Effects of ortho-eugenol on anxiety, working memory and oxidative stress in mice.

Ortho-eugenol is a synthetic derivative from eugenol, the major compound of clove essential oil, which has demonstrated antidepressant and antinociceptive effects in pioneering studies. Additionally, its effects appear to be dependent on the noradrenergic and dopaminergic systems. Depression and anxiety disorders are known to share a great overlap in their pathophysiology, and many drugs are effective in the treatment of both diseases. Furthermore, high levels of anxiety are related to working memory deficits and increased oxidative stress. Thus, in this study we investigated the effects of acute treatment of ortho-eugenol, at 50, 75 and 100 mg/kg, on anxiety, working memory and oxidative stress in male Swiss mice. Our results show that the 100 mg/kg dose increased the number of head-dips and reduced the latency in the hole-board test. The 50 mg/kg dose reduced malondialdehyde levels in the prefrontal cortex and the number of Y-maze entries compared to the MK-801-induced hyperlocomotion group. All doses reduced nitrite levels in the hippocampus. It was also possible to assess a statistical correlation between the reduction of oxidative stress and hyperlocomotion after the administration of ortho-eugenol. However, acute treatment was not able to prevent working memory deficits. Therefore, the present study shows that ortho-eugenol has an anxiolytic and antioxidant effect, and was able to prevent substance-induced hyperlocomotion. Our results contribute to the elucidation of the pharmacological profile of ortho-eugenol, as well as to direct further studies that seek to investigate its possible clinical applications.

Evaluation of the antinociceptive effect generated by citronellal monoterpene isomers.

Due to the complex nature of pain and the participation of physical, cognitive, psychological and behavioral aspects, pain management has several approaches. The use of medicinal plants in developing countries is quite expressive. Seeking new options for the treatment of emerging or debilitating diseases. Therefore, the present study seeks to elucidate the effects of the monoterpene, citronellal, differentiating its activity by isomers (R)-(+) and (S)-(-) citronellal. The study used several methods to evaluate the effects of citronellal isomers on motor coordination, nociceptive response, and the involvement of opioid, glutamatergic, and transient receptor pathways. The methods included rota-rod, hot-plate, and formalin tests, as well as the use of specific inhibitors and agonists. Data were analyzed using inferential statistics with a 95% confidence level. Both isomers did not significantly affect the motor coordination of the studied animals. The isomer (S)-(-) citronellal showed better results in relation to its structural counterpart, managing to have an antinociceptive effect in the formalin and hot plate tests with a lower concentration (100 mg/kg) and presenting fewer side effects, however, the this study was not able to elucidate the mechanism of action of this isomer despite having activity in studies with substances that act on specific targets such as glutamate and capsaicin, its activity was not reversed with the use of antagonists for pathways related to nociception. While the (R)-(+) citronellal isomer, despite showing total activity only at a concentration of 150 mg/kg, was able to determine its mechanism of action related to the opioid pathway by reversing its activity by the antagonist naloxone, being this is a pathway already correlated with nociception control treatments, however, it is also related to some unwanted side effects. In this way, new studies are sought to elucidate the mechanism related to the isomer (S)-(-) citronellal and a possibility of use in other areas related to the treatment of pain or inflammation.

The prevalence of human papillomavirus in paediatric tonsils in Southwestern Ontario.

OBJECTIVE: To determine the prevalence of human papillomavirus in paediatric tonsils in Southwestern Ontario, Canada. MATERIALS AND METHODS: Patients aged 0-18 years undergoing tonsillectomy were recruited. Two specimens (left and right tonsils) were collected from each participant. Tonsillar DNA was analysed using quantitative polymerase chain reaction to determine the presence of human papillomavirus subtypes 6, 11, 16 or 18. RESULTS: A total of 102 patients, aged 1-18 years (mean age of 5.7 years), were recruited. Ninety-nine surveys were returned. There were 44 females (44.4 per cent) and 55 males (55.6 per cent). Forty patients (40.4 per cent) were firstborn children and 73 (73.7 per cent) were delivered vaginally. Six mothers (6.1 per cent) and one father (1.0 per cent) had prior known human papillomavirus infection, and one mother (1.0 per cent) had a history of cervical cancer. All tonsil specimens were negative for human papillomavirus subtypes 6, 11, 16 and 18. CONCLUSION: No human papillomavirus subtypes 6, 11, 16 or 18 were found in paediatric tonsil specimens from Southwestern Ontario.

Enhanced laser-driven proton acceleration using nanowire targets.

Laser-driven proton acceleration is a growing field of interest in the high-power laser community. One of the big challenges related to the most routinely used laser-driven ion acceleration mechanism, Target-Normal Sheath Acceleration (TNSA), is to enhance the laser-to-proton energy transfer such as to maximize the proton kinetic energy and number. A way to achieve this is using nanostructured target surfaces in the laser-matter interaction. In this paper, we show that nanowire structures can increase the maximum proton energy by a factor of two, triple the proton temperature and boost the proton numbers, in a campaign performed on the ultra-high contrast 10 TW laser at the Lund Laser Center (LLC). The optimal nanowire length, generating maximum proton energies around 6 MeV, is around 1-2 [Formula: see text]m. This nanowire length is sufficient to form well-defined highly-absorptive NW forests and short enough to minimize the energy loss of hot electrons going through the target bulk. Results are further supported by Particle-In-Cell simulations. Systematically analyzing nanowire length, diameter and gap size, we examine the underlying physical mechanisms that are provoking the enhancement of the longitudinal accelerating electric field. The parameter scan analysis shows that optimizing the spatial gap between the nanowires leads to larger enhancement than by the nanowire diameter and length, through increased electron heating.

Sources and space-time distribution of the electromagnetic pulses in experiments on inertial confinement fusion and laser-plasma acceleration.

When high-energy and high-power lasers interact with matter, a significant part of the incoming laser energy is transformed into transient electromagnetic pulses (EMPs) in the range of radiofrequencies and microwaves. These fields can reach high intensities and can potentially represent a significative danger for the electronic devices placed near the interaction point. Thus, the comprehension of the origin of these electromagnetic fields and of their distribution is of primary importance for the safe operation of high-power and high-energy laser facilities, but also for the possible use of these high fields in several promising applications. A recognized main source of EMPs is the target positive charging caused by the fast-electron emission due to laser-plasma interactions. The fast charging induces high neutralization currents from the conductive walls of the vacuum chamber through the target holder. However, other mechanisms related to the laser-target interaction are also capable of generating intense electromagnetic fields. Several possible sources of EMPs are discussed here and compared for high-energy and high-intensity laser-matter interactions, typical for inertial confinement fusion and laser-plasma acceleration. The possible effects on the electromagnetic field distribution within the experimental chamber, due to particle beams and plasma emitted from the target, are also described. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Thomson parabola and time-of-flight detector cross-calibration methodology on the ALLS 100 TW laser-driven ion acceleration beamline.

We report on the cross-calibration of Thomson Parabola (TP) and Time-of-Flight (TOF) detectors as particle diagnostics, implemented on the most recent setup of the ALLS 100 TW laser-driven ion acceleration beamline. The Microchannel Plate (MCP) used for particle detection in the TP spectrometer has been calibrated in intensity on the tandem linear accelerator at the Université de Montréal. The experimental data points of the scaling factor were obtained by performing a pixel cluster analysis of single proton impacts on the MCP. A semi-empirical model was extrapolated and fitted to the data to apply the calibration also to higher kinetic energies and to extend it to other ion species. Two TOF lines using diamond detectors, placed at +6° and -9° with respect to the target-normal axis, were benchmarked against the TP spectrometer measurements to determine the field integrals related to its electric and magnetic dispersions. The mean integral proton numbers obtained on the beamline were about 4.1 × 1011 protons/sr with a standard deviation of 15% in the central section of the spectrum around 3 MeV, hence witnessing the high repeatability of the proton bunch generation. The mean maximum energy was of 7.3 ± 0.5 MeV, well in agreement with similar other 100 TW-scale laser facilities, with the best shots reaching 9 MeV and nearly 1012 protons/sr. The used particle diagnostics are compatible with the development of a high-repetition rate targetry due to their fast online readout and are therefore a crucial step in the automation of any beamline.

Ultrafast electron and proton bunches correlation in laser-solid matter experiments.

The interaction of an ultra-intense laser with a solid state target allows the production of multi-MeV proton and ion beams. This process is explained by the target normal sheath acceleration (TNSA) model, predicting the creation of an electric field on the target rear side, due to an unbalanced positive charge. This process is related to the emission of relativistic ultrafast electrons, occurring at an earlier time. In this work, we highlight the correlations between the ultrafast electron component and the protons by their simultaneous detection by means of an electro-optical sampling and a time-of-flight diagnostics, respectively, supported by numerical simulations showing an excellent agreement.

Publisher Correction: Characterization of nitrogen doped graphene bilayers synthesized by fast, low temperature microwave plasma-enhanced chemical vapour deposition.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Characterization of nitrogen doped grapheme bilayers synthesized by fast, low temperature microwave plasma-enhanced chemical vapour deposition.

New techniques to manipulate the electronic properties of few layer 2D materials, unveiling new physical phenomena as well as possibilities for new device applications have brought renewed interest to these systems. Therefore, the quest for reproducible methods for the large scale synthesis, as well as the manipulation, characterization and deeper understanding of these structures is a very active field of research. We here report the production of nitrogen doped bilayer graphene in a fast single step (2.5 minutes), at reduced temperatures (760 °C) using microwave plasma-enhanced chemical vapor deposition (MW-PECVD). Raman spectroscopy confirmed that nitrogen-doped bilayer structures were produced by this method. XPS analysis showed that we achieved control of the concentration of nitrogen dopants incorporated into the final samples. We have performed state of the art parameter-free simulations to investigate the cause of an unexpected splitting of the XPS signal as the concentration of nitrogen defects increased. We show that this splitting is due to the formation of interlayer bonds mediated by nitrogen defects on the layers of the material. The occurrence of these bonds may result in very specific electronic and mechanical properties of the bilayer structures.

Low-energy proton calibration and energy-dependence linearization of EBT-XD radiochromic films.

In this work, we calibrate the newly developed EBT-XD radiochromic films (RCFs) manufactured by Gafchromictm using protons in the energy range of 4-10 MeV. Irradiation was performed on the 2 × 6 MV tandem linear accelerator located at the Université de Montréal. The RCFs were digitized using an Epson Perfection V700 flatbed scanner using both the red-green-blue and grayscale channels. The proton fluences were measured with Faraday cups calibrated in absolute terms. The linear energy transfer function within the active layer of the films was calculated using the mass stopping power tables coming from the PSTAR database from the National Institute of Standards and Technology (NIST) to allow retrieval of the deposited dose. We find that the calibration curves for 7 and 10 MeV protons are nearly equivalent. The 4 MeV calibration curves exhibit a quenching effect due to the Bragg peak that falls close to the active layer. A linearization of this energy dependence was developed using a semiempirical parametric model to allow the generation of calibration curves for any incident proton energy within the present range. Excellent correspondence (<5% dose difference for the same netOD) of the 10 MeV calibration curves was noted when compared to existing high-energy proton (148.2 MeV) calibration curves reported in the literature. Our calibration extends the range of operation of EBT-XD films to low-energy proton beam dosimetry.

Antibiotic prescribing for endodontic infections: a survey of dental students in Italy.

AIM: To determine the knowledge of final year undergraduate students attending Italian universities on the appropriate use of systemic antibiotics for endodontic infections. METHODOLOGY: Final year dental students from twenty Italian universities completed a one-page questionnaire on antibiotic use for the treatment of endodontic infections. Data were analysed using descriptive statistics and chi-square tests. RESULTS: A total of three hundred and three students completed the questionnaire. The average duration of antibiotic prescription proposed by respondents was 5.48 ± 1.06 days. Amoxicillin with clavulanic acid was the first-choice antibiotic (85.2%) followed by amoxicillin alone (13.5%), azithromycin (1.0%) and clarithromycin (0.3%), for patients not allergic to penicillin. Clarithromycin was the first-choice drug for patients with a penicillin allergy (56.1%), followed from azithromycin (31.7%), clindamycin (11.9%) and levofloxacin (0.3%). Alveolar abscess with systemic manifestations was reported as the principal reason to prescribe antibiotics (97.7%) followed by the same condition without systemic manifestations (85.5%). For the scenario of irreversible pulpitis, 5% of students considered antibiotics necessary. Almost 52% of students would prescribe antibiotics for apical acute periodontitis; 29.7% would prescribe antibiotics for chronic apical periodontitis with sinus tract, and 13.5% indicated these drugs for chronic apical periodontitis without sinus tract. CONCLUSIONS: The results demonstrate that it is necessary to improve the knowledge of Italian students on antibiotics and indications for their use in endodontics.

Role of efflux transporters in the absorption, distribution and elimination in rodents of a novel PDE4 inhibitor, CHF6001.

CHF6001 is a new and potent PDE4 inhibitor for the treatment of human lung diseases, designed for topical administration by inhalation. In preclinical assessment CHF6001 appeared safe and devoid of emetic effect, which is typical side effect of PDE4 inhibitors in humans. CHF6001 absorption, distribution and excretion were evaluated in rats by PO and IV administration of [14C]CHF6001; additionally the role of transporters was investigated by using transfected cells expressing either human transporters or MDR1 and BCRP KO mice. [14C]CHF6001 intravenously administered as bolus distributed in all the tissues (with very low levels in brain and fetus) and it was mainly eliminated in bile. Following oral administration [14C]CHF6001 about half of the dose was absorbed through the gut. In vitro, CHF6001 was a substrate of human membrane transporters MDR1 and BCRP. In wild and BCRP KO mice CHF6001 was not detectable in brain, whereas it was measurable in Mdr1a/b KO mice. Therefore, in animal species Mdr1a/b plays a significant role in CHF6001 disposition, limiting its distribution into brain and contributing to the safety profile observed in preclinical evaluation. This behavior was confirmed by the results of the first human studies, where CHF6001 was safe and with no emetic effect at all the evaluated doses.

Updated NACI recommendations for measles post-exposure prophylaxis.

BACKGROUND: Human immune globulin (Ig) products are currently recommended as post-exposure prophylaxis (PEP) for measles in certain susceptible groups. However, successful measles vaccination programs in North America have led to low circulation of measles virus and most blood donors now have vaccine-derived immunity. Concurrently, the concentrations of anti-measles antibodies in human Ig products have shown trends of gradual decline and previously recommended doses and routes of administration may no longer be optimally protective. OBJECTIVES: To review the literature and update recommendations on post-exposure prophylaxis for measles, including dosing and route of administration, for measles Ig PEP in susceptible infants and in individuals who are immunocompromised or pregnant, in order to prevent severe disease. APPROACH: The National Advisory Committee on Immunization (NACI) Measles, Mumps, Rubella, Varicella Working Group reviewed key literature, international practices, and product information for current Ig products pertaining to the optimal dosage and routes of Ig administration for measles PEP. It then proposed evidence-based changes to the PEP recommendations that were considered and approved by NACI. RESULTS: NACI continues to recommend that susceptible immunocompetent individuals six months of age and older, who are exposed to measles and who have no contraindications be given measles-mumps-rubella (MMR) vaccine within 72 hours of the exposure. NACI recommends that for susceptible infants younger than six months of age, if injection volume is not a major concern, intramuscular immunoglobulin (IMIg) should be provided at a concentration of 0.5 mL/kg, to a maximum dose of 15 mL administered over multiple injection sites. Susceptible infants six to 12 months old who are identified after 72 hours and within six days of measles exposure should receive IMIg (0.5 mL/kg) if injection volume is not a major concern. For susceptible contacts who are pregnant or immunocompromised, if injection volume is not a concern, IMIg can be provided at a concentration of 0.5 mL/kg understanding that recipients 30 kg or more will not receive the measles antibody concentrations that are considered to be fully protective. Alternatively, in cases where injection volume is a major concern or for recipients 30 kg or more, intravenous immunoglobulin (IVIg) can be provided at a dose of 400 mg/kg.NACI does not recommend that susceptible immunocompetent individuals older than 12 months of age receive Ig PEP for measles exposure due to the low risk of disease complications and the practical challenges of administration for case and contact management. CONCLUSION: NACI has updated the recommendations for measles PEP to reflect current evidence and best practices in order to prevent severe disease in Canada. Consistent with recommendations in other countries, this includes consideration of off-label use of IVIg in some instances.

Pharmacokinetic/pharmacodynamic evaluation of grapiprant in a carrageenan-induced inflammatory pain model in the rabbit.

Grapiprant is the novel selective EP4 receptor inhibitor recently issued on the veterinary market for dogs affected by osteoarthritis. The aim of this study was twofold: to evaluate the pharmacokinetics and the pharmacodynamics of grapiprant in the induced inflammatory pain model in the rabbit after a single IV injection of 2 mg/kg; to compare the thermal antinociception effect after 2 mg/kg IV grapiprant, with that generated by 0.5 mg/kg meloxicam SC injected. Rabbits (n = 12) were randomly assigned to two crossover studies (single-dose, two-period crossover). The first study group A (n = 3) received a single IV dose of grapiprant at 2 mg/kg dissolved in ethanol. Group B (n = 3) received a single IV injection of ethanol (equivalent volume to grapiprant volume) at the same site. The second study group C (n = 3) received a single SC dose of meloxicam at 0.5 mg/kg. Group D (n = 3) received a single SC injection of 15% ethanol (equivalent volume to grapiprant volume) at the same site. After a 2-week washout period, the groups were rotated and the experiments repeated. Blood samples (0.7 mL) were collected from the right ear artery at assigned times and grapiprant plasma concentrations determined by a validated HPLC-FL method. Three hours prior to administration of the drugs, inflammation was induced by SC injection of lambda carrageenan (200 µL, 3% in physiological saline) under the plantar surface of the right hind paw. At a similar time to the blood collection, an infrared thermal stimuli (40 °C) was applied to the plantar surface of the rabbits' hindlimbs to evaluate the thermal withdrawal latency (TWL). The thermal antinociceptive effect was expressed as maximum possible response (% MPR). Grapiprant plasma concentrations were detectable up to the 10-h time point (concentration range 17-7495 ng/mL). The grapiprant-treated group showed a significant increase in TWL from 1 h and up to 10 h after drug administration compared to the control. In contrast, the meloxicam group showed a significant increase in TWL from 4 up to 10 h after drug administration, compared to control. The maximal MPR% was not statistically different between the grapiprant and meloxicam group from 4 to 8 h, while significant differences were shown at 1, 1.5, 2, 10 and 24 h. Given these findings, grapiprant appears to be an attractive option for antinociception in rabbits, due to its rapid onset and extended duration of effect.

Pharmacokinetic and pharmacodynamic evaluations of a 10 mg/kg enrofloxacin intramuscular administration in bearded dragons (Pogona vitticeps): a preliminary assessment.

Enrofloxacin (E) is commonly used in veterinary medicine. It is necessary to perform pharmacokinetic/dynamic studies to minimize the selection of resistant mutants of bacteria and extend the efficacy of antimicrobial agents. Eight healthy adult Pogona vitticeps were assigned into two groups of equal size and treated with a single intramuscular injection of E at 10 mg/kg. Blood samples were withdrawn at different scheduled times for each group, and rectal swabs were collected. E and ciprofloxacin (active metabolite) blood concentrations were quantified by an HPLC validated method, while the in vitro antimicrobial susceptibility was evaluated by the Kirby-Bauer disc diffusion susceptibility test. The pharmacokinetic profiles of E gave similar pharmacokinetic parameters irrespective of the collection time schedule. Bacteria isolation showed the presence of both E. coli, Salmonella enterica subspecies enterica and subspecies 3a, Proteus spp., and Pseudomonas spp. The majority of isolated colonies were sensitive to E, but the treatment did not reduce the number of bacteria in faeces. Results suggest that E is able to reach blood concentrations high enough to kill susceptible bacteria (MIC < 0.9 µg/mL), but at the same time does not significantly affect intestinal bacteria.

Cell growth on 3D microstructured surfaces.

Chinese Hamster Ovary (CHO) cell cultures were grown on surfaces lithographed with periodic 3D hexagonal microcavity array morphology. The range of microcavity size (inscribed circle diameter) was from 12 µm to 560 µm. CHO cells were grown also on flat surfaces. The characterization was performed with respect to cell growth density (number of nuclei per unit area) by fluorescence optical microscopy and evaluated by correlation function analysis. We found that optimum microcavity radius was 80 µm, concerning to the maximum cell growth density, being even greater than the growth density on a flat (unstructured) substrate of the same material. This finding can be important for optimization of biotechnological processes and devices.

European Renal Best Practice Guideline on kidney donor and recipient evaluation and perioperative care

The European Best Practice Guideline group (EBPG) issued guidelines on the evaluation and selection of kidney donor and kidney transplant candidates, as well as post-transplant recipient care, in the year 2000 and 2002. The new European Renal Best Practice board decided in 2009 that these guidelines needed updating. In order to avoid duplication of efforts with kidney disease improving global outcomes, which published in 2009 clinical practice guidelines on the post-transplant care of kidney transplant recipients, we did not address these issues in the present guidelines.The guideline was developed following a rigorous methodological approach: (i) identification of clinical questions, (ii) prioritization of questions, (iii) systematic literature review and critical appraisal of available evidence and (iv) formulation of recommendations and grading according to Grades of Recommendation Assessment, Development, and Evaluation (GRADE). The strength of each recommendation is rated 1 or 2, with 1 being a 'We recommend' statement, and 2 being a 'We suggest' statement. In addition, each statement is assigned an overall grade for the quality of evidence: A (high), B (moderate), C (low) or D (very low). The guideline makes recommendations for the evaluation of the kidney transplant candidate as well as the potential deceased and living donor, the immunological work-up of kidney donors and recipients and perioperative recipient care.All together, the work group issued 112 statements. There were 51 (45%) recommendations graded '1', 18 (16%) were graded '2' and 43 (38%) statements were not graded. There were 0 (0%) recommendations graded '1A', 15 (13%) were '1B', 19 (17%) '1C' and 17 (15%) '1D'. None (0%) were graded '2A', 1 (0.9%) was '2B', 8 (7%) were '2C' and 9 (8%) '2D'. Limitations of the evidence, especially the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.We present here the complete recommendations about the evaluation of the kidney transplant candidate as well as the potential deceased and living donor, the immunological work-up of kidney donors and recipients and the perioperative recipient care. We hope that this document will help caregivers to improve the quality of care they deliver to patients. The full version with methods, rationale and references is published in Nephrol Dial Transplant (2013) 28: i1-i71; doi: 10.1093/ndt/gft218 and can be downloaded freely from http://www.oxfordjournals.org/our_journals/ndt/era_edta.html.

Pharmacokinetic/pharmacodynamic assessments of 10 mg/kg tramadol intramuscular injection in yellow-bellied slider turtles (Trachemys scripta scripta).

In reptiles, administration of opioid drugs has yielded unexpected results with respect to analgesia. The aims of this study were to assess the pharmacokinetic/pharmacodynamic (PK/PD) properties of tramadol and its active metabolite M1 and to evaluate the effect of the renal portal system on the PK/PD parameters in yellow-bellied slider turtles. Turtles (n = 19) were randomly assigned to four treatment groups, according to a masked, single-dose, four-treatment, unpaired, four-period crossover design. Group A (n = 5) received a single i.m. dose of tramadol (50 mg/mL) at 10 mg/kg in the proximal hindlimb. Group B (n = 5) received the same i.m. dose but in the forelimb. Groups C (n = 5) and D (n = 4) received a single i.m. injection of saline (NaCl 0.9%) of equivalent volume to the volumes of tramadol injected in the hind- and forelimb, respectively. Groups were rotated (1-month washout period) until the completion of the crossover study. Tramadol plasma concentrations were evaluated by a validated HPLC-FL method. An infrared thermal stimulus was applied to the plantar surface of the turtles' hindlimbs to evaluate the thermal withdrawal latency (TWL). The two PK profiles of tramadol differed in the first 2 h following administration, but overlapped in the elimination phases. The metabolite M1 was formed in both the treatment groups, showing similar pharmacokinetic trends, although the amount of M1 was significantly higher (20%) in the hindlimb vs. forelimb group. Turtles given tramadol in the hind- and forelimb showed a significant increase in TWL over the periods of 0.5-48 and 8-48 h, respectively. The calculated % maximal possible response (% MPR) was low (about 24%). The PK/PD correlations between M1 plasma concentrations vs. % MPR appeared to show a counterclockwise hysteresis loop shape.

CO2 Laser Glazing Treatment of a Veneering Porcelain: Effects on Porosity, Translucency, and Mechanical Properties.

This work tested CO2 laser as a glazing agent and investigated the effects of irradiation on the porosity, translucency, and mechanical properties of veneering porcelain. Sixty discs (diameter 3.5 × 2.0 mm) of veneering porcelain for Y-TZP frameworks (VM9, VITA Zahnfabrik) were sintered and had one of their faces mirror polished. The specimens were divided into six groups (n=10/group) according to surface treatment, as follows: no treatment-control; auto-glaze in furnace following manufacturer's instructions (G); and CO2 laser (45 or 50 W/cm(2)) applied for four or five minutes (L45/4, L45/5, L50/4, L50/5). Optical microscopy (Shimadzu, 100×) was conducted and the images were analyzed with Image J software for the determination of the following porosity parameters: area fraction, average size, and Feret diameter. The translucency parameter studied was masking ability, determined by color difference (ΔE) over black and white backgrounds (CM3370d, Konica Minolta). Microhardness and fracture toughness (indentation fracture) were measured with a Vickers indenter (HMV, Shimadzu). Contact atomic force microscopy (AFM) (50 × 50 µm(2), Nanoscope IIIA, Veeco) was performed at the center of one sample from each group, except in the case of L45/5. With regard to porosity and translucency parameters, auto-glazed and laser-irradiated specimens presented statistical similarity. The area fraction of the surface pores ranged between 2.4% and 5.4% for irradiated specimens. Group L50/5 presented higher microhardness when compared to the G group. The higher (1.1) and lower (0.8) values for fracture toughness (MPa.m(1/2)) were found in laser-irradiated groups (L50/4 and L45/4, respectively). AFM performed after laser treatment revealed changes in porcelain surface profile at a submicrometric scale, with the presence of elongated peaks and deep valleys.