SEARCH · Search PubMed

Results for “Ink”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,711 records · Page 95Linked to original sources

PubMed2005

Expression of phosphorylated c-Jun N-terminal protein kinase (JNK) in experimental glaucoma in rats.

To examine the expression of phosphorylated c-Jun N-terminal kinase (JNK) in cells in the retinal ganglion cell layer of glaucoma, intraocular pressure (IOP) of adult Wistar rats was elevated unilaterally by repeated trabecular argon laser photocoagulation 5 days after intracameral injection of India ink. Animals were euthanized after 3 days, and 1, 2, and 5 weeks of IOP elevation. Immunohistochemistry with specific antibodies against phosphorylated JNK was performed on retinas. Retrograde labeling using Fluorogold and fluorescence immunohistochemistry was performed on retinas 5 weeks after IOP elevation. TdT-mediated biotin-dUTP nick end labeling (TUNEL) was performed on the retinal sections to determine the rate of cell death. There was increased IOP (52.3%) from 3 days to 5 weeks after repeated trabecular laser photocoagulation. Mean number of TUNEL-positive cells in the retinal ganglion cell layer of eyes with experimental glaucoma was 0.43, 0.36, 0.57, and 0.19 per retinal section at 3 days, and 1, 2 and 5 weeks, respectively. No TUNEL-positive cells were noted in controls. In parallel to TUNEL, significantly increased numbers of phosphorylated JNK-labeled cells in the retinal ganglion cell layer were noted at 3 days (9.95 versus 4.15; P=0.005), 1 week (7.65 versus 4.00; P=0.006), 2 weeks (9.13 versus 4.48; P=0.032), and 5 weeks (8.06 versus 4.96; P=0.017) of IOP elevation when compared with contralateral control eyes. Fluorogold labeled RGCs were co-localized with increased phosphorylated JNK immunoreactivity. Some TUNEL-positive cells were phosphorylated JNK immuno-positive. Phosphorylation of JNK occurs in experimental glaucoma and may play a role in retinal ganglion cell death.

Animals↗

PubMed2006

The volume and hydration of the Cryptococcus neoformans polysaccharide capsule.

We present a new method to measure capsule size in the human fungal pathogen Cryptococcus neoformans that avoids the limitations and biases inherent in India ink measurements. The method is based on the use of gamma-radiation, which efficiently releases the capsule from the cell. By comparing the volume of irradiated and non-irradiated cells, one can accurately estimate the relative size of the capsule per cell. This method was also used to obtain an estimate of the capsule weight and water content. The C. neoformans capsule is a highly hydrated structure in all the conditions measured. However, after capsule enlargement, the amount of capsular polysaccharide significantly increases, suggesting a that capsule growth has a high energy cost for the cell.

Cryptococcus neoformans↗

PubMed2006

Potentiality of 3D laser profilometry to determine the sequence of homogenous crossing lines on questioned documents.

The determination of the sequence of line crossings is still a current problem in the field of forensic documents examination. Optical examination, lifting technique, ESDA technique, and electron microscopy are the most widely used methods for the determination of the writing order of crossing texts. However, at present many examinations of intersecting lines result in an inconclusive opinion, particularly if the same type and colour of ink is involved. This paper presents the potentiality of the 3D laser profilometry, which has been to determine the chronological sequence of homogenous "crossing lines". The laser profilometry, illustrated in this paper, has been developed on a conoscopic holography based system. It is a non-contact three-dimensional measuring system that allows producing holograms, even with incoherent light, with fringe periods that can be measured precisely to determine the exact distance to the point measured. This technique is suitable to obtain a 3D micro-topography with high resolution also on surfaces with unevenness reflectivity (usual for the paper surface). The proposed technique is able to obtained 3D profile in non-invading way. Therefore, the original draft are not physically or chemically modified, allowing a multi-analysis in different times. The experiments performed with line crossings database show that the proposed method is able of "positive identification" of writing sequence in the majority of the tests. In absence of a positive identification, the result has been "inconclusive" (no false determination did occur in this work).

Journal Article↗

PubMedDate not supplied

Real-time spectroscopic assessment of thermal damage: implications for radiofrequency ablation.

Radiofrequency ablation (RFA) is an evolving technology used to treat unresectable liver tumors. Currently, there is no accurate method to determine RFA margins in real-time during the procedure. We hypothesized that a fiber-optic based spectroscopic monitoring system could detect thermal damage from RFA in real-time. Fluorescence (F) and diffuse reflectance (Rd) spectra were continuously acquired from within the expected ablation zone during canine hepatic RFA using a fiber-optic microinterrogation probe (MIP). The F and Rd spectral feedback were continuously monitored and ablations were stopped based on changes in spectra alone. After each ablation, the MIP tract was marked with India ink and the ablation zone was excised. The relationship of the MIP to the zone of ablation was examined grossly and microscopically. F and Rd spectral changes occurred in three characteristic phases as the ablation zone progresses past the MIP. Phase 1 indicates minimal deviation from normal lives. Phase 2 occurs as the MIP lies within the hemorrhagic zone of the ablated tissue. Phase 3 correlates with complete tissue coagulation. The absolute magnitude of spectral change correlates with the gross and histologic degree of thermal damage. Optical spectroscopy is a technology that allows real-time detection of thermal tissue damage. In this study, both F and Rd spectroscopy accurately defined the advancing hemorrhagic edge of the zone of ablation and the central coagulation zone. These results suggest that F and Rd spectroscopy can be used to create a real-time feedback system to accurately define RFA margins.

Animals↗

PubMed2006

[Glycol ethers reproductive risks].

Glycol ethers (GE) are a family of solvents, the use of which has increased dramatically since the 60's, in domestic and occupational mainly water-based products, such as paintings, inks, varnishes, cleaning agents. There are two subgroups: E series and P series. EGME, among the E series, is the reference substance. This is a reprotoxic chemical causing infertility and genital apparatus atrophy on both sexes, embryofetal toxicity through maternal exposure (malformation, growth alterations and functional deficits). European Union has classified nine other GE as reprotoxic. P series, with the beta isomers exception, has no specific reprotoxicity. Epidemiological studies published from the 80's onwards, have confirmed animal data (malformation, oligoazoospermia, spontaneous abortion, hypofertility). The effects can be observed even after the end of exposure. Risk assessment studies tend to prove that this massive exposure during several decades could have had an important impact on reproductive human health. Even if this exposure has considerably decreased since the last few years, a ban of reprotoxic GE, as required by two official bodies (CSC, CSHPF), seems necessary, due to the high risk level. Classification should be completed for some GE, not classified now (EGBE). Health assessment of past exposure should be carried out. Physicians should look after a possible glycol ethers responsibility when facing this kind of reprotoxic effects.

Abnormalities, Drug-Induced↗

PubMed2006

Significance and fate of septal fibrosis of the liver.

Septal fibrosis commonly occurs during chronic diseases of the liver. It is experimentally reproduced in a proportion of rats treated with pig-serum, and in 100% of rats infected with Capillaria hepatica. These models have only been used in relatively short-term studies. To contribute to the natural history and significance of hepatic septal fibrosis it is important to disclose its fate after prolonged observation, and following partial or total withdrawal of its inciting cause. Adult Wistar rats were sacrificed 3, 6, 9 and 12 months following inoculation of 800 embryonated eggs of C. hepatica. Besides routine histology, liver sections were submitted to immunohistochemical, immunofluorescence and ultrastructural techniques for the identification of cells and extracellular matrix components present in the fibrous septa. Septal blood vessels were studied after portal vein perfusion with India-ink, while the hepatic functional profile and levels of anti-C. hepatica antibodies were determined in collected sera. Results revealed that all parasites were already dead 2 months from inoculation, and the accumulated eggs in the liver lost their capacity to embryonate around the 4th-6th month, when progressive reduction in the number of cells and in the amount of collagen occurred in the septa. Septal fibrosis persisted throughout the time of experimentation (12 months). This fibrosis was seen as a supporting stroma for septal vessels that conducted portal blood directly to the sinusoids. Thus, persistence of fibrosis was probably related to its morphological and functional association with blood vessels.

Journal Article↗

PubMed2006

Event-related potentials during an emotional Stroop task.

Emotional Stroop tasks have gained wide interest in scientific literature in the last two decades. Although no direct measure of attention is employed, these studies infer the presence of preferential processing of threatening information based on reaction time (RT) impairment in a competing task. Because event-related potential (ERP) measures are sensitive to both the extent (amplitude) and speed (latency) of cerebral processing, they are valuable tools with which to examine more directly the claim that threatening stimuli are associated with enhanced attention. Twenty-two students rated a pool of words to identify those that were personally disturbing. Two word types (threat and neutral) were then compared in two tasks (color relevant, in which the color ink of words was identified, and word relevant in which words were classified as threatening or not). No emotional Stroop effect was observed in terms of longer RTs to identify the colors of threat words. ERP results provided valuable information about threat processing which was not observed with behavioral measures. Threat content was associated with larger P2 amplitude in the right than left hemisphere, and larger P3 amplitude, across tasks. The results indicate strong evidence for enhanced processing of threat-related stimuli in healthy individuals. It is concluded that ERPs are a sensitive measure of processes underlying emotional Stroop performance, which can be used to elucidate attentional biases in healthy and clinical populations.

Adolescent↗

PubMed2006

The impact of lobular carcinoma in situ in association with invasive breast cancer on the rate of local recurrence in patients with early-stage breast cancer treated with breast-conserving therapy.

PURPOSE: The significance of lobular carcinoma in situ (LCIS) associated with invasive breast cancer in patients undergoing breast-conserving therapy (BCT) remains controversial. We examined the impact of the presence and extent of LCIS associated with invasive breast cancer on clinical outcome in BCT patients. METHODS AND MATERIALS: From 1980 to 1996, 607 cases of invasive breast cancer were treated with BCT. All slides were reviewed by a single pathologist. Positive margin was defined as presence of invasive carcinoma/ductal carcinoma in situ at the inked margin. Multiple clinical, pathologic, and treatment-related variables were analyzed for their association with ipsilateral breast tumor recurrence (IBTR) and true recurrence/marginal miss (TR/MM). Median follow-up was 8.7 years. RESULTS: Fifty-six patients (9%) had LCIS in association with invasive cancer. On univariate analysis, positive final margin, positive/no reexcision, smaller maximum specimen dimension, and the presence of LCIS predicted for IBTR. The 10-year IBTR rate was 14% for cases with LCIS vs. 7% without LCIS (p=0.04). On multivariate analysis, positive margin (p<0.01), positive/no reexcision (p=0.04), and presence of LCIS (p=0.02) remained independently associated with IBTR; positive margin (p<0.01) and LCIS (p=0.04) were also associated with TR/MM failure. When examining only cases with negative final margins, the presence of LCIS remained associated with higher IBTR and TR/MM rates (p<0.01). CONCLUSION: The presence of LCIS was independently associated with higher rate of IBTR and TR/MM after BCT for invasive breast cancer. LCIS may have significant premalignant potential and progress to an invasive IBTR at the site of index lesion. The adequacy of excision of LCIS associated with invasive carcinoma should be considered in patients undergoing BCT.

Adult↗

PubMed2003

Mesoscale constitutive modeling of magnetic dispersions: material functions for shear flows.

We recently developed a constitutive model for magnetic dispersions by modeling the magnetic particles as rigid dumbbells dispersed in a solvent. The theory yielded a constitutive equation in which the stress tensor could be expressed as a function of the velocity gradient, an orientational order tensor, S, an average alignment vector, J, and any imposed external magnetic field, H. The constitutive equation is used here to predict material functions for steady shear flow (shear-rate dependent viscosity and first normal stress coefficient) as well as those for unsteady shear flows (stress growth upon inception of steady shear and small-amplitude oscillatory shear). The importance of effects of concentration, equilibrium nematic ordering in the dispersion, and anisotropy in the hydrodynamic drag are emphasized. Comparisons with available experimental data on viscosity for magnetic inks under steady shear flow and inception of steady shear flow show reasonably good agreement.

Journal Article↗

PubMed2004

Penetration into three-dimensional complex porous structures.

The short-term uptake of a fluid by porous media is important in a number of processes, such as in coating and printing operations. We present a new model to predict short-term absorption into real pore geometries taking into account fluid properties, surface forces, and the complex pore geometry. Two assumptions are made to reduce the complexity of the situation: (1) the flow resistance between pores can be estimated from pore geometry or air permeability measurements, and (2) the volume of fluid in the constrictions between pores is small. Pores can be connected in any manner and can be in any arrangement. The absorption rates predicted by the model are compared to experimental values obtained with coating layers of plastic, kaolin, and calcium carbonate pigments. These coatings are characterized in terms of void fraction, pore size, contact angle, and permeability. The comparison is good for water and inks when the air permeability of the porous layer is used to determine the average resistance to flow in the sample. These resistance values are close to the values obtained from pore geometries estimated from particle packing simulations.

Journal Article↗

PubMed2004

Stability of films with nanoparticles.

Numerous products (such as paints, inks, foods, and beverages) and processes (such as coating, coagulation, sedimentation, lubrication, and paper-making) depend on the stability of the liquid films separating the dispersed phase from the continuous phase in the presence of nanoparticles or surfactant micelles. Nanoparticles exhibit a tendency to form ordered layers (i.e., stratification) and particle in-layer structures in these thin films at a sufficiently high concentration, resulting in a structural force that stabilizes the dispersion. The dispersion stability depends on the film size and the nanoparticle concentration.

Journal Article↗

PubMed2005

Influence of anisotropy on the dynamic wetting and permeation of paper coatings.

A void network model, named Pore-Cor, has been used to study the permeation of an ink solvent into paper coating formulations coated onto a synthetic substrate. The network model generated anisotropic void networks of rectangular cross-sectional pores connected by elliptical cross-sectional throats. These structures had porosities and mercury intrusion properties which closely matched those of the experimental samples. The permeation of hexadecane, used as an analogue for the experimental test oil, was then simulated through these void structures. The simulations were compared to measurements of the permeation of mineral oil into four types of paper coating formulation. The simulations showed that the inertia of the fluid as it enters void features causes a considerable change in wetting over a few milliseconds, a timescale relevant to printing in a modern press. They also showed that in the more anisotropic samples, fast advance wetting occurred through narrow void features. It was found that the match between experimental and simulated wetting could be improved by correcting the simulation for the number of surface throats. The simulations showed a more realistic experimental trend, and much greater preferential flow, than the traditional Lucas-Washburn and effective hydraulic radius approaches.

Journal Article↗

PubMed2005

Synthesis of functional microcapsules containing suspensions responsive to electric fields.

A sort of functional microcapsules, which contain a suspension responsive to electric fields, is prepared by in situ polymerization of urea and formaldehyde. The suspension is made up of pigment phthalocyanine green (PPG) and tetrachloroethylene. In order to solve the particles' separation from the suspension during the microencapsulation and to obtain microcapsules applying to electronic ink display, the dispersibility of the particles, the contact angles between the particles and the tetrachloroethylene, and the influences of different emulsifiers on the microencapsulation are investigated. It is found that the dispersion extent and lipophilicity of the PPG particles are improved due to their surface modification with octadecylamine. The contact angles between the modified PPG particles and the tetrachloroethylene increase, and the PPG particles modified with 2 wt% octadecylamine have the best affinity for tetrachloroethylene. The interfacial tension between C(2)Cl(4) and H(2)O with urea-formaldehyde prepolymer descends from 43 to 35 mN/m, which indicates that the polymer has certain surface activity. However, water-soluble emulsifiers have an important influence during the microencapsulation because they can absorb on the surfaces of internal phase and prevent the resin of urea-formaldehyde from depositing there. From the SEM images of shell surface and cross section, the microcapsules have relatively smooth surfaces and the average thickness is about 4.5 mum. When the microcapsules are prepared with agitation rates of 1000 and 600 rpm, the mean diameters of the obtained microcapsules are 11 and 155 mum, respectively. The particles in the capsules move toward positive electrode with a responsive time of several hundred milliseconds while providing an electric field.

Journal Article↗

PubMed2006

Alternative models for determining the surface energy components in offset printing.

Different ways of calculating surface energy components for substrates used in offset printing are compared. The results of the very useful van Oss-Chaudhury-Good bi-bidentate model (vOCG) are simplified to mono-bidentate and mono-monodentate models. The unbalance in the acid-base values often obtained by the vOCG model is strongly reduced when applying the simple mono-monodentate model. Moreover, the frequently encountered problem of negative square roots of the acid and base components is removed. An attempt to describe the ink transfer during offset printing by calculating theoretical works of adhesion between ink/plate and ink/paper is also made. The effect of paper roughness on the wetting was studied with atomic force microscopy (AFM).

Journal Article↗

PubMed2006

Chitosan-N-poly(ethylene oxide) brush polymers for reduced nonspecific protein adsorption.

The possibility of using a novel comb polymer consisting of a chitosan backbone with grafted 44 units long poly(ethylene oxide) side chains for reducing nonspecific protein adsorption to gold surfaces functionalized by COOH-terminated thiols has been explored. The comb polymer was attached to the surface in three different ways: by solution adsorption, covalent coupling, and microcontact printing. The protein repellent properties were tested by monitoring the adsorption of bovine serum albumin and fibrinogen employing surface plasmon resonance and imaging null ellipsometry. It was found that a significant reduction in protein adsorption is achieved as the comb polymer layer is sufficiently dense. For solution adsorption this was achieved by adsorption from high pH solutions. On the other hand, the best performance of the microcontact printed surfaces was obtained when the stamp was inked either at low or at high pH. For a given comb polymer layer thickness/poly(ethylene oxide) density, significant differences in protein repellent properties were observed between the different preparation methods, and it is suggested that a reduction in the mobility of the comb polymer layer generated by covalent attachment favors a reduced protein adsorption.

Adsorption↗

PubMed2004

The reproducibility of ultrasonic enamel thickness measurements: an in vitro study.

OBJECTIVES: The diagnosis of tooth wear is mostly based on visual scoring systems. Recently, methods measuring ultrasonic enamel thickness have been proposed. The aim of this study was to evaluate the reproducibility and evaluate factors affecting variation of ultrasonic enamel thickness measurements in an in vitro set up. METHODS: Four observers (1-4) in two institutes (G and S) performed ultrasonic enamel thickness measurements at buccal and palatal surfaces of extracted teeth placed in a phantom jaw. A Panametrics 25DL thickness gauge (Panametrics, Waltham MA, USA), with a 15 MHz transducer, covered by a plexi-glass delay line with a tip diameter of 2 mm was used, coupled to a laptop computer. After one week these measurements were repeated. Subsequently four selected teeth were measured 20 times at a fixed buccal site by one observer. Finally, two observers made ink marks with the instrument probe tip on the buccal and palatal surfaces of all teeth. This was repeated after one week. Digital images were made of the marked teeth and analysed to determine variation in positioning. The underlying enamel thickness variation was subsequently estimated. Results were analysed by calculating the 95% range of measurement variation (RMV, 4 x standard deviation) for each experiment. RESULTS: The main reproducibility experiment showed a 95% RMV of 0.79 mm (observer 1G), 0.64 mm (observer 2G), 0.63 mm (observer 3S), 0.71 mm (observer 4S), 0.51 mm (observer 1S). The repeatability experiment showed a mean 95% RMV of 0.26 mm. The probe position variation in the cervical-incisal direction resulted in an estimated thickness 95% RMV of 0.10 mm (1G) and 0.09 mm (2G). CONCLUSIONS: It was concluded that, due to measurement variation, thickness changes of less than 0.33 mm cannot be detected reliably. Probe positioning and a poor repeatability were responsible for only a small part of the total variation. Hence other factors influencing variation in enamel thickness are still to be identified.

Dental Enamel↗

PubMed2006

Biopotential fiber sensor.

UNLABELLED: We have developed a new biopotential fiber sensor (BFS) technology as an alternative to traditional wet-gel Ag/AgCl electrodes in long-term monitoring applications. Biopotential fiber sensor technology uses proprietary method of bonding copper sulfide to the surface of acrylic fibers, thus creating an electrically conductive medium (10(-1) ohms/cm). Surface modified bundles of acrylic fibers form stable biopotential sensors when doped with proprietary ink comprising organic acids and nano particles of Ag and AgCl. Biopotential fiber sensors are characterized by a small footprint 0.1 mm2 and low mass of 0.005 g. Biopotential fiber sensor systems are disposable 1-piece assemblies combining the functions of the electrodes, lead wires and a patient cable. METHODS: The electric performance characteristics of BFS were obtained according to American National Standards Institute/Association for the Advancement of Medical Instrumentation EC-12:2000 standard and compared with Ag/AgCl wet-gel electrodes. The noise characteristics were determined from 250 hours of 3-lead electrocardiographic (ECG) data recorded with BFS over a period of 10 days from healthy volunteers. RESULTS: The BFS direct current offset voltage was 0.11 mV and alternate current impedance at 10 Hz was 22 ohms. The sensors average longevity on the body surface with no detachments was at least 7 days. BFS demonstrated high immunity to motion and electric field-induced artifacts. CONCLUSIONS: Biopotential fiber sensors are well suited for routine long-term ECG monitoring applications because of increased patient comfort through integration of the electrode, lead wire, and a patient cable, which function into one disposable BFS fiber assembly. Biopotential fiber sensor have electrical characteristics comparable to Ag/AgCl wet electrodes. We observed an improved ECG signal quality, reduced frequent electrode detachments, reduced wire clutter and entanglement, and improved sensor adherence to the skin over longer periods of time.

Action Potentials↗

PubMed2004

Site- and exercise-related variation in structure and function of cartilage from equine distal metacarpal condyle.

OBJECTIVE: Determine (1) the site-associated response of articular cartilage of the equine distal metacarpal condyle to training at a young age as assessed by changes in indentation stiffness and alterations in cartilage structure and composition, and (2) relationships between indentation stiffness and indices of cartilage structure and composition. METHOD: Experimental animals (n=6) were trained on a track (increasing exercise to 1km/day by 5 months); controls (n=6) were pasture-reared. Animals were euthanized at 18 months and four osteochondral samples were harvested per metacarpal condyle from dorsal-medial, dorsal-lateral, palmar-medial, and palmar-lateral aspects. Cartilage was analyzed for India ink staining (quantified as reflectance score (RS)), short-term indentation stiffness (sphere-ended, 0.4mm diameter), thickness, and biochemical composition. RESULTS: Cartilage structural, biochemical and biomechanical properties varied markedly with site in the joint. Sites just medial and just lateral to the sagittal ridge showed signs of early degeneration, with relatively low RS, indentation stiffness, and collagen content, and relatively high water content. Effects of exercise and side (left vs right) were not detected for any measure. Overall, indentation stiffness correlated positively with RS and collagen content, and inversely with thickness and water content. CONCLUSION: Gentle exercise-imposed mechanical stimulation did not markedly affect articular cartilage function or structure. However, the marked site-associated variation suggests that biomechanical environment can initiate degenerative changes in immature cartilage during joint growth and maturation.

Animals↗