原人参三醇减轻MDA-MB-231细胞紫杉醇耐药性的机制研究

目的:探讨原人参三醇(PPT)对耐紫杉醇(PTX)人乳腺癌MDA-MB-231细胞(MB231-PR细胞)耐药性的影响。方法:构建MB231-PR耐药细胞作为细胞模型。以不同浓度的PPT作用于MB231-PR细胞一定时间。用Cell Titer-Glo试剂和集落形成实验测定MB231-PR细胞和MDA-MB-231亲本细胞(MB231-PT细胞)的活力。用流式细胞术测定PPT和PTX联合使用后细胞sub-G1期的变化。Western blot法用于评估细胞凋亡相关蛋白cleaved caspase-3、cleaved多腺苷二磷酸核糖聚合酶(PARP)、survivin、B细胞淋巴瘤2(Bcl-2)和Bcl-2相关X蛋白(Bax)的表达水平。萤光素酶报告基因实验和免疫荧光染色用于检测核因子κB(NF-κB)活性。ELISA检测白细胞介素6(IL-6)和IL-8蛋白表达水平。q PCR检测IL-6、IL-8、CXC趋化因子配体1(CXCL1)、CC趋化因子配体2(CCL2)、CD44、NANOG、八聚体结合转录因子4(OCT4)、性别决定区Y框蛋白2(SOX2)和醛脱氢酶1(ALDH1)的m RNA表达水平。肿瘤球形成实验用于评估干细胞特性。结果:(1)PPT以剂量依赖性方式显著降低MB231-PR细胞活力(P<0.01),半数抑制浓度(IC50)为18.17μmol/L。PPT和PTX联合治疗后,MB231-PR细胞活力显著降低(P<0.01),诱导sub-G1期的积累(P<0.01),Bax/Bcl-2的比值上调(P<0.01),cleaved caspase-3和cleaved PARP蛋白水平升高(P<0.05),survivin蛋白表达水平下降(P<0.01)。(2)PPT与PTX联合治疗后,炎症细胞因子(IL-6、IL-8、CXCL1和CCL2)和肿瘤干细胞标志物(OCT4、SOX2、NANOG、ALDH1和CD44)的m RNA表达水平下调(P<0.05),IL-6和IL-8的蛋白表达水平降低,显著抑制MB231-PR细胞NF-κB的活性(P<0.05),并损害MB231-PR细胞的肿瘤球体生长(P<0.05)。(3)PTX处理诱导了核p-p65的表达,这种作用可以被PPT减弱。结论:PPT联合PTX可通过抑制炎症细胞因子和肿瘤干细胞来降低MB231-PR细胞对紫杉醇的耐药性。

Key factors for causing poplar Ice Nucleation Active bacterial canker and its control techniques

The isolation, culture and the active determination of poplar ice nucleation active (INA) bacteria and the inoculation tests in laboratory and field were conducted, and the varieties, distribution and number of poplar INA bacteria and its pathoge-nicity and freezing injury property were determined. The study results showed that the INA bacteria widely spread on poplar in Northeast China and caused the frozen injury for poplar under the frost condition in Spring or Autumn, which was the key factor to induce INA bacterial canker. Through evaluation and investigation of different poplar varieties and inoculation tests, fine dis-ease-resistant varieties and strains of poplar suitable for Northeast China were selected. Further tests for strong seedling showed that burying cuttings in sand and covering with plastic film could effectively avoid the frostbite, frozen and drought damage, reduce INA bacteria infection, and promote poplar growth. INA bacterial canker was detected early by highly special-ized antiserums of INA bacteria and the agglutinated test of ring-shaped boundary surface. The inducers such as streptomycin, phenylmercuric acetae, salicylic acid and heat-killed bacteria to immerse cuttings, have obvious induced disease-resistant effect. Before poplar sprouted in early spring, through spraying the solution of frostbite agent, the control effect also was obvious.

ITS共用信息平台系统结构及集成

从ITS共用信息平台的内容出发,分析了ITS共用信息平台的信息来源与应用需求体系,提出ITS共用信息平台的系统结构,探讨了ITS共用信息平台集成的技术实现模式,并就我国ITS共用信息平台集成的主导模式和策略——基于ITMS集成的共用交通信息平台问题进行了讨论.

ITS/TICS中央数据登记薄标准及其在交通共用信息平台建设中的应用

在我国交通共用信息平台建设过程中,如何实现不同部门、不同地域之间的信息共享和信息交换成为面临的主要问题.为了满足ITS建设者在数据管理机制和规范方面的需求,ISO提出了中央数据登记薄(Central Data Registry)标准草案(ISO/DIS 14817),其主要目的是提供一种数据管理机制,以加强各个ITS/TICS部门或应用系统之间共享交通数据的能力.本文分析了我国当前交通共用信息平台建设对中央数据登记簿数据管理机制的需求,概括介绍了ISO中央数据登记簿标准的基本思想和主要内容,介绍了国外在相关系统建设中应用中央数据登记簿数据管理机制的实例,提出了我国在相关领域应当尽快开展的工作.

Feature Extraction of Fabric Defects Based on Complex Contourlet Transform and Principal Component Analysis

To extract features of fabric defects effectively and reduce dimension of feature space,a feature extraction method of fabric defects based on complex contourlet transform （CCT） and principal component analysis （PCA） is proposed.Firstly,training samples of fabric defect images are decomposed by CCT.Secondly,PCA is applied in the obtained low-frequency component and part of highfrequency components to get a lower dimensional feature space.Finally,components of testing samples obtained by CCT are projected onto the feature space where different types of fabric defects are distinguished by the minimum Euclidean distance method.A large number of experimental results show that,compared with PCA,the method combining wavdet low-frequency component with PCA （WLPCA）,the method combining contourlet transform with PCA （CPCA）,and the method combining wavelet low-frequency and highfrequency components with PCA （WPCA）,the proposed method can extract features of common fabric defect types effectively.The recognition rate is greatly improved while the dimension is reduced.

Fractal characteristics of filamentous bacteria in activated sludge and its significance

On the basis of fractal theory, the fractal characteristics of filamentous bacteria in activated sludge are studied by image dissector system. The results show that the spatial distribution structure of filamentous bacteria in activated sludge has high self similarity in statistics and the filamentous bacteria have clear phenomenon of fractal growth. The critical fractal dimension values of filamentous bacteria bulking such as Eikelboom 021N, Eikelboom 1701, Sphaerotilus natans and Eikelboom 0041 are determined initially. The fractal dimensions can be taken as a parameter to describe filamentous bacteria of activated sludge quantitatively and bring to light the disorder in appearance and the rule in inherence of filamentous bacteria system.

Mixed surfactant washing of petroleum contaminants from the soils and sediments in the unsaturated zone

A laboratory study was conducted to evaluate the suitability of a mixed surfactant for washing oil from soils in the unsaturated zone. The commercial surfactant used for making mixed surfactant were alcohol polyethoxylate (AEO\|9, nonionic) and sodium alcohol polyethoxylated ethers sulfate (AES, anionic). Based on the properties (critical micelle concentration, hydrophilic/ lipophilic balance and surface tension) of individual surfactants and the mixed surfactant, the preferred composition of an aqueous mixed surfactant solution was determined which consisted of 0 5% AEO\|9 and 0 1% AES. The batch washing experiments have shown that the removal efficiency of oil from soils with mixed surfactant was higher than that with individual surfactants. Soil column washing results have shown that the sequence of oil removal efficiency was mixed surfactant (0.5% AEO\|9 and 0.1% AES)>AEO\|9 (0.1%)>AES (0.2%)>water, and the ratio was 1∶0 84∶0 66∶0 06. Biodegradation experiments by growth cells and resting cells were carried out to evaluate the environmental acceptability of the test surfactants. The results have shown that the surfactants were able to serve as sole carbon source for strains Pseudomonos sp. 52 and Weeksella sp. 6 which were isolated from petroleum contaminated soil. More than 90% of the parent mixed surfactants disappeared in two weeks under growth cell conditions.

Response of cucumber plants to increased UV-B radiation under water stress

Three days old cucumber (Cucumis sativus L.) was grown in a factorial design under two levels of water condition (well watered and drought) and two supplemental levels of ultraviolet\|B(280—320 nm) irradiance(0, 0\^24, 0\^42 W/m\+2) for 30 days. Plants were grown in a greenhouse under visible light with 400 μmol/(m\+2.s), day\|night temperature 32/20℃ and relative humidity 70±10%. The combination of UV\|B radiation and water stress resulted in the decrease in plant height, leaf area ratio and relative growth rate, and increase in specific leaf mass and net assimilation rate. There was almost no effect of ultraviolet\|B radiation on the contents of chlorophyll a and b under water stress. However, interactive effects of ultraviolet\|B radiation and water conditions on the content of anthocyanin were much great. UV\|B irradiance with water stress also caused a reduction in net photosynthesis, apparent quantum efficiency, gas exchange and stomatal resistance, and an increase in evaporation.

Human impacts on the terrestrial ecosystem of Fildes Peninsula of King George Island, Antarctica

Antarctic environment has valuable baseline information for understanding the global change. The objectives of this study were to investigate the impacts of human activities on Antarctic terrestrial ecosystem. Based on the investigation results and the sampling analysis of the environment of Fildes Peninsula, King George Island, Antarctica, it was shown that there are some artificial radioactive elements—? ? 137 Cs in Antarctic environment: the radioactivity of 137 Cs in the surface soil, the surface moss, the fruticose lichen and the crustaceous lichen are 6 00—14 80, 25 07, 29 04 and 58 07 Bq/kg separately; i.e. the sequence of 137 Cs specific activity is as follows: crustaceous lichen>fruticose lichen>surface moss>surface soil, which demonstrates that the crustaceous lichen is one of the most sensitive monitor ways for the effect of the long term diffusion of 137 Cs. The impacts of the scientific research activities on the partial ecosystem of Fildes Peninsula include: the changes of the landscape and the soil material have made a strong freezing thawing process, which decreases the stability of the ground surface, causes the degradation of the vegetation in the some small areas; some small lakes, runoff and lichens in middle areas of Fildes Peninsula have been affected by the wastes of the stations, in the surrounding areas of the expedition stations, the concentration of Cr, Cu, Ni, Pb and Zn in the lichen and the water are higher than that of the contrasting area. Fildes Peninsula is one of the most crowded areas of expedition stations, at some extent, the environment and terrestrial ecosystem have been affected by the human activities. The conservation of the environment and ecosystem should be an important aspect of Antarctic environmental sciences.

Effects of allelochemicals on activity of nitrate reductase

Study on the effects of allelochemicals such as trans \|ferulic acid ( t \|FA), benzoic acid (BA) and p \|hydroxybenzoic acid ( p \|HA), isolated from decomposed wheat straw on the activity of nitrate reductase at different concentrations of allelochemicals and different pH is described. t \|FA (0.26, 2.58 and 5.15 mmol/L) and BA (4.09, 8.19 mmol/L) showed a certain inhibition to the activity of nitrate reductase. The highest inhibition rate was 18.40%, but BA (0.41 mmol/L) and p \|HA (0.36, 1.81 and 3.62 mmol/L) showed stimulation, the more strong stimulation rate was 15.80%. At pH 6 condition, the activity of nitrate reductase was stronger inhibited than pH 7 and pH 8, but the mixture of 3 allelochemicals at pH 6 showed a stimulation. The mixture, however, at pH 7 and pH 8 showed some inhibition. It was found that there was a relationship between production of NO\+-\-2 and transformation of NO\+-\-3.

Levels of toxic metal in Achatina achatina from parts of Akwa Ibom State, Nigeria

Tropical land snail (Achatina achatina) were collected from three areas viz.Nsit Ibom Local Government Area (NTB), Nsit Ubium Local Government Area (NTU) and Uyo Municipality (UYM), all in Akwa Ibom State to determine the levels of Ni, Pb, Zn and Cr in their shells and muscles. Generally, the levels of all the metals in the muscles were comparatively higher than that in the shells. Correspondingly, the metals appear to have been more stable in the muscles with comparatively lower coefficients of variation than in the shells. Moreover while there was no significant correlation between the levels of all the metals in shells and muscles of NTU samples, Pb and Zn in NTB correlated very significantly. The correlation between levels of Cr in NTB samples and of Zn in UYM samples in shells and muscles were equally significant. On the whole, the levels of these metals were found to be much lower in both shells and muscles of NTU samples obtained from the “enclosed and restricted” environment than in NTB and UYM samples collected randomly from “open and unrestricted” environments.

Effects of grassland degradation on chestnut soil properties in Bashang Plateau, China

The repeated effects of vulnerable habitat and unreasonable human activities on the Bashang Plateau of China led the chestnut soil to degrade. It expresses in reducing soil CEC, decreasing nutrient content, decomposing organic complexes, and reducing humus in loose, steady and tight bond forms, respectively. The percentage of three forms are 21%—34%, 44%—55% and 5%—6.2%, respectively.

Responses of landform development to tectonic movements and climate change during Quaternary in Fenhe drainage basin

Tectonic movements and climate changes are two main controllers on the development of landform. In order to reconstruct the history of the evolution of the landform in the Fenhe drainage basin during middle-late Quaternary comprehensively, this paper has provided a variety of geomorphological and geologic evidences to discuss how tectonic movements and climate changes worked together to influence the landform processes. According to the features of the lacustrine and alluvial terraces in this drainage basin, it is deduced that it was the three tectonic uplifts that resulted in the three great lake-regressions with an extent of about 40-60 m and the formation of the three lacustrine terraces. The times when the tectonic uplifts took place are 0.76 MaBP, 0.55 MaBP and 0.13 MaBP respectively, synchronous with the formation of paleosol units S 8 , S 5 and S 1 respectively. During the intervals between two tectonic uplifts when tectonic movement was very weak, climate changes played a major role in the evolution of the paleolakes and caused frequent fluctuations of lake levels. The changes of the features of lacustrine sediment in the grabens show the extent of such fluctuations of lake level is about 2-3 m.

Effects of Substrate Pretreatment Conditions on Quality of GaN Epilayer

The pure cubic GaN(c-GaN) has been grown on (001)GaAs substrates by ECR-PAMOCVD technique at low temperature using TMGa and high pure N2 as Ga and N sources, respectively. The effects of substrate pretreatment conditions on quality of cubic GaN epilayer are investigated by the measurements of TEM and XRD.It is found that hydrogen plasma cleaning, nitridation and buffer layer growth are very important for quality of cubic GaN epilayer.

Elimination of Zig-zag Defects in Surface-stabilized Ferroelectric Liquid Crystal Cells

The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of SSFLC cell is 3 μm. The optical spectral transmittance measurement confirmed that there is no change of layer structure, and the memory capability was not improved. The different effects of low-frequency electric field applied on the different thickness FLC cells have been observed, and experimental results were presented.

Acoustic anisotropy of piezoelectric LiNbO_(3)crystals and its application in integrated acousto-optical tunable filters

We use Jones’s matrix method and the global optimal method to investigate the propagation characteristic of surface acoustic wave（SAW） for X-cut single crystal Lithium Niobate（LiNbO3）.As an application,a novel integrated acousto-optical filter,which allows to minimize the dimension of AO cells and suppress side-lobes,was designed on the base of LiNbO3 crystal.

Geochemical constraints on seasonal recharge of water and major dissolved solutes in the Huangshui River,China

The Huangshui River,an important tributary in the upper reaches of the Yellow River,has been regarded as a mother river which gestates Qinghai civilization in China.This paper presents the results of hydrogen and oxygen isotopic and water chemical analyses for the summer and winter Huangshui River water to study its seasonal recharge and major dissolved solutes.Characteristics of hydrogen and oxygen isotopes suggest that precipitation in the Qilian Mountains is the original recharge of the Huangshui River.However,in winter,the basic flow of the Huangshui River only depends on spring recharge and spring water originates from melt and infiltration of bottom layer glaciers.In summer,besides spring water,much rainfall directly recharges the Huangshui River,thus making its flux increase greatly.Water chemistry shows that the processes affecting dissolved solutes in the Huangshui River are also different between summer and winter.In summer,major ions in the river water are dominantly derived from carbonate and evaporate dissolution and anthropogenic inputs.In winter,carbonate dissolution decreases greatly while anthropogenic inputs play a much more important role for dissolved solutes in the river.Hence,further measures should be taken to lay stress on the winter Huangshui River water in order to protect the environment of the Huangshui River and reduce effects of dissolved solutes on,or prevent their pollution toward the upper Yellow River.Moreover,some measures also need to be introduced to prevent the possibility of water eutrophication caused by agricultural activities or stock raising in summer.

(Al_xGa_(1-x))_yIn_(1-y)P Films and Its Optical Constants on the Surface

The optical parameters for three samples of intrinsic, doped Si and doped Mg (Al x Ga 1- x ) y In 1- y P prepared by the MOCVD on GaAs substrate were measured by using ellipsometry and were calculated by the two-layer absorption film model. The results obtained were discussed. The grown rates and thickness of oxidic layer on the intrinsic (Al x Ga 1- x ) y In 1- y P surface exposed in the atmosphere were studied. A linear dependence of oxidic layer thickness on the time was obtained.

Test on oxygen and benzene contents in gasoline by mid-infrared spectroscopy

This paper aims at testing oxygen and benzene contents in gasoline by mid-infrared spectroscopy.The experimental results prove that infrared spectroscopy(IR)is reliable.Compared with gas chromatography(GC)technology,this paper draws a conclusion that IR has several advantages,including rapid analysis,excellent repeatability and low analysis cost.

Optimization of Process Parameters of Continuous Microwave Drying Raspberry Puree Based on RSM and ANN-GA

To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexes(average temperature,average moisture content,average retention rate of the total anthocyanin content,temperature contrast value,and moisture dispersion value)were investigated via the response surface method(RSM)and the artificial neural network(ANN)with genetic algorithm(GA).The results showed that the microwave intensity and drying time dominated the changes of evaluation indexes.Overall,the ANN model was superior to the RSM model with better estimation ability,and higher drying uniformity and anthocyanin retention rate were achieved for the ANN-GA model compared with RSM.The optimal parameters were microwave intensity of 5.53 W•g^(-1),air velocity of 1.22 m·s^(-1),and drying time of 5.85 min.This study might provide guidance for process optimization of microwave drying berry fruits.