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1.
This study used self-report and observation techniques to investigate how students study computer-based materials. In addition, it examined if a study method called SOAR can facilitate computer-based learning. SOAR is an acronym that stands for the method's 4 theoretically driven and empirically supported components: select (S), organize (O), associate (A), and regulate (R). There were 2 experiments. In Experiment 1, 114 undergraduates completed a questionnaire about how they study computer-based materials. Students reported using more ineffective study strategies than effective SOAR strategies. In Experiment 2, 108 different undergraduates read an online text about wildcats and then created materials that reflected their preferred study method, the full SOAR method, or parts of the SOAR method. Specifically, the control group created their preferred study notes; the S group created a complete set of linear notes; the SO group created graphically organized matrix notes; the SOA group created a matrix and associations; and the SOAR group created a matrix, associations, and practice questions that aid self-regulation. The SOAR materials were also created in line with four theoretical principles for technology design (Mayer, 2009). Students studied their materials in preparation for fact and relationship tests. Results from both tests showed that those using the full SOAR method outscored the control group and most other groups using parts of the SOAR method. In addition, observations of students' preferred study methods confirmed the Experiment 1 self-reports that unaided students use ineffective study strategies. Study limitations, suggestions for future research, and instructional implications are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

2.
An automated two column HPLC system with the new packing material LiChrospher RP-18 ADS (alkyl-diol-silica) was tested for the determination of several drugs and metabolites (talinolol, celiprolol, metoprolol, oxprenolol, triamterene, trimethoprim, tiracizine, articaine, detajmium, ajmaline, lamotrigine) in various biological fluids (serum, urine, intestinal aspirates, supernatants of cell cultures and supernatants after protein denaturation). The method allows the direct injection of biological fluids into a reversed-phase HPLC system and on-line clean-up and sample enrichment by a column-switching technique. Precision, accuracy and sensitivity were similar to conventional assays as described in the literature. With this new method it was possible to measure drug concentrations in various biological fluids without changing the sample preparation procedure. In some cases an additional sample preparation like protein denaturation or solid-phase extraction was advantageous to enhance the sensitivity of the method and the life-time of the ADS column.  相似文献   

3.
An immunoaffinity capillary electrophoresis (ICE) system for rapidly quantifying recombinant cytokines in human body fluids has been developed. Cytokines within biological fluids were labeled with a red light emitting fluorochrome and injected into the capillary. Selected cytokines were captured by immobilized antibodies on the internal surface of the capillary, and held while unbound materials were purged. The cytokines were then eluted electrophoretically in acidic buffer. Individual cytokine peaks were detected by on-line laser-induced fluorescence detection coupled to a computerized fiber-optic spectrometer, and analyzed by integration of the eluted peaks. The comparison of the results of ICE to routine assays used for these cytokines demonstrates that ICE provides a fast and accurate procedure for defining these cytokines in complex biological samples. Immunoaffinity separations can be used for any material to which a specific antibody can be raised, making this procedure applicable to a wide range of molecules of biomedical interest.  相似文献   

4.
To purify and characterize low-abundance proteins in complex biological mixtures, we used a novel strategy that combined preparative two-dimensional liquid-phase electrophoresis (2D-LPE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Preparative 2D-LPE is based on the same isoelectric focusing and gel electrophoresis principles as the widely used analytical 2D gel electrophoresis, except that analytes remain in solution throughout separation. This novel approach shows many improvements compared to analytical 2D gel electrophoresis for the separation of proteins in biological fluids. For example, larger volumes/amounts of samples can be loaded, yielding sufficient amounts of low-abundance proteins for further characterization. Since proteins remain in liquid phase during the entire procedure, extra steps such as electroelution, extraction, or transfer to membranes from the gels prior to mass spectrometric analysis are obviated. We report the usefulness of 2D-LPE combined with MALDI-TOF MS for the purification and characterization of cystatin C and beta-2 microglobulin in human cerebrospinal fluid. This method should be applicable to a wide range of biological fluids, such as cerebrospinal fluid, serum, tissue extracts, cell media, whole cells, and bacterial lysates.  相似文献   

5.
The development and application of membrane solid phase extraction (SPE) in 96-well microtiter plate format is described for the automated analysis of drugs in biological fluids. The small bed volume of the membrane allows elution of the analyte in a very small solvent volume, permitting direct HPLC injection and negating the need for the time consuming solvent evaporation step. A programmable liquid handling station (Quadra 96) was modified to automate all SPE steps. To avoid drying of the SPE bed and to enhance the analytical precision a novel protocol for performing the condition, load and wash steps in rapid succession was utilized. A block of 96 samples can now be extracted in 10 min., about 30 times faster than manual solvent extraction or single cartridge SPE methods. This processing speed complements the high-throughput speed of contemporary high performance liquid chromatography mass spectrometry (HPLC/MS) analysis. The quantitative analysis of a test analyte (Ziprasidone) in plasma demonstrates the utility and throughput of membrane SPE in combination with HPLC/MS. The results obtained with the current automated procedure compare favorably with those obtained using solvent and traditional solid phase extraction methods. The method has been used for the analysis of numerous drug prototypes in biological fluids to support drug discovery efforts.  相似文献   

6.
A method for determining opiate agonists (morphine, morphine-3-glucuronide, morphine-6-glucuronide, 6-monoacetylmorphine, codeine, codeine-6-glucuronide, dihydrocodeine, dihydromorphine, buprenorphine, methadone, tramadol, and ibogaine), cocaine and its metabolites (benzoylecgonine and ecgonine methyl ester) and lysergic acid diethylamide in serum, blood, urine and other biological matrices is presented. Aliquots (0.5-1.5 mL) of biological fluids were spiked with appropriate deuterated internal standards and extracted using a common solid-phase extraction method (C18 cartridges). The extracts were subjected to liquid chromatographic-atmospheric-pressure chemical-ionization mass spectrometric examination using selected ion monitoring procedures. These procedures were developed after analysis of full-scan mass spectra of examined compounds. The extraction method appeared very universal; the recoveries were high for almost all drugs and the extracts were very clean. The procedure was applied for routine forensic casework.  相似文献   

7.
A simple and highly sensitive fluorimetric method was developed for the routine determination of prenalterol hydrochloride in bulk, in dosage forms and in biological fluids. The method is based on the fluorescence induced by reaction of the nitroso-derivative of prenalterol hydrochloride with 2-cyanoacetamide in the presence of ammonia. The different experimental parameters were carefully studied and incorporated into the procedure. The fluorescence is measured at 440 nm after excitation at 368 nm. Fluorescence intensity is a linear function of prenalterol hydrochloride concentration over the range of 0.1-2.8 microg x ml(-1) in the solution finally measured. A proposal for the reaction pathway was suggested.  相似文献   

8.
A sensitive analytical procedure is described for the simultaneous determination of lignocaine and the enantiomers of bupivacaine in biological fluids using diazepam as an internal standard. After solvent extraction into hexane, the local anaesthetics were separated using an alpha1-acid glycoprotein (AGP) column and detected at 214 nm. Calibration curves were linear (r2>0.99) in the concentration range of 5 to 500 ng/ml for the enantiomers of bupivacaine and 12.5 to 1000 ng/ml for lignocaine. The corresponding limits of detection were 4 ng/ml and 10 ng/ml, respectively. The method was applied to the analysis of plasma from a healthy woman undergoing tubal ligation.  相似文献   

9.
It has been demonstrated that low concentrations of basic lipophilic drugs in biological fluids may be extracted and concentrated 10(4)-10(6) times by a series of extraction procedures in which the ratio of the extracting solvent to that of the solution to be extracted is of the order of 1:100 (microphase extraction procedure). Typically, basic drugs (atropine, aminopentamide, hyoscine, chloroquine, pyrimethamine) were extracted and concentrated sufficiently for direct GC analysis from 24-hour urine samples by a procedure involving three simple consecutive extraction steps. Using this procedure, it was demonstrated that after administration of aminopentamide (300 micrograms) to patients in the form of anti-diarrhoeal tablets, measurable quantities of the free, unchanged drug can be demonstrated in 24-hour urine samples. The main advantages of the method are simplicity, rapidity and sensitivity due to the low background interference in the GC separations. The principle involved can be extended to the analysis of acidic drugs with suitable solubility properties.  相似文献   

10.
A method for the rapid estimation of free acetaminophen in biological fluids is described. The assay involves either extraction and high-pressure liquid chromatographic analysis on a 10-mum particle-size silica gel column, using a mobile phase of 10% chloroform in tetrahydrofuran. The procedure was used to determine acetaminophen levels in urine from two healthy volunteers who ingested 650 mg of 14C-acetaminophen (20 muCi), and the accuracy of the method was compared with the carbon-14 determination. The limit of detectability for acetaminophen is 1 mug/ml.  相似文献   

11.
12.
A rapid and sensitive method for detecting amphetamine and methamphetamine in drug preparations and biological fluids has been developed. Amphetamine and methamphetamine in pharmaceutical and clandestine drug preparations can be easily screened from other contaminating drugs and readily identified by their fluorescence, with subsequent separation accomplished by TLC. The same general procedure can also be used to detect amphetamine and methamphetamine in human urine at concentrations of 0.1 mug/ml.  相似文献   

13.
14.
A procedure for assaying lipoic acid concentration in biologic fluids and tissues was devised using a eukaryotic protozoan Tetrahymena thermophila. T.thermophila has a specific and sensitive (30 pg/ml) requirement for lipoic acid. Unlike humans and other microorganisms, T.thermophila can not synthesize lipoic acid; hence, its requirement for exogenous lipoic acid is specific. The lipoic acid supplied to T. thermophila by the processing of biologic fluids and tissues during the assay procedure, permits the derivation of a practical assay for lipoate concentration as described here. Lipoate concentration in biologic fluids and tissue obtained from healthy humans, compared to those obtained from patients with renal and liver disease, indicate deviations from normal during disease. Absorption chartings of 200 mg of DL-alpha-lipoic acid in humans indicate a peak concentration of lipoate in plasma 2 h after ingestion and then a steady descent of lipoate to a baseline level after 24 h. With this practical assay, it is now possible to chart lipoate's antioxidant activity and therapeutic action during health and disease.  相似文献   

15.
粉末注射成形中喂料充模过程的一维流动分析   总被引:1,自引:0,他引:1  
通过对宾汉体和假塑性体的流变行为与实际喂料流变行为的比较,建立了能较好地与实际喂料符合的流变模型。对喂料的一维流动作了分析,建立了求解模内温度场、压力场、速度场及剪切速率的控制方程,并给出了其求解过程。  相似文献   

16.
The analysis of morphine in biological fluids is of vital interest in monitoring opiate abuse and in drug abuse research. Although methods for analysis of morphine and its metabolites are well established, studies are still being carried out to improve sample preparation procedures as well as detection levels of morphine in biological samples. In this study, morphine-specific immunosorbents were developed to concentrate morphine prior to HPLC analysis. Urine (0.1 ml) was diluted 10-fold with phosphate-buffered saline, pH 7.4 (PBS), loaded onto a solid-phase immunoextraction column and washed with 15 ml PBS followed by elution with 2 ml of elution buffer (40% ethanol in PBS, pH 4). The eluted fraction was analysed for morphine by HPLC-electrochemical detection using a cyanopropyl (CN) analytical column with 25% acetonitrile in phosphate buffer-sodium lauryl sulphate, pH 2.4 as the mobile phase. Duration of the extraction procedure was approximately 40 min. Calibration graphs were linear from 100 ng ml-1 to 500 ng ml-1 in urine. The inter-assay R.S.D. was < 10% and the recovery of morphine from urine was > 98%. Immunocolumns demonstrated remarkably high specificity towards morphine showing minimal binding with other opiate metabolites such as codeine, normorphine, norcodeine, morphine-3-glucuronide, morphine-6-glucuronide.  相似文献   

17.
A new sensitive assay has been developed for the quantitative measurement of BN50727 at the picomole level in human plasma and urine. The drug and the internal standard (BN50788) were measured by combined liquid chromatography/negative ion chemical ionization mass spectrometry with methane as the reagent gas. A simple solid-liquid extraction procedure was used to isolate BN50727 from the complex biological matrices. The mass spectrometer was tuned to monitor the intense and stable ion at m/z 333 which was generated in the ion source by a dissociative capture process. This assay was performed with 1 ml of plasma or 0.1 ml of urine and the quantification limit of the method was statistically calculated as 1 ng ml-1. The very low relative standard deviations and mean percentages of error calculated during the different within-day or between-day repeatability assays have clearly demonstrated the ruggedness of the technique for the routine determination of BN50727 in biological fluids. Some preliminary results on the pharmacokinetics of the drug are presented to illustrate the applicability of this powerful liquid chromatographic/mass spectrometric method.  相似文献   

18.
The structure of a plate apparatus for detoxication of biological fluids has been described. The operation of the apparatus for cholesterol recovery from blood and artificial biological fluid by the extracting emulsions "water in oil" has been investigated. The parameters of the apparatus, such as the number of plates, the height of the apparatus, the volume of extracting emulsion, have been determined. The blood flow velocity which excludes the entry of extracting emulsion drops into biological fluid has been chosen. The values of cholesterol recovery (22.4%) and of red blood cell hemolysis when blood is present in the working apparatus chamber have been defined.  相似文献   

19.
The application of capillary electrophoresis (CE) methods in forensic toxicology for the determination of illicit and/or misused drugs in biological samples is reviewed in the present paper. Sample pretreatments and direct injection modes used in CE for analysis of drugs in biological fluids are briefly described. Besides, applications of separation methods based on capillary zone electrophoresis or micellar electrokinetic chromatography with UV absorbance detection to (i) analysis of drugs of abuse, (ii) analysis of other drugs and toxicants of potential forensic interest and (iii) for metabolism studies are reviewed. Also, alternative CE methods are briefly discussed, including capillary isotachophoresis and separation on mixed polymer networks. High sensitivity detection methods used for forensic drug analysis in biological samples are then presented, particularly those based on laser induced fluorescence. A glimpse of the first examples of application of CE-mass spectrometry in forensic toxicology is finally given.  相似文献   

20.
A novel pH shock extraction procedure was used to measure nerve growth factor (NGF) levels in both normal and inflamed synovial fluids using a sensitive and specific two-site enzyme linked immunosorbant assay. To date no data is available on NGF levels in normal synovial fluids. Synovial fluids were taken from 5 normal volunteers, 12 patients with rheumatoid arthritis and 10 patients with other inflammatory arthropathies. The mean +/- SEM NGF concentration in normal synovial fluids was 95 +/- 33.2 pg/ml (range 39.1-143.1 pg/ml), whereas the mean NGF concentration in the synovial fluids taken from patients with rheumatoid arthritis was 532.5 +/- 123.8 pg/ml (range 152-1686 pg/ml). The mean NGF concentration in patients with other inflammatory arthropathies was also raised (430.6 +/- 90 pg/ml; range 89-1071 pg/ml). The NGF concentrations were significantly higher in the synovial fluids from both inflamed groups (ANOVA p < 0.05) compared to normals. Raised levels of NGF in synovial fluid may contribute directly to joint inflammation via activation of inflammatory cells.  相似文献   

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