Samples slides

Stress and Energy Distribution in Rubber Samples Sliding... 

Very fast sample preparation and measurement (20 samples on a sample slide in 1 h)... 

Focus on the sample by raising the objective. Warning Do not lower the objective as it will crack the sample slide and possibly damage the objective. 

Again, rather than becoming overly analytical, let s just look at some sample slides created for the presentation discussed earlier. The first is the title slide (Figure 6.1). As you will notice, it contains the talk title, speaker name, address, and electronic address. Too many speakers begin their talks without mentioning who they are, where they are from, or what they will be talking about. It is a simple matter to ensure that your audience knows you, the title of your talk, and your affiliation. 

Very fine droplets tend to follow the streamlines. To account for this fact, any possible disturbance of the sampling slides to the flow field must be minimized to prevent the fine droplets escaping from the slides. For this purpose, the number and positions of the sampling slides in each run are arranged according to the moving tendency of the droplets. 

Mechanical Loading A mechanical load was applied to approximately half of the samples during environmental exposure. The shape of the molded samples matched slots in the stress rig so that the sample slides into the stress rig. The design of the rig and the shape of the molded samples are such that the sample is automatically aligned when it is installed in the stress rig. 

MALDI-TOF was done on a Kratos Kompact Maldi III mass spectrometer fitted with a standard 337 nm nitrogen laser and operated in the linear mode at an accelerating voltage of 20 kV. The matrix used was a-cyano-4-hydroxyciimamic acid (33mM in acetonitrile/methanol, premade from BRS) at a ratio of 1 1 with purified peptide samples. MALDI sample slides were loaded with O.S-1.0 uL of matrix/sample mixture (estimated 1-10 pmol peptide). The data was reprocessed using the Kratos software provided with the instrument. Theoretical masses were determined by utilizing a spreadsheet in which individual peptide masses were added to all possible caibohycfrate forms these masses were then compared to the observed masses to identify structures consistent with the mass results obtained. 

All mass spectra were acquired on a Kratos Kompact MALDI III time of flight mass spectrometer with a 337 nm N2 laser and a 20 kV extraction potential in the linear mode. Membranes were affixed to the Kratos sample slide with tape. Every spectrum was the average of 50 laser shots. Spectra were calibrated from external standards desorbed from the same membrane being tested. 

However a simple microscope may also be used given a degree of simple improvization. Obtain some polaroid sheet and secure a piece beneath the stage between the sample slide and light source (or reflecting mirror) as indicated in the Figure. 

A recommended indicator cell line is the Vero African green monkey kidney cell line, which has a high cytoplasm/nucleus ratio. The indicator cells are added at a concentration of approximately 1 x 10" cells ml to sterile coverslips in tissue culture dishes 10-24 h before inoculation. The test sample should be added at a concentration of approximately 5 x 10 cells ml" to give a semi-confluent mono-layer at the time of observation (at 1 and 3 days post-inoculation of the sample). Slides are prepared in the same way as those prepared by the direct method. 

With the experimental set up safely within a photochemical safety cabinet, a 125 W Hg arc lamp (medium pressure) is fixed at a distance of 10 cm from the sample slide. 

II. Repeat step 10 but take comer C to comer D. Then B to A and D to C. Note do not raise the comers so high that the sample slides across the paper. Keep the comers low so that the sample tumbles into itself, thus mixing the fine material in with the coarser particles. 

Tilt the cylinder and carefully insert the metal sample. Let the sample slide down the cylinder without splashing any water, as shown in Figure A. Make sure that the sample is completely under water and that there are no air bubbles. Then record the volume of water plus metal sample. 

FIGURE 4.7 Simplified TOF process of mass analysis. Ion source (matrix with analyte molecules) and sample slide (opening to drift region) possess a potential difference for accelerating different charged analyte ions. Source Harth-Smith and Barner-Kowollik [11], figure 1. Reproduced with permission of John Wiley Sons. 

The silsesquioxane mixtures or the separated silsesquioxanes can be analyzed by MALDl-TOF-MS (Table 2). MALDI-TOF mass spectrometry was carried out on a Kratos Kompact MALDI 111. 0.5 pL of a solution (25 mg/mL) of 2,4,6-trihydroxyacetophenone or 20 mg/mL of 2-nitrophenyl octyl ether and 10 mg/mL silver trifluoroacetate were mixed on a stainless steel sample slide. The solvent was evaporated in a stream of air at ambient temperature. Bovine insulin was used for calibration. Conditions for the measurements polarity positive, flight path reflection, 20 kV acceleration voltage, nitrogen laser (A = 337 nm). 

Figure 13.4 Details of fluorescence micrographs of the textile samples with endotheUal cells dyed with Rhodamine Phalloidin and DAPl, after 5 days of proliferation on the hiomaterial woven/velour sample. Slide (a) shows a representative plain woven section of the prosthesis, where few cells have proliferated. Slide (b) shows a representative velour section where endothelial cells have proliferated only along the fibers, with very few coimections between fibers.

Place the prepared sample slide on the mechanical stage of the microscope. Position the center of the wedge under the objective lens and focus upon the sample. 

For other types of polymers, especially glassy polymers that exhibit a high stiffness at room temperatnre, the effect of the snbstrate chemistry on the tribological behavior can be different. For example, previons stndies have been performed on polystyrene (PS) samples sliding against both hydrophobic and hydrophilic wafers [28, 29]. 

The availability of genome information for a particular pathogen allows the adaptation of bottom-up [36,37] or top-down [38 0] proteomics methodologies for microorganism identification by MS [41 5] (Fig. 3). These proteomics-based approaches are based on the initial identification of one or more individual protein biomarkers (from, e.g., their corresponding tryptic peptides and/or tandem mass spectra). By inference, the microorganism from which these proteins originate is then identified. For instance, rapid in situ (on a MALDI sample slide) proteolysis of... 

The large variety of possible sample applications (transmission of thin sample slides, reflection mode of thicker sections by Raman, MIRS, and NIRS with several millimeters of penetration depths) allows the direct analysis of infected plant tissue without any previous steps of isolation or cleanup, as demonstrated on the following plant fungal disease. 

FIG U RE 4.19 A sample holder for transmission analysis shown installed in the sample slide mount of an FTIR. The protruding metal arms can support the KBr windows, KBr pellets, mulls, cast films, and capillary thin films. 

In reflectance sampling it takes extra mirrors to focus the light onto the sample and to collect the reflected light. These extra mirrors are contained in reflectance accessories that either mount on the base plate in the FTIR sample compartment or slide into the sample slide mount. These accessories must be custom built for the make and model of FTIR in which they are going to be used. A problem with reflectance accessories is that they are thousands of dollars more expensive than transmission accessories. There are several companies that make customized FTIR reflectance accessories, and they can be found via an Internet search. 

This particular specular reflectance accessory slides into the sample slide mount in the FTIR s sample compartment. Its optical diagram is seen on the right in Figure 4.38. The sample is placed on top of the device, covering the hole. The infrared beam reflects from a flat mirror, from the sample, off a second flat mirror, and is then focused onto the FTIR s detector. The reflectance-absorbance spectrum of the paint on the outside of a full soda can taken with this device is shown in Figure 4.39. 

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