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1.
The integration of water quality analysis simulation program （WASP） with a geographical information system （GIS） is presented.This integration was undertaken to enhance the data analysis and management ability of the widely used water quality model.Different types of data involved in WASP modeling were converted and integrated into GIS using a database method.The spatial data modeling and analysis capability of GIS were used in the operation of the model.The WASP water quality model was coupled with the environmental fluid dynamics code （EFDC） hydrodynamic model.A case study of the Lower Charles River Basin （Massachusetts,USA） water quality model system was conducted to demonstrate the integration process.The results showed that high efficiency of the data process and powerful function of data analysis could be achieved in the integrated model,which would significantly improve the application of WASP model in water quality management.  相似文献   

2.
Decomposition mechanism of chloramphenicol under electron beam irradiation   总被引：1，自引：0，他引：1  
The purpose of this study was to evaluate the potential of electron beam to decompose chloramphenicol （CAP） in aqueous solutions. At the absorbed dose of 15 kGy, the decomposition rate of CAP was 95.24%. The degradation of CAP under electron beam irradiation followed pseudo-first-order kinetics. Redox reactions of CAP aqueous solutions with hydroxyl radicals （.OH）, hydrated electrons （eaq） and hydrated atoms （·H） were studied. The increase of the additives would result in the decrease of the degradation efficiency. The concentration of Cl- and NO3- in aqueous solution increased after electron beam irradiation. On the basis of the experimental results, a photocatalytic mechanism was discussed. The rate constant for reactions of .OH and CAP was 9.36×10^7 L/（mol.s） and for reaction of eaq and CAP was 7.33×10^7 L/（mol.s）..OH was supposed to play the key role in the radiation system of aqueous solution. Other free radicals like eaq and .H could also initiate the degradation.  相似文献   

3.
A discriminant method for optimizing activity in nuclear medicine studies is validated by comparison with ROC （received operating characteristic）-curves. The method is tested in 21 single photon emission computerized tomography （SPECT）, performed with a cardiac phantom. Three different lesions （Lb L2 and L3） were placed in the myocardium-wall by pairs fbr each SPECT. Three activities （84, 37 or 18.5 MBq） of 99mTc were used as background. Linear discriminant analysis was used to select the parameters that characterize image quality among the measured variables in the images [（Background-to-Lesion （B/Li） and Signal-to-Noise （S/N） ratios）]. Two clusters with different image quality （P=0.021 ） were obtained. The ratios B/Lj, B/L2 and B/L3 are the parameters used to construct the function with 100% of cases correctly classified into the clusters. The value of 37 MBq was the lowest tested activity for which good results for the B/Li ratios were obtained. The result coincides with the applied ROC-analysis （r=0.89）.  相似文献   

4.
Objective： To investigate the potential and early effect of hypertonic saline resuscitation on T-lymphocyte subpopulations in rats with hemorrhagic shock. Methods： A model of rat with severe hemorrhagic shock was established in 18 Sprague-Dawley （SD） rats. The rats were randomly divided into Sham group, HTS group （hypertonic saline resuscitation group） and NS group （normal saline resuscitation group）. Each group contained 6 rats. The CD4~ and CD8~ subpopulations of T-lymphocytes in peripheral blood were detected respectively before shock and after resuscitation by double antibody labelling and flow cytometry. Results： In the early stage after hemorrhagic shock, fluid resuscitation and emergency treatment, the CD4^＋ lymphocytes of peripheral blood in HTS and NS groups markedly increased. Small volume resuscitation with HTS also induced peripheral CD8^＋ lymphocytes to a certain extent, whereas NS resuscitation showed no effect in this respect. Consequently, compared with Sham and HTS groups, CD4^＋/CD8^＋ ratio of peripheral blood in NS group was obviously increased, and showed statistically differences. Conclusion： In this model of rat with severe hemorrhagic shock, small volume resuscitation with HTS is more effective than NS in reducing immunologic disorders and promoting a more balanced profile of T-lymphocyte subpopulations regulating network.  相似文献   

5.
Objectives： To detect the serum proteomic patterns by using SELDI-TOF-MS （surface enhanced laser desorption/ ionization-time of flight-mass spectrometry） technology and CM10 ProteinChip in colorectal cancer （CRC） patients, and to evaluate the significance of the proteomic patterns in the tumour staging of colorectal cancer. Methods： SELDI-TOF-MS and CM10 ProteinChip were used to detect the serum proteomic patterns of 76 patients with colorectal cancer, among them, 10 Stage Ⅰ, 19 Stage Ⅱ, 16 Stage Ⅲ and 31 Stage Ⅳ samples. Different stage models were developed and validated by support vector machines, disctiminant analysis and time-sequence analysis. Results： The Model Ⅰ formed by 6 protein peaks （m/z： 2759.58, 2964.66, 2048.01, 4795.90, 4139.77 and 37761.60） could be used to distinguish local CRC patients （Stage Ⅰ and Stage Ⅱ） from regional CRC patients （Stage Ⅲ） with an accuracy of 86.67% （39/45）. The Model Ⅱ formed by 3 protein peaks （m/z： 6885.30, 2058.32 and 8567,75） could be used to distinguish locoregional CRC patients （Stage Ⅰ, Stage Ⅱ and Stage Ⅲ） from systematic CRC patients （Stage IV） With an accuracy of 75.00% （57/76）. The Model Ⅲ could distinguish Stage Ⅰ from Stage Ⅱ with an accuracy of 86.21% （25/29）. The Model Ⅳ could distinguish Stage Ⅰ from Stage Ⅲ with accuracy of 84.62% （22/26）. The Model Ⅴ could distinguish Stage Ⅱ from Stage Ⅲ with accuracy of 85.71% （30/35）. The Model Ⅵ could distinguish Stage Ⅱ from Stage Ⅳ with accuracy of 80.00% （40/50）. The Model Ⅶ could distinguish Stage Ⅲ from Stage Ⅳ with accuracy of 78.72% （37/47）. Different stage groups could be distinguished by the two-dimensional scattered spots figure obviously. Conclusion： This method showed great success in preoperatively determining the colorectal cancer stage of patients.  相似文献   

6.
The vapor-liquid equilibrium（VLE） properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solvent.Hence,Gibbs ensemble Monte Carlo（GEMC） simulations were used to estimate vapor-liquid equilibrium for the binary and ternary mixtures of CH4,C2H4 and iso-C4H10 with the united atom potential NERD model.The selected simulation conditions are based on the experiment in the literature.The results of this work were shown to be in satisfactory agreement with available experimental data and predictions of Peng-Robinson equation of state.The structure of simulated liquid phase is also characterized by radial distribution function（RDF）,which contributes to further understanding of the VLE curve of these systems.RDF is not sensitive to the pressure and temperature range.With the increase of pressure or the decrease of temperature,the molecules tend to gather together.  相似文献   

7.
The purpose of the study is to teach urban young children music concepts and English by composing creative music and songs with contrast elements. The subjects were seven urban young children aged from three to four in a Taiwan kindergarten. The duration was twenty-four weeks, with two sessions per week. The teaching contents included Hello Song, Musical Movement, Music Appreciation and Goodbye Song. The study applied the thematic music elements to the teaching content. The main methodology was a qualitative study and quantitative data used to receive objective support. Assessment included a pre-test at the beginning, a post-test and participation observation at the end of the study. The head of the kindergarten, the classroom teacher and a parent completed activity feedback forms to obtain social validity. The results show that through the use of creative music pieces of contrast and song activities, urban young children＇s understanding of music concepts was progressive and English ability was improved. The study findings are： （1） Using contrastive music pieces is a good method for teaching very young urban children to understand music concepts; （2） Creating simple target objective songs with contrast elements is a good way for urban young children to learn simple English; （3） Music with contrastive elements could motivate urban young children to do movement spontaneously and learn the spoken language simultaneously; and （4） Contrastive music could be used for pre-classical music learning.  相似文献   

8.
This paper studies phantom linear scalar field （LSF） and phantom non-linear Born-Infeld （NLBI） scalar field with square potential of the form V（Ф） =1/2m^2Ф^2. The equation of state parameter w（z）, and evolution of scale factor a（t） in both phantom LSF and phantom NLBI scalar model are explored. The age of universe Hot and the transition redshift Z are obtained. The Gold data set of 157-SN-Ia is used to constrain parameters of the two models by numerical calculation. The phantom LSF is slightly better than the phantom NLBI type scalar field model for a large m. Although a smaller m corresponding to a slower rolling of field Ф better fits the observation data, the difference between phantom NLBI scalar field and phantom LSF is not distinct in this case.  相似文献   

9.
Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.  相似文献   

10.
Fermentation ofPhaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using （NH4）2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L （NH4）2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively.  相似文献   

11.
Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 (15.5 and 511.6(6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH˙) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH˙ color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (TEC90) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.  相似文献   

12.
Dried ground leaves ofPsidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1∶10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin-Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3±15.5 and 511.6±6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH') colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH' color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (T EC 50) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.  相似文献   

13.
INTRODUCTION Image quality in nuclear medicine tomography is critically dependent on the activity undergone by the patient. The optimal activity is the smallest amount of activity which preserves diagnostic accuracy. Nev- ertheless, the optimum depends on the gamma camera used for imaging, the size of the patient and the im- aging application (Mattsson et al., 1998). To optimize, one has to study how diagnostic accuracy depends on the activity undergone for each particular study, taking i…  相似文献   

14.
为了研究番石榴果实粗蛋白提取液抗糖尿病的效果,利用四氧嘧啶造糖尿病小鼠模型,通过灌胃给样,7 d后检测小鼠血糖值的变化,并进行胰腺组织切片观察.结果表明,灌胃番石榴果实提取液的实验小鼠血糖明显降低,模型组及空白对照组血糖值无显著变化.切片观察结果也显示,治疗组的切片病变相比于模型组有不同程度的良性改善.因此,番石榴果实...  相似文献   

15.
The implementation of inclusive practices in mainstream education remains particularly difficult in the French context and is influenced by various factors including the types of disability labels, and the type of assessment practices that are used. Indeed, how student disability is labelled could impact teacher attitudes by notably disfavouring students labelled with autism. Moreover, normative assessment is strongly linked with selection at schools—a function that works against teacher attitudes towards inclusive education. This article reports on a study in which we examined teacher intentions to use materials accommodated to special educational needs students, as a function of special needs labelling. Specifically, this refers to the use of labels for either a disability or special educational need, in connection to tasks associated with learning or assessment. The results of our study revealed that, for both types of labels, the intentions to use accommodated materials are lower when teachers are asked to assess student competence than when prompted to teach this competence. These findings are discussed with consideration to the incompatibility between selection in schools—which is aligned with the principle of meritocracy—and efforts to promote inclusive education practices.  相似文献   

16.
黄芪水提物对α-葡萄糖苷酶活性的抑制及其降血糖作用   总被引：1，自引：0，他引：1  
应用黄芪水提物与不同浓度的α-葡萄糖苷酶,不同浓度的底物PNP-glucoside进行反应,研究中药黄芪中α-葡萄糖苷酶抑制剂的抑制活性及其对正常小鼠血糖和糖耐量的影响.通过绘制酶量-反应速度曲线和双倒数曲线,确定其抑制剂类型,并对正常小鼠以40～160 mg.kg-1剂量灌胃后,观察其对血糖值和糖耐量的影响.结果表明,黄芪中α-葡萄糖苷酶抑制剂为可逆、非竞争性抑制;可降低正常小鼠血糖值,并且以80 mg.kg-1的剂量时血糖值最低,还可显著提高小鼠糖耐量.黄芪水提物中含有α-葡萄糖苷酶抑制剂成分,可用于糖尿病治疗.  相似文献   

17.
Antimicrobial activity of organic and aqueous extracts from fruits, leaves and roots of Tribulus terrestris L., an Iraqi medicinal plant used as urinary anti-infective in folk medicine, was examined against 11 species of pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Corynebacterium diphtheriae, Escherichia coli,Proteus vulgaris, Serratia marcescens, Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans using microdilution method in 96 multiwell microtiter plates. All the extracts from the different parts of the plant showed antimicrobial activity against most tested microorganisms. The most active extract against both Gram-negative and Gram-positive bacteria was ethanol extract from the fruits with a minimal inhibitory concentration (MIC) value of 0.15 mg/ml against B. subtilis,B. cereus, P. vulgaris and C. diphtheriae. In addition, the same extract from the same plant part demonstrated the strongest antifungal activity against C. albicans with an MIC value of 0.15 mg/ml.  相似文献   

18.
Little is known regarding the profiles of whole body donors in Muslim majority countries where donation is scarce. Therefore, this study aims to profile registered donors in Turkey by means of a survey. The explored data could be used to improve ongoing campaign efforts and ethical practices such as commemoration services. Registered donors of the donation programs at the two faculties of medicine of Istanbul University were compared with the national population and a cluster analysis was performed to reveal any concealed sub-groups. Data from 188 respondents were analyzed. The majority of registered donors were married (42%), male (65.4%), aged over 50 years (76%), held a tertiary education degree (49.7%), and were irreligious (58.5%). Cluster analysis revealed two groups with significantly different educational levels, marital statuses, and religious choices. Regarding whether their bodies could be used for education or research, the majority (64.5%) of the respondents left the decision to the anatomy department. Similarly, 73.8% approved indefinite use of their organs, body parts and/or skeletons. The respondents were also willing to share their medical history (94.2%) and personal information (81.6%) if needed. Motivational themes for body donation including usefulness, impermanence, religion, awareness, and kinship were devised after a thematic analysis. Among the respondents, 56.5% were registered organ donors and 63.3% were frequent blood donors. The results of this study provide data that may help revising informed consent forms, developing and implementing thanksgiving ceremonies, and selecting additional targets for supporting body donation campaign activities such as organ and blood donation units.  相似文献   

19.
In the split-attention effect spatial proximity is frequently considered to be pivotal. The transition from a spatially separated to a spatially integrated format not only involves changes in spatial proximity, but commonly necessitates text segmentation and picture labelling as well. In an experimental study, we investigated the influence of spatial proximity, text segmentation, and picture labelling on learning performance. A total of 165 students, divided into five groups, participated in the study. Four of the groups learned from spatially separated texts and pictures in a 2 × 2 design with the factors text segmentation (continuous vs. segmented text) and picture labelling (unlabelled vs. labelled picture). The fifth group learned from a spatially integrated text and picture. Retention and comprehension of the learning material were assessed. Students' working memory capacity and spatial ability were also assessed. The results replicated the split-attention effect with respect to retention only. This effect is attributed mainly to text segmentation and only partially to picture labelling. Spatial integration, however, did not enhance learning.  相似文献   

20.
海金沙提取液抑制草酸钙结石的化学基础研究   总被引：2，自引：0，他引：2  
文中采用体外模拟方法研究了海金沙提取液对草酸钙结石的影响,用X射线衍射、红外光谱、扫描电子显微镜等对结果进行了表征．研究表明,海金沙提取液可以抑制COD晶体向热力学更稳定态的COM晶体转变,这种抑制作用随海金沙提取液浓度增大而增大,且COD晶体尺寸随着海金沙提取液浓度的增大而减小,这有利于抑制草酸钙结石．  相似文献   

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