Piece Of Adhesive Tape Research Articles

Mass producible, robust SERS substrates based on metal film on nanosphere (MFON) on an adhesive substrate for detection of surface-adsorbed molecules and their evaluation by helium ion microscopy.

We have developed a SERS stamp that can be pressed directly onto a solid surface for characterization of surface-adsorbed target molecules. The stamp was fabricated by transfer of a dense monolayer of SiO2 nanospheres from a glass surface onto a piece of adhesive tape and subsequent evaporation of silver. The performance of the resulting SERS stamps was evaluated by their exposure to methyl mercaptan vapor, and immersion in rhodamine 6G and ferbam solutions. It was found that beside the nanosphere diameter and metal deposition thickness, the extent of burial of the nanospheres into the adhesive tape, dictated by the pressure during the nanosphere transfer process, had a significant effect. We carried out FDTD calculations of the near field. Models are based on morphological information obtained from helium ion microscopy, which can provide high-resolution images of poor electrical conductors such as our SERS stamp. While one of our main eventual goals is detection of pesticides on agricultural produce, we have begun to take a careful step by testing our SERS stamp on better characterized surfaces such as a porous gel surface, having been immersed in fungicides such as ferbam. We also present our preliminary results with ferbam on oranges. It is expected that our well-characterized SERS stamp will play a role in shedding light on the poorly studied transfer process of target molecules onto a SERS surface as well as serving as a new SERS platform.

Adhesive-tape recovery combined with molecular and microscopic testing for the detection of Cryptosporidium oocysts on experimentally contaminated fresh produce and a food preparation surface

A proof of concept study was conducted to determine if transparent double-sided adhesive tape could be used to recover and detect [by polymerase chain reaction (PCR) and immunofluorescence microscopy (IFA)] Cryptosporidium parvum oocysts on fresh produce and on a food preparation surface. Oocysts were applied on the surface of ten apples, ten peaches, eight cucumbers, and eight tomatoes within circles drawn with a permanent marker. Approximately 18h later, skin excised from three uncontaminated and three contaminated circles from each piece of produce was subjected to PCR. Pieces of transparent double-sided adhesive tape were lightly pressed onto the surface of three other contaminated circles and examined by PCR. Other pieces of adhesive tape were pressed against the surfaces of three other circles and examined by IFA. At concentrations of 100 and 50 oocysts per circle, every produce item examined by PCR of contaminated excised skin was found positive, and every item examined by adhesive tape subjected to PCR and IFA was found positive, except one. At ten oocysts per circle, every produce item was found positive by PCR of contaminated excised skin, and all apples, cucumbers, and tomatoes were found positive by adhesive tape subjected to IFA. Detection of low numbers of oocysts on peaches by IFA examination of adhesive tape was problematic because trichomes that cover peaches and impart the fuzzy surface partially restrict the tape from reaching some areas where oocysts adhere. Tape combined with IFA was successful in recovering and identifying oocysts from six areas of laminate countertop where the oocysts had been applied and allowed to dry for 30-60min. These are the first findings to demonstrate that adhesive tape can be used to recover and identify a protozoan parasite from fresh produce and from a laminate food preparation surface.

Measurement of the amount and number of pollen particles of Cryptomeria japonica (Taxodiaceae) by imaging with a photoacoustic microscope

A photoacoustic microscope (PAM), which includes a condenser microphone and a pair of linear-motor-driven pulse stages, was specially designed for spectroscopic applications. The PAM was applied to measure the amount and number of pollen particles of Cryptomeria japonica (CJ), which is known for its allergic function against eyes and nose. The advantage of photoacoustic (PA) imaging is both its high sensitivity and its counting ability up to high concentrations of the specimen. The CJ pollen particles were fixed on a piece of adhesive tape or on albumen (egg white) on a glass slide set in a PA cell. The PA image showed the ability of this method to count CJ pollen from the several-hundred-milligram region to even a single particle. The PA signal obtained was integrated over the specimen surface. The dependence of the PA signal on the amount or number of the pollen particles was measured. The resulting coefficients of correlation of the calibration curves for the amount and the number of pollen particles were 0.94 and 0.97, respectively.

The Organs of Adhesion in the Aphid Megoura Viciae

ABSTRACT The anatomy of the adhesive organs is described in Megoura viciae Buckton. The claws serve as grappling hooks which are locked in position by the retractor unguis tendon. The pulvilli, pliable cuticular sacs, are everted from the tibiotarsal articulation. They bear a surface adhesive, a non-volatile oil, which is secreted through the cuticle. The pulvilli are everted by blood pressure and are withdrawn inside the tibia by contraction of the tibial muscles. The adhesion of these organs to various types of surface was tested by covering over the pulvilli or by claw amputation. Pulling forces were applied by progressively loading the aphid with weights. The pulvilli perform best on relatively smooth surfaces. Aphids are dislodged from the underside of polished glass by a mass of approx. 9-14 mg (a pulling force of 8·8-13·7xl0-5N). The claws cannot engage a completely smooth surface but are highly effective on rough ones, withstanding a load of approx. 57 mg on dry filter paper. Adhesion of the pulvilli to waxy surfaces is only slightly less than on glass but is greatly reduced on surfaces with still lower free energies, such as Teflon. On a glass surface the pulvilli sometimes leave ‘footprints’ consisting of oily droplets of variable size. Nevertheless, in many instances such deposits are small or absent, indicating that the bond sometimes breaks between the adhesive and the substratum. In a selected series of footprints with large deposits, their volume was found to be sufficient to form a layer at least 17·7xl0-9m in thickness over the area of pulvillar contact. This is consistent with the view that surface tension forces would adequately account for adhesion, an additional limiting factor being the physical properties (wettability) of the substratum. Viscous forces would impede the very rapid (less than 0-02 s) removal of the pulvilli, were it not for the retraction mechanism which peels off the pulvillus from the distal edge, like a piece of adhesive tape. The ultrastructure of the pulvillar gland is described. The epidermal cells discharge into a cavity which is confluent with a further reservoir within the spongy endocuticle, itself a meshwork of dissociated cuticular microfibrils. The points of exit of the secretion appear to be the epicuticular filaments. The product of the gland, which can be collected by pricking the pulvilli, is water soluble and proteinaceous, differing entirely from the hydrophobic lipid-soluble end-product on the pulvillar surface. We presume that the lipoprotein precursor is dissociated enzymatically at the level of the inner epicuticle.

Improved Microscopic Techniques for Droplet Size Determination of Emulsions

□ A novel, disposable cell for microscopic determination of the droplet size of emulsions is described. It is made from a piece of adhesive tape in which a hole has been punched which is placed between a glass slide and a cover glass. This cell is easier to fill with emulsions thickened to reduce Brownian motion and creaming than commercial counting chambers, and it prevents field flow. Droplet size averages and distributions obtained with this cell and another counting chamber agreed, provided that the emulsion viscosity was ~20 cp or higher. The sample size required to provide arithmetic mean diameters with a specified accuracy at a preselected confidence probability was calculated.

Fixation of Skin Grafts in the Horse using Stainless Steel Staples

Three horses with a chronic wound on the distal part of a leg were treated successfully by grafting. Small split skin grafts were fixed onto pieces of adhesive tape. The tape pieces were spread over and fixed to the granulation surface with stainless steel staples. A tight pressure bandage including strongly compressed cellular rubber was then applied over the wound. The combination of staple fixation and strong pressure proved effective in immobilising the skin graft. It was stressed that a firm covering of granulation tissue was a prerequisite for success and therefore the technique should not be used for fresh wounds.

Effects of Cellophane Tape Stripping of Mouse Skin on Epidermal Growth Regulators (Chalones)

Variations in epidermal chalones after a single surface application of methylcholanthrene and croton oil have been described in previous papers. This paper reports a study of the effect of adhesive tape stripping of the skin on epidermal growth regulators (G1 and G2 chalones). Pieces of adhesive tape were applied 6 times to the same area of skin in groups of mice. The short-term effects of tape stripping on epidermal DNA synthesis and on mitotic rate were studied at different intervals after stripping. Other groups of mice were killed at similar time intervals after stripping, and the treated area of skin was homogenized and extracted with water. The inhibitory effect of these extracts on normal epidermal DNA synthesis and mitotic rate was assayed in normal hairless mice. The resulting inhibitions were interpreted as an expression of the concentration of G1 or G2 chalone in the skin extracts. The first experiment confirmed that cellophane tape stripping gives rise to a short block in epidermal mitotic activity and probably also in DNA synthesis. This was followed by bimodal peaks of increased activity, the two maxima of labelling index being found on days 2 and 6, and the two maxima of mitotic rate on days 1-2 and 7. The concentrations of the two chalones in the skins of treated animals varied in inverse proportion to the alterations in the DNA synthesis and the mitotic rate, with one exception. Here there was initially a depression of the mitotic rate and a low concentration of G2 chalone. This was interpreted as a short reaction of the basel cells to the stripping trauma. It is concluded that adhesive tape stripping removes the differentiating cells and injures some basel cells, simultaneously altering the content of G1 and G2 chalones. The resulting increase in the rates of DNA synthesis and mitosis lasts only until the number of cells is high enough to produce growth-regulating substances (chalones) again. This theory may explain the changes observed. Since similar reactions are seen after both carcinogenic and co-carcinogenic chemical injury of the epidermis, the reaction pattern seems to be a general response to cell injury or cell removal.

Tape test as a simple new method for the study of compounds increasing the problem-solving ability of the rat.

A simple new method, the "tape test" has been developed for studying the enhancement of learning by drugs in "learning-dull" rats. A piece of adhesive tape is pressed on the left front pad of the rats. The time of tape removal by the animal, i.e., the problem-solving time is measured. In our experiments the selected learning-dull rats were used which were unable to remove the tape within 60 s observed on 3 consecutive days. The problem-solving ability of the rats was studied on 4 consecutive days, by posttrial administration. The problem-solving ability was found to be increased after treatment with different drugs such as para-chlorphenylalanine (PCPA), pemolin, orotic acid, vitamin B12. The stimulatory effect of vitamin B12 could be inhibited by vincristine.

A Method of Localizing Roots of Teeth, Residual Granulomas, or Foreign Bodies

The removal of a root of a tooth, or a foreign body, is sometimes difficult, especially if the object to be removed is distant from any landmark. Such difficulty is accentuated in supposedly edentulous mouths. Failure to determine the exact location may result in the loss of valuable processes and, in the upper jaw, of the opening into the antrum. In many instances, a patient may continue to wear the same denture if the root can be removed without loss of very much process; on the other hand, without localization, so much process may be destroyed as to make it necessary to rebase or build a new denture. Figures1, 2 and 3 illustrate the method of localizing roots and foreign bodies. A modified Boley gauge is used in conjunction with a small piece of metal (a clipping from a metal back of a dental X-ray film) and a piece of adhesive tape. While the gauge is being used to make the measurement, the number of millimeters is noted, and the same or a similar gauge is used during the operation. Thus it is possible for the operator to make an incision and lay back a flap that will expose the process directly over the root or foreign body to be removed. The advantage of the adhesive tape is in holding the metal to the gum without inflicting pain. If the measurement is made after the field of operation has been anesthetized, the method has no advantage over the older methods of inserting something metallic directly into the gum.