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At least 1,387 records · Page 77Linked to original sources
PubMed2005

Waterline disinfectant effect on the shear bond strength of orthodontic brackets.

The purpose of this study was to determine whether the use of an iodine compound for disinfecting the waterlines in dental units has an effect on the shear bond strength of orthodontic brackets bonded to enamel. Forty molar teeth were divided randomly into two groups- group 1 control: twenty teeth were etched for 15 seconds with 35% phosphoric acid, washed with a distilled water spray for 10 seconds, stored in distilled water for 5 minutes, dried to a chalky white appearance, and the sealant applied to the etched surface; group 2 experimental: twenty teeth were etched for 15 seconds with 35% phosphoric acid and washed for 10 seconds with water containing iodine. The teeth were stored for five minutes in the iodinated water, dried to a chalky white appearance, and the sealant applied to the etched surface as in the control group. Precoated brackets were placed on all the teeth and light cured for 20 seconds. All teeth were debonded within 30 minutes from the initial time of bonding. The t-test results (t = 1.74) indicated that there were no significant (P = .09) differences in the shear bond strengths of the teeth that were washed and immersed in the iodine solution and the control group in which distilled water was used. The mean shear bond strengths for the two groups were 6.5 +/- 3.5 MPa and 4.7 +/- 3.1 MPa, respectively.

Acid Etching, Dental↗
PubMedDate not supplied

Study of the microencapsulation of camu-camu (Myrciaria dubia) juice.

The camu-camu, like many other Amazonian fruits, shows an excellent potential for use due to its high vitamin C content, and the use of these natural resources could result in greater development of the Amazonian region. Few studies have been conducted with this fruit, and such studies are necessary in order to develop the required technology to allow for its utilization, thus avoiding or at least decreasing wastage of such a rich raw material. The principle objective of this study was to develop a process for the microencapsulation of camu-camu juice, optimizing the operational conditions. The processing conditions consisted of blanching at a temperature of 95 +/- 2 degrees C for 2 min, followed by cooling in an ice bath and juice extraction using a brush type depulper. The juice was dried with gum arabic or malt dextrin in a mini-spray dryer using an air entry temperature of between 100-160 degrees C and wall material concentration varying between 5-35%, in accordance with a factorial experimental design. Both the air entry temperature and the amount of wall material, plus the interaction between the two, gave significant positive effects at the level of 5% probability on the yield of juice powder. The optimum conditions for juice yield and vitamin C retention were established as 15% wall material and an air entry temperature of 150 degrees C.

Ascorbic Acid↗
PubMedDate not supplied

Subjective and clinical evaluation of oral lubricants in xerostomic patients.

The purpose of this investigation was to evaluate and compare four oral lubricants in relation to oral mucosal status, perceived relief of dry mouth symptoms, and patient acceptance. Three commercial oral lubricants--two sprays and one gel--and a home remedy of margarine were evaluated. Twenty-five xerostomic/salivary gland dysfunctional patients demonstrating < 0.20 mL/min of unstimulated whole saliva participated in the randomized, four-phase, cross-over study. Each phase included a ten-day use of oral lubricants, followed by a four-day washout period. On the first and tenth days of use, lip and buccal mucosa dryness and perceived oral dryness were evaluated. Patient acceptance of the oral lubricant was evaluated at the end of each ten-day period. The Wilcoxon matched-pairs signed-rank test was used to analyze data over time and between-group differences. The gel group reported a statistically significant improvement in perceived oral dryness from Day 1 to Day 10. No other significant within-group differences were found. Subjects rated the gel significantly better than margarine for convenience, perceived value, minutes of relief, and in the "overall" rating. No other significant between-group differences were noted.

Administration, Topical↗
PubMedDate not supplied

Microencapsulation of soluble pharmaceuticals.

A method to microencapsulate water-soluble and liquid-paraffin insoluble drugs into spherical, discrete and free-flowing particles of approximately 175 microns size with excellent yield has been described taking diethylcarbamazine citrate as a model drug. In this method a gelatin-drug dispersion at 50 degrees C is sprayed, using a simple apparatus designed in our laboratory, into chilled, dry liquid paraffin present in a china dish previously coated with a layer of hard paraffin and maintained at 5 degrees C. After allowing the droplets to gel at 5 degrees C for an hour, water was removed by freeze drying. Later liquid paraffin adhering to freeze-dried microcapsules was removed by washing with chilled, dry acetone. Various factors affecting the yield, size, shape and size distribution of microcapsules were optimized.

Diethylcarbamazine↗
PubMedDate not supplied

An in vitro investigation of the temperature rises produced in dentine by Nd:YAG laser light with and without water cooling.

Infrared lasers are reported to have thermal side effects which may damage pulp tissue. This study investigated the thermal effects of the pulsed Nd:YAG laser. Prepared, extracted teeth were measured prior to irradiation. Temperature was recorded using a thermocouple/data logging system. Laser irradiation was carried out with or without water spray for an exposure time of ten seconds. Results indicated that dry irradiation produced unacceptable temperature rises with dentine thicknesses used. Wet irradiation produced a significantly lower temperature rise. It was concluded that the Nd:YAG laser produced thermal effects which could potentially cause pulpal trauma. A water coolant was effective in reducing these thermal effects, but the temperature rise achieved whilst using water coolant may still cause pulpal damage.

Dental Cavity Preparation↗
PubMed2002

Ki-67 antigen detection in unstained and destained cytologic samples.

OBJECTIVE: To evaluate the effect of different tissue preservation, fixation and staining procedures on the expression of proliferation-associated Ki-67 antigen in cytologic samples to establish an easy and uniform way to handle cytologic specimens with an automated staining technique. STUDY DESIGN: Multiple touch imprints were made from eight breast tumors. The specimens were treated according to different protocols, and Ki-67 nuclear expression was compared to that in the corresponding histologic sections. RESULTS: In the unstained specimens, air drying at room temperature for up to four months or ethanol spray fixation preserved the material and offered excellent results. Processing effectively removed previous stain without additional chemical destaining. Antigen retrieval was not achieved in the previously Giemsa stained imprints and was suboptimal in those stained according to Papanicolaou. CONCLUSION: Immunocytochemical detection of Ki-67 is recommended for previously unstained cytologic specimens.

Cytological Techniques↗
PubMed1990

The Ilizarov external fixation system: the new perioperative challenge.

1. All Ilizarov components should be dried well after decontamination and protected with a layer of silicone spray to prevent corrosion and rust formation. 2. Never immerse the dynamometric wire tensioner in saline. Never store the wire tensioner with the handle turned fully to the left or right position. 3. Preoperatively, the Ilizarov patient must be psychologically prepared for the visual impact of the device and the possibly long duration of the healing process if lengthening is performed. 4. Wire site care should begin 24 hours postoperatively. The patient or family member must be instructed on wire site care and give successful return demonstrations prior to discharge.

Fracture Fixation↗
PubMed1980

Heat stress exposure of aerial spray pilots.

Heat stress (WBGT index) in the cockpits of agricultural spray pilots, and its physiological and subjective effects, were measured for 9 pilots flying in hot weather for a large Israeli aerial spray company. There was concern that heat exposure may be one of the factors involved in a recent increase in the fatal and non-fatal crash rate among Israeli spray pilots. WBGT index calculations were based on sequential cockpit wet bulb, dry bulb, and globe temperatures read when aircraft landed. The WBGT was always above 25 degrees C and exceeded 26.7 degrees C in 70% of observations. In pilots, a daily weight loss of 0.6-1.2% of total body weight was usual, as were rectal temperature increases of 0.5 degrees C. Daily water intakes ranged from less than 100 ml to 2000 ml per workshift. Questionnaires indicated that 42 of 45 pilots said they would drink more fluids if they were provided between flights by ground crews. An unresolved problem was whether conventional threshold standards for heat exposure were set at levels that may produce insidious impairments in pilot psychomotor performance. Cockpit air cooling is suggested as a measure for preventing heat stress in hot climates. However, appropriate filter technologies would be needed to prevent pesticide exposures during flight. Engineering and other measures to prevent heat stress and dehydration should rank high as part of a comprehensive program to protect the health and performance levels of agricultural spray pilots.

Accidents, Aviation↗
PubMed2006

Efficacy and tolerability of a spray with Salvia officinalis in the treatment of acute pharyngitis - a randomised, double-blind, placebo-controlled study with adaptive design and interim analysis.

OBJECTIVE: This randomised, double-blind, parallel group phase II/III study with adaptive two-stage design and interim analysis compared the efficacy and tolerability of spray (containing a Salvia officinalis fluid extract) against placebo in the treatment of patients with acute viral pharyngitis. - STUDY PARTICIPANTS: in two study parts, a total of 286 patients with subjective and objective evidence of pharyngitis were randomized. In the first study part 122 patients were enrolled. In the second study part 164 patients were included. The treatment duration per patient was 3 days, including one baseline visit and one final visit. - MAIN OUTCOME MEASURES: Area under Curve for change of throat pain intensity (spontaneous pain), documented every 15 minutes within the first 2 hours after the first application as compared to baseline using a visual analog scale (VAS 100 mm). - RESULTS: Following the interim analyses of the first study part the 15 % spray containing 140 microl sage extract per dose was the most promising preparation for the second study part (main study) whereas for the 30% and the 5% preparation results made superiority over placebo unlikely in the final analysis. Overall, the 15 % spray was significantly superior to placebo for the primary efficacy variable with regard to a reduction of the throat pain intensity score. Only minor side effects such as dry pharynx or burning of mild intensity were seen. - CONCLUSIONS: The efficacy and tolerability profile of a 15 % sage spray indicated that this preparation provides a convenient and safe treatment for patients with acute pharyngitis. A symptomatic relief occurred within the first two hours after first administration and was statistically significantly superior to placebo.

Acute Disease↗
PubMed1997

Imaging of individual biopolymers and supramolecular assemblies using noncontact atomic force microscopy.

A variety of biopolymers is imaged using noncontact atomic force microscopy. Samples are prepared by aerosol spray deposition of aqueous solutions on freshly cleaved mica followed by air drying. The distributions of contour lengths and chain or fibril thicknesses normal to the mica substrate can be measured for individual polymer molecules or molecular assemblies. In many cases it is possible to conclude that the structures imaged and quantitatively analyzed are representative of those present in solution and not artifacts of the deposition/dessication process. Imaging of linear and cyclic triple helices of the polysaccharide scleroglucan is demonstrated. Measurements of the triple helix thickness normal to the mica surface are analyzed, and successful measurements of the molecular weight distribution and mean molar mass are described. It is demonstrated that the extent of chain association in the polysaccharide xanthan can be modulated by the addition of low molecular weight salts. The contour length and chain thickness distributions in a xanthan fraction are presented. Increases in the extent of chain association with increasing polymer concentration are documented for the gelling polysaccharide gellan, and the formation of stiff fibrillar gellan aggregates in the presence of added low molecular salt is demonstrated. Images are presented of the polysaccharide kappa-carrageenan in its disordered, and presumably single-stranded, state. Biopolymers other than polysaccharides can be imaged by the same technique; this is demonstrated with the fibrous protein collagen. In general it is shown that aerosol spray deposition of biopolymer samples can be used in conjunction with noncontact atomic force microscopy to provide a fast, reliable, and reproducible method for assessing the size and shape distributions of individual biological macromolecules and macromolecular assemblies in solution with a minimum of time and effort devoted to sample preparation.

Aerosols↗
PubMed2002

Hazards of insecticides to the bumble bees Bombus impatiens (Hymenoptera: Apidae) foraging on flowering white clover in turf.

Insecticides used on turf are sometimes applied to areas with flowering weeds that attract honey bees and native pollinators. We tested residual effects of such treatments on colony vitality and behavior of the bumble bees Bombus impatiens Cresson foraging on turf containingwhite clover, Trifolium repens L. Imidacloprid, a syst emic chloronicotinyl used for preventive control of root-feeding grubs, was applied as granules, followed by irrigation, or sprayed as a wettable powder, with or without irrigation. Hives were confined on the plots in large field cages after residues had dried and colony vitality (i.e., numbers of brood, workers, and honey pots, and weights of queens, workers, and whole colonies with hives) was evaluated after 28-30 d. Workers' foraging activity and defensive response to an aggressive stimulus also were evaluated. In another test, weedy turf was sprayed with chlorpyrifos, carbaryl, or cyfluthrin at labeled rates for surface-feeding pests. Bee colonies were confined on the plots after residues had dried, with effects on colony vitality evaluated after 14 d. Finally, foraging activity of wild bumble bees was monitored on open plots to determine if insecticide-treated areas were avoided. Imidacloprid granules, and imidacloprid sprays applied with posttreatment irrigation, had no effect on colony vitality or workers' behavior, suggesting that such treatments pose little systemic or residual hazard to bumble bees. In contrast, exposure to dry nonirrigated residues of all of the aforementioned insecticides had severe impact on colony vitality. Foraging workers did not avoid insecticide-treated areas. Means by which turf managers can reduce hazards of insecticide applications to pollinators are discussed.

Agriculture↗
PubMed2000

Use of the near-infrared reflectance method for measurement of moisture content during granulation.

The purpose of this study was to demonstrate the use of a near-infrared (NIR) method for in-process control of a placebo formulation. An NIR setup with a multichannel detector was applied in the measurement of water during fluidized bed granulation. The effects of two critical granulation parameters were studied using the central composite design. The present NIR setup with three wavelengths proved applicable for in-line moisture measurement. The 1990 nm signal was used for measurement of water and the 1745 and 2145 nm signals were used to correct the change in spectra baseline during granulation. Variations in inlet air conditions proved to be critical factors, explaining differences in the granule size distributions. Differences in granule moistening and drying rates resulting from varying inlet air conditions could be measured with the NIR setup. The moisture content of granules at the end of the spraying phase explained part of the differences in granule size distributions. The moisture content of granules at the end of the drying phase affected the tableting behavior of granules. The results suggested that direct measurement of granule moisture content facilitates the in-process control of the granulation.

Drug Compounding↗
PubMed1993

Chemical disinfection to interrupt transfer of rhinovirus type 14 from environmental surfaces to hands.

Rhinoviruses can survive on environmental surfaces for several hours under ambient conditions. Hands can readily become contaminated after contact with such surfaces, and self-inoculation may lead to infection. Whereas hand washing is crucial in preventing the spread of rhinovirus colds, proper disinfection of environmental surfaces may further reduce rhinovirus transmission. In this study, the capacities of Lysol Disinfectant Spray (0.1% o-phenylphenol and 79% ethanol), a domestic bleach (6% sodium hypochlorite diluted to give 800 ppm of free chlorine), a quaternary ammonium-based product (7.05% quaternary ammonium diluted 1:128 in tap water), and a phenol-based product (14.7% phenol diluted 1:256 in tap water) were compared in interrupting the transfer of rhinovirus type 14 from stainless steel disks to fingerpads of human volunteers upon a 10-s contact at a pressure of 1 kg/cm2. Ten microliters of the virus, suspended in bovine mucin (5 mg/ml), was placed on each disk, and the inoculum was dried under ambient conditions; the input number on each disk ranged from 0.5 x 10(5) to 2.1 x 10(6) PFU. The dried virus was exposed to 20 microliters of the test disinfectant. The Lysol spray was able to reduce virus infectivity by > 99.99% after a contact of either 1 or 10 min, and no detectable virus was transferred to fingerpads from Lysol-treated disks. The bleach (800 ppm of free chlorine) reduced the virus titer by 99.7% after a contact time of 10 min, and again no virus was transferred from the disks treated with it.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1998

Alveolar bone formation at dental implant dehiscence defects following guided bone regeneration and xenogeneic freeze-dried demineralized bone matrix.

The present study evaluated rate and extent of alveolar bone formation in dental implant dehiscence defects following guided bone regeneration (GBR) and implantation of xenogeneic freeze-dried demineralized bone matrix (xDBM). A total of 16 titanium plasma-sprayed (TPS) and 16 hydroxyapatite-coated (HA) titanium cylinder implants were inserted in 4 mongrel dogs following extraction of the mandibular premolar teeth. Four implant sites per jaw quadrant (2 TPS and 2 HA implant sites) were prepared into extraction sockets in each dog. Buccal alveolar bone was removed to create 3 x 5 mm dehiscence defects. Two jaw quadrants in separate animals received GBR, GBR + xDBM, xDBM (control), or gingival flap surgery alone (GFS; control). Thus, four conditions were available for each implant type (TPS or HA): GBR, GBR + xDBM; xDBM and GFS. The animals received fluorescent bone labels to allow observations of rate and extent of bone formation. Animals were sacrificed at 12 weeks postsurgery and block sections were harvested for histologic analysis. There were no apparent histologic differences between TPS and HA implant defects. GBR and GBR + xDBM resulted in almost complete bone closure of the dental implant dehiscence defect. Rate of bone formation appeared higher following GBR alone. Extent of bone formation appeared somewhat greater following GBR + xDBM; however, delayed. xDBM alone did not adequately resolve the bony defect. In conclusion, GBR results in rapid, clinically relevant bone closure of dental implant dehiscence defects. Adjunctive implantation of xDBM does not appear to significantly improve the healing response in the model used.

Alveolar Process↗
PubMed1988

Application of spray-freezing to the study of rapid platelet reactions by a quenched-flow approach.

A spray-freezing approach coupled to quenched-flow techniques has been developed to study rapid (0.3-5.0 s) biochemical and morphological changes during platelet activation. Platelet-rich plasma (PRP) pumped through the quenched-flow system was atomized and quenched within 50 ms in liquid propane at -196 degrees C. Analysis of platelet size and morphology by scanning electron microscopy (SEM) indicated that platelets can be sprayed without morphological damage. The spray-frozen platelets can be subjected to freeze-fracture, freeze-substitution, or freeze-drying procedures for later analysis by electron microscopy. Quenched-flow techniques have permitted investigation of rapid increases in cytosolic calcium protein phosphorylation and morphological changes which occur within 0.5 s after exposure to an activator. The combination of quenched-flow and spray-freezing methodologies should prove useful for studying equally rapid changes in protein distribution in activated platelets by means of electron microscopy coupled with immunocytochemical approaches.

Blood Platelets↗
PubMed1998

The major species of heavy metal aerosol resulting from water cooling systems and spray dryer systems during incineration processes

Trace toxic metals in municipal solid waste may escape from the incineration process in flue gas, in dry collected ash, in wet scrubbed ash, or as a suspended aerosol. Therefore, understanding the behavior of heavy metals in the flue gas and the best controls in the air pollution control equipment are important and necessary. The control conditions of water cooling and spray dryer systems during incineration processes significantly influence the formation of heavy metal compounds. The formation of chromium (Cr), lead (Pb), and cadmium (Cd) species under various control conditions (water cooling tower and spray dryer reactor) was investigated in this study. The object of the experiment is to understand the effects of water cooling and spray dryer systems individually on the formation of heavy metal species. The operating parameters that are evaluated include different control systems, control temperatures, and chlorine content. A thermodynamic equilibrium model was also used to evaluate experimental data. In order to match real incineration conditions, a two-stage simulation was performed in this experiment. The results showed that the relationship of speciation between the simulation prediction and X-ray diffraction (XRD) analysis is consistent for Cr compounds; both indicated that Cr2O3 is the major species. The relationship is almost the same for Cd compounds, but not for Pb compounds.

Journal Article↗
PubMed2002

An investigation into the use of pilocarpine as a sialagogue in patients with radiation induced xerostomia.

BACKGROUND: Radiation therapy to the head and neck region can be an effective form of treatment for malignancies. Unfortunately damage to salivary glands may occur. Treatment of resultant dry mouth is at present very poor. The purpose of this pilot study was to investigate whether pilocarpine dissolved in artificial saliva and administered in a mouth spray would be effective in relieving such symptoms. METHODS: Twenty-three patients with radiation induced hyposalivation were recruited for this randomized, double-blind investigation. Subjects were randomly allocated to placebo or control medicaments used for eight weeks. All subjects were evaluated for the severity of their xerostomia associated symptoms prior to administration of the spray and again eight weeks later. RESULTS: The questionnaire and the visual analogue scale did not reveal any improvements in the dry mouth symptoms between cases and controls. Side-effects were reported among cases, mostly mild and tolerable. All patients taking pilocarpine (with base salivary flow rates > 0ml/min) demonstrated improvement in stimulated and unstimulated salivary flow rates. Candida counts decreased among the cases and controls although decrease among the cases was much greater. CONCLUSIONS: The results obtained indicate that provided residual functioning salivary tissue exists, pilocarpine used as formulated is effective and warrants further investigation.

Aerosols↗
PubMedDate not supplied

Salmonella typhimurium penetration through the eggshell of hatching eggs.

This study was undertaken to demonstrate penetration of Salmonella typhimurium through the eggshell of newly laid broiler hatching eggs. Eggs were challenged either by lightly spraying the bacteria over the blunt end of the egg or by contact with contaminated dry nest litter. Exposure time for both groups was 10 minutes; afterward, all eggs were disinfected and incubated 19 days under normal conditions. Chorioallantoic membranes and yolk sacs were cultured in brain-heart infusion broth on day 19 to demonstrate penetration. Isolation of the bacteria from chorioallantoic membranes and yolk sacs, respectively, were as follows: sprayed group: 100% and 83%; contact group: 59% and 29%. These results showed that although water enhanced S. typhimurium penetration, its presence on the eggshell is not essential for penetration to occur.

Allantois↗