Alterations In Surface Topography Research Articles

Laser texturing and oxidation of TiZrTa thin films to improve the biocompatible performance of titanium alloys

Titanium (Ti) and Ti alloys possess extensive applications in the medical field due to their non-toxic, biocompatible, and antibacterial properties. This study investigates the biocompatibility enhancement of a Ti-based alloy, Ti-6Al-4V, through a multi-step process involving cathodic arc ion plating of a TiZrTa thin film and subsequent laser-textured oxidation (LTO). LTO treatment produced a structured microtopography with regular groove patterns, including straight lines (L-s), circles (L-c), and checkboards (L-ch), resulting in surface oxidation and the formation of various oxides on the TiZrTa coating. Microstructure analyses revealed substantial alterations in surface topography induced by laser texturing. Antibacterial assessments against Staphylococcus aureus (S. aureus) showed that the films with LTO treatment did not exhibit significant advantages after 12 or 24 h of coculture because the laser-textured portions consisted of a combination of the film and the substrate, and the antibacterial effect was not obvious. Coatings with LTO treatment significantly improved L-929 mouse fibroblasts cell viability at 48 h, particularly for samples with a 50 μm spacing of straight and circular patterns (L-s and L-c). After two weeks of MG-63 human osteosarcoma cell culture, the viability of all samples reached similar levels. It suggested that the TiZrTa-coated Ti-6Al-4V exhibited good biocompatibility with both cells. This study contributed to the understanding of surface modification techniques for enhancing the biocompatibility of Ti-based alloys in biomedical applications.

Surface Topography, Microbial Adhesion, and Immune Responses in Silicone Mammary Implant-Associated Capsular Fibrosis.

Breast cancer is the most common cancer in women globally, often necessitating mastectomy and subsequent breast reconstruction. Silicone mammary implants (SMIs) play a pivotal role in breast reconstruction, yet their interaction with the host immune system and microbiome remains poorly understood. This study investigates the impact of SMI surface topography on host antimicrobial responses, wound proteome dynamics, and microbial colonization. Biological samples were collected from ten human patients undergoing breast reconstruction with SMIs. Mass spectrometry profiles were analyzed for acute and chronic wound proteomes, revealing a nuanced interplay between topography and antimicrobial response proteins. 16S rRNA sequencing assessed microbiome dynamics, unveiling topography-specific variations in microbial composition. Surface topography alterations influenced wound proteome composition. Microbiome analysis revealed heightened diversity around rougher SMIs, emphasizing topography-dependent microbial invasion. In vitro experiments confirmed staphylococcal adhesion, growth, and biofilm formation on SMI surfaces, with increased texture correlating positively with bacterial colonization. This comprehensive investigation highlights the intricate interplay between SMI topography, wound proteome dynamics, and microbial transmission. The findings contribute to understanding host-microbe interactions on SMI surfaces, essential for optimizing clinical applications and minimizing complications in breast reconstruction.

Effect of Charcoal, Probiotic, and Chlorhexidine Mouthwashes on Mechanical Properties and Surface Characterization of Ceramic-Coated Nickel-Titanium Orthodontic Arch Wires: A Comparative In-Vitro Study.

To determine the impact on the mechanical properties and surface features of ceramic-coated nickel-titanium (CC-Ni-Ti) archwires when subjected to charcoal, probiotic, and chlorhexidine mouthwashes in in vitro conditions. Eighty samples of 25 mm were cut from the posterior end of preformed maxillary 0.016'' CC-Ni-Ti super elastic archwires (Koden Company, USA) anddistributed into four equal groups. Each group of wires was immersed in artificial saliva (Wet Mouth Mouthwash, ICPA Health Products Ltd., India) (control), charcoal mouthwash (Hello activated charcoal extra freshening mouthwash, Hello Products LLC, USA), probiotic mouthwash (Perfora, Probiotic Rinse, India), and 0.2% chlorhexidine gluconate mouthwash (Sensorange, Orange Biotech, Pvt., Ltd., India) (experimental groups) for 90 min at 37 °C. All samples were taken out of their respective solutions and washed with distilled water prior to testing. A three-point bending test was performed on 15 samples from each group using a universal testing device. During the loading and unloading of the archwires, the yield strength (YS), flexural modulus of elasticity (E), and spring back ratio (YS/E) were calculated. The remaining five wires from each group were observed under the scanning electron microscope (SEM) for surface topography evaluation. The mean differences of loading YS, E, and YS/E between chlorhexidine and charcoal are 302.91 MPa, 4.28 GPa, and 0.0004, whereas unloading values are 172.32 MPa, 4.16 GPa, and 0.0003, respectively, with a statistical significance of <0.001 in terms of YS and E. The mean differences of loading YS, E, and YS/E between charcoal and probiotic are 305.36 MPa, 4.54 GPa, and 0.0005, whereas unloading values are 173.77 MPa, 3.66 GPa, and 0.0003, respectively, with a statistical significance of <0.001 in terms of YS and E. The mean differences of loading YS, E, and YS/E between chlorhexidine and probiotic are 2.45 MPa, 0.26 GPa, and 0.00007, whereas unloading values are 1.44 MPa, 0.49 GPa, and 0.0000533, respectively, with no statistical significance of >0.001 in terms of YS, E, and YS/E. Surface topography alteration was clearly appreciated in the charcoal and probiotic mouthwash groups compared to charcoal mouthwash. Loading and unloading of 0.016" ceramic-coated nickel-titanium archwires showed an increase in mechanical properties except for the spring back ratio on exposure to chlorhexidine, probiotic, and charcoal mouthwashes. Chlorhexidine and probiotic mouthwashes had a higher yield strength and flexural modulus of elasticity in comparison with charcoal mouthwash and artificial saliva on 0.016" ceramic-coated nickel-titanium archwires. More corrosive changes were seen on 0.016" ceramic-coated nickel-titanium archwires when immersed in chlorhexidine, followed by probiotic and charcoal mouthwashes.

Effect of Sodium Flouride Mouthwash and Ozone-Infused Oil Pulling Solution With Coconut Oil on Mechanical Properties and Surface Characterization of Copper-Nickel-Titanium Orthodontic Archwires.

To determine the impact on the mechanical properties and surface characteristics of prefabricated 0.016" copper-nickel-titanium (Cu-Ni-Ti) type 35oC (Ormco Company, USA)archwires when subjected to 0.05% sodium fluoride (NaF) mouthwash (ACT Anti-Cavity Fluoride Mouthwash, Sanofi Company, USA) and ozone-infused oil-pulling solution with coconut oil (O3) (O3 Essentials, Health Ranger Store, USA). Sixty samples of preformed maxillary 0.016" Cu-Ni-Ti archwires were cut at the straight posterior ends for a length of 25 mm and then equally distributed into three groups (n=20). Each group of wires was immersed in distilled water (dH2O), NaF, and O3 solutions for 90 minutes at 37oC. All samples were taken out of their solutions and washed with distilled water prior to testing. On a universal testing device, a three-point bending test was performed on 15 samples. Yield strength (YS), flexural modulus of elasticity (E), and springback ratio (YS/E) were calculated. The remaining five samples from respective solutions were observed under a scanning electron microscope (SEM) for surface topography evaluation. The mean differences in loading YS, E, and YS/E between NaF and O3 are 41.14 MPa, 4.58 GPa, and -0.0006 whereas unloading values are 23.45 MPa, 4.38 GPa, and -0.0004, respectively with a statistical significance of <0.001. Surface topography alteration was appreciated in the NaF mouthwash group compared to the O3 solution. The mechanical properties of 0.016" Cu-Ni-Ti archwires during loading and unloading were changed after exposure to NaF mouthwash and O3 solution. The mechanical properties of Cu-Ni-Ti archwires were more negatively affected by NaF mouthwash than by O3 solution. Sodium fluoride mouthwash offers more corrosive changes when compared with the O3 solution.

Picosecond laser-induced hybrid groove structures on Ti-6Al-4V bio-alloy to accelerate osseointegration.

Regulating cell growth, extracellular matrix deposition and mineralization of artificial implants are some important parameters that decide the longevity of implants in the body. Picosecond laser-induced hybrid groove structures have been shown to improve these properties of the Ti-6Al-4V bio-alloy. Two hybrid structures containing groove patterns with periodic and non-periodic substructures therein were generated on Ti-6Al-4V by varying the extent of laser pulse overlapping on sample surface. Laser-induced alteration in surface topography, chemical composition and wettability of Ti-6Al-4V resulted in 3-fold increase in the rate of hydroxyapatite growth, 2.5-fold increment in protein adsorption and 2-fold enhancement in cell adhesion in comparison to pristine sample. While the periodic substructure was found to guide cell growth, the nonperiodic sub structure offered homogenous growth leading to higher overall cell density on the substrate surface.

Limitations in the existing models for predicting accurate interdependencies between wear and friction noise,

In recent years, the investigation of friction noise has gained increasing attention within the field of tribology. Wear processes pose a significant hurdle in the industrial sector as reduce the lifespan of machine components. The replacement of damaged components, including brake systems and high-speed running machines, incurs substantial expenses. Thus, there arises a need for a method capable of identifying alterations in surface contact conditions, enabling the monitoring of the process and anticipation of the noise and rate of wear. To directly measure wear, it would be necessary to remove one of the contact surfaces (i.e., mechanical contacts such as gears and bearings.) for visual inspection, resulting in significant downtime. Alternatively, indirect measurements of wear can be performed by assessing the emitted machine noise and establishing a correlation between the noise and the alteration in surface topography caused by wear progress. Friction noise refers to the acoustic emissions generated during the contact between rough surfaces in motion. These emissions contain valuable information about the dynamics and characteristics of the sliding surfaces. Therefore, the researchers have attempted to model the interdependencies in between friction, wear and noise to find out the mentioned information and mapped it with the surface health of the mechanical contacts. The objective of this research paper is to examine all the prominent current models to discuss their approaches about how the noise can be generated from friction and later generate surface wear. This paper mainly aims to highlight their key limitations and identify the current challenges in modeling the mentioned interdependencies with accuracy.

Testing the harmfulness of chemical cleaning methods for the removal of incrustations from a glazed stoneware public artwork

• Cleaning methods were evaluated for removing a Ca-rich incrustration formed over a crystalline glaze of an stoneware outdoor public artwork that comprised a water jet system. • Incrustration was characterized and cleaning methods were selected: mechanical method (dry microblasting with sand, alumina and peach pit) and chemical methods (HNO 3 , Na 3 EDTA, Ionex H and Kalkrent® an “environmental friendly” commercial detergent). • Harmfullness was tested in laboratory on replicas produced with artist using a multianalytical approach to evaluate the effect of the cleaning methods. • Mechanical methods were damaging, but could be used to reduce the thickness of incrustration. • All chemical cleaning methods caused alteration of the glaze, except Ionex H, altering mostly the glassy phase. Incrustations are a common conservation problem, particularly in artworks exposed to water. Calcium-rich layers tend to build over their surface making cleaning interventions necessary to improve the chemical stability and restore readability. Harmfulness tests are crucial for selecting cleaning methodologies for glazed surfaces due to their mechanical and chemical susceptibility. This study selected a combination of cleaning methods to test their adequacy to remove a Ca incrustations from a modern glazed artwork. The tested methods were mechanical (dry-blasting with sand, alumina and peach) and chemical (HNO 3 , Na 3 EDTA, Ionex H and Kalkrent® an “environmental friendly” commercial detergent). To assess the effect of the cleaning methods replica substrates of the glazed ceramic were subjected to the different methodologies. Harmfulness was assessed by: (i) mass variation measurements to evaluate the material loss; (ii) microscopy techniques (optical, scanning electron and confocal laser microscopy) to evaluate morphological and surface topography alterations and (iii) μ-Raman to detect changes in the glass structure. Results indicated that the glassy phase was the most affected, and Ionex H was the less harmful of the tested cleaning products. The first in situ testing revealed that a combined approach will be most effective using microblasting for reducing the thickness of the incrustation, followed by the selected chemical method Ionex H.

Study of wear and micropitting in rolling/sliding contacts operating under boundary lubrication conditions

Rolling contact fatigue is a common failure mode in gears and bearings. However, this failure mode is getting greater attention due to the increasing tendency to use lower viscosity lubricants to reduce losses. Though several types of research have been done over the past decades, there are still scopes for further investigations. This study aims to study the effect of the slide to roll ratios (SRR), surface roughness and surface treatment on wear and pitting behaviour under realistic contact conditions. Fatigue and wear damages were quantified by studying the surface topography alteration at different contact cycle intervals.It was found that under boundary lubrication, initiation of micropitting took place in almost all test runs. However, once the adhesive wear mechanism activated at a higher contact cycle, the initially formed micropitted area started to wipe off. Moreover, for an extended test period and high sliding, wear volume is almost similar irrespective of SRR. Later, a surface treatment was studied, which was found effective in delaying the micropitting initiation by improving the tribological parameters compared to the untreated samples.

Physicochemical Changes of Contaminated Titanium Discs Treated With Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser Irradiation or Air-Flow Abrasion: An In Vitro Study.

Introduction: Peri-implantitis is a common complication of dental implant treatment. A cause-and-effect relationship has been previously documented between microbial plaque and peri-implantitis and implant failure. A difference has been reported in the disinfection efficacy of erbium laser irradiation and air-flow abrasion for contaminated titanium surfaces. Also, the surface changes caused by lasers and air-flow abrasion have not been well studied. Thus, the purpose of this study was to compare the surface changes of contaminated titanium discs following decontamination by erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and air-flow abrasion. Methods: Twenty-eight intact, sandblasted, and acid-etched (SLA) titanium discs were used. Twenty-four titanium discs were contaminated with Escherichia coli. Then, they were decontaminated by using Er:YAG laser irradiation and air-flow abrasion. Four discs remained intact. The mean and standard deviation of the contact angle and the weight percentage of aluminum, titanium, oxygen, carbon, phosphorus, and calcium were measured. Qualitative changes in surface topography of titanium discs were assessed by scanning electron microscopy (SEM). Results: The mean weight percentage of carbon in the air-flow abrasion group (4.98%) experienced a significant reduction compared with the contaminated (positive control) group (P=0.035). The contact angles were 46.54° and 38.67° in the laser and air-flow abrasion groups respectively, which were significantly lower than the value in the positive control group (75.15°) (P ≤0.001). SEM micrographs showed no significant change in the surface area in either technique. Conclusion: Air-flow abrasion was more successful in improving the surface characteristics of titanium discs with no alteration in surface topography or elements, compared with Er:YAG laser irradiation. Further studies regarding the safety of the Er:YAG laser for the decontamination of titanium surfaces are recommended.

Oxidative Imbalance in Candida tropicalis Biofilms and Its Relation With Persister Cells.

BackgroundPersister cells (PCs) make up a small fraction of microbial population, can survive lethal concentrations of antimicrobial agents. In recent years, Candida tropicalis has emerged as being a frequent fungal agent of medical devices subject to biofilm infections. However, PCs are still poorly understood.ObjectivesThis study aimed to investigate the relation of PCs on the redox status in C. tropicalis biofilms exposed to high doses of Amphotericin B (AmB), and alterations in surface topography and the architecture of biofilms.MethodsWe used an experimental model of two different C. tropicalis biofilms exposed to AmB at supra minimum inhibitory concentration (SMIC80), and the intra- and extracellular reactive oxygen species (iROS and eROS), reactive nitrogen species (RNS) and oxidative stress response were studied. Light microscopy (LM) and confocal laser scanning microscopy (CLSM) were also used in conjunction with the image analysis software COMSTAT.ResultsWe demonstrated that biofilms derived from the PC fraction (B2) showed a higher capacity to respond to the stress generated upon AmB treatment, compared with biofilms obtained from planktonic cells. In B2, a lower ROS and RNS accumulation was observed in concordance with higher activation of the antioxidant systems, resulting in an oxidative imbalance of a smaller magnitude compared to B1. LM analysis revealed that the AmB treatment provoked a marked decrease of biomass, showing a loss of cellular aggrupation, with the presence of mostly yeast cells. Moreover, significant structural changes in the biofilm architecture were noted between both biofilms by CLSM—COMSTAT analysis. For B1, the quantitative parameters bio-volume, average micro-colony volume, surface to bio-volume ratio and surface coverage showed reductions upon AmB treatment, whereas increases were observed in roughness coefficient and average diffusion distance. In addition, untreated B2 was substantially smaller than B1, with less biomass and thickness values. The analysis of the above-mentioned parameters also showed changes in B2 upon AmB exposure.ConclusionTo our knowledge, this is the first study that has attempted to correlate PCs of Candida biofilms with alterations in the prooxidant-antioxidant balance and the architecture of the biofilms. The finding of regular and PCs with different cellular stress status may help to solve the puzzle of biofilm resistance, with redox imbalance possibly being an important factor.

Biocorrosion of copper metal by Aspergillus niger

Several geoactive fungi were investigated for their biocorrosion impact on metallic copper, to further understanding of the potential roles that fungi may have in the biotransformation of such substrate, and the mechanisms involved. Copper metal showed little toxicity and test fungi were able to grow in direct or indirect contact with copper and to colonize copper sheet. A. niger was able to biodeteriorate copper metal through proton- and ligand-mediated dissolution mechanisms, leading to significant mass loss and surface etching. The formation of a secondary copper oxalate (moolooite) biomineral crust together with cuprite deposition lead to alteration of surface topography and visual appearance, highlighting the significance of oxalate excretion in effecting fungal metal biotransformations. The metal transforming influence of fungal colonization may have some implications for biodeterioration, protection and preservation of cultural relics and artefacts as well as certain components of the built environment.

Novel antifungal activity of oligostyrylbenzenes compounds on Candida tropicalis biofilms.

This study aimed to investigate the antifungal activity of four OSBs (1, 2, 3, and 4) on planktonic cells and biofilms of Candida tropicalis. Our results revealed an antibiofilm activity, with compound 2 being a potential candidate for the treatment of C. tropicalis infections.

“AN EFFECT OF TWO COMMERCIALLY AVAILABLEDENTRIFICES ON NICKEL-TITANIUM AND STAINLESS STEEL ORTHODONTIC ARCHWIRES: AN IN-VITRO STUDY”

Aim The study aimed to evaluate the effect of two commercially available dentifrices on Nickel-Titanium and Stainless Steel orthodontic arch wires. Methods A total of 33 rectangular NiTi (0.019” x 0.025”) and 33 rectangular Stainless Steel (0.019” x 0.025”) wires were taken for this study. Each group containing 16 wires were treated with the following dentifrices; Group A - Colgate Strong Teeth Toothpaste Group B – PatanjaliDantKanti Toothpaste when mounted on typhodont with help of power toothbrush. the sample were scanned under Stereo Microscope at 35x magnification and Scanning Electron Microscope at 500x magnification to check whether the dentifrices have deleterious effects on the orthodontic arch wires. The recorded data was tabulated in MS-Excel and analyzed using one-way ANOVA. Statistical analysis was performed using SPSS statistical software at the 0.05 significance level. Descriptive statistics were done using the paired t- test for the intra group comparison and unpaired t- test for the inter group comparison. Results The SEM surface analysis revealed that the most surface variations were seen with the Stainless Steel arch wires treated with the Group A toothpaste followed by the Stainless steel wires treated with the Group B toothpaste. Both the groups demonstrated depressions, pores, furrows or grains in 1/3rd of the surface of the arch wire. However, the dimensions of the depressions, pores furrows was greater in the wires treated with Group A toothpaste when compared to the Group B toothpaste. Also, with the NiTiarchwires treated with the Group A toothpaste showed more surface variation compared to the NiTi wires treated with the Group B toothpaste. Both the groups demonstrated depressions, pores, furrows or grains in 1/3rd of the surface of the archwire. However, the dimension of the depressions, pores, furrows was greater in the wires treated with Group A toothpaste when compared to then Group B toothpaste. Conclusion The stainless steel archwires exhibited the maximum alterations in surface topography after treatment with both the dentifrices when compared to the Nickel-Titanium wires.

Bi-fractal and bi-Gaussian theories to evaluate impact of polythiophene-coated Fe3O4 nanoparticles on asphaltene precipitation and surface topography

Use of nanoparticles can effectively inhibit asphaltene precipitation. The present study aims to explore the role of polythiophene-coated Fe3O4 nanoparticles in both asphaltene precipitation and surface topography alteration. Topography information of the surface is obtained through employing atomic force microscopy (AFM) imaging technique. Fractal theory, Gaussian theory, and statistical parameters (e.g., skewness and kurtosis parameters) are used to analyze the surface topography in the presence and absence of nanoparticles. The mono-fractal theory does not adequately describe the irregularity of the surface. Thus, the bi-fractal approach is utilized for investigating the topography alteration of the glass substrate as a result of asphaltene precipitation in the presence and absence of nanoparticles in both light and heavy oil samples. In this theory, the asperity of the surface is divided into two categories: micro- and macro-asperity; the fractal dimensions are calculated for each surface separately. Also, this work employs the bi-Gaussian theory for the first time to study characteristics of a surface that consists of summits. The results of the bi-Gaussian theory are in acceptable agreement with those obtained using the bi-fractal theory. It is found that nanoparticles greatly affect the surface topography. The results also confirm that asphaltene can be adsorbed more on nanoparticles in heavy synthetic oil, compared to light synthetic oil. The fractal theory is more accurate than the bi-Gaussian and statistical approaches as the fractal theory considers all scales/dimensions while other methods take into account only the height of asperity. According to the modeling results, the nanoparticles have potential to considerably lower asphaltene precipitation. This study can provide useful guidelines/tips for inhibiting the wettability alteration of the surface upon asphaltene precipitation over production and transportation processes while using nanoparticles.

Effects of severe plastic deformation on pre-osteoblast cell behavior and proliferation on AISI 304 and Ti-6Al-4V metallic substrates

In this study, titanium alloy (Ti-6Al-4V) and austenitic stainless steel (AISI 304) biomedical alloys were subjected to surface severe plastic deformation (SSPD) via severe shot peening (SSP) with the conditions of A28-30 Almen intensity. SSP is widely accepted as much more effective than the conventional surface modification techniques since it forms a nano-grain layer with large number of dislocations and grain boundaries. The SSP treatment in this study was led to a very thin rough layer in Ti-6Al-4V titanium alloy compared to that of AISI 304. The thicker layer of AISI 304 was created by twin-twin intersections and a martensite structure transformations. SSP treatment was resulted in a severe plastically deformed material surface and led to an increase in full width half maximum (FWHM) that expresses grain size reduction below nanometer regime. Also, SSP treatment increased the surface roughness of materials by forming pits and bumps and led to deterioration on surface topography. Besides physical and microstructural innovations, SSP treatment was improved the surface mechanical properties of the metals. On the other hand, it was noted that the effects of the alteration of surface topography and structural innovations (nano-grain crystal-deformation induced layer) were led to improved cellular behavior and increased cell proliferation regardless of material type.

Surface engineering of titanium-based implants using electrospraying and dip coating methods

Titanium and its alloys due to their low density, good mechanical and biological properties are of the most common orthopedic metals. One of the main challenges regarding to titanium implants is their loosening after long term implantation in patient's body. Many methods such as alteration in surface topography with focus on improving osseointegration or biocompatibility in overall are supposed to overcome this issue. In this research, titanium surface topography is altered via electrospraying a solution of titanium salt, carrier polymer (polyvinylpyrrolidone) and solvents. The dip coated samples in the same solution are prepared and investigated as control. The electrosprayed or dip coated samples were pyrolysised in furnace at 500 °C to remove polymeric components. Then the stabilized microstructures on the surfaces were evaluated via scanning electron microscopy (SEM), water contact angle (WCA) measurement, X-ray diffraction (XRD) and atomic force microscope (AFM). Also, in order to study the bioactivity of modified samples, they were immersed in simulated body fluid (SBF) and their precipitates were studied. The cellular investigations were done by studying the cell morphology, MTT and alkaline phosphatase (ALP) activity assays. The results showed improvement in bioactivity and cellular response for DP3 and SP15 more than other samples implying the promising potential of these two approaches for titanium implant surface modification.

ANTISCHISTOSOMAL ACTIVITY OF BALANITIES AEGYPTIACA FRUIT AQUEOUS EXTRACT AGAINST SCHISTOSOMA MANSONI INFECTED MICE

This study aims to evaluate the anthelminthic effect of Balanities aegyptiaca fruit aqueous extract against Schistosoma mansoniin vivo. Parasitological aspects were determined to evaluate the antischistosomal activity of B. aegyptiaca. In addition, tegumental surface topography alterations of S. mansoni adult male worms were noticed via scanning electron microscopic (SEM) investigation after treatment the infected mice orally with 200 mg/kg body weight (BW) B. aegyptiaca alone or combined with 300 mg/kg BW Praziquantel (PZQ). Results showed that treatment of S. mansoni infected mice with B. aegyptiaca, PZQ, or in combination led to a significant decrease (P<0.05) in the weight of liver and intestine as compared with those of S. mansoni-infected mice. Meanwhile, administration of the B. aegyptiaca, PZQ, or in combination decreased significantly (P<0.05) the total worm burden and ova count/g in hepatic and intestinal tissue. B. aegyptiaca and/or PZQ showed a remarkable effect on the oogram pattern in liver and intestine, where the immature and mature eggs were significantly decreased (P<0.05); whereas, dead eggs were significantly increased (P<0.05). The electron microscopy observation exhibited swelling, vacuolization, fusion of the tegumental folds, and loss or shortening of the spines on the tubercles, erosion, cracks and peeling of S. mansoni adult male worm after treatment with B. aegyptiaca and/or PZQ. This study revealed that B. aegyptiaca has a remarkable antischistosomal activity through deteriorating action on the adult worm evidenced by scanning electron microscopy.

ANTISCHISTOSOMAL ACTIVITY OF BALANITIES AEGYPTIACA FRUIT AQUEOUS EXTRACT AGAINST SCHISTOSOMA MANSONI INFECTED MICE

This study aims to evaluate the anthelminthic effect of Balanities aegyptiaca fruit aqueous extract against Schistosoma mansoniin vivo. Parasitological aspects were determined to evaluate the antischistosomal activity of B. aegyptiaca. In addition, tegumental surface topography alterations of S. mansoni adult male worms were noticed via scanning electron microscopic (SEM) investigation after treatment the infected mice orally with 200 mg/kg body weight (BW) B. aegyptiaca alone or combined with 300 mg/kg BW Praziquantel (PZQ). Results showed that treatment of S. mansoni infected mice with B. aegyptiaca, PZQ, or in combination led to a significant decrease (P<0.05) in the weight of liver and intestine as compared with those of S. mansoni-infected mice. Meanwhile, administration of the B. aegyptiaca, PZQ, or in combination decreased significantly (P<0.05) the total worm burden and ova count/g in hepatic and intestinal tissue. B. aegyptiaca and/or PZQ showed a remarkable effect on the oogram pattern in liver and intestine, where the immature and mature eggs were significantly decreased (P<0.05); whereas, dead eggs were significantly increased (P<0.05). The electron microscopy observation exhibited swelling, vacuolization, fusion of the tegumental folds, and loss or shortening of the spines on the tubercles, erosion, cracks and peeling of S. mansoni adult male worm after treatment with B. aegyptiaca and/or PZQ. This study revealed that B. aegyptiaca has a remarkable antischistosomal activity through deteriorating action on the adult worm evidenced by scanning electron microscopy.

Desiccation-induced alterations in surface topography of thylakoids from resurrection plant Haberlea rhodopensis studied by atomic force microscopy, electrokinetic and optical measurements.

With their ability to survive complete desiccation, resurrection plants are a suitable model system for studying the mechanisms of drought tolerance. In the present study, we investigated desiccation-induced alterations in surface topography of thylakoids isolated from well-hydrated, moderately dehydrated, severely desiccated and rehydrated Haberlea rhodopensis plants by means of atomic force microscopy (AFM), electrokinetic and optical measurements. According to our knowledge, so far, there were no reports on the characterization of surface topography and polydispersity of thylakoid membranes from resurrection plants using AFM and dynamic light scattering. To study the physicochemical properties of thylakoids from well-hydrated H. rhodopensis plants, we used spinach thylakoids for comparison as a classical model from higher plants. The thylakoids from well-hydrated H. rhodopensis had a grainy surface, significantly different from the well-structured spinach thylakoids with distinct grana and lamella, they had twice smaller cross-sectional area and were 1.5 times less voluminous than that of spinach. Significant differences in their physicochemical properties were observed. The dehydration and subsequent rehydration of plants affected the size, shape, morphology, roughness and therefore the structure of the studied thylakoids. Drought resulted in significant enhancement of negative charges on the outer surface of thylakoid membranes which correlated with the increased roughness of thylakoid surface. This enhancement in surface charge density could be due to the partial unstacking of thylakoids exposing more negatively charged groups from protein complexes on the membrane surface that prevent from possible aggregation upon drought stress.

Efficacy of Various Pretreatments on the Bond Strength of Denture Teeth to Denture Base Resins.

This in vitro study evaluated the shear bond strength (SBS) of heat-cured denture base resin (PMMA) to acrylic resin teeth treated with different pretreatments, especially laser irradiation of different powers (1-4 W). The acrylic resin teeth were separated into seven groups (n = 10) for the following different pretreatments: control group (no surface treatment) (G1), grinding with a tungsten carbide bur (G2), sandblasting (G3), and erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation at 1 W, 2 W, 3 W, 4 W output powers in (G4-7), respectively. Test specimens were produced according to the PMMA manufacturers' instructions and were subjected to a SBS test at a crosshead speed of 1 mm/min until fracture. Debonded surfaces were evaluated by a stereomicroscope for the type of failure. SEM (scanning electron microscope) analyses were done to estimate the surface changes of the acrylic resin teeth. The data were submitted using a one-way ANOVA and post hoc Tukey-Kramer multiple comparison tests (p = 0.05). The highest bond strength was obtained in G3, and similar SBS values were considered in other groups, and no significant differences were found among the surface treatments and the control group (p < 0.05). All groups had a high percentage of adhesive failures. Laser irradiations promote surface topography alterations. However laser irradiation of the adhesive surface was found ineffective. The SBS of acrylic resin teeth to a PMMA denture base material is independent of the surface pretreatments Er,Cr:YSGG laser irradiation, sandblasting, and grinding with a carbide bur. All the surface treatments provided a similar bond between the acrylic denture base and the teeth.