On the interactions involving serine proteases obtained from Monacrosporium thaumasium (Ascomycota: Orbiliomycetes) and deoxyribonucleic acid (DNA): biological macromolecules in action.

The use of force spectroscopy approaches performed with optical tweezers can be very useful in determining the binding modes and the physical chemistry of DNA interactions with ligands, from small drugs to proteins. Helminthophagous fungi, on the other hand, have important enzyme secretion mechanisms for various purposes, and the interactions between such enzymes and nucleic acids are very poorly studied. Therefore, the main goal of the present work was to investigate, at the molecular level, the mechanisms of interaction between fungal serine proteases and the double-stranded (ds) DNA molecule. Experimental assays performed with this single molecule technique consist in exposing different concentrations of the protease of this fungus to dsDNA until saturation while monitoring the changes on the mechanical properties of the macromolecular complexes formed, from where the physical chemistry of the interaction can be deduced. It was found that the protease binds strongly to the double-helix, forming aggregates and changing the persistence length of the DNA molecule. The present work thus allowed us to infer information at the molecular level on the pathogenicity of these proteins, an important class of biological macromolecules, when applied to a target specimen.

Microextraction technique associated with gas chromatography-mass spectrometry for determining pesticide residues in urine.

Urine is one of the biological matrices most used for detecting human contamination, as it is representative and easily obtained via noninvasive sampling. This study proposes a fast, accurate, and ecological method based on liquid-liquid microextraction with low-temperature partition (µLLE/LTP). It was validated to determine nine pesticides (lindane, alachlor, aldrin, chlorpyrifos, dieldrin, endrin, DDT, bifenthrin, and permethrin) in human urine, in association with gas chromatography coupled with mass spectrometry (GC-MS). The technique was optimized through a factorial design. The best conditions for the simultaneous extraction of the analytes comprised the addition of 600 µL of water and 600 µL of acetonitrile (extracting solvent) to a 500-µL urine sample, followed by vortexing for 60 s. By freezing the samples for 4 h, it was possible to extract the pesticides and perform the extract clean-up simultaneously. The parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy were used to appraise the performance of the method. Good values of selectivity and linearity (R2 > 0.990), LOQ (0.39-1.02 µg L-1), accuracy (88-119% recovery), and precision (%CV ≤ 15%) were obtained. The µLLE/LTP-GC-MS method was applied to authentic urine samples collected from volunteers in Southeast Brazil.

Towards an inclusive digital literacy: An experimental intervention study in a rural area of Brazil.

About half of the world's population remains without access to internet in an era of digital transformation. In this study, we aimed to investigate the impact of implementing the use of logic and mathematics through digital literacy on a population of elementary school students in a town in Northeast Brazil. In a non-randomized experimental longitudinal intervention study, 5th-grade students were followed during one semester. They underwent observational testing during class with the use of scales to evaluate their activities in a digital environment, and they were evaluated with respect to their ability to use digital devices. A logic/math assessment was applied prior to and at the end of the course for intervention group and compared to a control group. Questionnaires were used to assess the educators', legal guardians' and students' perceptions on digital habits and their respective sociodemographic features. The intervention consisted of a 16-h long course developed consisting of 8 2-h long classes which focused on digital technology, digital culture, and computational thinking. The students had a strong interest in the classes. Although some students did not have prior contact with computers, their development was outstanding. Digital literacy competencies and technology-use behavior increased throughout the semester independent of family income and use of digital devices at home. Students progressively improved their interaction with the computer (e.g. touchpad and typing skills) and their confidence in the digital environment. Students' scores on the logic/math assessment showed significant improvement. This was not observed in the control group, demonstrating the importance of this type of intervention even with one provided by a 16-h course. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10639-021-10711-z.

Disseminated Cutaneous Leishmaniasis and Alcohol Misuse, Northeast Brazil, 2015-2018.

Disseminated cutaneous leishmaniasis (DCL) is an uncommon form of Leishmania braziliensis infection. It remains unknown why some people develop this clinical condition. We describe 14 DCL patients in Northeast Brazil during 2015-2018. These patients regularly drank large amounts of alcohol, possibly increasing their risk for DCL.

Proteolytic and nematicidal potential of the compost colonized by Hypsizygus marmoreus.

Spent mushroom compost (SMC) is a residue generated in edible mushrooms production, such as Hypsizygus marmoreus. Its genome was recently sequenced, demonstrating cuticle-degrading protease genes. The present work aims to investigate the proteases from H. marmoreus spent mushroom compost (SMC) by verifying its action on nematode larvae. The extraction of the crude extract directly with water from H. marmoreus SMC proved to be efficient for proteases obtainment, with proteolytic activity of 195.36 ±â€¯18.38 U g-1 of compound. Moreover, the zymogram and SDS-PAGE indicated the presence of two proteases with estimated molecular weights of 30.2 and 33.7 kDa. Due to the protease activity present in H. marmoreus SMC extract, there was a significant reduction in the number of Panagrellus redivivus and L3 in treated group compared to control group (p < 0.01), with 52% and 26% of reduction, respectively. A0A151VWY3 mature protein is composed of 296 amino acid residues, exhibiting molecular weight and pI of 29.5 kDa and 6.72. A0A151WD28 mature protein is composed of 343 amino acid residues, exhibiting molecular weight and pI of 34.4 kDa and 8.04. In the present work it was demonstrated that SMC from H. marmoreus has easily extracted protease content, presenting two proteases, possibly with cuticle-degrading activity, which had significant nematicidal effect on P. redivivus and bovine infective larvae.

Evaluation of the antimicrobial and antioxidant activity of 7-hydroxy-4', 6-dimethoxy-isoflavone and essential oil from Myroxylon peruiferum L.f.

This study evaluated the antibacterial, antifungal, and antioxidant effect of 7-hydroxy-4',6-dimethoxy-isoflavone and essential oil of Myroxylon peruiferum. The compound was isolated and its structure elucidated by NMR. The chemical composition of essential oil determined by GC-MS analysis. To evaluation of antimicrobial activity, the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) were performed. In addition to analysis of antioxidant activity, DPPH radical scavenging tests, iron chelating assay (FIC), antioxidant reducing power assay (FRAP) and ß-carotene bleaching assay (BCB) were performed. For the essential oil were identified 24 organized compounds having as main constituents; Germacrene D (17.2%), α-pinene (14.8%) and E-caryophyllene (10.8%). The results showed that isoflavone (2000 to 156 µg/mL) and essential oil (5.0 to 1.25%) present antibacterial and antifungal activity against Gram-positive bacteria and filamentous fungi. The isoflavone and the essential oil also presented antioxidant activity in all the tests, mainly on inhibition of the oxidation of ß-carotene test concentrations ranging from 60 to 100%. In conclusion, isoflavone and essential oil from M. peruiferum present an antimicrobial alternative against Gram-positive bacteria, especially of the genus Staphylococcus and dermatophyte fungi of the genus Trichophyton, as well as a natural compound antioxidant.

Egos has a reduced capacity to predicts GBS prognosis in Northeast Brazil.

OBJECTIVE: The Erasmus Guillain Barre Outcome Score (EGOS) is a prognostic model that predicts the chance of being able to walk independently at 6 months after Guillain Barré syndrome (GBS). This study was conducted aiming to determine the validity of EGOS in a Brazilian population. MATERIAL AND METHODS: Data collected from GBS patients in Rio Grande do Norte, Brazil, were used to determine the validity of EGOS. GBS disability score was assessed in the second week of disease and at 6 months. RESULTS: A total of 206 subjects were studied. The Brazilian patients were younger, with a more severe clinical presentation, with higher percentage of cranial nerve involvement and upper respiratory infection. There was no difference relative to sex or presence of anti-gangliosides antibodies. The demyelinating variant was more common (73.9%). However, only 24% of the Brazilians with EGOS 5.5-7 were not able to walk after 6 months, compared to 52% to European Group. Nine patients (3.8%) presented nodopathies, of these four had an EGOS >5, but only one of the latter group was unable to walk after 6 months of GBS. CONCLUSIONS: Erasmus Guillain Barre Outcome Score was not a good predictor for the ability to walk after 6 months of GBS in Rio Grande do Norte, Brazil. Differences could be that the Brazilian GBS were younger, or alternatively, it could be due to a different infection profile or in the incidence of nodopathies.

Statistical tools application on dextranase production from Pochonia chlamydosporia (VC4) and its application on dextran removal from sugarcane juice.

The aim of this study was to optimize the dextranase production by fungus Pochonia chlamydosporia (VC4) and evaluate its activity in dextran reduction in sugarcane juice. The effects, over the P. chlamydosporia dextranase production, of different components from the culture medium were analyzed by Plackett-Burman design and central composite design. The response surface was utilized to determine the levels that, among the variables that influence dextranase production, provide higher production of these enzymes. The enzymatic effect on the removal of dextran present in sugarcane juice was also evaluated. It was observed that only NaNO3 and pH showed significant effect (p<0.05) over dextranase production and was determined that the levels which provided higher enzyme production were, respectively, 5 g/L and 5.5. The dextranases produced by fungus P. chlamydosporia reduced by 75% the dextran content of the sugarcane juice once treated for 12 hours, when compared to the control treatment.

Influence of plasma-based dry etching on the bond strength of Y-TZP ceramic.

The aim of this study was to evaluate the bond strength between an yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic and a luting agent when submitted to plasma etching surface treatment before and after thermocycling (TC) with 3000 cycles of 5°C-55°C. The null hypothesis was that the surface treatments and thermocycling would not influence the bond strength. A total of 160 Y-TZP ceramic blocks in 2 sizes (10 size 1 and 10 size 2 blocks in each group) were distributed into 8 groups: group C (control), no surface treatment; group C-TC, TC without prior surface treatment; group SAO, sandblasting with aluminum oxide (Al2O3); group SAO-TC, sandblasting with Al2O3 followed by TC; group SAOS, sandblasting with silica-coated Al2O3; group SAOS-TC, sandblasting with silica-coated Al2O3 followed by TC; group PE, plasma etching; and group PE-TC, plasma etching followed by TC. In each group, size 1 blocks were cemented to size 2 blocks to fabricate specimens for microshear bond strength testing (n = 10 per group). Cementation followed surface treatments (except in control groups) and preceded any TC. All specimens were cemented using a luting agent that contained 10-meth-acryloyloxydecyl dihydrogen phosphate (MDP). The specimens were submitted to a microshear bond strength test and the means were analyzed with a 2-factor analysis of variance and Tukey test. Group PE showed the highest bond strength value before thermocycling (17.31 MPa). After thermocycling, the highest value was observed in the SAO-TC group (9.73 MPa), and statistically significant differences were observed between SAOS-TC and SAO-TC (P < 0.05) and PE-TC and SAO-TC (P < 0.05). Plasma etching improved the bond strength values between the Y-TZP ceramic and MDP-containing luting agent before thermocycling. After thermocycling, all groups showed lower bond strength values.

Influence of Two Types of Connections in Driver-Retention Screw Assembly.

Rehabilitation with implant-supported prostheses has reached high success rates. However, mechanical failures are still reported, mainly in retention screws of abutments in single implant-supported crowns; which is designed to be the weakest structure and the first component to fail under overloading. In this sense, the aim of this in vitro study was to evaluate the influence of different joint designs (square or hexagonal) on resistance to deformation of driver-retention screw assembly of 3 commercial brands (Neodent, Singular, and Sin). A total of 42 retention screws from 3 commercial brands were used. The samples were divided into 2 joint groups, square (SQU) and hexagonal (HEX), and separated by commercial brands. Several components (implants and abutments) with standard platform (4.1 mm in diameter) were used. The resistance to deformation of the driver-retention screw assembly was measured using an accurate digital torque wrench for all commercial brands (Neodent [NEO], Singular [SGL], and Sin [SIN]) and joint designs (square or hexagonal). It was found no statistically significant difference (P <0.05) among the brands evaluated. On the other hand, square screws showed higher resistance to torsion than hexagonal screws; regardless the commercial brand.

Dislodgement Resistance of Zirconia Copings Cemented onto Zirconia and Titanium Abutments.

PURPOSE: To determine the effect of the cement type and abutment material on the tensile strength required to dislodge zirconia copings. MATERIALS AND METHODS: Two experimental groups of abutments were prepared: (1) titanium abutments (n = 30) and (2) zirconia abutments (n = 30). Sixty zirconia copings (custom designed) were fabricated using 3-dimensional computer-assisted design to have a 6-mm projection above the abutment to accommodate a hole, through which a wire was inserted to attach the zirconia coping to a universal testing machine. Each abutment was placed onto an implant analog embedded in acrylic resin blocks to fit onto the universal testing machine. The zirconia copings were cemented onto the abutments with a provisional luting agent, zinc phosphate (ZP) cement, and adhesive resin cement, and after 5500 thermocycles, a tensile force was applied at a crosshead speed of 0.5 mm/min. The removal force was recorded for each specimen. Two-way analysis of variance (ANOVA) and 1-way ANOVA were used for the statistical analysis (P < 0.05). RESULTS: The mean forces necessary to remove the zirconia copings from titanium abutments were 6.52, 83.09, and 251.18 N for temporary cement, ZP cement, and resin cement, respectively. For zirconia abutments, the required forces were 17.82, 116.41, and 248.72 N. CONCLUSIONS: The abutment material had no effect on retention, but the cement type affected the retention of the zirconia copings.

Evaluation of spatial and functional roughness parameters on air-abraded zirconia as a function of particle type and deposition pressure.

PURPOSE: This study evaluated the spatial and functional roughness parameters on air-abraded zirconia as a function of particle type and deposition pressure. MATERIALS AND METHODS: Polished zirconia blocks (Cercon, Degussa/Dentsply) (N=30) with dimensions of 5 × 4 × 4 mm3 were air abraded according to 2 factors: a) particle type - 30-µm silica-coated alumina (CoJet) or alumina particles (45 µm); b) deposition pressure (1.5, 2.5 and 4.5 bar). Roughness parameters (Sdr, Vi, Sci and Svi) were measured in an optical profilometer (Wyko NT 1100) at the center of the air-abraded area (301.3 × 229.2 µm). Two measurements were made for each parameter from each surface. The means of each group were analyzed by 2-way ANOVA followed by Tukey's adjustment test and Student's t-test (alpha = 0.05). RESULTS: Both the particle type (p < 0.05) and deposition pressure (p < 0.05) significantly affected the roughness parameters. Interaction terms were significant except for Sci and Svi. With the increase in pressure from 1.5 to 4.5 bar, Sdr (CoJet 1.5: 15.7 ± 0.2; CoJet 4.5: 26.6 ± 0.2; alumina 1.5: 14.7 ± 0.2; alumina 4.5: 24.4 ± 0.2) and Vi (CoJet 1.5: 0.66 ± 0.01; CoJet 4.5: 1.37 ± 0.07; alumina 1.5: 0.62 ± 0.02; alumina 4.5: 1.19 ± 0.02) parameters showed a significant increase with both alumina and CoJet particles. Mean Sci values (CoJet 1.5: 1.62 ± 0.01, CoJet 4.5: 1.49 ± 0.02; alumina 1.5: 1.6 ± 0.03; alumina 4.5: 1.42 ± 0.04) and SVi (CoJet 1.5: 0.98 ± 0.01, CoJet 4.5: 0.112 ± 0.01; alumina 1.5: 0.98 ± 0.01, alumina 4.5: 0.12 ± 0.01) decreased significantly (p < 0.05) with the increase in pressure from 1.5 to 4.5 bar. The pressure increase from 2.5 to 4.5 bar did not cause any significant difference (p > 0.05) in these parameters for either particle type. CONCLUSION: Considering roughness parameters for micromechanical retention and parameters for adsorption mechanisms of adhesion, zirconia surfaces presented better morphological features when air abraded with silica-coated alumina than alumina particles at pressures higher than 1.5 bar. Particle deposition at 2.5 bar may be preferable to 4.5 bar pressure for avoiding possible deposition-related damage on zirconia, as there were no significant differences for the functional parameters.

The Effect of Water or Wax-based Binders on the Chemical and Morphological Characteristics of the Margin Ceramic-Framework Interface.

This study evaluated the effect of binder choice in mixing ceramic powder on the chemical and morphological features between the margin ceramic-framework interfaces. Titanium and zirconia frameworks (15 x 5 x 0.5 mm3) were veneered with margin ceramics prepared with two different binders, namely a) water/conventional or b) wax-based. For each zirconia framework material, four different margin ceramics were used: a- Creation Zi (Creation Willi Geller International); b- GC Initial Zr (GC America); Triceram (Dentaurum); and d- IPS emax (voclar Vivadent). For the titanium framework, three different margin ceramics were used: a- Creation Ti (Creation Willi Geller International); b- Triceram (Dentaurum); and c- VITA Titaniumkeramik (Vita Zahnfabrik). The chemical composition of the framework-margin ceramic interface was analyzed using Energy Dispersive X-ray Spectroscopy (EDS) and porosity level was quantified within the margin ceramic using an image program (ImageJ) from four random areas (100 x 100 pixels) on each SEM image. EDS analysis showed the presence of Carbon at the margin ceramic-framework interface in the groups where wax-based binder technique was used with the concentration being the highest for the IPS emax ZirCAD group. While IPS system (IPS ZirCAD and IPS Emax) presented higher porosity concentration using wax binder, in the other groups wax-based binder reduced the porosity of margin ceramic, except for Titanium - Triceram combination.

Feeding preferences of Lutzomyia longipalpis (Diptera: Psychodidae), the sand fly vector, for Leishmania infantum (Kinetoplastida: Trypanosomatidae).

Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in Brazil, is spread mostly by the bite of the sand fly Lutzomyia longipalpis (Lutz & Neiva). We trapped sand flies in endemic neighborhoods near Natal, Brazil, where cases of human and dog VL were documented. Amplification of species-specific cytochrome b (Cyt b) genes by polymerase chain reaction revealed that sand flies from rural and periurban areas harbored blood from different sources. The most common source ofbloodmeal was human, but blood from dog, chicken, and armadillo was also present. We tested the preference for a source of bloodmeal experimentally by feeding L. longipalpis F1 with blood from different animals. There were significant differences between the proportion of flies engorged and number of eggs laid among flies fed on different sources, varying from 8.4 to 19 (P < 0.0001). Blood from guinea pig or horse was best to support sand fly oviposition, but human blood also supported sand fly oviposition well. No sand flies fed on cats, and sand flies feeding on the opossum Monodelphis domestica Wagner produced no eggs. These data support the hypothesis that L. longipalpis is an eclectic feeder, and humans are an important source of blood for this sand fly species in periurban areas of Brazil.

Carbon film coating of abutment surfaces: effect on the abutment screw removal torque.

PURPOSE: To evaluate the effect of diamond-like carbon (DLC) coating of prefabricated implant abutment on screw removal torque (RT) before and after mechanical cycling (MC). MATERIALS AND METHODS: Fifty-four abutments for external-hex implants were divided among 6 groups (n = 9): S, straight abutment (control); SC, straight coated abutment; SCy, straight abutment and MC; SCCy, straight coated abutment and MC; ACy, angled abutment and MC; and ACCy, angled coated abutment and MC. The abutments were attached to the implants by a titanium screw. RT values were measured and registered. Data (in Newton centimeter) were analyzed with analysis of variance and Dunnet test (α = 0.05). RESULTS: RT values were significantly affected by MC (P = 0.001) and the interaction between DLC coating and MC (P = 0.038). SCy and ACy showed the lowest RT values, statistically different from the control. The abutment coated groups had no statistical difference compared with the control. Scanning electron microscopy analysis showed DLC film with a thickness of 3 µm uniformly coating the hexagonal abutment. CONCLUSION: DLC film deposited on the abutment can be used as an alternative procedure to reduce abutment screw loosening.

Improved adhesion of Y-TZP ceramics: a novel approach for surface modification.

The aim of this study was to evaluate the effect of novel surface treatments of Y-TZP ceramics on initial shear bond strengths to resin cement. Eighty-four samples (7 x 6 x 5 mm) were randomly divided into 6 groups (n=14): Group1 (G1), no treatment; Group 2 (G2), air-borne particle abrasion with silica-coated aluminum oxide particles; Group 3 (G3), vitreous application 1 + etching with hydrofluoric acid; Group 4 (G4), vitreous application 1 + tribosilicatization; Group 5 (G5), vitreous application 2 + etching; Group 6 (G6), vitreous application 2 + tribosilicatization. Surface roughness (Ra) evaluation was performed by optical profilometry, scanning electron microscopy, and X-ray spectroscopy. The samples were silanized, and resin cement cylinders (3 x 2 mm) were built on the treated surfaces, light-cured and submitted to shear testing (1 mm/min). The failure mode was evaluated by SEM. Bond strength data were statistically analyzed using 1-way ANOVA and Tukey's test (α=0.05). Bond strength results were significantly affected by surface treatments (P = 0.0001). G5 and G3 presented increased Ra parameters and showed highest bond strength results (17.8 ± 5.5 and 13.3 ± 4.1, respectively). Failure modes were mainly mixed in all groups except for G1. The results confirmed that the approach of coating surface-conditioned Y-TZP with a vitreous material increased the initial shear bond strength to resin cement.

Is phase angle associated with visceral adiposity and cardiometabolic risk in cardiology outpatients?

BACKGROUND/OBJECTIVES: Phase angle (PhA) serves as a prognostic marker in various clinical scenarios, reflecting oxidative stress and cellular damage. Despite its clinical relevance, its connection with adiposity and cardiovascular risk markers remains underexplored. Hence, our study sought to investigate the relationship between PhA and metabolic, adiposity, and cardiovascular risk parameters among outpatients with cardiology diagnosis. SUBJECTS/METHODS: Adults aged between 26 and 59 years, under the care of a cardiology unit, were included. Ultrasound imaging was used to assess visceral adipose tissue (VAT). Single-frequency bioelectrical impedance analysis (BIA) [50 kHz] was employed to calculate PhA, from BIA's resistance and reactance measurements. Muscle strength, body mass index, waist circumference, and waist-to-height ratio were also evaluated. Framingham's risk score was calculated to estimate the cardiovascular risk events. Metabolic blood samples' results were obtained from medical records. RESULTS: One hundred and five participants were included in our study. Low PhA was observed in 29.5% of our sample. Higher PhA values were independently and inversely associated with both higher VAT and cardiovascular risk (adjusted OR: 0.79 [95% CI 0.69;0.91], OR: 0.74 [95% CI 0.60;0.89], respectively). Lower PhA values (≤5.59) were goodly associated with high VAT (AUC: 0.82 p < 0.001). Lower PhA values (≤5.06) were fairly associated with higher cardiovascular risk (AUC: 0.70 p = 0.003). CONCLUSION: Our study provides evidence that PhA is independently and inversely associated with elevated VAT and cardiovascular risk. These findings underscore the potential of PhA as a valuable complementary marker in assessing cardiometabolic health.

Preeclampsia is associated with increased maternal body weight in a northeastern Brazilian population.

BACKGROUND: Preeclampsia is a disease with great variability in incidence across the world. The mortality is higher in lower income countries, where it is the leading cause of maternal mortality. This study aimed to determine the frequency of and risk factors for preeclampsia in a low income population from an urban area of Brazil. METHODS: A prospective case control study of 242 women of which 30 developed preeclampsia, 4 had gestational hypertension, 2 had superimposed hypertension, 11 had spontaneous abortion, 13 were lost to follow up and 192 had normal pregnancy. This latter group was considered the normotensive controls. The rate of preeclampsia and the risk of cardiovascular disease, after onset of preeclampsia, were determined. RESULTS: Of the 218 women who completed the study, the frequency of hypertensive disorder of pregnancy was 16.5% (36 of 218) and of preeclampsia was 13.8% (30 of 218). Women with preeclampsia had a higher body mass index (BMI), mean of 25.3 ± 4.8 compared to 23.5 ± 3.7 for the normotensive controls, p = 0.02. The risk of preeclampsia increased with BMI [Odds ratio (OR) 1.12, 95% Confidence Interval (CI = 1.02;1.24, p-value = 0.023)]. Women with preeclampsia developed chronic hypertension more often than normotensive controls (p = 0.043) and their systolic and ambulatory blood pressure monitoring was elevated (p = 0.034). Women with preeclampsia had higher BMI even 5 years post-pregnancy (p = 0.008). CONCLUSIONS: Women who are overweight or older have an increased risk of preeclampsia. Previous history of preeclampsia increases the risk of early onset of chronic hypertension. Therefore, effective preventive measures are needed, particularly women at lower social economic stratum who have less access to proper medical care and adequate nutrition.

Nematicidal activity of three novel extracellular proteases of the nematophagous fungus Monacrosporium sinense.

Extracellular proteases are an important virulence factor for the nematophagous fungi Monacrosporium. The objective of this study was to optimize, purify, partially characterize, and to evaluate the nematicidal activity of the proteases produced by the nematophagous fungus Monacrosporium sinense (SF53) by solid-state fermentation. Wheat bran was used as substrate for protease production. The variables moisture, pH, incubation time, temperature, glucose, yeast extract, and the number of conidia were tested for their influences on protease production by SF53. To determine the optimal level of the selected variables the central composite design was applied. The crude extract obtained was purified in two steps, an ion exchange chromatography and a gel excision. SDS-PAGE and zymogram were performed for analysis of the purification process. Proteolytic activity was also tested at different pHs and temperatures. In the in vitro assay, the nematicidal activity of the three proteases was evaluated. pH and incubation time showed a significant effect (p<0.05) on production of protease. The highest value of activity was 38.0 (U/ml) under the conditions of pH 5.0 and incubation time of 211 h. SF53 produced three different proteases (Ms1, Ms2, and Ms3) which were directly purified from the zymogram. Ms1, Ms2, and Ms3 showed the following percentage of reduction (p<0.05) on the number of Panagrellus redivivus compared to control after 24 h: 76.8, 68.1, and 92.1%. This is the first report of the use of proteases of the isolate SF53 on a phytonematode, which may be a research tool in future works.

Silica-based nano-coating on zirconia surfaces using reactive magnetron sputtering: effect on chemical adhesion of resin cements.

PURPOSE: To compare the effect of silica (Si)-based nano-coating deposited by reactive magnetron sputtering (RMP) with that of conventional surface conditioning using metal/zirconia primer alone or after air-particle abrasion on the adhesion of resin cements to zirconia ceramic. MATERIALS AND METHODS: Two hundred forty zirconia ceramic blocks (Cercon) were sintered, finished with 1200- grit SiC paper under water cooling, and cleaned ultrasonically in distilled water for 10 min. The blocks (4.5 mm x 3.5 mm x 4.5 mm) were randomly divided into 24 groups (n = 10) according to 3 testing parameters: a) resin cements (Multilink, Panavia F, RelyX U100), b) surface conditioning (no conditioning as control group; Metal/Zirconia Primer; air abrasion + Metal/Zirconia Primer; Si-based nanofilm + Monobond s); c) aging (no aging vs thermocycling at 5°C to 55°C, 6000 cycles). The nanofilm was deposited by direct current using argon/oxygen plasma (8:1 in flux) on the zirconia surface. Resin cements were bonded to zirconia surfaces using polyethylene molds. The shear bond strength (SBS) test was performed using a universal testing machine (1 mm/min), and after debonding, the substrate and adherent surfaces were analyzed using optical and scanning electron microscopes to categorize the failure types. The data were statistically evaluated using 3-way ANOVA and Tukey's test (5%). RESULTS: Resin cement type (p < 0.05), surface conditioning method (p < 0.05), and aging condition (p < 0.05) had a significant effect on the bond strength results. Interactions were also significant (p < 0.05). In the nonaged condition, while control groups presented the lowest results with all cements (0 to 5.2 MPa), the airabraded group in combination with RelyX U100 resulted in the highest SBS (21.8 ± 6.7 MPa). After aging, the SBS results decreased in the air-abraded groups for all cements (4.54 to 9.44 MPa) and showed no statistical significance compared to the Si-based nanocoated groups (4.24 to 6.44 MPa). After air-abrasion and primer application, only Panavia F and RelyX U100 cements showed exclusively mixed failures, but after nanofilm coating and silanization, all cements showed exclusively mixed failures with and without aging. CONCLUSION: Chemical adhesion of the resin cements tested to zirconia was similar after silica-based nanofilm deposition and air abrasion followed by primer application.