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PubMed2004

Development and evaluation of biocompatible inks for the local measurement of oxygen using in vivo EPR.

In vivo EPR oximetry is a powerful minimally invasive method that allows the measurement of oxygen in tissues through the use of a paramagnetic probe. In the present study, we investigated new strategies for preparing biocompatible inks containing carbon black particles (Printex U), which could be used as oxygen sensors. The carbon black particles were dispersed in solutions of biocompatible polymers of carboxy methyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC) or polyvinyl pyrrolidone (PVP). A total of 12 polymers with different molecular weights were tested. A physico-chemical characterization of the inks was carried out to assess the sedimentation of the particles, the rheological behavior of these inks, and the relative diffusion of the inks. The preparations with CMC and PVP had the highest viscosity and stability. The presence of the polymers did not modify the calibration curves (EPR linewidth as a function of the pO2) of the carbon black. In vivo, the oxygen sensors were stable for at least one month in muscles as the EPR linewidth remained fully sensitive to induced ischemia or carbogen challenge. The calibration curve was not modified after this period of implantation. A first study of biocompatibility was carried out in vitro (hemolysis and cytotoxicity assay) and in vivo (histological examination). No sign of toxicity was observed using these inks. These preparations are good candidates for future in vivo studies including clinical trials.

Animals↗
PubMed1983

Electron microscopic studies on multinucleate foreign body giant cells derived from Kupffer cells in mice given Indian ink intravenously.

Changes in Kupffer cells in mice given intravenous Indian ink were studied with the electron microscope. Kupffer cells as well as hepatic sinusoidal endothelial cells take up Indian ink particles by pinocytosis. In addition, a few Ito cells and hepatocytes ingest a small number of particles. The carbon particles are stored in cytoplasmic vacuoles in all these cell types. Aggregates of Kupffer cells containing many vacuoles stuffed with carbon particles are seen in the sinusoidal lumen, Disse space and interlobular connective tissue space 3 and 4 days after injection with Indian ink. One month after the injection, large clumps of aggregated Kupffer cells containing numerous carbon-filled vacuoles are distributed in the Disse space and other connective tissue spaces. The Kupffer cells in these clumps are in close contact and are partly fused with one another. After 3, 4 and 6 months, large multinucleate foreign body giant cells with numerous large vacuoles containing densely-packed ink particles are seen throughout the liver tissue. They are considered to be formed by fusion of Kupffer cells. Some endothelial cells also store ink particles in cytoplasmic vacuoles for as long as 6 months after injection.

Animals↗
PubMed2001

A comparison of ink-directed and traditional whole-cavity re-excision for breast lumpectomy specimens with positive margins.

BACKGROUND: Excising a breast tumor with negative margins minimizes local recurrence. With a positive margin, the standard re-excision consists of excising the whole cavity and all surrounding breast tissue. By marking the sides of the lumpectomy specimen with six different colored inks, the surgeon can limit the re-excision to the involved margin. We compared the local recurrence rate after these two re-excision methods. METHODS: Records were reviewed of 527 women (546 breasts) treated with lumpectomy at two institutions. The log-rank test was used to compare the local recurrence-free survival. RESULTS: Of 546 tumors, 245 (45%) had negative margins on the initial lumpectomy and were not re-excised. Fifty-five percent had a positive or close margin; 181 underwent whole-cavity re-excision, and 120 had ink-directed re-excision. The mean follow-up time was 3.4 years. There was no significant difference in local recurrence for the patients whose initial margin was negative (3.7%) compared with the 243 patients with initially positive margins who underwent a re-excision (3.3%). Eleven of 181 (6%) patients undergoing a whole-cavity re-excision developed a local recurrence, compared with none of 120 (0%) patients with an ink-directed re-excision (P = not significant). Tissue mass excised was significantly smaller in the ink-directed group (23 vs. 83 g, P < .05). CONCLUSIONS: Ink-directed re-excision of lumpectomy specimens with positive margins minimizes the amount of breast tissue removed without increasing the incidence of local recurrence and is therefore preferable to the standard whole-cavity method.

Breast Neoplasms↗
PubMed1999

Chromatographic and electrophoretic approaches in ink analysis.

Inks are manufactured from a wide variety of substances that exhibit very different chemical behaviors. Inks designed for use in different writing instruments or printing methods have quite dissimilar components. Since the 1950s chromatographic and electrophoretic methods have played important roles in the analysis of inks, where compositional information may have bearing on the investigation of counterfeiting, fraud, forgery, and other crimes. Techniques such as paper chromatography and electrophoresis, thin-layer chromatography, high-performance liquid chromatography, gas chromatography, gel electrophoresis, and the relatively new technique of capillary electrophoresis have all been explored as possible avenues for the separation of components of inks. This paper reviews the components of different types of inks and applications of the above separation methods are reviewed.

Chromatography↗
PubMedDate not supplied

Using Raman spectroscopy to solve crime: inks, questioned documents and fraud.

Raman microscopy is becoming a tool of major importance in forensic analysis, particularly of drugs and explosives. It is a non-invasive, non-destructive chemical probe allowing samples to be examined in their entirety without any preparation. This paper demonstrates the use of the technique as a general tool for inks analysis. Furthermore, it addresses two important issues that historically have been extremely difficult for the professional document examiner, namely, comparison of black ballpoint inks and the chronological sequencing of crossed ink lines. We show that Raman can successfully distinguish between a representative sample of commercially available black ballpoint inks. This data has been converted into a database for future reference. A method for chronological sequencing of crossed ink lines has been developed using confocal Raman microscopy. Case study work has shown the feasibility of this approach.

Databases, Factual↗
PubMedDate not supplied

An ink impregnation study of the migratory skin in the external auditory canal of the guinea-pig.

If the tympanic membrane or attic skin is wounded with a fine needle dipped in ink, ink particles are introduced into the epidermis and underlying tissue. These particles are subsequently taken up by cells in the epidermis and dermis. In this experiment the distribution of ink within the skin of ear canal was studied in nineteen guinea-pigs, one to ten days after wounding. Examination of the intact canal reveals that ink becomes distributed along a precise line from the wound to the point of desquamation. On sectioned tissue, the ink in this line is found to be mainly intracellular, initially in the epidermis, and subsequently in the upper dermis. When considered with other evidence, these results indicate that migration probably occurs in the deeper layers of the epidermis, and that it stops at the junction of the deep and superficial parts of the ear canal.

Animals↗
PubMed2000

[Spectral analysis and composition determination of blue ballpoint writing inks].

Main compositions of ballpoint inks were determined by analyzing some tropical Fourier Transform Infrared(FTIR) spectra of 108 kinds of ballpoint inks. By using this method, the blue ink samples have been divided to two groups, 18 species depend on their spectral characteristics such as peak location, peak intensity. The reaction mechanism of age changes due to aging of the ink's compositions was discussed. The study is the first step for establishing the analytical date base of ballpoint inks system and estimating the age of ballpoint in written text has been offered. The advantage of this method is fast, reliable and nondestructive.

Handwriting↗
PubMed2001

[Studies of black roller pen inks by NIR FT-Raman spectrometry].

36 kinds of black roller pen inks collected from Chinese market were analyzed by NIR FT-Raman spectroscopic technique and they were divided into 10 groups (from A to J group) according to their characteristic Raman spectra. Based on studying main component of roller pen inks and peculiarity of Raman spectrum by documents, the main Raman peaks of each group of roller ball inks were interpreted particularly. It have also been investigated that the influence factors from paper matrix, humidity of the samples, laser power and writing time, especially the forth item showed some relationships of the peak intensity ratio with the relative age of inks. This method is speediness, convenience, high sensitivity and no ink-extraction process. The insufficiency of the method is that fluorescence and heat background comes forth when a few samples were irradiated by laser.

Forensic Medicine↗
PubMed2006

[Determination of writing age of blue ballpoint pen inks by high performance liquid chromatography].

As it is a frequently encountered problem in the laboratory of forensic science nowadays to distinguish whether the questioned documents, such as deeds, contracts, and receipts, written in ballpoint pen inks are true or not, and identify the writing age of them, it is very essential to establish a simple, sensitive and accurate method to examine the similarities and differences of the ballpoint pen inks and identify the writing age. The present paper introduces a technique that allows identifying the kind and the writing age of the blue ballpoint pen inks. The technique is based on using a high performance liquid chromatographic method for distinguishing the similarities and differences in dyes of blue ballpoint pen inks and determining changes in dyes of blue ballpoint pen inks developed with age, and these changes can be evaluated by the ratio of peak areas.

Chromatography, High Pressure Liquid↗
PubMed1998

[Lichenoid contact dermatitis from the ink of a red pen].

INTRODUCTION: Numerous cutaneous inflammatory reactions have been reported in literature, after using red dyes; most of them are lichenoid reactions and occur after tattooing. Few reports have mentioned inflammatory complications after using red ink. CASE REPORT: A 21-year-old woman was examined for papular erythematous, pruritic lesions on the back of her left hand. They developed within the area of a red inked pen writing, a few days before. There was an isomorphic reaction on the cheek which was in contact with the hand during sleep. Diagnosis of lichen reaction to red ink was made, and histologically confirmed on the hand. DISCUSSION: We report the first case to our knowledge of lichen reaction to red inked pen, which can be compared to hypersensitivity reactions to red pigment reported in literature. A Koebner phenomenon by friction, usual with lichen, is possible, but doesn't explain the reaction on the cheek. A contact dermatitis to red pigment of ink can also be suggested, although mostly eczema-like reactions have so far been reported; it seems moreover that lichenoid reactions reported only occur after intradermal injection of pigment during tattooing. This contact mechanism would nevertheless explain both localizations of lichen reaction in our patient.

Adult↗
PubMed1981

Simulation of the neural activity underlying a short-term modification of inking behavior in aplysia.

Carew and Kandel (1977) found that weak stimuli to the head or siphon fail to elicit the release of ink. When paired with each other, however, the second of the two leads to the release of ink. The present paper quantifies and simulates the neural events which underlie this short-term modification of the behavior. Noxious stimuli to the intact animal were mimicked by delivering trains of electrical stimuli to the connectives (conditioning input) and siphon nerve (test input) which drive the ink gland motor neurons located within the abdominal ganglion. Estimates of the synaptic conductance and equilibrium potential during the conditioning and test inputs were made and used to drive a previously developed Hodgkin-Huxley model of the ink motor neurons. The experimental and simulated results are in good agreement. Activation of one stimulus pathway augments or facilitates the ability of the other pathway to fire the ink motor neurons. The behavioral modification is causally related to a sustained synaptic current activated by the conditioning stimulus.

Animals↗
PubMed1995

Comparison of the sensitivity of different India inks staining of electro-blotted proteins on filter membranes.

The sensitivity of different brands of India ink for staining proteins blotted onto filter membranes is described. Proteins that are electro-blotted onto filter membranes show better retention than those dot-blotted alone. Higgins engrossing waterproof black ink No. 893 can detect protein at a concentration as low as 5 ng which is much more sensitive than Coomassie blue. The nitrocellulose membrane from S&S is ideal for blotting proteins and gives low levels of background staining. The sensitivity of protein staining is however, affected by the types of India ink, ink concentrations, staining times and membrane lots. India ink is also found to be useful for staining circulating immune complexes separated by SDS-PAGE and electro-blotted onto filter membranes.

Antigen-Antibody Complex↗
PubMed2006

Spreading on and penetration into thin, permeable print media: application to ink-jet printing.

This paper examines spreading and penetration of surfactant-laden drops on thin-permeable media with reference to ink-jet printing. A detailed review of the interaction of both pure liquids and surfactant containing solutions with porous substrates is given for individual spreading and penetration and for the combined processes. A new model based on energy arguments is derived and compared to current hydrodynamic equations used to describe simultaneous spreading and penetration. Three studies of how surfactant solutions interact with thin commercial ink-jet photographic quality papers are presented. Here, two relevant systems are examined: Tergitol 15-S-5 and 1,2-octanediol. The first study examines the spreading and penetration profiles for surfactant solutions over a range of concentrations spanning their critical micelle concentration. As expected, these profiles depend on the concentration of surfactant and the chemistry of the medium with which it interacts. In many cases, partial vertical penetration of the region directly beneath the drop dominates at low interaction times and will be significant in ink-jet applications. The second study consists of a parametric investigation of the energy-based model derived herein. It shows that the model can capture all of the behaviors observed in the first study. In the final study, the ability of the energy-based model to fully predict the spreading behavior of Tergitol 15-S-5 solutions is tested. It is found that the model produces good quantitative agreement at the highest concentrations and, as such, will be useful in screening spreading dynamics concentrated systems like ink-jet inks. Agreement at low to intermediate concentrations is often limited by finite induction periods prior to significant spreading and penetration. Possible corrections that could improve the agreement for weakly concentrated solutions are discussed, and directions for future studies of simultaneous spreading and penetration are proposed.

Journal Article↗
PubMed1991

Ophthalmic pre-inked marking pad.

Various markers that facilitate incision and suture placement are available. The majority are used in conjunction with a surgical marking pen or ink. This report describes a new, disposable pre-inked marking pad which is conveniently packaged, easy to use, and compatible with most markers. The pad is saturated with gentian violet ink which enables an ideal transfer of inked marks from the marker to the eye or skin. The ink marks remain on the tissue for two to four hours before fading, even on wet and moist surfaces such as the cornea and sclera.

Cataract Extraction↗
PubMedDate not supplied

Differentiation of coloured inks of inkjet printer cartridges by thin layer chromatography and high performance liquid chromatography.

Document examiners are frequently asked to determine whether or not a colour printout has originated from a particular inkjet printer. The printer can rarely be identified unless some unique defects or irregularities of the printer are present on the printout. However, it is possible to decipher the make and/or model of the printer by comparing the ink-profile of the questioned printout with that of a seized inkjet printer cartridge or from one in a database. This paper presents an overview of a systematic approach to characterising and discriminating the inks of different inkjet printer cartridges using thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC) with multi-wavelength ultra-violet/visible (UV/Vis) detection. Ink samples from 23 different inkjet printer cartridges (including originals and substitutes) of different brands and colour printouts, printed by known printers were examined with newly developed chromatographic methods. Subsequently, a database of the ink-profiles was generated. The methods provide a useful tool for discriminating coloured inks in inkjet printer cartridges of different brands.

Journal Article↗
PubMed2006

Double-ink dip-pen nanolithography studies elucidate molecular transport.

We have investigated the transport mechanism of the inks most typically used in dip-pen nanolithography by patterning both 16-mercaptohexadecanoic acid (MHDA) and 1-octadecanethiol (ODT) on the same Au{111} substrate. Several pattern geometries were used to probe ink transport from the tip to the sample during patterning of both dots (stationary tip) and lines (moving tip). When ODT was written on top of a pre-existing MHDA structure, the ODT was observed at the outsides of the MHDA structure, and the transport rate increased. In the reverse case, the MHDA was also observed on the outsides of the previously patterned ODT features; however, the transport rate was reduced. Furthermore, the shapes of pre-existing patterns of one ink were not changed by deposition of the other ink. These results highlight the important role hydrophobicity plays, both of the substrate as well as of the inks, in determining transport properties and thereby patterns produced in dip-pen nanolithography.

Journal Article↗
PubMed2000

Spectral model of a fluorescent ink halftone.

A model is presented of a fluorescent ink halftone. Unlike a nonfluorescent ink, which only absorbs, a fluorescent ink absorbs higher-energy photons and emits lower-energy photons. The amount of fluorescent light produced depends on the percent absorption of the incident light. For fluorescent ink printed on paper, both photon scattering within the paper substrate and multiple internal reflections between the ink layer and the paper substrate significantly increase the percent absorption, so a realistic model must include these effects. The model presented here utilizes the generalized Clapper-Yule theory, which accounts for photon diffusion that is due to both scatter and internal reflection. It is shown that while multiple internal reflections alone only marginally increase the percent absorption, when there are both scattering and internal reflection, the percent absorption is increased significantly. The current study is a theoretical model and does not present experimental results.

Journal Article↗
PubMed2001

The effect of various root canal sealers on India ink and different concentrations of methylene blue solutions.

In this study, the effect of different root canal sealers on 1%, and 2% methylene blue (MB) solutions and India ink were analyzed using spectrophotometry. One hundred and twelve specimens were used in this study. One hundred and five plastic tubes were filled with Sealapex, Endomethasone, Sultan, AH Plus or Ketac Endo. Twenty-one plastic tubes were used for each group. Seven plastic tubes were not filled, serving as controls. Seven specimens were taken from each group randomly and immersed in 0.8 ml 1% MB, 2% MB or black India ink. The optical density of the solutions after 0, 24, 48 and 72 hours of immersion was measured in a spectrophotometer at 416 nm. The optical density (OD) of the solutions was stable for the control group. The OD values for the 1% MB solutions were increased in the Sealapex and Sultan groups. The OD values for the 2% MB solutions were also increased for Sealapex and AH Plus. OD values were decreased for all India ink groups. The change in OD values relating to each time interval was statistically analyzed for each test material using two-way ANOVA. In the dye leakage studies, India ink, when compared to MB solutions, was a more reliable tracer as no dissolution of the root canal sealers occurred in contact with India ink.

Administration, Topical↗