous
wavy MTs or short MT fragments at the cell periphery. Cadmium caused irregular nuclear disorder in cells where the MT organization
and function was disturbed. Furthermore, with increased Cd concentration and duration of treatment the MTs depolymerized more
severely, the frequency of abnormal cell increased and the mitotic index decreased progressively. The above findings showed
that MT cytoskeleton is one of target sites of Cd toxicity in root tip cells. 相似文献
18.
Abstract The terrestrial orchid, Orchis pauciflora Ten., growing in poor grassland and garrigue of Central Mediterranean region, is local and rare and has been included in the red lists of several Italian regions. We investigated the diversity of fungal associates in O. pauciflora adult plants collected in two protected areas of Tuscany (Central Italy). Genomic DNA was extracted from mycorrhizal roots of 12 orchid plants and the fungal ITS were amplified and sequenced. Several fungal associates, belonging to different taxa of basidiomycetes (Tulasnellaceae) and ascomycetes such as Leptodontidium, Exophiala and Phialophora species, were recovered. The trophic role of these fungi and their impact on O. pauciflora growth and conservation are discussed. 相似文献
19.
Protein phosphorylation and dephosphorylation are major regulatory mechanisms that cells use to transmit signals from their
extracellular environment to the interior. Up to now, two structurally distinct groups of ser/thr phos-phatases are known
of: the PP1/PP2A family and the PP2C family. Here, we focus our efforts to reveal the functions of the PP2C family in rice.
It has been known that PP2C has diverse functions related to developments and stress responses. We have obtained a rice EST
clone, OsPP2C4, that contained the highly conserved PP2C motifs. RNA gel-blot analysis showed that OsPP2C4 was expressed highly
in panicles, while it was expressed weakly in seedling leaves, seedling roots, and mature leaves. Assay of the PP2C enzyme
activity with a substrate, para-nitrophenyl phosphate, showed that OsPP2C4 encoded an active PP2C. Transgenic plants expressing
the antisense construct of this clone were generated to study the functional roles of the PP2C clone in rice. 相似文献
20.
L. Jaakola J. J. Koskimäki K. R. Riihinen A. Tolvanen A. Hohtola 《Biologia Plantarum》2008,52(2):391-395
The influence of artificial wounding on biosynthesis of flavonoids and hydroxycinnamic acids was studied in bilberry leaves
using two separate wounding experiments. In the first experiment bilberry leaves were wounded by cutting. The expression of
the first gene from flavonoid pathway, chalcone synthase (CHS) and a wound induced pathogenesis related PR-10 gene was analysed from samples collected immediately and after 3, 6, 24 h and 4 d from the wounding treatment. In the second
experiment annual shoots were removed. Proanthocyanidins, flavonol glycosides and hydroxycinnamic acids were quantified in
leaf samples after 0–5 d (experiment 1) and 5 weeks (experiment 2) from the treatment. In the first experiment, no change
was observed in the expression of CHS whereas increase in expression of PR-10 gene was detected after 6 h of wounding treatment. In both experiments, the contents of flavonol glycosides and hydroxycinnamic
acids were not influenced by the wounding treatment and the contents of proanthocyanidins were decreased. 相似文献