Manganese Defective Clustering: Influence on the Spectroscopic Features of Ceria-Based Nanomaterials.

The influence of manganese modification on the spectroscopic features of manganese-doped CeO2 systems synthesized by the microwave-assisted hydrothermal route and their correlation with the presence of O defective structures were verified, focusing on their interaction with poisonous atmospheres. Raman and electron paramagnetic resonance studies confirmed the presence of defective clusters formed by dipoles and/or quadrupoles. The number of paramagnetic species was found to be inversely proportional to the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ species after the interaction with CO. X-ray photoelectron spectroscopy data showed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after the first modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thus becoming nonparamagnetic Ce4+ species. On the contrary, 58% of the manganese species remain in the Mn2+ configuration with five unpaired electrons, corroborating the paramagnetic feature of the samples seen in the electron paramagnetic resonance study.

The Relationship between Photoluminescence Emissions and Photocatalytic Activity of CeO2 Nanocrystals.

In this work, we focus on understanding the morphology and photocatalytic properties of CeO2 nanocrystals (NCs) synthesized via a microwave-assisted solvothermal method using acetone and ethanol as solvents. Wulff constructions reveal a complete map of available morphologies and a theoretical-experimental match with octahedral nanoparticles obtained through synthesis using ethanol as solvent. NCs synthesized in acetone show a greater contribution of emission peaks in the blue region (∼450 nm), which may be associated with higher Ce3+ concentration, originating shallow-level defects within the CeO2 lattice while for the samples synthesized in ethanol a strong orange-red emission (∼595 nm) suggests that oxygen vacancies may originate from deep-level defects within the optical bandgap region. The superior photocatalytic response of CeO2 synthesized in acetone compared to that of CeO2 synthesized in ethanol may be associated with an increase in long-/short-range disorder within the CeO2 structure, causing the Egap value to decrease, facilitating light absorption. Furthermore, surface (100) stabilization in samples synthesized in ethanol may be related to low photocatalytic activity. Photocatalytic degradation was facilitated by the generation of ·OH and ·O2- radicals as corroborated by the trapping experiment. The mechanism of enhanced photocatalytic activity has been proposed suggesting that samples synthesized in acetone tend to have lower e'─h· pair recombination, which is reflected in their higher photocatalytic response.

Chronic Aerobic Training at Different Volumes in the Modulation of Macrophage Function and in vivo Infection of BALB/c Mice by Leishmania major.

Physical inactivity is one of the main causes of chronic diseases; however, strenuous exercise can induce immunosuppression. Several studies suggest that moderate amounts of exercise lead to a Th1 response, favoring the resolution of infections caused by intracellular microorganisms, while high volumes of exercise tend to direct the response to Th2, favoring infection by them. Leishmaniasis is a parasitic disease promoted by parasites of the Leishmania genus, with clinical manifestations that vary according to the species of the parasite and the immune response of the host. The experimental Leishmania major-BALB/C mouse model provides a good model for the resistance (Th1 response) or susceptibility (Th2 response) that determines the progression of this infection. The aim of this study was to evaluate the effect of aerobic training at different volumes on modulation of in vitro macrophage infection by L. major, as well as to assess the effect of high volume (HV) aerobic training on the development of L. major in vivo in BALB/c mice. Uninfected animals were submitted to various exercise volumes: none (SED), light (LV), moderate (MV), high (HV), very high (VHV), and tapering (TAP). The macrophages of these animals were infected by L. major and the LV and MV groups showed a decrease in the infection factor, while the VHV showed an increase in the infection factor, when treated with LPS. The cytokine concentration pattern measured in the supernatants of these macrophages suggested a predominant Th1 response profile in the LV and MV groups, while the Th2 profile predominated in the VHV and TAP groups. Groups of BALB/C mice infected with L. major were subjected to high volume (iHV) or non-periodized high volume (iNPHV) exercise or kept sedentary (iSED). The exercised animals suffered a significant increase in injuries caused by the parasites. The animals in the group submitted to high volume exercise (iHV) showed visceralization of the infection. These data strongly suggest that a very high volume of aerobic training increased the susceptibility of BALB/C mice to L. major infection, while moderate distribution of training loads promoted immunological balance, better controlling the infection by this parasite.

Does a single application of contraceptive cause pathological changes in bitches? / [Uma única aplicação de anticoncepcional causa alterações patológicas em cadelas?]

O presente trabalho objetivou avaliar os efeitos da administração em dose única de progestágenos em fêmeas caninas hígidas, as quais nunca haviam recebido tais fármacos. Foram selecionadas 20 cadelas, que foram examinadas clinicamente e por meio de exames complementares. Nessas cadelas, foi aplicado medroxiprogesterona por via subcutânea. Noventa dias após, as fêmeas foram esterilizadas cirurgicamente, sendo os tecidos reprodutivos encaminhados para histopatologia. Foi possível verificar que, aos 30 dias, 12 animais (60%) apresentaram hiperplasia mamária. Aos 90 dias, 18 animais (90%) apresentavam sinais de hiperplasia endometrial cística, tendo cinco (27,77%) destes animais apresentado conteúdo purulento no lúmen uterino. No exame microscópico, apenas uma fêmea não demonstrou alterações patológicas, sendo a única que recebeu o contraceptivo na fase correta (anestro). As demais fêmeas apresentaram alterações que variaram entre alterações circulatórias a hiperplasia endometrial cística grave. Assim, foi possível concluir que uma única aplicação de anticoncepcional em fêmeas hígidas pode causar complicações leves a graves.(AU)

Photodynamic inactivation of S. aureus with a water-soluble curcumin salt and an application to cheese decontamination.

In this study, the optimal parameters for the photodynamic inactivation (PDI) of Staphylococcus aureus in bacterial suspensions and in cheese were assessed using a water-soluble curcumin salt as the photosensitizer (PS). The in vitro study aimed at finding the optimal concentration and light dose to promote S. aureus photokilling. Four main groups were proposed: CONTROL (L-C-), LIGHT (L+C-), CUR (L-C+) and PDI (L+C+). A fixed light dose (LED, 450 ± 10 nm, 10 J cm-2) was applied using four different PS concentrations (0.75, 1.0, 1.5 and 3.0 mg mL-1). The dose also varied from 10-100 J cm-2 for a fixed concentration. High inactivation rates were observed for all light doses, with a maximum reduction of 7.58 log10 at 100 J cm-2 (p ≪ 0.05). Saturation of the PDI effect was observed after a 10 minute illumination time, as well as a slight decrease in the S. aureus population for increasing illumination times in the L+C- group. As an application, the concentration showing the best decontamination performance in vitro (0.75 mg mL-1) was applied to decontaminate cheese in loco. PDI in two types of coalho cheese, a rennet-coagulated cheese commonly consumed in Brazil, was investigated. The results showed no significant inactivation in unpasteurized cheese, but a 4.34 log10 reduction for t > 5 min in pasteurized specimens. In conclusion, the present PDI-catalyzed curcumin photosensitizer inactivated S. aureus at statistically significant levels in vitro, in pasteurized cheese, but not in unpasteurized specimens.

Ag Nanoparticles/α-Ag2WO4 Composite Formed by Electron Beam and Femtosecond Irradiation as Potent Antifungal and Antitumor Agents.

The ability to manipulate the structure and function of promising systems via external stimuli is emerging with the development of reconfigurable and programmable multifunctional materials. Increasing antifungal and antitumor activity requires novel, effective treatments to be diligently sought. In this work, the synthesis, characterization, and in vitro biological screening of pure α-Ag2WO4, irradiated with electrons and with non-focused and focused femtosecond laser beams are reported. We demonstrate, for the first time, that Ag nanoparticles/α-Ag2WO4 composite displays potent antifungal and antitumor activity. This composite had an extreme low inhibition concentration against Candida albicans, cause the modulation of α-Ag2WO4 perform the fungicidal activity more efficient. For tumor activity, it was found that the composite showed a high selectivity against the cancer cells (MB49), thus depleting the populations of cancer cells by necrosis and apoptosis, without the healthy cells (BALB/3T3) being affected.

Assessment of viral and bacterial contamination of fresh and ripened semi-hard cheeses.

This study aimed to evaluate viral and bacterial contamination from typical Brazilian cheeses, such as Minas (fresh) and Prato (ripened), commercially obtained in the Greater Metropolitan Region of the State of Rio de Janeiro, Brazil. Minas [30], Prato [30] and sliced Prato [30] cheese samples were investigated for norovirus genogroup I and II (NoV GI-II) and human adenovirus (HAdV) by direct nucleic acid extraction using TRIzol and amplification by TaqMan based quantitative polymerase chain reaction. Listeria monocytogenes, Salmonella spp., coagulase-positive staphylococci (CPS) and fecal coliforms were also assessed by using standard counting methods. NoV GI and GII were detected in one sample (1.1%) each and HAdV in nine samples (10.0%) while bacteriological analysis revealed five samples (5.5%) contaminated with L. monocytogenes, 27 (30.0%) with fecal coliforms and 10 (11.1%) with CPS. Salmonella spp. was not detected in any sample. Viruses were detected in 11 samples (12.2%), of which 9 met the microbiological criteria used to evaluate the microbiological quality of the cheeses, stressing the importance of considering virological parameters for monitoring this food matrix.

ZnWO4 nanocrystals: synthesis, morphology, photoluminescence and photocatalytic properties.

The present joint experimental and theoretical work provides in-depth understanding on the morphology and structural, electronic, and optical properties of ZnWO4 nanocrystals. Monoclinic ZnWO4 nanocrystals were prepared at three different temperatures (140, 150, and 160 °C) by a microwave hydrothermal method. Then, the samples were investigated by X-ray diffraction with Rietveld refinement analysis, field-emission scanning electron microscopy, transmission electronic microscopy, micro-Raman and Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and photoluminescence measurements. First-principles theoretical calculations within the framework of density functional theory were employed to provide information at the atomic level. The band structure diagram, density of states, Raman and infrared spectra were calculated to understand the effect of structural order-disorder on the properties of ZnWO4. The effects of the synthesis temperature on the above properties were rationalized. The band structure revealed direct allowed transitions between the VB and CB and the experimental results in the ultraviolet-visible region were consistent with the theoretical results. Moreover, the surface calculations allowed the association of the surface energy stabilization with the temperature used in the synthesis of the ZnWO4 nanocrystals. The photoluminescence properties of the ZnWO4 nanocrystals prepared at 140, 150, and 160 °C were attributed to oxygen vacancies in the [WO6] and [ZnO6] clusters, causing a red shift of the spectra. The ZnWO4 nanocrystals obtained at 160 °C exhibited excellent photodegradation of Rhodamine under ultraviolet light irradiation, which was found to be related to the surface energy and the types of clusters formed on the surface of the catalyst.

Occurrence of human sapoviruses in wastewater and stool samples in Rio De Janeiro, Brazil.

AIM: To determine the prevalence and molecular epidemiology of human sapovirus (SaV) in both wastewater and stool samples in a 3-year (2012-2014) surveillance study performed in Rio de Janeiro State, Brazil. METHODS AND RESULTS: A total of 156 wastewater and 341 stool samples were analysed using quantitative real-time PCR. SaV was detected in 3·5% (12/341) in stool samples with virus load concentrations ranging from 10(4) to 10(9) genome copies per gram (gc g(-1) ), and in 33·0% (51/156) wastewater samples, with range concentration varying from 10(4) to 10(6)  gc l(-1) . Partial genome sequencing of wastewater and stool samples revealed the circulation of genotypes GI.1, GI.2, GI.6, GII.1 and GV.1. CONCLUSION: This study demonstrated the prevalence of human SaV in acute gastroenteritis (AGE) cases and revealed, for the first time, the environmental dissemination of those viruses in Brazil. SIGNIFICANCE AND IMPACT OF THE STUDY: SaV diagnosis should be considered in hospitalized children with AGE and the higher positive rate detection in environmental samples suggests that SaV infection could be underestimated or associated with asymptomatic cases.

Assessment of lifetime resolution limits in time-resolved photoacoustic calorimetry vs. transducer frequencies: setting the stage for picosecond resolution.

Time-resolved photoacoustic calorimetry (PAC) gives access to lifetimes and energy fractions of reaction intermediates by deconvolution of the photoacoustic wave of a sample (E-wave) with that of the instrumental response (T-wave). The ability to discriminate between short lifetimes increases with transducer frequencies employed to detect the PAC waves. We investigate the lifetime resolution limits of PAC as a function of the transducer frequencies using the instrumental response obtained with the photoacoustic reference 2-hydroxybenzophenone in toluene or acetonitrile. The instrumental response was obtained for a set of transducers with central frequencies ranging from 0.5 MHz up to 225 MHz. The simulated dependence of the lifetime resolution with the transducer frequencies was anchored on experimental data obtained for the singlet state of naphthalene with a 2.25 MHz transducer. The shortest lifetime resolved with the 2.25 MHz transducer was 19 ns and our modelling of the transducer responses indicates that sub-nanosecond lifetimes of photoacoustic transients can be resolved with transducers of central frequencies above 100 MHz.

Collagen-induced arthritis increases inducible nitric oxide synthase not only in aorta but also in the cardiac and renal microcirculation of mice.

Rheumatoid arthritis (RA) may promote endothelial dysfunction. This phenomenon requires further investigation, especially in collagen-induced arthritis (CIA), as it is considered the experimental model most similar to RA. The objectives of this study were to identify CIA-induced changes in noradrenaline (NE) and acetylcholine (ACh) responses in mice aortas that may suggest endothelial dysfunction in these animals. Moreover, we characterize CIA-induced modifications in inducible nitric oxide synthase (iNOS) expression in the aortas and cardiac and renal tissues taken from these mice that may be related to possible endothelial dysfunction. Male DBA/1J mice were immunized with 100 µg of emulsified bovine collagen type II (CII) plus complete Freund's adjuvant. Twenty-one days later, these animals received a boost of an additional 100 µg plus incomplete Freund's adjuvant. Fifteen days after the onset of the disease, aortic rings from CIA and control mice were challenged with NE and ACh in an organ bath. In these animals, iNOS was detected through immunohistochemical analysis of aorta, heart and kidneys. Plasma nitrite concentration was determined using the Griess reaction. CIA did not change NE or ACh responses in mice aorta but apparently increased the iNOS expression not only in aorta, but also in cardiac and renal microcirculation. In parallel, CIA reduced nitrite plasma concentration. In mice, CIA appears to increase the presence of iNOS in aorta, as well as in heart and in kidney microcirculation. This iNOS increase occurs apparently in parallel to a reduction of the bioavailability of NO. This phenomenon does not appear to change NE or ACh responses in aorta.

Transition Patterns of Frailty Syndrome in Comunity-Dwelling Elderly Individuals: A Longitudinal Study.

BACKGROUND: Little information is available about transitional patterns related to frailty syndrome in elderly individuals living in the community. OBJECTIVE: To assess transitional patterns and determine which frailty phenotype variables are more involved in this process. DESIGN: Longitudinal study. POPULATION: Community-dwelling elderly individuals in Belo Horizonte, Minas Gerais, Brazil. PARTICIPANTS: Two hundred individuals over 65 years old. MEASUREMENTS: The frailty phenotype was assessed at two different times, with a mean interval of 13 months. Comparison of the frequency distributions between the baseline and second assessment was conducted through Pearson's chi-squared test, and a binary logistic regression was conducted to assess the most important items in this transition. RESULTS: Sixty-eight percent of the elderly were women, with an average age of 73.7 (± 6.1) years. The pre-frail group transitioned the most between evaluations. Eighty-five individuals transitioned among frailty levels: 46 showed improvement while 39 worsened. Individuals who did scored low on the handgrip strength test in the first evaluation were more likely to have their frailty level worsen. Among individuals who showed improvements, those who were positive for weight loss and poor physical activity level in the first evaluation were less likely to improve. In this study, a greater number of individuals showed improved frailty levels over 13 months than worsened levels. CONCLUSION: Poor handgrip strength, weight loss, and poor physical activity are the most influential variables in frailty transitioning, leading to worsening levels of frailty or difficulty in making improvements.

Identification of oxidoreductases from the petroleum Bacillus safensis strain.

A gram-positive bacterium, denominated CFA-06, was isolated from Brazilian petroleum in the Campos Basin and is responsible for the degradation of aromatic compounds and petroleum aromatic fractions. The CFA-06 strain was identified as Bacillus safensis using the 16S rRNA and gyrase B sequence. Enzymatic assays revealed the presence of two oxidoreductases: a catalase and a new oxidoreductase. The oxidoreductases were enzymatically digested and analyzed via ESI-LTQ-Orbitrap mass spectrometry. The mass data revealed a novel oxidoreductase (named BsPMO) containing 224 amino acids and 89% homology with a hypothetic protein from B. safensis (CFA-06) and a catalase (named BsCat) with 491 amino acids and 60% similarity with the catalase from Bacillus pumilus (SAFR-032). The new protein BsPMO contains iron atom(s) and shows catalytic activity toward a monooxygenase fluorogenic probe in the presence of cofactors (NADH, NADPH and NAD). This study enhances our knowledge of the biodegradation process of petroleum by B. safensis.

Validation of a web-based questionnaire to assess the dietary intake of Brazilian children aged 7-10 years.

BACKGROUND: The Food Intake and Physical Activity of School Children (CAAFE) comprises an online questionnaire to self-report diet and physical activity of Brazilian schoolchildren. BACKGROUND: The present study aimed to assess the validity (matches, omissions and intrusions) and moderating factors of the CAAFE. METHODS: Direct observation was made of foods consumed (five public schools) and child self-reporting on the CAAFE. Additional data included school grade, gender, body mass index, completion of food diary, socioeconomic status and access to computer. Data were analysed using regression. RESULTS: In total, 602 children participated in the study [mean (SD) age 9.5 (1.24) years; 53.6% boys]. On average, there were 43% matches, 29% intrusions and 28% omissions. Matches doubled in third grade compared to the second grade (P = 0.004); matches almost tripled for afternoon snack compared to morning snack (P < 0.001); and matches were 69% higher for children with access to a computer at home (P < 0.01). Intrusions decreased by almost one-half in fifth compared to fourth grades (P = 0.004). Omissions declined significantly in the third and fourth grades but increased in the fifth grade. Omissions were 47% lower for children in the highest income and lower among children who completed the food diary. No differences were found for gender or body mass index. CONCLUSIONS: Children older than 8 years old, who owned a computer and completed a food diary, performed better in the CAAFE. A high incidence of disagreement was found in relation to the schools and the type of meal. Overall matches (43%), intrusions (29%) and omissions (28%) indicate that further studies are required to improve the validity of the CAAFE.

Qualitative analysis of the contributions of nutritionists to the development of an online instrument for monitoring the food intake of schoolchildren.

BACKGROUND: The Consumo Alimentar e Atividade Fisica de Escolares (CAAFE) questionnaire is an online research tool that has been developed to enable the self-report of physical activity and diet by Brazilian schoolchildren aged 7-10 years. Formative research was conducted with nutritionists during the development of the web-based questionnaire. The suggestions and insights obtained were used to design a tool to monitor schoolchildren's food consumption based on the concept of healthy and unhealthy food indicators. The present study aimed to report the focus group discussions conducted with nutritionists concerning the CAAFE questionnaire. METHODS: Focus group discussions were conducted using a semi-structured questionnaire, and these were then analysed thematically. RESULTS: Twenty-four nutritionists participated (four focus groups; average per group: six people); the majority (n = 22) had experience with 7-10-year-old children. Four themes emerged: (i) healthy and unhealthy food indicators; (ii) suggestions for the online instrument; (iii) potential applications; and (iv) challenges for its construction. CONCLUSIONS: Comments made by nutritionists enabled the construction of an instrument that is able to answer questions related to food consumption in schools and at home.

The experience of using the scale of functional independence measure in individuals undergoing spinal cord injury rehabilitation in Brazil.

STUDY DESIGN: Retrospective cohort. OBJECTIVES: The aim of this study was to evaluate the correlation between the level and completeness of the injury with Functional Independence Measure (FIM) score and the validity and responsiveness of the FIM in Brazilian individuals with spinal cord injury admitted to rehabilitation. SETTING: SARAH Network of Rehabilitation Hospitals, Brasília, Brazil. METHODS: A total of 218 patients with spinal cord injury admitted for rehabilitation in 2006 was included in this study. The validity was assessed as the ability of the FIM to discriminate different levels of disability (cervical, thoracic and lumbar) at admission and the responsiveness was obtained by analyzing admission and discharge data for each of the three injury groups. RESULTS: Total FIM score, motor FIM score and each of the 13 items were valid when comparing three groups and comparing groups two by two, except the items 'eating' and 'grooming' among paraplegics, and 'stairs' at cervical and thoracic levels. The scale was not responsive to the five cognitive items, 'stairs' and 'eating', among paraplegics, or 'grooming', 'bathing' and 'dressing upper body' in lumbar level patients. The patient difficulty in performing tasks can vary among populations. Therefore, the continuous evaluation process of psychometric characteristics is important to validate the use of the instrument in different contexts.

Do thyroid ultrasonographic features change according to age in euthyroid dogs?

The thyroid gland was assessed by ultrasound in healthy euthyroid mixed-breed medium size dogs in different age groups. The objective was to verify ultrasonographic imaging patterns in these groups, as well as to identify possible changes in imaging features resulting from ageing. Thirty dogs - 10 young (<1 year), 10 adult and 10 elderly - without clinical signs or history of thyroid gland disease with complete blood count and thyroid function tests within the reference values were evaluated. Each thyroid lobe was examined by ultrasound for shape, size, echogenicity and echotexture. The analysis of echogenicity and echotexture was made by histogram. Thyroid volume was estimated by the equation for ellipsoid (length × width × height) π/6. The thyroid volume of the young dogs in this study had a tendency to be higher than in adult dogs (P = 0.068) and older dogs (P = 0.120). The height of the thyroid lobe in the longitudinal plane was significantly higher (P = 0.026) in young dogs compared with the other dogs. The echotexture and echogenicity had no significant differences between groups, but the echogenicity was greater in older dogs. The results point out that ultrasound imaging of the thyroid volume is influenced by age in euthyroid dogs.

Molecular Detection of Leishmania in Sand Flies (Diptera: Psychodidae: Phlebotominae) Collected in the Caititu Indigenous Reserve of the Municipality of Lábrea, State of Amazonas, Brazil.

Phlebotominae sand flies are of medical importance because they are vectors of human pathogens, such as protozoa of the genus Leishmania Ross, etiological agent of American cutaneous leishmaniasis (ACL). In Lábrea, a municipality in the state of Amazonas, Brazil, ACL is primarily associated with subsistence activities, such as collection and extraction of forest products, undertaken by both indigenous and nonindigenous people. Data on ACL in indigenous populations are scarce, such that there is little information on the identity of the etiologic agent(s), reservoir host(s) and insect vector(s). The aim of this work was to study the sand fly fauna collected during an 8-d surveillance of different habitats in the Indigenous Reserve Caititu, Lábrea. In total, 1,267 sand flies were collected in different habitats for eight consecutive days, of which 819 (64.6%) were females and 448 (35.4%) males, from 10 genera and 32 species. The most abundant genera were Psychodopygus (34.3%), Trichophoromyia (22.9%), and Nyssomyia (15.3%). The most abundant species were Trichophoromyia ubiquitalis (Mangabeira) (n = 235, 18.5%), Psychodopygus davisi (Root) (n = 228, 18.0%) and Nyssomyia antunesi (Coutinho) (n = 135, 10.7%). Direct sequencing of polymerase chain reaction products demonstrated the presence of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis in the following species of sand flies: Evandromyia apurinan (Shimabukuro, Silveira, & Silva), Nyssomyia umbratilis (Ward & Fraiha), Nyssomyia yuilli yuilli (Young & Porter), Ps. davisi, Sciopemyia servulolimai (Damasceno & Causey), and Th. ubiquitalis. The presence of natural infection by Leishmania detected in the sand fly species investigated in this study suggests their possible role in the transmission cycle of ACL in the studied area.

Influence of the hydration state on the ultrashort laser ablation of dental hard tissues.

Since about 40 years, laser-based surgical tools have been used in medicine and dentistry to improve clinical protocols. In dentistry, femtosecond lasers have been claimed to be a potential ablation tool. It would, however, be good to perform a more fundamental investigation to understand ablation interaction mechanisms and possible side effects, depending on different specific components of the target tissue. The goal of this study is to show the changes of ablation characteristics in the femtosecond regime at different levels of structural water within dental hard tissues. Thirty human teeth samples were split into three hydration groups and subdivided into dentin and enamel groups (n = 5). The specimens were irradiated using a 70-fs Ti:sapphire laser (with a 1-kHz repetition rate and a 801-nm wavelength output). Ablation was performed using five different power levels and three exposure times. The results clearly show an inversely proportional dependence of the ablation threshold to the hydration level of the tissues. A known mathematical model was adapted in order to include the influence of the changes on the relative fractional composition of dental hard tissues. This analysis was consistent with the experimental results regarding the ablation threshold. High thermal and mechanical damages were observed as a high repetition rate had been applied. Macroscopic images and scanning electron microscopy images were used to preliminarily analyze both the thermal and mechanical damage thresholds, and their variations according to the hydration level present. By manipulating the hydration states, the modifications in the proportions of the molecules that build dental hard tissues clearly shift, and therefore, the characteristics of a plasma-induced ablation change.

Does treatment guided by vitamin K in the diet alter the quality of life of anticoagulated patients?

PURPOSE: To compare whether health-related quality of life (HRQoL) is altered in patients undergoing a treatment strategy guided by changes in dietary vitamin K. METHODS: This study is a randomized clinical trial carried out with chronic oral anticoagulation outpatients randomized into a control group (conventional dose adjustment of oral anticoagulants) (n = 66) and an intervention group (strategy based on changes in dietary vitamin K intake) (n = 66). HRQoL was measured using the Duke Anticoagulation Satisfaction Scale (DASS) at baseline and 90 days of follow-up. RESULTS: Patients with worse HRQoL were younger (p = 0.005) and were using a higher dose of baseline oral anticoagulants (p = 0.008), while those with better HRQoL scores had a higher level of education (p = 0.01). Both groups had significant improvements in HRQoL from baseline to 90 days in the global DASS score (p < 0.001), as well as in the negative and positive psychological impact (p < 0.001) domains. We did not observe differences in the variations of HRQoL scores in any of the DASS domains (p values > 0.05) between groups of interventions. Patients who achieved oral anticoagulation stability (n = 23) had significantly better HRQoL scores than patients who did not achieve stability (p = 0.003). CONCLUSION: Patients receiving the treatment strategy based on changes in dietary vitamin K intake did not have better HRQoL scores; however, both treatment approaches to manage oral anticoagulation improved HRQoL. Patients with greater oral anticoagulation stability had better HRQoL scores.