The purpose of this study was to investigate wether a radiographic estimate of osseous fractal dimension is useful in the characterization of structural changes in bone. Ten specimens of bone were progressively decalcified in fresh 50ml solutions of 0.1N hydrochloric acid solution at cummulative timed periods of 5, 10, 20, 30, 60 and 90 minutes, and radiographed from 0 degree projection angle controlled by intraoral parelleling device. The test set of 70 radiographs was digitally filtered to reduce film-grain noise. I performed one-dimensional variance and fractal analysis of bony profiles or scan lines, Correlation analysis quantified the relationship between variance and fractal dimension. The obtained results were as follow ; 1. After the first stage of decalcification variance and fractal dimension of scan line pixel intensities generally decreased with a range of 57.94 to 12.64 and 1.59 to 1.36. 2. Correlation coefficient(r) relating variance to fractal dimension was consistantly excellent(range r=0.90 to 0.98). 3. Variance and fractal dimension were much alike in ability to discriminate, at leat on a group basis, between contrl and decalcified specimens.
Fractals* ; Hydrochloric Acid ; Noise ; Osteoporosis*

No abstract available.
Eating* ; Gastric Mucosa* ; Hydrochloric Acid* ; Mucous Membrane*

The purpose of this study was to investigate whether a radiographic estimate of osseous fractal dimension and power spectrum of 2D discrete Fourier transform is useful in the characterization of structural changes in bone. Ten specimens of bone were decalcified in fresh 50 ml solutions of 0.1 N hydrochloric acid solution at cummulative timed periods of 0 and 90 minutes, and radiographed from 0 degree projection angle controlled by intraoral parelleling device. I performed one-dimensional variance, fractal analysis of bony profiles and 2D discrete Fourier transform. The results of this study indicate that variance and fractal dimension of scan line pixel intensities decreased significantly in decalcified groups but Fourier spectral analysis didn't discriminate well between control and decalcified specimens.
Fourier Analysis* ; Fractals* ; Hydrochloric Acid ; Osteoporosis

STATEMENT OF PROBLEM: Titanium has many advantages of high biocompatibility, physical porperties, low-weight, low price and radiolucency, but it is incompatible with conventional dental porcelain due to titanium's oxidative nature. Many previous studies have shown that they used the method of sandblast for surface treatment prior to porcelain application, the researchs are processing about the method of acid etching or surface coating. PURPOSE: The purpose of this research is to study the effect on bond strength between titanium and porcelain when using macro-surface treatment and micro-surface treatment and macro and micro surface treatment . MATERIAL AND METHOD: In this study, we evaluated the bond strength by using 3-point bending test based on ISO 9693 after classified 7 groups - group P : polished with #1200 grit SiC paper, group SS : sandblasted with 50 micrometer aluminum oxides, group LS : sandblasted with 250 micrometer alumium oxides, group HC : treated with 10 % hydrochloric acid, group NF : treated with 17% solution of fluoric acid and nitric acid, group SHC : treated with 10 % hydrochloric aicd after sandblsting with 50 micrometer alumium oxides, group SNF : treated with 17 % solution of fluoric acid and nitric acid. RESULTS: Within the confines of our research, the following results can be deduced. 1. Group SS which was sandblasted with 50 micrometer aluminum oxides showed the highest bond strength of 61.74 MPa and significant differences(P<0.05). The bond strengths with porcelain in groups treated acid etching after sandblasting decreased more preferable than the group treated with sandblasting only. It gives significant differences(P<0.05). 2. After surface treatments, the group treated with sandblasting showed irregular aspect formed many undercuts, in the SEM photographs. The group treated with hydrochloric acid had the sharp serrated surfaces, the group treated with the solution of fluoric acid and nitric acid had the smooth surfaces, the group with sandblasting and hydrochloric acid had irrigular and porous structure, the group with sandblasting and the solution of fluoric acid and nitric acid had craterlike surfaces. But all of the groups treated with acid etching was not found and undercut. CONCLUSION: In above results, average surface roughness increase, bond strength also increase, but surface topographs influences more greatly on bond strengths.
Aluminum ; Dental Porcelain ; Hydrochloric Acid ; Nitric Acid ; Oxides ; Titanium

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition: concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 degrees C, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 microg/g and 1516.0 microg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.
Basidiomycota ; chemistry ; Hydrochloric Acid ; Lactic Acid ; Xanthophylls ; isolation & purification

PURPOSE: We evaluated the fractal dimension changes on bovine rib radiographs according to the decalcification degree and the exposure time in the bovine rib. MATERIALS AND METHODS: Twenty 5 mm thick cross-sectional blocks from bovine rib bone were progressively decalcified in 30 mL 0.1 N hydrochloric acid for 5, 30, and 90 minutes. They were radiographed at three exposure time settings (0.22, 0.36, 0.43 mAs) before and after each decalcification stage. We selected 100 x 100 pixel-sized regions of interests (ROIs) on trabecular bone and calculated fractal dimensions by box-counting method. RESULTS: Repeated measures ANOVA showed that fractal dimensions gradually decreased after acid-induced demineralization and with more exposure (P<0.001). CONCLUSION: The fact that fractal dimensions decrease after decalcification might support the hypothesis that patients with osteoporosis have decreased radiographic fractal dimension in trabecular bone in comparison to normal subjects.
Bone and Bones ; Fractals* ; Humans ; Hydrochloric Acid ; Osteoporosis ; Radiography ; Ribs*

Recently the use of hydrochloric acid as a toilet disinfectant has become more common, and the risk of its ingestion is though to be increasing. We experienced a case of 67 year-old man who accidentally ingested hydrochloric acid and as a result developed a postprandial epigastric fullness end pain 3 weeks thereafter, The patient underwent an UGI series, fiberoptic gastroscope and abdominal ultrasonography and was found to have a gastric midbody stricture. A total gastreetomy and Roux-en- Y esophagojejunostomy was performed. We report this case with brief review of the literature.
Aged ; Constriction, Pathologic ; Eating ; Gastritis* ; Gastroscopes ; Humans ; Hydrochloric Acid* ; Ultrasonography

The rabbit's cornea was injured by tile application of concentrated hydrochloric acid, and the effects of beta-ray on this Chemical burn were studied. The epithelization of the corneal ulceration, the extent of opacity and neovascularization of irradiated eyes showed no significant difference from the nonirradiated eyes by fractionated irradiation of betaray, the total doses being 900 rep.
Burns* ; Burns, Chemical ; Cornea* ; Corneal Ulcer ; Hydrochloric Acid

Resin infiltration has been used as a treatment option for the management of early caries lesions recently. However, the etching procedure with hydrochloric acid might be somewhat stressful for the clinicians due to safety problem especially for young children, leading to less utility.This study aims at searching for some alternative surface pretreatment methods of resin infiltration for the early caries lesions in primary anterior teeth by comparing penetration depth of various methods.No significant difference was found in penetration ratio between etched surface with 15% hydrochloric acid and 35% phosphoric acid. However, the penetration ratio was significantly higher in groups pretreated either with dental pumice or abrasive metal strip (p < .05).By the result of this study, etching with phosphoric acid as an alternative of hydrochloric acid was thought clinically acceptable as a pretreatment method for resin infiltration in early caries lesions for primary anterior teeth.It was notable that surface conditioning with dental pumice or metal strip before etching was effective in increasing the penetration. This procedural modification might be much more correspondent with minimally invasive concept and hopefully contribute to increased safety and utility in pediatric dentistry.
Child ; Humans ; Hydrochloric Acid ; Methods ; Pediatric Dentistry ; Tooth

This study aimed to evaluate surface morphology and resin tag penetration of resin infiltration into primary anterior teeth after enamel deproteinization with sodium hypochlorite (NaOCl) prior to phosphoric acid (H₃PO₄) etching.Ninety primary anterior teeth with non-cavitated caries lesion were devided five groups according to enamel pretreatment as follows, group I-15% hydrochloric acid (HCl) 2min. ; group II-5.25% NaOCl 1min., 35% H₃PO₄ 1min. ; group III-5.25% NaOCl 2min., 35% H₃PO₄ 1min. ; group IV-5.25% NaOCl 1min., 35% H₃PO₄ 2min. ; group V-5.25% NaOCl 2min., 35% H3PO4 2min. Fifteen teeth were examined etched surface structure using field emission-scanning electron microscope. Seventy five teeth were infiltrated with resin, maximum penetration depth and percentage penetration were analysed using dual fluorescence confocal microscopy.As the application time of NaOCl increased, ratio of enamel type I, II were increased. Percentage penetration (PP) was higher in group V than group II, III (p < 0.05). PP of group IV, V did not show any differences.Non-cavitated caries of primary anterior teeth can be treated with resin infiltration. Enamel deproteinization with NaOCl prior to 35% H3PO4 etching could be an alternative of 15% HCl etching in resin infiltration.
Dental Enamel ; Fluorescence ; Hydrochloric Acid ; Microscopy, Confocal ; Sodium Hypochlorite ; Tooth