Showing papers on "Blisters published in 1999"

Explanations for the clinical and microscopic localization of lesions in pemphigus foliaceus and vulgaris

Abstract: Patients with pemphigus foliaceus (PF) have blisters on skin, but not mucous membranes, whereas patients with pemphigus vulgaris (PV) develop blisters on mucous membranes and/or skin. PF and PV blisters are due to loss of keratinocyte cell–cell adhesion in the superficial and deep epidermis, respectively. PF autoantibodies are directed against desmoglein (Dsg) 1; PV autoantibodies bind Dsg3 or both Dsg3 and Dsg1. In this study, we test the hypothesis that coexpression of Dsg1 and Dsg3 in keratinocytes protects against pathology due to antibody-induced dysfunction of either one alone. Using passive transfer of pemphigus IgG to normal and DSG3null neonatal mice, we show that in the areas of epidermis and mucous membrane that coexpress Dsg1 and Dsg3, antibodies against either desmoglein alone do not cause spontaneous blisters, but antibodies against both do. In areas (such as superficial epidermis of normal mice) where Dsg1 without Dsg3 is expressed, anti-Dsg1 antibodies alone can cause blisters. Thus, the anti-desmoglein antibody profiles in pemphigus sera and the normal tissue distributions of Dsg1 and Dsg3 determine the sites of blister formation. These studies suggest that pemphigus autoantibodies inhibit the adhesive function of desmoglein proteins, and demonstrate that either Dsg1 or Dsg3 alone is sufficient to maintain keratinocyte adhesion.

Onset of blistering in hydrogen-implanted silicon

Abstract: The onset of surface blistering in hydrogen-implanted single crystalline silicon was studied. A combination of atomic force microscopy and optical measurements shows that hydrogen-containing platelets grow laterally below silicon surface until they suddenly pop up as surface blisters due to the internal hydrogen pressure after a critical size has been reached. Experimentally and theoretically, the critical size of the onset blisters was found to increase with increasing implantation depth or top layer thickness.

Blister fluid cytokines in cutaneous inflammatory bullous disorders.

Abstract: Cytokines are important regulators of immune and inflammatory reactions in the skin, and may contribute to inflammatory blister induction. We examined the profiles of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) in fluid of spontaneous blisters in the immune-based inflammatory disorders bullous pemphigoid (8 patients), allergic contact dermatitis (5 patients) and toxic epidermal necrolysis (5 patients). These were compared with levels in 9 patients with burns, i.e. inflammatory blisters of non-immune aetiology, and 4 patients with blisters of physical origin. Very high levels of IL-6 were found in bullous pemphigoid and toxic epidermal necrolysis (p<0.001) compared with non-inflammatory and burn blisters. TNF-alpha levels were high in bullous pemphigoid and burns, but undetectable in non-inflammatory blisters. The pattern in bullous pemphigoid (very high IL-6, high TNF-alpha) differed substantially from toxic epidermal necrolysis (very high IL-6, low TNF-alpha), while burns and allergic contact dermatitis showed lesser elevation of both cytokines. Hence, differences in cytokine profiles were identified, although the relevance to underlying pathomechanisms is uncertain.

Blister package with easy tear blister

Abstract: A blister package (10) is disclosed that comprises a blister layer having an article receiving blister (38) formed therein for holding medicaments, and a base layer (32). The blister layer has one or more tearing blisters (34) joined to the base layer except in the areas of the article receiving blister and the tearing blisters. The portions of the base layer (32) and the blister layer (30) that are joined together cannot be readily torn from the outer edges of the blister package, but the portion of the blister layer that forms the tearing blister (34) is thin enough that the tearing blister and the portion of the base layer under the tearing blister can be readily torn from the outer edge of the blister package.

Treating traumatic burns or blisters of the skin

Abstract: Blisters of the skin are treated by applying to the skin over the blister a flexible moisture-containing hydrophilic hydrogel patch that includes a backing support such as paper, cloth or plastic and a water-based hydrogel layer applied to the backing. The hydrogel layer comprises a hydrophilic natural or synthetic polymer to provide body dispersed in water and can be a tacky adhesive. The polymer can comprise any high molecular weight hydrophilic carbohydrate such as karaya, cornstarch, or a kelp gel and/or a synthetic hydrophilic polymer such as polyacrylamide or polyacrylic acid. A humectant such as a polyhydric alcohol, keeps the gel layer moist. A solute such as salt, protein, sugar or an alcohol is dissolved in the water in a quantity sufficient to raise the osmotic pressure enough to maintain the hydrogel layer in a hypertonic state with respect to the blister. The hydrogel which hydrates the normally dry upper layer of skin forms a hydrophilic bridge with the patient's skin that allows fluid to be drawn by osmotic pressure from the blister through the normally dry stratum corneum into the patch. In addition, the hydrogel very quickly significantly dimishes the pain secondary to skin burns and blisters.

The influence of boron ion implantation on hydrogen blister formation in n-type silicon

Abstract: We have studied the formation of surface blisters in 〈100〉 n-type silicon following co-implantation with boron and hydrogen. The silicon substrates had four different n-type dopant levels, ranging from 1014 to 1019 cm−3. These substrates were implanted with 240 keV B+ ions to a dose of 1015 cm−2, followed by a rapid thermal anneal at 900 °C for 30–60 s to force the boron atoms into substitutional lattice positions (activation). The samples were then implanted with 40 keV H+ to a dose of 5×1016 cm−2. The implanted H+ distribution peaks at a depth of about 475 nm, whereas the distribution in the implanted B+ is broader and peaks at about 705 nm. To evaluate the role of the B+ implantation, control samples were prepared by implanting with H+ only. Following the H+ implantation, all the samples were vacuum annealed at 390 °C for 10 min. Blisters resulting from subsurface cracking at depths of about 400 nm, were observed in most of the B+ implanted samples, but not in the samples implanted with H+ only. This s...

Hydrogen blister depth in boron and hydrogen coimplanted n-type silicon

Abstract: We have studied the depths of hydrogen surface blisters in 〈100〉 n-type silicon, which formed after B+H coimplantation and heat treatment. The silicon substrates had three different dopant levels, ranging from 1014 to 1019 cm−3. The Si substrates were first implanted with B+ ions at 147 keV to a dose of 1015 cm−2. Some of the B-implanted samples were left in their as-implanted state; others were electrically activated by a rapid thermal anneal. The samples were then implanted with 40 keV H+ to a dose of 5×1016 cm−2. At the chosen implantation energies, the hydrogen- and boron-implantation distributions overlap. Following H+ implantation, all the samples were vacuum annealed and examined by ion-beam analysis and scanning electron microscopy. In all cases, the blister depth was consistently found to be strongly correlated with the H damage profile rather than the H or B concentration profiles.

Substrate composition effects on the interfacial fracture of tantalum nitride films

Abstract: In this study we combined nanoscratch testing with a multilayer sapphire and aluminum nitride single-substrate system to determine the effects of interface composition and structure on susceptibility to fracture of hard, thin tantalum nitride films. Nanoindentation tests showed that the elastic moduli of the tantalum nitride and aluminum nitride films, as well as the sapphire substrate, were essentially equal at 400 GPa. On both portions of the substrate, these tests also showed that near surface hardness was near 35 GPa. Nanoscratch tests triggered long blisters and circular spalls on both the sapphire and aluminum nitride portions of the substrate. The blisters showed that the tantalum nitride film was subjected to a compressive residual stress of {minus}6.7 GPa. The spalls showed that failure occurred along the tantalum nitride film-substrate interface regardless of substrate composition. Most importantly, the blisters and spalls showed that the mode I component of the fracture energies were essentially equal on both substrate materials at a value near 3.1 J/m{sup 2}. These energies are on the order of the energies for metallic bonding. {copyright} {ital 1999 Materials Research Society.}

Impurity effects on the adhesion of aluminum films on sapphire substrates

Abstract: The adhesion of aluminum (Al) films onto sapphire substrates in the presence of controlled contaminants is being investigated. In this study, adhesion strength is evaluated by continuous scratch and nanoindentation tests to induce delamination of the Al film from the sapphire substrate. If delamination blisters or spallations can be induced, then fracture mechanics based models can be used to calculate the fracture energy or work of adhesion based on the radius of the blister. Initial specimens of 178 nm thick Al films were vapor deposited onto (0001) oriented sapphire substrates with a 5--19 nm layer of carbon sputter deposited onto the sapphire surface of selected samples. Continuous scratch tests promoted blistering of the film in specimens with carbon on the sapphire surface. Delamination blisters could not be induced by continuous indentation testing in samples with or without carbon at the interface. An overlayer of sputtered tantalum (Ta) was then used on a second set of 500 nm thick Al films with and without 10--20 nm of sputtered carbon on the sapphire surface to promote delaminations. With Ta overlayers, continuous nanoindentation techniques induced larger diameter delamination blisters in the specimens with carbon, than in the specimens without carbon. Resistance to blistering, or smaller induced blisters, indicates a higher interfacial strength.

Oxidation of MoSi2 and MoSi2-based materials

Abstract: Oxidation experiments, at 500°C, of MoSi2 and MoSi2-based compounds such as Mo(Al,Si)2 and MoSi2+1 wt% C compacts have been carried out. These compacts were prepared byin situ synthesis and a compaction method, starting from the elemental powders. For comparison, commercial MoSi2 and Mo(Al,Si)2 infiltrated into SiC preform were also studied under similar conditions. It was found that the synthesized high density MoSi2 and Mo(Al,Si)2 infiltrated into SiC preform did not show any oxidation even after 100 h of heating in air. The colour of the polished surfaces of commercial MoSi2, Mo(Al,Si)2 and MoSi2+1 wt% C had changed. The SEM of Mo(Al,Si)2 showed open blisters with rods of MoO3 in them whereas MoSi2+1 wt% C surface had MoO3 rods but no blisters and the oxidation was superficial with no penetration into the compact. It is suggested that in compounds, the presence of small amounts of impurities is not as detrimental to pesting as presence of defects like open pores or cracks. Hence, high density of the compact is essential for the prevention of complete disintegration of the compact.

Suction blister formation in skin after acute and repeated mast cell degranulation.

Abstract: Mast cells and their proteases are thought to participate in the development of skin blisters in various pathological conditions. In this study, suction blistering was used as an experimental model to evaluate the significance of mast cells in blister formation after pre-treatment of normal skin with intradermal injections of 100 microg/ml compound 48/80 (a mast cell degranulator) or with 0.1% capsaicin cream. Tryptic and chymotryptic enzyme activities in blister fluids were measured with sensitive p-nitroanilide substrates. Repeated injections of compound 48/80 once a day on 3 or 5 consecutive days or capsaicin applications 3 times a day for 7 or 10 days were used to induce mast cell degranulation and inflammation in normal skin. Both treatments ultimately led to decreased wheal and erythema reactions before suction blistering, but neither treatment affected the size or formation rate of suction blisters. No suction blister fluids had detectable levels of chymotryptic activity, but blister fluids from bullous pemphigoid, herpes zoster and insect bullous eruption, used as the control, revealed clear chymotryptic activity. In addition, tryptic activity in suction blister fluids was not significantly altered after compound 48/80 and capsaicin pre-treatments. However, if the wheal reaction was induced immediately before suction blistering, a significantly increased rate in blister formation together with increased tryptic activity was found, but, unexpectedly, no chymotryptic activity could be detected in blister fluids. The results show that repeated mast cell degranulation in normal skin has no effect on the formation rate of suction blisters, which developed more rapidly on acutely whealing skin. This is probably due to skin oedema rather than mast cell proteases, since no chymotryptic activity was detected in suction blisters where tryptic activity exhibited high individual variation.

Indentation-induced debonding of ductile films

Abstract: Thin film adhesion can be measured by means of the nanoindentation technique [1]. In the case of a ductile film (Cu, Al, Au, etc.) well adhered to a brittle substrate, plastic deformation in the film acts as an energy dissipation mechanism, preventing film debonding. Depositing a brittle layer of W (about 1 micron thick) on top of the film of interest increases the driving force for delamination, thus solving the problem [2]. Indentation produces circular delaminations (blisters), sometimes two orders of magnitude bigger than the indenter contact radius. Thin film adhesion was shown to scale with the film thickness, approaching the true work of adhesion of 0.8 J/m2 for Cu films less than 100 nm thick [3]. Conceptually it is important to know along what interface the fracture occurs during the blister formation. Auger electron spectroscopy (AES) has been used to determine where fracture occurs for different film systems. Cu films on SiO2 failed along the Cu/SiO2 interface. Fracture of Cu films with a 10 nm adhesion-promoting Ti underlayer occurred along the Ti/Cu interface. Significantly, Ti increased the thin Cu film adhesion by a factor of ten. Blisters were removed from the substrate, and the fracture surface was analyzed. In the case of thin Cu films, crack arrest (fiducial) marks were found upon blister removal, and represent the shape of the crack tip [4]. AFM has been used to determine the geometry of the marks. The main component of the arrest marks is carbon, which comes either from the diamond tip or from the hydrocarbons adsorbed on the newly formed surfaces in the indentation process.

The formation of indicia in the base of a blister pack for transference to a body cast therein

Abstract: In a process for creating one or more blisters in a blister film (4), indicia are formed in the base of the blister in the final stage of a single pass of the blister forming punch (2) or pin. The blister is cold formed by advancing the pin (2) in a direction transversely relative to the plane of the film (4), towards and into engagement with a platen carrying indicia-forming die (12). The end face of the pin is formed with a mould for indicia complementary to the die (2), and movement of the pin (2) towards the platen draws and stretches film (4) predominantly from around the blister, thereby minimizing stretching of the film (4) at the base of the blister.

Breakage prevention device for blister packs

Abstract: The present invention is a protective system for a plurality of pills contained within a blisterpack. It includes a plurality of hollow modules formed of a non-flexible plastic material, each hollow module having a sufficient size and shape to fit over individual blister-contained pills in the blister pack, and a plurality of spacing bars connecting the plurality of modular hollow modules. The hollow modules may be arranged in predetermined geometric patterns linearly or in an x-axis, y-axis plane to coincide with the pattern of blisters of a blisterpack so as to fit over the blisterpack for packaging and shipping to prevent breakage and damage to the blisters and the pills contained therein.

Effect of annealing atmosphere on the delamination of Pt layer in SiO2/Pt/PZT/Pt ferroelectric capacitor

Abstract: Blister formation has been studied for SiO2/Pt/PZT/Pt capacitors. Plasma-enhanced chemical vapor deposited (PECVD) and sputtered SiO2 was used to compare the characteristic morphology with different oxide layer. With increasing the annealing temperature, the blisters are observed at the temperature of 325°C in O2 atmosphere, while no blisters are formed even at 500°C in N2 and Ar atmosphere. Hydrogen evolution analysis from PECVD SiO2 layer shows a sharp peak near 320°C. From these results, we could suggest that the high gaseous pressure developed by chemical reaction between oxygen and hydrogen cause the blister formation in PECVD SiO2/Pt/PZT/Pt capacitors.

Dispenser for blisters containing small items

Abstract: The dispenser consists of a basically parallelpiped box (2) open at the top for loading a cartridge (4) filled with blister packs (6). The box is also open at the bottom, where it has guides (14) for sliding the blister packs out one by one in a horizontal direction as they drop down from the cartridge. Each pack has a series of transparent blisters (9) each containing a single article (12) which is pushed out through a fragile base layer (8) when required for use.

The Influence of Damage and Dopant on the Blister Formation in Hydrogen Implanted Silicon

Abstract: We have studied the formation of surface blisters in n-type silicon following coimplantation with boron and hydrogen. In this work we study the effect of having the boron depth larger than the hydrogen depth. The silicon substrates had four different dopant levels, ranging from 1014 cm−3 to 1019 cm−3. The Si substrates were first implanted with B ions at 240 keV (Rp = 705nm) to a dose of 1015cm−2. Some of the B implanted samples were left in their as-implanted state, others were given a rapid thermal anneal (RTA) at 900°C. Boron implanted and virgin n-type Si samples were then implanted at cryogenic temperatures with 40 keV H+ (Rp= 475nm) to a dose of 5 x 1016 cm−2. Following H+ implantation, all the samples were vacuum annealed at 390°C for 10 minutes and examined for hydrogen blister formation. No blistering was observed in samples implanted with H only. In all cases, the blister depth was consistently found to be strongly correlated with H damage profile rather than the H or B concentration profiles. These results will be discussed in terms of defect-dopant interactions and the influence of doping on H kinetics and H-bubble nucleation.