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This paper studied the effects of Ca(2+) -carrier A23187 and Ca(2+) -chelator EGTA on the bud differentiation of cut flower chrysanthemum (Dendranthema grandiflorium 'Shenma') under photoperiodic induction, as well as the Ca2+ distribution and the sucrose, soluble sugar, and starch contents in 'Shenma' leaves during the differentiation. In the control, the leaf Ca2+ content was lower at the vegetative stage of apical bud (I), increased rapidly and reached a peak at the stage of initial differentiation (II), and decreased then. At stage I, the Ca2+ was mainly allocated in vacuole, cell wall, and cell lacuna; while at stage II, it was more in cytoplasm. Compared with the control, the leaf Ca2+ content of A23187-treated plants increased significantly, and the days of initiation and ending of bud differentiation were advanced by 2 days and 3 days, respectively. On the other hand, the leaf Ca2+ content of EGTA-treated plants decreased significantly, and the days of initiation and ending of bud differentiation were postponed by 4 days and 8 days, respectively. For both A23187- and EGTA-treated plants, their leaf Ca2+ at stage II was more allocated in cytoplasm. The leaf sucrose and soluble sugar contents of A23187-treated plants reached a peak on the 2nd day after treatment, and the time to reach the peak was shortened by 2 days, compared with the control, which was consistent with the peak time of Ca2+. The leaf sucrose and soluble sugar contents of EGTA-treated plants had no significant changes on the 2nd day of treatment, but increased rapidly and reached the peak on the 8th day of treatment (stage II), and then decreased. However, the leaf sucrose and soluble sugar contents during the whole period of bud differentiation were higher than those before photoperiodic induction. The leaf starch content of A23187-treated plants and the control decreased 2 days after treatment, while that of EGTA-treated plants began to decrease 8 days after treatment, and maintained at a lower level by the end of bud differentiation. The results indicated that Ca2+ and carbohydrates participated in the flower formation of chrysanthemum under photoperiodic induction.

In this study, cucumber seedlings were cultivated in nutrient solution added with different concentration (0.05, 0.1, 0.2, and 0.3 mmol x L(-1)) sodium nitroprusside (SNP) as nitric oxide (NO) donor to study the effects of exogenous NO on the growth of cucumber seedlings and the activities of antioxidant enzymes in cucumber leaves under NO3- stress. Under the stress of 140 mmol x L(-1) NO3-, treating with 0.1 mmol x L(-1) of SNP for 1 d or 7 d increased the leaf soluble protein content and superoxidase (SOD), catalase (CAT), and ascorbic acid peroxidase (APX) activities, and decreased the leaf malondialdehyde (MDA) content significantly, suggesting that exogenous NO could enhance the capacity of cucumber seedlings in scavenging active oxygen species, protect the seedlings from the peroxidation of membrane lipids, and promote the seedlings growth and increase their resistance to high concentration NO3- stress. After the cucumber seedlings grew in 0.3 mmol x L(-1) of SNP for 7 d, the activities of leaf SOD, POD, and CAT decreased, and the MDA content increased, resulting in the injury of cucumber seedlings. It was indicated that certain concentration (0.1-0.2 mmol x L(-1)) exogenous NO could alleviate the NO3- stress to cucumber seedlings.

A pot experiment was conducted to study the effects of rotation and fallowing on the microbial communities and enzyme activities in a greenhouse soil continuously cropped with cucumber and on the growth and yield of followed cucumber. Comparing with continuous cropping, rotation improved the components of soil microbial communities, which was manifested in the increase of bacteria and actinomycetes and the decrease of fungi. Rotation and fallowing enhanced the activities of soil invertase, urease, catalase, and polyphenol oxidase significantly. The quantities of soil bacteria and actinomycetes and the activity of soil invertase increased at the fruiting stage of cucumber plants, being the maximum at harvest stage, but decreased thereafter. In contrast, the quantity of soil fungi had a linear increase, and the activities of soil urease, catalase, and polyphenol oxidase decreased gradually during fruit development. Welsh onion and waxy maize promoted the growth and fruiting of the followed cucumber plants significantly, being the optimal rotation crops for cucumber.

By the method of hydroponic culture, this paper studied the alleviation effects of LaCl3 on the photosynthetic characteristics of cucumber seedlings under nitrate (140 mmol NO3(-) x L(-1)) stress, with the related mechanisms discussed. Under nitrate stress, the seedlings leaf chlorophyll and carotenoids contents decreased significantly, and the leaf Mg2+-ATPase, Ca2+-ATPase activities also decreased. On the 7th day of nitrate stress, the decrease of seedlings photosynthetic rate was mainly due to stomatal limitation; but on the 12th day of nitrate stress, the decrease was mainly due to no-stomatal limitation. Supplement with LaCl3 could make the cucumber seedlings keep relatively higher leaf Mg2+-ATPase and Ca2+-ATPase activities and chlorophyll and carotenoids contents, and applying 20 micromol x L(-1) of LaCl3 could increase the carotenoids content significantly. LaCl3 could also improve the leaf gas exchange, and alleviate the decrease of leaf Fv/Fm, PhiPSII, AQY, CE, and qp under nitrate stress, which helped the leaves making good use of light energy and maintaining higher CO2 assimilation capacity. An additional 20 micromol x L(-1) of LaCl3 could alleviate the nitrate stress on the photosynthesis of cucumber seedlings efficiently, but an additional 200 micromol x L(-1) of LaCl3 only had the alleviation effect at the initial period of nitrate stress. Our results could benefit to the improvement of greenhouse soil.

To examine whether the cell growth inhibitory effect of the combination of baicalin and baicalein is related to apoptosis. Moreover, to determine whether the expression of some apoptosis-related proteins is regulated by the ERK/p38 MAPK pathway.Cell viability was measured using a 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected by acridine orange (AO) staining, DNA ladder assay and flow cytometric analysis. Apoptosis-related proteins were observed using Western blot analysis.Compared with baicalin or baicalein alone, the combination treatment of baicalin (50 micromol/L) and baicalein (25 micromol/L) had an anti-proliferative effect in a time-dependent manner. Isobologram analysis demonstrated that the combination treatment had a synergistic effect. Moreover, apoptosis in MCF-7 cells was increased by 12% and 20% with the combination treatment at 24 h and 48 h, respectively. With the combination treatment in MCF-7 cells, cleaved caspase-3 and caspase-9 were observed, and the level of bcl-2 expression was decreased approximately 20% and 40% at 24 h and 48 h, respectively. The expression of bax and p53 were increased about 25% and 15% at 48 h, respectively. Moreover, the activation of caspase-3, -9 and the regulation of bcl-2, bax and p53 were related to ERK /p38 MAPK activation.In this study, apoptosis was enhanced by the combination treatment of baicalin and baicalein, which activated caspases-3 and caspase-9, downregulated the level of bcl-2 and upregulated the level of bax or p53 via the ERK/p38 MAPK pathway.

Invasion and metastasis are the basic characteristic of malignant tumor. It is the major cause of death in cancer patients. Preventing and suppressing tumor invasion and metastasis is a key pathway to decrease the mortality of malignant tumor. Since the limitations and the toxicity of chemotherapy, it was more and more attended to looking for safer and more effective agents from the Chinese herbal medicine to prevent and suppress metastasis. There are certain advantages in Chinese herbal medicine to suppressing tumor metastasis. The recent researches suggested new results that the Chinese herbal medicines treat tumor metastasis. This review summarized the research results in recent years and provides a reference for the further research.

Cut flower chrysanthemum (Dendranthema grandflora 'Jinba') plants were treated with 40 degrees C/35 degrees C or 33 degrees C/28 degrees C (day/night) for 11 days and then transferred to 23 degrees C/18 degrees C for 5 days to study the changes in their photosynthesis and fluorescence parameters under high temperature stress and normal temperature recovery. The results showed that on the 5th day of 33 degrees C/28 degrees C treatment, net photosynthesis (P(n)) decreased gradually and stomatal conductance (G(s)) decreased evidently; while after recovery for 5 days, both P(n) and G(s) resumed to 80% of the control. At 40 degrees C/35 degrees C, P(n) and G(s) decreased dramatically. The increase of intercellular CO2 concentration (C(i)) at the early stage under given high temperatures showed that the photosynthesis inhibition by high temperature stress was resulted from non-stomatal limitations. However, 9 days later, stomatal limitation became the mainly cause of photosynthesis inhibition. The intrinsic photochemical efficiency (F(v)/F(m)), quantum yield of PS II (phi(PS II), and the efficiency of excitation energy capture by open PS II reaction center (F(v)'/F(m)') at 33 degrees C/28 degrees C and 40 degrees C/35 degrees C all decreased, with antenna heat dissipation increased, indicating that reaction center was protected by decreased light capture and efficiency of electron transfer through PS II. The photochemical quenching (q(p)) at 33 degrees C/28 degrees C descended first and turned to rise then, suggesting that the electron transfer was firstly restrained by the stress. Contrastively, q(p) rose continuously at 40 degrees C/35 degrees C, indicating that oxygen-evolving complex (OEC) was the location in chrysanthemum photosynthesis apparatus most sensitive to extreme high temperature.

By a solution culture experiment, cucumber seedlings were treated with different concentration (0, 25, 50 and 75 mmol x L(-1)) NaCl and NaHCO3, and their physiological responses were studied. The results showed that with increasing NaCl and NaHCO3 stress, the shoot and root growth, the leaf chlorophyll content and relative water content of the seedlings decreased dramatically, and the decrements were greater under NaHCO3 than under NaCl stress. The shoot Na content increased significantly with increasing NaCl and NaHCO, stress, while shoot K+ content was in adverse. At the same concentration of Na+ in culture solution, the addition of NaHCO3 induced a greater decrement of shoot K+ content, and thus, a lower shoot K+/Na+ ratio. Under NaHCO3 stress, the leaf electrolyte leakage rate and the leaf MDA, proline, and soluble sugar contents increased much greater, compared with those under NaCl stress. Under NaCl and NaHCO3 stress, the leaf superoxide dismutase (SOD), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) activities were induced significantly, while the leaf peroxidase (POD) activity was inhibited obviously.

The study with water culture showed that nitrate stress had significant inhibitory effects on the plant growth, especially the shoot growth of cucumber seedlings. On the 7th day under nitrate stress, the shoot fresh mass per plant decreased by 12.77 g, leaf SOD, POD and CAT activities increased, while leaf APX, DHAR and GR activities decreased significantly, compared with the control. The addition of low concentration (0.05 mmol L(-1)) LaCl3 increased the shoot fresh mass per plant by 35%, enhanced the leaf thermally stable protein content and SOD, POD, CAT, APX, DHAR and GR activities, and decreased the leaf MDA content and electrolytic leakage, resulting in a definite alleviation of the inhibitory effects of nitrate. However, an addition of high concentration (0.5 mmol L(-1)) LaCl3 had no obvious alleviation effect. It was concluded that the addition of certain concentration LaCl3 could alleviate the nitrate stress on cucumber via increasing anti-oxidative enzymes activities and thermally stable protein content.

This paper studied the effects of different NO3- concentration on the photosynthetic rate, photochemical efficiency, and absorbed light energy allocation in cucumber seedling leaves. The results indicated that when the available NO3- concentration in the medium was low (14-98 mmol NO3- x L(-1)), an appropriate supplement of NO3- could enhance the capability of cucumber leaves in capturing light energy, and promote the photosynthesis. However, with further increase of NO3-, the photochemical efficiency of PS II decreased, electron transfer restrained, and net photosynthetic rate as well as the absorbed light energy used in photochemical reaction of PS II decreased. At the same time, the light energy used in antenna heat dissipation increased, while the photochemical efficiency decreased. After treated with 140 and 182 mmol NO3- x L(-1) for 6 days, the photosynthetic rate (P(n)) was decreased by 35% and 78%, respectively, maximal PS II efficiency at open centers in the absence of NPQ (F(v)/F(m)), antenna efficiency at open centers in the presence of NPQ (F(v)'/F(m)'), actual PS II efficiency (phi (PSII ) and photochemical quenching (q(P)) were lower, non-photochemical quenching (NPQ) was higher, and the deviation from full balance between PS I and PS II (beta/alpha - 1) was improved significantly, compared with the control. The fluctuant ranges of these chlorophyll fluorescence parameters were increased at higher NO3- concentration, compared with those at lower NO3- concentration. The absorbed light energy allocated to the photochemical reaction of PS II (P) was reduced by high light intensity and high NO3- concentration. Meanwhile, the proportion allocated in antenna heat dissipation (D) increased significantly. Antenna heat dissipation was the main way for excessive energy dissipation.

This paper presents a multi-agent based architecture of context-aware systems. Our objective is to make the architecture more extensible and can be easily applied to developing most context-aware applications. We also discussed how to add context-aware abilities to the existing applications. In our research, we divide the context-aware system into several parts, and we use multiple agents to process corresponding information respectively. Each agent is highly independent of the others, and we nearly don't need to make any changes to other agents when we want to modify one of them.

WLAN location determination systems are gaining increasing attention due to the value they add to wireless networks. This paper focuses on how to determine the mobile devices’ location indoor by using signal strength (SS) in 802.11-based system. We propose an 802.11-based location determinat-ion technique Nearest Neighbor in Signal Space (NNSS) which locates mobile objects via collecting the sensed power strengths. Based on NNSS, we present a modification Modified Nearest Neighbor in Signal Space (MNNSS) to enhance the location determination accuracy by taking into account signal strength of more reference points in each estimating location of the mobile objects. In NNSS, we compare the measured SS (signal strength) with the SS of each reference point recorded in database to find the best match, but in MNNSS, we not only compare the measured SS with that of each reference point, but also the reference points around it, so it increases the location determination preciseness. The experimental results show that the location information provided by MNNSS assures higher correctness than NNSS. Implementation of this technique in the WLAN location determination system shows that the average system accuracy is increased by more than 0.5 meters. This significant enhancement in the accuracy of WLAN location determination systems helps increase the set of context-aware applications implemented on top of these systems.

Context-aware computing are gaining increasing attention due to the value they add to wireless networks. We described the innards of IGS (intelligent guide system), an 802.11 location-based tour guide system. Our objective is to empower mobile devices to recognize the context when the tourists visit some scenic spots and provide corresponding services. In our work, we proposed BAFO (be away from obstacles) algorithm to deploy access points (APs), and proposed a received signal strength (RSS) based algorithm MNNSS (modified nearest neighbor in signal space) to position mobile terminals. We divided the whole IGS system into four parts, and each part can do its job independently. We also used a friendly user interface so that the user can easily get the information they need. These proposed techniques can be further extended to the indoor guiding and tracing system.

Context-aware computing is emerging as a promising technology for mobile and pervasive environments. Unfortunately, complex context-aware applications are still hard to build. In this paper, we describe an 802.11 based indoor context-aware system used in hospital. Our objective is to empower mobile devices to recognize the context in which hospital workers perform their tasks. This system is an accessory of the management system in the hospital, and it can add Context-aware ability to the existing system by providing Context-aware communications. In our work, we use BAFO (Be Away From Obstacles) algorithm to deploy APs (Access Points), and use a Received Signal Strength (RSS) based Algorithm MNNSS (Modified Nearest Neighbor in Signal Space) to position mobile terminals, then describe the implementation of this multi-agent based system

Effects of high concentration manganese on active oxygen production and antioxidant enzymes in cucumber leaves under natural irradiation and 1/2 natural irradiation were studied. High concentration manganese increased the H2O2 content and O2*- producing rate of cucumber leaves (Fig.1A, B) and caused lipid peroxidation (Fig.1C). Compare to natural irradiation, 1/2 natural irradiation significantly decreased active oxygen production and lipid peroxidation (Fig.1). CAT activities in cytosols and chloroplasts were inhibited by high concentration manganese (Fig.2B), and other antioxidant enzyme activities were enhanced by high concentration manganese (Fig.2A, C-F). Especially activities of APX, DHAR and GR in chloroplasts were greatly stimulated by high concentration manganese under natural irradiation compared to 1/2 irradiation, which may play important roles in scavenging active oxygen species. Antioxidant enzymes in mitochondria showed higher activities under high concentration manganese under natural irradiation, but the differences were not significant under 1/2 natural irradiation (Fig.2A, C-F).

To understand further the mechanism of agrobacteria transformation by vacuum infiltration, the distribution and viability changes of the agrobacteria in infiltrated Chinese cabbage( B. rapa ssp. chinesis) plants were investigated by histochemical staining and bacteria plating techniques. Results revealed that there were different quantities of Agrobacteria in different organs, among which the most quantity occurred in flowers, especially in ovules. The Agrobacteria lied in the space between cells and concentrated in the vascular bundle no matter the type of the organs examined. The CFUs (colony forming unit) of the Agrobacteria derived from the flowers were always the most in every experiment. The viabilities of the agrobacteria in the plants declined dramatically along with the elongation of the time after plant infiltration in all organs, but there were still 10(3) CFUs per gram fresh tissue in the flowers after 15 days of infiltration. These results may explain the fact that the ovules were the targets for the Agrobacteria mediated vacuum infiltration transformation.

In this paper we introduce a new method of PCR and RAPD reaction by using a small quantity of wheat leaf tissue with alkali treatment. It can be used either to detect target gene or to analyze polymorphism of wheat varieties. This method is simple and reliable, especially for a large-scale detection.

In this paper we introduce a new storage method of PCR ingredient. PCR mixture except DNA template has been frozen to dry powder by the DNA-Plus system. This kind of powder was stored at room temperature or 4 degrees. PCR has been run in different period of storage. It was discovered that the samples of lyophilization could keep activity for a long time.

By cross breeding, the maize pepc gene in the pepc transgenic rice was successfully incorporated into the parents of two-, three-line hybrid rice, including sterile lines (Peiai64S, 2302S, 2304S, 2306S and Shuangjiu A) and restorer lines (5129, 02428 and Wanjing97) to breed the high-photosynthetic efficiency parents of hybrid rice and utilize heterosis between C4 and C4/C3 rice. Some lines of pepc transgenic rice (LPTR) have been developed. The study on the generations of LPTR suggests the following: (1) The segregation observed in F2 and BC1 progenies demonstrated that pepc transgene inherited as a single dominant gene in the progenies of LPTR. (2) The maize pepc gene is actively expressed at high level in LPTR, and changes of pepc gene expression in the progenies of LPTR may be related to position effect, difference of gene copy number and environmental factors. (3) Through the selection method of soaking seeds into hygromycin solution to germinate, tracing the pepc gene by PCR analysis, evaluating the performance of the rice plants in the field and examining PEPC activities, the segregation of the pepc transgene in LPTR was controlled effectively. Based on the above strategy three pepc transgene lines, H1596, H1597 and Y1470, have been selected. The result suggests that it is possible to breed practical, stable and high-expression pepc transgenic rice by conventional crossing.

Mitochorndrial DNA (mtDNA), nuclear DNA (nDNA), and genomic DNA (gDNA) were individually extracted from Zhenshan 97A, Xieqingzao A and A-23, which were cytoplasmic male sterile (wild abortive, dwarf abortive and BT), and from Zhenshan 97B, Xieqingzao B and BT, which were maintainers lines. Each of them was analyzed with 500 random primers by RAPD. Six fragments specific to male sterile lines were amplified. A fragment, PWH-17, associated with wild and dwarf abortive type cytoplasmic male sterility was analyzed by Southern blotting and sequencing, and also tested by SCAR. It was 1879 bp in length, which contained 6 open reading frames and 8 repeated sequences. BLAST search revealed that partial sequence in PWH-17 showed high similarity to the upstream sequence of tRNA-Asp gene in Elytrigia elongate (GenBank accession number U14335) and wheat (X13243). The similarity ratios were 97% and 100%. It was inferred that the possible position of PWH-17 in rice (wild abortive) could be located between tRNA-Asp and Cox II, which will be discussed further.

In this paper, the properties of the gray level mixing function in two-dimensional chaotic map image encryption are analyzed. We also discuss the necessity of introducing parameters and the methods how to present diffusion mechanism and interfuse a pseudo-random number sequence in the gray level mixing function. We proposed a new kind of gray level mixing function which not only have diffusion mechanism but also have random variable . It is shown in experiment that this method has good performance.

HA-Bioglass-Al2O3 composites were successfully fabricated by mixing HA, synthesized by wet chemical method between precursor materials H3PO4 and Ca(OH)2, with 25 wt% Al2O3 and different content of bioglass (5, 25, 45, and 65 wt%), respectively, with a mole fraction of 53.9%SiO2, 22.6%Na2O, 21.8%CaO, and 1.7 wt%P2O5, sintered in air at relative low temperature (750–950°C) for 2 h. It can be seen that when the content of bioglass is above 45 wt% in the composite, the decomposition of HA to β-TCP, considerable thermal reaction and phase degradation are suppressed, and the main phases in this case are Al2O3, HA, and a small amount of DCP (CaHPO4) and β-TCP, which almost have the same chemical composition, forming ternary-glass phase, and have better bioactive than pure HA. It can also be found that the exposed HA particles increase with the increasing of the bioglass content in the mixture. A large number of HA particles stacked together are subjected to form roughened surface, wherein microcracks, voids, and...

A stable electron emission was obtained at as low as about 2.5 V/μm from acid treated diamond films. The emission data were fitted with Folwer-Nordheim theory. It is found that the non-electrons are emitted from some protrusions on surface of diamond films, and that after acid treatment, the effective work function is lowered, and the emission area is increased to two folds of those of as-grown films. These results were discussed.

Self-tuning regulators have been successfully applied to two installations in a chemical plant. A self-tuning regulator for liquid level in the acetic acid evaporator went into formal use in April 1979; a self-tuning regulator for temperature in the central part of a vinyl acetate synthesis reactor went into operation in July 1979. Both regulators show marked improvement over PI-regulators