No abstract available.
Cystectomy* ; Lasers, Gas* ; Volatilization*

No abstract available.
Embolism, Air ; Volatilization

OBJECTIVES: This study examined how ethanolamines (EAs) with the same functional alcohol group (HOCH2CH2), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. METHODS: Two types of experimental apparatus were manufactured to achieve these objectives. RESULTS: Vaporization tests using a water bath showed that the vaporization rate increased markedly from 0.19 mg/m2.min at 23.5degrees C to 8.04 mg/m2.min at 60degrees C. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was 0.45 mg/m3 in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. CONCLUSION: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.
Baths ; Ethanolamines ; Hot Temperature ; Tea ; Volatilization ; Water

BACKGROUND AND OBJECTIVES: The efficiency of second harmonic generation at 532 nm is high when a pulsed Nd : YAG laseris used as a pump source of fundamental waves. The pulse durations of 532 nm-irradiation can be varied from 10 ns to 1000 ns by changing the pumping method. The purpose of this study was to compare the macroscopic and micropscopic changes in the muscle and skin after irradiation by 532 nm Flash lamp pumped solid state (FPSS) laser and Diode pumped solid state (DPSS) laser, whose pulse durations are 600 ns and 100 ns, respectively. MATERIALS AND METHOD: Two experiments were conducted on the muscle and skin of guinea pig. First, the guinea pig muscle and skin were irradiated by the 532 nm FPSS and DPSS lasers with various intensities and time duration. Macroscopic examinations were performed on the muscle lesions and immediate histopathologic examinations on the skin were carried out. RESULTS: The volume of vaporization and necrosis of the guinea pig muscle by the FPSS laser was larger than that by the DPSS laser. The vaporization and necrosis reaction of skin by the FPSS was significantly stronger than that by the DPSS laser. CONCLUSION: It appears that the DPSS laser system would be superior over the FPSS laser system in providing more accurate and precise surgery with less intense injury on the surrounding tissue.
Animals ; Guinea Pigs* ; Guinea* ; Necrosis ; Skin* ; Volatilization

The operative methods for the choanal atresia or stenosis are transseptal, transnasal, transpalatal and transmaxillary approaches. Among them, endoscopic transnasal approach provides excellent visualization and little age limitation. The use of CO2 laser in the management of choanal atresia enables the accurate incision and vaporization. We experienced a case of acquired bilateral choanal stenosis which developed after external irradiation for nasopharyngeal carcinoma. She presented with the symptoms of slowly progressive bilateral nasal obstruction and persistent nasal discharge for the past three years prior to visiting hospital. We successfully managed her by endoscopic transnasal repair with CO2 laser and found this technique to safe and simple.
Choanal Atresia ; Constriction, Pathologic* ; Lasers, Gas ; Nasal Obstruction ; Volatilization

After the introduction of the Laser into clinical medicine in recent years, the Laser has become increasingly useful clinically, and has even proved, as a new surgical modality that utilizes high-intensity beams of radiant energy to vaporize or coagulate tissue, superior to coventional surgical techniques in selected procedures. Using the carbon dioxide Laser beam, the authors had experienced good results in 8 cases of brain tumor with its unique properties of tissue vaporization and nonmechanical bloodless excision.
Brain Neoplasms* ; Brain* ; Clinical Medicine ; Lasers, Gas* ; Volatilization

OBJECTIVES: The goal was to model and quantify the atmospheric concentrations of volatile organic compounds (VOCs) as the result of the Hebei Spirit oil spill, and to predict whether the exposure levels were abnormally high or not. METHODS: We developed a model for calculating the airborne concentration of VOCs that are produced in an oil spill accident. The model was applied to a practical situation, namely the Hebei Spirit oil spill. The accuracy of the model was verified by comparing the results with previous observation data. The concentrations were compared with the currently used air quality standards. RESULTS: Evaporation was found to be 10- to 1,000-fold higher than the emissions produced from a surrounding industrial complex. The modeled concentrations for benzene failed to meet current labor environmental standards, and the concentration of benzene, toluene, ortho- meta- para-xylene were higher than the values specified by air quality standards and guideline values on the ocean. The concentrations of total VOCs were much higher than indoor environmental criteria for the entire Taean area for a few days. CONCLUSIONS: The extent of airborne exposure was clearly not the same as that for normal conditions.
Benzene ; Humans ; Petroleum Pollution ; Toluene ; Volatile Organic Compounds ; Volatilization ; Xylenes

Xanthoma disseminatum (XD) is one of cutaneous nonhistiocytosis X, and characterized by multiple, widely distributed red, brown, yellowish papules and nodules that tend to coalesce. We present a case of XD with characteristic clinical findings and treated with the combination therapy of COz laser vaporization and high dose steroid.
Histiocytosis, Non-Langerhans-Cell* ; Laser Therapy ; Lasers, Gas* ; Volatilization* ; Xanthomatosis*

Disseminated superficial actinic porokeratosis (DSAP) is a skin condition that usually shows a poor response to different modalities of treatment. Herein we describe 2 patients with DSAP on the face, each treated with 3 to 4 sessions of photodynamic therapy combined with laser vaporization.
Actins ; Humans ; Laser Therapy ; Lasers, Gas ; Photochemotherapy ; Porokeratosis ; Skin ; Volatilization

BACKGROUNDTransparent dressings are commonly used to cover central venous catheter sites. However, it has been suggested that they might not allow adequate moisture vapor transmission, resulting in local moistness that promotes bacterial growth. We compared the moisture vapor transmission rates (MVTRs) of different, currently used transparent and traditional gauze dressings. We aimed to determine the MVTRs at different temperatures and humidities.

METHODSThe dressings were used to seal 50-ml plastic centrifuge tubes containing 20 ml deionized water: Tubes in group 1 were covered with 12 layers of ordinary gauze, group 2 with IV3000, group 3 with OPSITE FLEXIGRID, group 4 with 3M HP Tegaderm, and group 5 with 3M Tegaderm. The tubes were placed upright in an artificial climate cabinet, so that the dressings were not touching the water, in order to simulate the conditions of medical dressings in contact with the skin. The average MVTRs were determined under different conditions. MVTRs were also determined with tubes from groups 2 - 5 laid on their sides, allowing the dressings to touch the water, so simulating contact of the dressings with sweating skin, or wounded skin with exudates. We also calculated the dressings' self-reactive abilities by comparing their MVTRs in contact with the water surface with those when not in contact with the water surface.

RESULTSGroup 1 demonstrated the highest MVTR, followed by groups 2, 4, 3 and 5 under conditions simulating contact of the dressings with normal skin at the following temperatures and humidities: 20 degrees C/30%, 20 degrees C/60%, 20 degrees C/90%, 37 degrees C/30%, 37 degrees C/60% and 37 degrees C/90%. When the relative humidity (RH) increased, the MVTRs decreased. The MVTRs differed significantly among different dressings and RHs: At high temperature (37 degrees C) and high humidity (90%), the MVTR of the transparent dressings in group 2 was higher than that of group 1 (P < 0.01). The reactive MVTR was highest in group 2 (10.2 - 16.3 times > MVTR) while that of group 4 was second highest (2.6 - 9.6 times > MVTR).

CONCLUSIONSRH and temperature had significant effects on the MVTRs of different dressings. The IV3000 transparent dressing used in group 2 was as effective as ordinary gauze. These results suggest that increased infection rates due to low MVTRs might not be a problem. The clinical implications of these observations for catheter-related infections need to be further investigated in multicenter studies.