Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Silicates”

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.

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

At least 577 records · Page 32Linked to original sources

[Quantitative determination of the nickel, tin, copper, scandium, zirconium and hafnium in silicate sample by laser microspectrochemical analysis].

Quantitative determination of the nickel, tin, copper, scandium, zirconium and hafnium in silicate sample were carried out by laser microspectrochemical analysis, results show that the method has good precision and accuracy. The stability of the laser output and the selection of auxiliary spark excitation condition in experimental process were discussed.

English Abstract↗

[Radiation doses from patients undergoing yttrium-90 silicate knee radiosynovectomy].

The present study was undertaken because we could not find references related to the minimal radiation doses emitted from patients treated with (90)Y-silicate colloid ((90)Y-SC) for radiosynectomy (RS). Radiation doses from 16 patients treated with about 181+/-13 MBq (90)Y-SC for RS of knee synovitis were estimated by dose rate measurements performed within 10 min after the (90)Y-SC injection with a calibrated survey dose ratemeter at 0.5 m, 1 m and 2 m distances from the treated joint. The mean dose rate values from the patients after bg subtraction were 0.6+/-0.4 microSv/h at 0.5 m, 0.1+/-0.1 microSv/h at 1 m and 0.1 +/- 0.0 microSv/h at 2 m distance. Dose rates at a distance of 0.5 m were significantly correlated (P<0.02) with the patient's weight but not with the height or the injected activity. The assumed estimated maximum whole body doses from a treated patient were 55 microSv for persons living with the patient, 2.9-3.4 microSv for the nursing staff, 0.2-1.8 microSv for the therapist physician and 0.3-0.6 microSv for the technologist, involved in the whole procedure. The above values were lower than those published with the same methodology for alternative RS radiopharmaceuticals for knee synovitis like dysprosium-165 ferric hydroxide macroaggregate ((165)Dy-FHMA) or holmium-166 ((166)Ho-FHMA), as estimated with their typical injected activities. In conclusion our results demonstrate that in (90)Y-SC knee synovectomy, the whole body radiation doses to medical and non medical personnel were as expected well below the maximum annual dose limits for the public and professionals exposed to radiation.

Body Burden↗

[The preparation and spectroscopic characteristics of ytterbium silicate glasses].

Yb3+-doped silicate glasses were prepared at high temperature, which had a small non-linear refractive index coefficient n2 (1.62), lower transformation temperature and lower softening temperature (540 degrees C and 585 degrees C, respectively). The absorption spectrum from 850 to 1100 nm showed that the main peak was at 975 nm with two subpeaks near 908 nm and 944 nm, respectively. Emission peak was at 1,010 nm in the fluorescence spectrum with a 65.5 nm fluorescence half-line width. The integrated absorption cross section, stimulated emission cross section and fluorescence time were caculated to be 3.44 X 10(4) pm2, 0.71 pm2 and 1.05 ms, respectively, which satisfy the requirements of laser glasses.

English Abstract↗

[Study on the spectral properties of nickel tetrasulfo-phthalocyanine doped vinyl modified silicate glass].

Nickel tetrasulfo-phthalocyanine (NiTSPc) was successfully doped into vinyltriethoxysilane (VTES)modified silicate gel glass by sol-gel technique, IR and UV-Vis spectral examination was carried out. The results show that vinyl has been introduced into SiO2 network, and the structure of gel glass is therefore changed. The encapsulation of NiTSPc does not make any noteworthy changes in the composition and structure of gel glass matrix. NiTSPc molecules are well dispersed in the organic modified matrix, and the phenomenon of aggregation is greatly suppressed.

English Abstract↗

Insulin secretion in magnesium silicate-induced osteopenia in rats.

Local inflammation induced in rats by subcutaneous injection of magnesium silicate is followed by general metabolic, endocrine and immune reactions. Three weeks after inflammation induction, important bone loss, inflammation-mediated osteopenia (IMO) were found. The study proposes to investigate if IMO influences endogenous insulin secretion and if insulin therapy modifies the amount of bone loss, knowing its osteoprotective effect. Experiments were carried out on adult rats, three weeks after local inflammation induction. Baseline glucose and insulin levels did not change as compared to controls. After glucose stimulation, insulinogenic index decreased in the IMO group, which evidences decrease of insulin secretion. Insulin treatment initiated at the same time with IMO did not induce significant changes as regards the response to glucose tolerance test. However, bone calcium was increased as compared to the untreated IMO group, without reaching the control level.

Animals↗

[Retention and dosage in radiation synovectomy with yttrium-90-silicate colloid].

Investigations on patients and on phantoms were performed to determine the retention and the absorbed dose in radiation synovectomy with 90Y silicate colloid. The electrons of 90Y are totally absorbed within the surrounding tissue and produce bremsstrahlung with a maximum intensity at about 110 keV. After application of 6 mCi 90Y the dose rate of the bremsstrahlung was measured at a distance of 10 cm over 13 knees in a total of 10 patients and was found to range between 0.6 and 1.3 mR/h. During a period of 3 hours up to 3 days after injection practically no removal of the material from the joint was observed. According to approximative calculations the mean dose absorbed in the knee ranged between 3650 and 7300 rad, and the absorbed dose in the synovium between 5500 and 11000 rad.

Body Burden↗

[Possibility of siliceous pollution in goldsmith workshops].

The AA. carried out a research in order to determine the entity and the localization of siliceous dust pollution in goldsmith-field in the industrial area near by Valenza Po, Northern Italy. The research put attention just on the microfusion process and it was carried out among factories that attend to this process continuously. In fact the "scagliola" is used only during microfusion. It is a sort of mixture containing a high quantity of quartz and cristobalite used for the moulding. Dangerous dusts are caused by the mentioned "scagliola" during stripping and mixing. The use of right technical precautionary measures can surely eliminate the risk.

Air Pollutants↗

[Intracystic instillation of yttrium 90 silicate colloid in cystic craniopharyngioma].

The authors evaluate the intracavital treatment with 90 Yttrium silicate colloid given in 31 occasion in 26 patients of cystic craniopharyngioma. The method has been applied since 1975 in the National Institute of Neurosurgery Budapest, using practically the same method as described by Backlund et al. (1972). Although the intracavital treatment was only one among several applied forms of treatment (resection, aspiration, shunting etc.) the effectiveness of the internal irradiation is obvious. The main effect is shrinkage of the cyst. At the 26 patients there was an average of more than 70% volume decrease of the cysts. In 5 cases the cysts totally disappeared and only on two occasions the volume has remained unchanged. Neuroophtalmological data: Preoperatively visual field defects or an impairment of visual activity have been observed in 24 out of the 26 patients studied. After the 90-Yttrium treatment the ophtalmological state of the patients improved 4, worsened in 2 cases. There was no change in 18 cases. The neuroophtalmological prognosis was good only when a relatively intact optic disc was seen; when the disc was atrophic the visual deterioration proved to be irreversible. Pathologically, the fibrotic tissue is responsible for the shrinkage of the cyst.

Administration, Topical↗

[Radiosynoviorthesis with yttrium-90-silicate. Results compared to aurum-198-colloid and whole body radiation load].

The results of the radiosynoviorthesis with yttrium-90 silicate in 36 joints, are reported. In comparison to the radiogold therapy in 64 joint, yttrium-90 was a little more effective. Additionally, the body distribution of radioactive yttrium after radiosynoviorthesis of knee joints, was measured in 6 patients. It could be shown that the uptake of the regional lymphnodes was between 4 and 5% of the yttrium administered. The radiation dose of the regional lymphnodes certainly exceeds 1000 rad. The results point to the importance of a careful selection of patients for radiosynoviorthesis.

Arthritis, Rheumatoid↗

[Are silicates only gravel stones?].

The presence of silicon dioxide in urinary calculi usually indicates the presence of artefacts. However in isolated cases infra-red and X-ray spectroscopy and electron-ray microanalysis have clearly demonstrated the presence of silicate in crystalline urinary sediment and as a phase of urinary calculi, probably as a result of overdoses of silicon preparations. A local silicon enrichment of up to 2% is certain in phosphate phases and makes an isomorphic incorporation of SiO4 ions probable.

Humans↗

[An etiological definition of a case of mixed pneumoconiosis due to silicates and coal in the absence of anamnestic data].

A case of pneumoconiosis with unknown occupational history was examined both pathologically and mineralogically by means of a variety of techniques, including analytical scanning and transmission electron microscopy with electron diffraction and energy dispersive x-ray analysis, and electron resonance spectroscopy. The pathologic features consisted of a diffuse interstitial fibrosis with deposits of amorphous and crystalline particles and granulomatous reaction. The identification of minerals, mainly talc, halloysite, coal and chlorite, allowed a definite diagnosis of mixed silicate pneumoconiosis to be made. This is an example of complete pathologic, mineralogic and physico-chemical analysis of a case of pneumoconiosis.

Aged↗

Cystic craniopharyngioma treated by 90yttrium silicate colloid.

UNLABELLED: Fourteen children and 3 adults with cystic craniopharyngiomas were treated with intracavitary 90Y, by the procedure described by Backlund. Their ages ranged from 2 to 65 years and postoperative follow-up ranged from 6 to 40 months. Leksell's stereotactic technique was employed to determine coordinates by CAT. Cyst volume was quantified both geometrically and isotopically with 99Tc, values differing by 7%. Dosimetry was determined by applying the formula developed by Loevinger et al., and 20,000 rads were administered throughout to the cystic wall. All 17 patients, except for 4 children, had previously received surgery, shunts or radiotherapy, alone or combined. In 4 cases, 90Y injection was the only treatment, while in 6, the cyst was evacuated at 10 days following radiocolloid injection. Skull and spinal column gamma chamber studies were carried out on all patients at 24, 48, and 72 hours post injection, but no isotope leakage could be detected. The patients returned to normal activities except one with multiple cysts who died. There were no changes in the endocrinologic profile. In one case, a decrease in visual acuity 18 months after treatment, improved following corticoid administration. CONCLUSIONS: Though preliminary, these results are encouraging since it seems that the severe neuro-endocrinologic sequelae of open surgery may be avoided.

Adolescent↗

[Death by peroral ingestion of soluble glass (sodium silicate)].

The intake of 0.51 of water glass (sodium metasilicate; colloid pH 12.5) led to death within 1-1.5 h. Autopsy revealed alkali burns of the stomach mucosa. The stomach contained a small amount of liquid with a pH of 11.5. Histologically, numerous bronchioles and alveoles were filled with amorphous material. This material was chemically proved to be condensed water glass. The obstruction of large parts of the lungs by water glass led to an inhibition of alveolar gas diffusion, which may have been the cause of death. The transformation of the water glass from liquid to solid occurred in the lungs by means of the carbonic acid of expiration air. This was made possible because the pH of water glass had been changed by gastric secretions from 12.5 to 11.5. Water glass starts to solidify around pH 11.4-11.3.

Aged↗