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1.
J Helminthol ; 93(1): 21-25, 2019 Jan.
Article in English | MEDLINE | ID: mdl-29179791

ABSTRACT

Alcoholic patients are more susceptible to Strongyloides stercoralis infection. The chronic use of alcohol raises the levels of endogenous corticosteroids, which regulates the development of larvae and stimulates the differentiation of rhabditiform into infective filariform larvae, thus inducing internal autoinfection. Therefore, early diagnosis is important to prevent severe strongyloidiasis. The aim of this study was to evaluate the efficacy of parasitological methods, according to the parasite load and the number of stool samples, for diagnosis of S. stercoralis infection, as well the peripheral blood eosinophil count in alcoholic patients. A total of 330 patients were included in this study. The diagnosis was established using three parasitological methods: agar plate culture, Baermann-Moraes method and spontaneous sedimentation. Peripheral eosinophilia was considered when the level was >600 eosinophils/mm3. The agar plate culture (APC) had the highest sensitivity (97.3%). However, the analysis of multiple samples increased the sensitivity of all parasitological methods. The sensitivities of the methods were influenced by the parasite load. When the larval number was above 10, the sensitivity of APC was 100%, while in spontaneous sedimentation the sensitivity reached 100% when the larval number was above 50. In the present study, 15.4% of alcoholic patients infected with S. stercoralis (12/78) had increased peripheral blood eosinophil count (above 600 eosinophils/mm3). For an efficient parasitological diagnosis of S. stercoralis infection in alcoholic patients, repeated examination by two parasitological methods must be recommended, including agar plate culture due to its higher sensitivity. Moreover, S. stercoralis infection was associated with eosinophilia, mostly in patients excreting up to 10 larvae/g faeces.


Subject(s)
Alcoholism/complications , Eosinophilia/etiology , Parasite Load , Strongyloides stercoralis/isolation & purification , Strongyloidiasis/complications , Strongyloidiasis/diagnosis , Alcoholism/parasitology , Animals , Brazil , Eosinophilia/parasitology , Feces/parasitology , Humans , Sensitivity and Specificity
2.
Med Oral Patol Oral Cir Bucal ; 23(1): e38-e43, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-29274154

ABSTRACT

BACKGROUND: The purpose of this study was to investigate the presence of punched-out lesions in craniofacial bones using three different radiographic protocols in a large cohort of patients. MATERIAL AND METHODS: One hundred fifty-five MM patients were evaluated using panoramic and skull (frontal and lateral) radiographs, which were performed in all patients at the time of MM diagnosis. The diagnostic potential for detecting punched-out lesions was compared among the radiographic techniques. RESULTS: MM punched-out lesions were identified in 135 (87%) panoramic radiographs, 141 (91%) frontal and 144 (93%) lateral skull radiographs. Punched out-lesions were synchronously present in skull and jawbones in 129 (83.23 %) cases. The lesions were detected exclusively in skull in 18 (11.61%) cases and exclusively in jawbones in 6 (3.87%) cases. Punched out-lesion mainly affected the skull and the jawbones in a synchronous way (p<0.001) rather than separately. CONCLUSIONS: All investigated radiographic techniques (panoramic, frontal and lateral skull approaches) demonstrated high detection rates for MM punched-out lesions in craniofacial bones. Panoramic radiography may aid to the radiographic protocols to identify multiple myeloma bone lesions.


Subject(s)
Bone Neoplasms/diagnostic imaging , Facial Bones/diagnostic imaging , Multiple Myeloma/diagnostic imaging , Radiography, Panoramic , Skull/diagnostic imaging , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Retrospective Studies
3.
Phys Chem Chem Phys ; 19(15): 9974-9982, 2017 Apr 12.
Article in English | MEDLINE | ID: mdl-28362013

ABSTRACT

In situ X-ray absorption spectroscopy and mass spectrometry measurements were employed to simultaneously probe the atom specific short range order and reactivity of Pd and PtPd nanoparticles towards NO decomposition at 300 °C. The nanoparticles were synthesized by a well controlled, eco-friendly wet chemical reduction of metal salts and later supported on activated carbon. Particularly for the bimetallic PtPd samples, distinct atomic arrangements were achieved using a seeding growth method, which allowed producing a random nanoalloy, or nanoparticles with Pt- or Pd-rich core. X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction provided additional insights on their electronic, morphological and long range order structural properties. The results revealed that the higher the thermal induced atomic migration observed within the nanoparticles during thermal treatments, the least were their reactivity for NO abatement.

4.
Eur J Gynaecol Oncol ; 37(5): 714-716, 2016.
Article in English | MEDLINE | ID: mdl-29787017

ABSTRACT

OBJECTIVE: To report a case of sarcoidosis post-treatment of adenocarcinoma of the uterine cervix. CASE: A 38-year-old, GlPlAO was admitted to the present hospital for palliative treatment of Stage IB 1 adenocarcinoma of the uterine cervix with hepatic recurrence post- hysterectomy. The patient initially received six cycles of cisplatin and taxol leading to complete remission. Six months after the palliative treatment, MRI revealed slight changes in the pelvis, suggestive of the involvement of the left iliac lymph node. Anatomo-pathological results after lymphadenectomy showed tumor recurrence. Following additional pelvic radiotherapy, the patient remained asymptomatic. However, oncologic control performed three months later exposed mediastinal lymphadenopathy and new biopsy revealed sarcoidosis. The patient remained asymptomatic in the subsequent follow-ups without evidences of tumor recurrence. This study shows the importance of differential diagnosis during the oncologic monitoring of cervical cancer patients to avoid unnecessary treatments at the expense of better therapeutic options.


Subject(s)
Adenocarcinoma/therapy , Sarcoidosis/diagnosis , Uterine Cervical Neoplasms/therapy , Adult , Diagnosis, Differential , Female , Humans , Lymph Node Excision , Magnetic Resonance Imaging , Palliative Care , Sarcoidosis/etiology , Sarcoidosis/therapy
5.
J Oral Rehabil ; 43(7): 511-8, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27043215

ABSTRACT

The relationship between type 2 diabetes oral physiology, nutritional intake and quality of life has not been fully elucidated. We assessed the impact of type 2 diabetes - exclusive or associated with hypertension with beta-blockers treatment - on oral physiology, mastication, nutrition and quality of life. This cross-sectional study was performed with 78 complete dentate subjects (15 natural teeth and six masticatory units minimum; without removable or fixed prostheses), divided into three groups: diabetics (DM) (n = 20; 45·4 ± 9·5 years), diabetics with hypertension and receiving beta-blockers treatment (DMH) (n = 19; 41·1 ± 5·1 years) and controls (n = 39; 44·5 ± 11·7 years) matched for gender, age and socioeconomic status. Blood glucose, masticatory performance, swallowing threshold, taste, food intake, stimulated and unstimulated salivary flow, pH and buffering capacity of saliva were assessed. Glycemia was higher in DM than in controls (P < 0·01). No differences were observed between DM and controls for nutrition and quality of life. Both stimulated and unstimulated salivary flow rate were lower in DMH (P < 0·01), which also presented the lowest number of teeth and masticatory units (P < 0·0001), and reduction in the number of chewing cycles (P < 0·01). Controls showed lower Decayed Missing Filled Teeth index (DMFT) scores in comparison with DMH (P = 0·021). Masticatory performance and saliva buffering capacity were similar among groups. Exclusive type 2 diabetes did not alter oral physiology, nutrition or quality of life. However, when hypertension and beta-blockers treatment were associated with diabetes, the salivary flow rate, chewing cycles and number of teeth decreased.


Subject(s)
Antihypertensive Agents/therapeutic use , Diabetes Mellitus, Type 2/physiopathology , Hypertension/physiopathology , Jaw, Edentulous, Partially/physiopathology , Mastication/physiology , Quality of Life , Saliva/metabolism , Adult , Antihypertensive Agents/pharmacology , Cross-Sectional Studies , DMF Index , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/psychology , Female , Humans , Hypertension/complications , Hypertension/psychology , Male , Mastication/drug effects , Middle Aged , Risk Factors , Saliva/drug effects , Xerostomia/physiopathology
6.
J Radiol Prot ; 36(4): 885-901, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27798410

ABSTRACT

Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members. We found that although the better description of the posture in which the aircrews are exposed, the results of the effective dose rate calculated with the phantom in the sitting posture were very similar to the results of the phantom in the standing posture. In fact we observed only a 1% difference. These findings indicate the adequacy of the use of dose conversion coefficients for the phantom in the standing posture in aircrew dosimetry. We also validated our results comparing the effective dose rate obtained using the standing phantom with values reported in the literature. It was observed that the results presented in this study are in good agreement with other authors (the differences are below 30%) who have measured and calculated effective dose rates using different phantoms.


Subject(s)
Aircraft , Cosmic Radiation , Occupational Exposure/analysis , Posture , Radiation Dosage , Radiometry/methods , Female , Humans , Male , Neoplasms, Radiation-Induced/prevention & control , Occupational Diseases/prevention & control , Phantoms, Imaging , Radiation Injuries/prevention & control
7.
Genet Mol Res ; 11(3): 1990-6, 2012 Aug 06.
Article in English | MEDLINE | ID: mdl-22911583

ABSTRACT

The fig (Ficus carica L.) is a fruit tree of great world importance and, therefore, the genetic improvement becomes an important field of research for better crops, being necessary to gather information on this species, mainly regarding its genetic variability so that appropriate propagation projects and management are made. The improvement programs of fig trees using conventional procedures in order to obtain new cultivars are rare in many countries, such as Brazil, especially due to the little genetic variability and to the difficulties in obtaining plants from gamete fusion once the wasp Blastophaga psenes, responsible for the natural pollinating, is not found in Brazil. In this way, the mutagenic genetic improvement becomes a solution of it. For this reason, in an experiment conducted earlier, fig plants formed by cuttings treated with gamma ray were selected based on their agronomic characteristics of interest. We determined the genetic variability in these fig tree selections, using RAPD and AFLP molecular markers, comparing them to each other and to the Roxo-de-Valinhos, used as the standard. For the reactions of DNA amplification, 140 RAPD primers and 12 primer combinations for AFLP analysis were used. The selections did not differ genetically between themselves and between them and the Roxo-de-Valinhos cultivar. Techniques that can detect polymorphism between treatments, such as DNA sequencing, must be tested. The phenotypic variation of plants may be due to epigenetic variation, necessitating the use of techniques with methylation-sensitive restriction enzymes.


Subject(s)
Ficus/genetics , Mutation/genetics , Trees/genetics , Amplified Fragment Length Polymorphism Analysis , Brazil , Flowers/genetics , Genetic Markers , Random Amplified Polymorphic DNA Technique
8.
Oper Dent ; 37(4): 356-62, 2012.
Article in English | MEDLINE | ID: mdl-22335301

ABSTRACT

The objective of this study was to determine whether the hardness of etch-and-rinse adhesives may be affected by the pretreatment of acid-etched dentin with potassium oxalate desensitizer. Unerupted human third molars were cut into crown segments by removing the occlusal enamel and roots. The pulp chamber of these crown segments was connected to a syringe barrel filled with phosphate-buffered saline so that the moisture of dentin was maintained during the bonding procedures. Three etch-and-rinse adhesives-two two-step systems (Adper Single Bond 2 [SB], One-Step [OS]) and one three-step system (Adper Scotchbond Multi-Purpose [MP])-were applied to acid-etched dentin that had been treated (experimental groups) or not (control groups) with potassium oxalate (BisBlock). The Knoop hardness (KHN) of adhesives was taken at different sites of the outer surface of the adhesive-bonded dentin. The KHN of the three tested adhesives applied to acid-etched dentin treated with potassium oxalate was significantly lower than that exhibited by the respective controls (not treated with oxalate; p<0.05). Regardless of the adhesive, the treatment with potassium oxalate reduced the adhesives' KHN (p<0.05), with the OS system exhibiting the lowest KHN compared with the MP and SB systems.


Subject(s)
Dentin Desensitizing Agents/chemistry , Dentin-Bonding Agents/chemistry , Oxalates/chemistry , Acid Etching, Dental/methods , Dental Cements/chemistry , Hardness , Humans , Light-Curing of Dental Adhesives , Materials Testing , Methacrylates/chemistry , Oxalic Acid/chemistry , Phosphoric Acids/chemistry , Polymerization , Resin Cements/chemistry , Surface Properties
10.
Radiat Prot Dosimetry ; 175(1): 75-86, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-27664429

ABSTRACT

The aim of this study was the calculation of conversion coefficients for absorbed doses per fluence (DT/Φ) using the sitting and standing male hybrid phantom (UFH/NCI) exposure to monoenergetic protons with energy ranging from 2 MeV to 10 GeV. Sex-averaged effective dose per fluence (E/Φ) using the results of DT/Φ for the male and female hybrid phantom in standing and sitting postures were also calculated. Results of E/Φ of UFH/NCI standing phantom were also compared with tabulated effective dose conversion coefficients provided in ICRP publication 116. To develop an exposure scenario implementing the male UFH/NCI phantom in sitting and standing postures was used the radiation transport code MCNPX. Whole-body irradiations were performed using the recommended irradiation geometries by ICRP publication 116 antero-posterior (AP), postero-anterior (PA), right and left lateral, rotational (ROT) and isotropic (ISO). In most organs, the conversion coefficients DT/Φ were similar for both postures. However, relative differences were significant for organs located in the lower abdominal region, such as prostate, testes and urinary bladder, especially in the AP geometry. Results of effective dose conversion coefficients were 18% higher in the standing posture of the UFH/NCI phantom, especially below 100 MeV in AP and PA. In lateral geometry, the conversion coefficients values below 20 MeV were 16% higher in the sitting posture. In ROT geometry, the differences were below 10%, for almost all energies. In ISO geometry, the differences in E/Φ were negligible. The results of E/Φ of UFH/NCI phantom were in general below the results of the conversion coefficients provided in ICRP publication 116.


Subject(s)
Phantoms, Imaging , Protons , Radiation Dosage , Whole-Body Irradiation , Female , Humans , Male , Monte Carlo Method , Neoplasms/radiotherapy , Posture , Radiation Protection
11.
Nanoscale ; 8(1): 641-7, 2016 Jan 07.
Article in English | MEDLINE | ID: mdl-26647173

ABSTRACT

This work reports on the synthesis and characterization of PdxCu1-x (x = 0.7, 0.5 and 0.3) nanoalloys obtained via an eco-friendly chemical reduction method based on ascorbic acid and trisodium citrate. The average size of the quasi-spherical nanoparticles (NPs) obtained by this method was about 4 nm, as observed by TEM. The colloids containing different NPs were then supported on carbon in order to produce powder samples (PdxCu1-x/C) whose electronic and structural properties were probed by different techniques. XRD analysis indicated the formation of crystalline PdCu alloys with a nanoscaled crystallite size. Core-level XPS results provided a fingerprint of a charge transfer process between Pd and Cu and its dependency on the nanoalloy composition. Additionally, it was verified that alloying was able to change the NP's reactivity towards oxidation and reduction. Indeed, the higher the amount of Pd in the nanoalloy, less oxidized are both the Pd and the Cu atoms in the as-prepared samples. Also, in situ XANES experiments during thermal treatment under a reducing atmosphere showed that the temperature required for a complete reduction of the nanoalloys depends on their composition. These results envisage the control at the atomic level of novel catalytic properties of such nanoalloys.

12.
Plant Biol (Stuttg) ; 6(6): 755-60, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15570482

ABSTRACT

General patterns of floral morphology and incompatibility mechanisms have been described for many distylous plants. The absence of these patterns in typically distylous groups, as observed especially in tropical environments, is interpreted as atypical distyly, or as a new reproductive strategy derived from it. Data are presented here on the morphological and compatibility relations between floral morphs of four Psychotria dimorphic species in the Atlantic rain forest in SE Brazil: Psychotria jasminoides, P. birotula, P. mapourioides, and P. pubigera. When significant differences were found, floral parts were larger in thrum flowers. Results of controlled crosses showed that most incompatible pollen tubes were arrested in the stigma, and only in a low proportion in the upper parts of the style. We conclude that, at the study site, the majority and most important morphological and mating features of typical distyly seem to be conserved in P. jasminoides and P. mapourioides, which presented reciprocal herkogamy, self and intramorph incompatibility, and a balanced morph ratio in the population. Typical distyly in P. birotula is supported by floral morphology, pollen tube data and morph ratio and, in P. pubigera, only by floral morphology and pollen tube data.


Subject(s)
Breeding/methods , Flowers/anatomy & histology , Psychotria/physiology , Brazil , Flowers/physiology , Psychotria/anatomy & histology , Psychotria/genetics , Sex Characteristics , Species Specificity
13.
Alcohol ; 7(2): 145-52, 1990.
Article in English | MEDLINE | ID: mdl-2328088

ABSTRACT

Previous studies demonstrated that alcohol induces marked deterioration of the cerebral cortex. However, quantitative evaluations of neurons and synapses of the prefrontal cortex from chronic alcohol-fed and withdrawn animals are nonexistent, in spite of the functional implications that can underlie structural changes in this cortical area. To achieve this evaluation, we used groups of rats alcohol-fed for 6, 12 and 18 months, their respective controls as well as groups of rats alcohol-fed for 6 and 12 months and then switched to water for 6 months--withdrawal groups. The thickness of the prelimbic cortical layers I-III was reduced in the alcohol-fed and withdrawal groups. A significant reduction in the density of cells was found, which was more marked after withdrawal. Conversely, the density of synapses increased after alcohol exposure and withdrawal; such numerical shifts lead to a significant increase in the synapse-to-neuron ratio. These results indicate that the cortical circuitry of the prelimbic cortex is vulnerable to prolonged periods of alcohol exposure and withdrawal and allow to advance the view that the alterations can induce functional implications.


Subject(s)
Ethanol/toxicity , Frontal Lobe/drug effects , Neurons/drug effects , Substance Withdrawal Syndrome/pathology , Synapses/drug effects , Animals , Cell Count , Frontal Lobe/pathology , Male , Microscopy, Electron , Neurons/pathology , Rats , Rats, Inbred Strains , Synapses/pathology
14.
J Submicrosc Cytol Pathol ; 20(1): 115-22, 1988 Jan.
Article in English | MEDLINE | ID: mdl-3370611

ABSTRACT

Previous investigations have demonstrated that prolonged alcohol consumption induces alterations of the neuronal lysosomal system in the cerebellum and hippocampus. To assess the effects of chronic alcohol consumption and withdrawal in the adult rat prefrontal cortex, we studied the pyramidal cells in the prelimbic area taking into particular account their lysosomal components. Alcohol-fed groups for 6, 12 and 18 months, respective age-matched pair-fed controls, and a 6-month recovery group after 12 months of alcohol consumption were used. No quantitative changes of primary lysosomes were depicted. Transitional forms of these organelles towards lipofuscin granules were more numerous among alcohol-fed and recovery animals. A precocious and progressive accumulation of lipofuscin granules occurred in greater amounts in alcohol-fed animals, increasing with the age and remaining after 6-months of withdrawal. Multivesicular bodies increased in alcohol-fed and recovery animals, displaying an inverse progression relative to the lipofuscin deposition. These results show that chronic alcohol consumption and withdrawal enhance the dynamic potentialities of the cell lysosomal system.


Subject(s)
Alcoholism/pathology , Cerebral Cortex/drug effects , Ethanol/adverse effects , Lysosomes/pathology , Substance Withdrawal Syndrome , Animals , Cerebral Cortex/pathology , Cerebral Cortex/ultrastructure , Lipofuscin/analysis , Lysosomes/analysis , Lysosomes/ultrastructure , Male , Microscopy, Electron , Rats , Rats, Inbred Strains
15.
Rev Saude Publica ; 35(5): 467-73, 2001 Oct.
Article in Portuguese | MEDLINE | ID: mdl-11723519

ABSTRACT

OBJECTIVE: To suggest changes in the sampling procedures for estimating the larval density of Aedes aegypti in the state of São Paulo, Brazil, by assessing the efficacy and level of complexity of the current procedures. METHODS: The "Superintendência de Controle de Endemias do Estado de São Paulo" - SUCEN's (Superintendence for Endemic Control of the State of São Paulo) sampling procedures for estimating the density of Aedes aegypti larvae was assessed. The Breteau index with one-stage cluster sampling was applied. An average of 35 blocks, 14 buildings per block, of a total of 510 buildings per sample, were assessed. One hundred and eleven samples were obtained in 6 municipalities of São José do Rio Preto. RESULTS: The Breteau index estimates higher than 3 had coefficients of variation smaller than 30% in 71% of the samples. The design effect was 1.19 and 1.79 for indexes lower and higher than 5, respectively. The estimates were obtained in less than 3 days, requiring a daily average of 5.5 men per sampling. CONCLUSION: This sampling design revealed to be a simplified one: fast, economic and easily managed. The operational easiness was due to the use of the one-stage cluster sampling, when there was not need to prepare lists of addresses and then sort and locate the buildings. Though the design effect shows a slight loss of the estimates' accuracy with the use of one-stage cluster sampling, this was proven to be under acceptable range. Simplifying changes in the process of determining the sample size and assessing sampling errors are proposed.


Subject(s)
Aedes/growth & development , Insect Vectors/growth & development , Sampling Studies , Animals , Brazil , Evaluation Studies as Topic , Larva , Models, Biological , Population Density
16.
Rev Saude Publica ; 25(4): 251-6, 1991 Aug.
Article in Portuguese | MEDLINE | ID: mdl-1820612

ABSTRACT

The Yellow Fever and Dengue Vector Control Program developed by the Superintendency for the Control of Endemic Diseases in the State of S. Paulo recommends Aedes aegypti and Aedes albopictus larval density monitoring in cities with domiciliar infestation. The sampling plan which has been applied in the countries of the Presidente Prudente region (SP- Brazil) since 1987 is described. The infestation is measured by using the Breteau Index. A sample of buildings is drawn, monthly and independently, in the infested cities, in which measurements are to be made. The sample is stratified and the elementary unit selection is made by using two-stage cluster sampling: of blocks and buildings. The sample sizes were defined using the coefficient of variation and the intraclass correlation as estimated for towns covered by the Regional Health Service of S. José do Rio Preto. These sizes must be corrected periodically in accordance with the values of the Breteau Index and its variance obtained in previous months.


Subject(s)
Aedes , Mosquito Control , Animals , Brazil , Cluster Analysis , Dengue/prevention & control , Insect Vectors , Larva , Population Density , Sampling Studies , Yellow Fever/prevention & control
17.
Acta Med Port ; 7(4): 237-41, 1994 Apr.
Article in Portuguese | MEDLINE | ID: mdl-8048361

ABSTRACT

Granulomatous inflammation is a well recognized environmentally produced skin disease. Four cases of sarcoid-type skin granuloma associated with foreign materials introduced into the skin are reported. In two of the cases, caused by windscreen glass debris and gunpowder, there were multiple lesions which revealed a tumor-like appearance several years after the accident. In a third case, associated with occupational exposure to cork dust, the granulomatous lesions was unique and formerly misdiagnosed as malignant. The skin lesions caused by gunpowder and cork dust coexisted with lung lesions caused by the inhalation of the same materials, which were identified in the histological sections with appropriate methods. The fourth case, caused by sea-urchin spines, revealed a progressive reduction in the latency period between the spine injury and granuloma formation. The relationship between the skin and lung lesions are discussed as well as the role of the foreign materials within the lesions.


Subject(s)
Granuloma, Foreign-Body , Skin Diseases , Adult , Granuloma, Foreign-Body/diagnosis , Granuloma, Foreign-Body/etiology , Humans , Male , Skin Diseases/diagnosis , Skin Diseases/etiology
18.
Phys Med Biol ; 59(24): 7957-8003, 2014 Dec 21.
Article in English | MEDLINE | ID: mdl-25427139

ABSTRACT

The conversion coefficients (CCs) relate protection quantities, mean absorbed dose (DT) and effective dose (E), with physical radiation field quantities, such as fluence (Φ). The calculation of CCs through Monte Carlo simulations is useful for estimating the dose in individuals exposed to radiation. The aim of this work was the calculation of conversion coefficients for absorbed and effective doses per fluence (DT/ Φ and E/Φ) using a sitting and standing female hybrid phantom (UFH/NCI) exposure to monoenergetic protons with energy ranging from 2 MeV to 10 GeV. The radiation transport code MCNPX was used to develop exposure scenarios implementing the female UFH/NCI phantom in sitting and standing postures. Whole-body irradiations were performed using the recommended irradiation geometries by ICRP publication 116 (AP, PA, RLAT, LLAT, ROT and ISO). In most organs, the conversion coefficients DT/Φ were similar for both postures. However, relative differences were significant for organs located in the abdominal region, such as ovaries, uterus and urinary bladder, especially in the AP, RLAT and LLAT geometries. Anatomical differences caused by changing the posture of the female UFH/NCI phantom led an attenuation of incident protons with energies below 150 MeV by the thigh of the phantom in the sitting posture, for the front-to-back irradiation, and by the arms and hands of the phantom in the standing posture, for the lateral irradiation.


Subject(s)
Computer Simulation , Phantoms, Imaging , Posture , Protons , Radiometry/instrumentation , Whole-Body Irradiation/methods , Adult , Biomimetics , Body Burden , Female , Humans , Monte Carlo Method , Organ Specificity , Radiation Dosage , Radiometry/standards
19.
Dentomaxillofac Radiol ; 39(1): 23-7, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20089740

ABSTRACT

OBJECTIVE: To evaluate the influence of alternative erasing times of DenOptix(R) (Dentsply/Gendex, Chicargo, IL) digital plates on subjective image quality and the probability of double exposure image not occurring. METHODS: Human teeth were X-rayed with phosphor plates using ten different erasing times. Two observers evaluated the images for subjective image quality (sharpness, brightness, contrast, enamel definition, dentin definition and dentin-enamel junction definition) and for the presence or absence of double exposure image. Spearman's correlation analysis and ANOVA was performed to verify the existence of a linear association between the subjective image quality parameters and the alternative erasing times. A contingency table was constructed to evaluate the agreement among the observers, and a binominal logistic regression was performed to verify the correlation between the erasing time and the probability of double exposure image not occurring. RESULTS: All 6 parameters of image quality were rated high by the examiners for the erasing times between 25 s and 130 s. The same erasing time range, from 25 to 130 s, was considered a safe erasing time interval, with no probability of a double exposure image occurring. CONCLUSIONS: The alternative erasing times from 25 s to 130 s showed high image quality and no probability of double image occurrence. Thus, it is possible to reduce the operating time of the DenOptix(R) digital system without jeopardizing the diagnostic task.


Subject(s)
Radiography, Dental, Digital/instrumentation , X-Ray Intensifying Screens , Dental Enamel/diagnostic imaging , Dentin/diagnostic imaging , Equipment Reuse , Humans , Light , Logistic Models , Time Factors
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