Mechano-Redox Control of Mac-1 De-Adhesion by PDI Promotes Directional Movement Under Flow.

BACKGROUND: Neutrophil migration is critical to the initiation and resolution of inflammation. Macrophage-1 antigen (Mac-1; CD11b/CD18, αMß2) is a leukocyte integrin essential for firm adhesion to endothelial ICAM-1 (intercellular adhesion molecule 1) and migration of neutrophils in the shear forces of the circulation. PDI (protein disulfide isomerase) has been reported to influence neutrophil adhesion and migration. We aimed to elucidate the molecular mechanism of PDI control of Mac-1 affinity for ICAM-1 during neutrophil migration under fluid shear. METHODS: Neutrophils isolated from whole blood were perfused over microfluidic chips coated with ICAM-1. Colocalization of Mac-1 and PDI on neutrophils was visualized by fluorescently labeled antibodies and confocal microscopy. The redox state of Mac-1 disulfide bonds was mapped by differential cysteine alkylation and mass spectrometry. Wild-type or disulfide mutant Mac-1 was expressed recombinantly in Baby Hamster Kidney cells to measure ligand affinity. Mac-1 conformations were measured by conformation-specific antibodies and molecular dynamics simulations. Neutrophils crawling on immobilized ICAM-1 were measured in presence of oxidized or reduced PDI, and the effect of PDI inhibition using isoquercetin on neutrophil crawling on inflamed endothelial cells was examined. Migration indices in the X- and Y-direction were determined and the crawling speed was calculated. RESULTS: PDI colocalized with high-affinity Mac-1 at the trailing edge of stimulated neutrophils when crawling on ICAM-1 under fluid shear. PDI cleaved 2 allosteric disulfide bonds, C169-C176 and C224-C264, in the ßI domain of the ß2 subunit, and cleavage of the C224-C264 disulfide bond selectively controls Mac-1 disengagement from ICAM-1 under fluid shear. Molecular dynamics simulations and conformation-specific antibodies reveal that cleavage of the C224-C264 bond induces conformational change and mechanical stress in the ßI domain. This allosterically alters the exposure of an αI domain epitope associated with a shift of Mac-1 to a lower-affinity state. These molecular events promote neutrophil motility in the direction of flow at high shear stress. Inhibition of PDI by isoquercetin reduces neutrophil migration in the direction of flow on endothelial cells during inflammation. CONCLUSIONS: Shear-dependent PDI cleavage of the neutrophil Mac-1 C224-C264 disulfide bond triggers Mac-1 de-adherence from ICAM-1 at the trailing edge of the cell and enables directional movement of neutrophils during inflammation.

Effect of Lignin Structure Characteristics on the Performance of Lignin Based Phenol Formaldehyde Adhesives.

As the second most abundant biopolymer, lignin remains underutilized in various industrial applications. Various forms of lignin generated from different methods affect its physical and chemical properties to a certain extent. To promote the broader commercial utilization of currently available industrial lignins, lignin sulfonate (SL), kraft lignin (KL), and organosolv lignin (OL) are utilized to partially replace phenol in the synthesis of phenol formaldehyde (PF) adhesives. The impact of lignin production process on the effectiveness of lignin-based phenolic (LPF) adhesives is examined based on the structural analysis of the selected industrial lignin. The results show that OL has more phenolic hydroxyl groups, lower molecular weight, and greater number of reactive sites than the other two types of lignins. The maximum replacement rate of phenol by OL reaches 70% w/w, resulting in organosolv lignin phenolic (OLPF) adhesives with a viscosity of 960 mPa·s, a minimal free formaldehyde content of 0.157%, and a shear strength of 1.84 MPa. It exhibits better performance compared with the other two types of lignin-based adhesives and meets the requirements of national standards.

Translating proof-of-concept for platelet slip into improved antithrombotic therapeutic regimens.

Platelets are central to thrombosis. Research at the intersection of biological and physical sciences provides proof-of-concept for shear rate-dependent platelet slip at vascular stenosis and near device surfaces. Platelet slip extends the observed biological "slip-bonds" to the boundary of functional gliding without contact. As a result, there is diminished engagement of the coagulation cascade by platelets at these surfaces. Comprehending platelet slip would more precisely direct antithrombotic regimens for different shear environments, including for percutaneous coronary intervention (PCI). In this brief report we promote translation of the proof-of-concept for platelet slip into improved antithrombotic regimens by: (1) reviewing new supporting basic biological science and clinical research for platelet slip; (2) hypothesizing the principal variables that affect platelet slip; (3) applying the consequent construct model in support of-and in some cases to challenge-relevant contemporary guidelines and their foundations (including for urgent, higher-risk PCI); and (4) suggesting future research pathways (both basic and clinical). Should future research demonstrate, explain and control platelet slip, then a paradigm shift for choosing and recommending antithrombotic regimens based on predicted shear rate should follow. Improved clinical outcomes with decreased complications accompanying this paradigm shift for higher-risk PCI would also result in substantive cost savings.

Effect of time and photoactivated face on bond strength of brackets and on degree of monomer conversion.

OBJECTIVE: To evaluate the effect of four different photoactivation protocols (according to "photoactivated faces" - mesial/distal, cervical/incisal or center - and "photoactivation time" - 6-3 s) of a high-power photo activator (Valo Cordless®-Ultradent) on the shear bond strength (SBS) between metal brackets and dental enamel and on the degree of conversion (DC) of an orthodontic resin. MATERIALS AND METHODS: 40 bovine incisor crowns were randomly assigned to 4 groups (n = 10). The brackets were bonded with Transbond XT® resin using 4 protocols according to the "photoactivation protocol" factor (which was subdivided into photoactivated faces and photoactivation time): V3C = 3 s + center; V6C = 6 s + center; V3M3D = 3 s on mesial + 3 s on distal; V3C3I = 3 s on cervical + 3 s on incisal. All the samples were stored for 4 months (water,37ºC) and then subjected to a SBS test (100KgF,1 mm/min). 40 resin discs were made to evaluate the monomer degree of conversion. Data from the SBS and DC were assessed by One-way ANOVA and Tukey's test (5%). Bond failures were analyzed according to the Adhesive Remnant Index (ARI) and evaluated by the Kruskal-Wallis test (5%). RESULTS: There was a statistically significant difference (p = 0.008) in the One-way ANOVA result for SBS values between all groups, but the protocols showed statistically similar results (p ≥ 0.05-Tukey's tests) concerning the photoactivated faces (V6C, V3M3D and V3C3I) and photoactivation time (V3C and V6C) factors individually. There was no statistically significant difference (p ≥ 0.05) in the One-way ANOVA result for DC values. CONCLUSION: The SBS and DC values will vary depending on the protocol applied. CLINICAL RELEVANCE: It is possible to maintain the bracket fixation quality with the use of a high-power LED photo activator associated with a shorter photoactivation time. However, it is assumed that not all types of protocols that might be applied will provide quality bonding, such as V3C, V3M3D and V3C3I, which may - depending on the SBS and DC values - affect the final treatment time, due to brackets debonding, or increase of possibility of damage to dental enamel during bracket removal. Clinical studies are suggested to confirm the hypotheses of this research.

Monitoring of Composite Structures for Re-Usable Space Applications Using FBGs: The Influence of Low Earth Orbit Conditions.

Fiber Bragg grating sensors (FBGs) are promising for structural health monitoring (SHM) of composite structures in space owing to their lightweight nature, resilience to harsh environments, and immunity to electromagnetic interference. In this paper, we investigated the influence of low Earth orbit (LEO) conditions on the integrity of composite structures with embedded optical fiber sensors, specifically FBGs. The LEO conditions were simulated by subjecting carbon fiber-reinforced polymer (CFRP) coupons to 10 cycles of thermal conditioning in a vacuum (TVac). Coupons with embedded optical fibers (OFs) or capillaries were compared with reference coupons without embedded OFs or capillaries. Embedded capillaries were necessary to create in situ temperature sensors. Tensile and compression tests were performed on these coupons, and the interlaminar shear strength was determined to assess the influence of TVac conditioning on the integrity of the composite. Additionally, a visual inspection of the cross-sections was conducted. The impact on the proper functioning of the embedded FBGs was tested by comparing the reflection spectra before and after TVac conditioning and by performing tensile tests in which the strain measured using the embedded FBGs was compared with the output of reference strain sensors applied after TVac conditioning. The measured strain of the embedded FBGs showed excellent agreement with the reference sensors, and the reflection spectra did not exhibit any significant degradation. The results of the mechanical testing and visual inspection revealed no degradation of the structural integrity when comparing TVac-conditioned coupons with non-TVac-conditioned coupons of the same type. Consequently, it was concluded that TVac conditioning does not influence the functionality of the embedded FBGs or the structural integrity of the composite itself. Although in this paper FBG sensors were tested, the results can be extrapolated to other sensing techniques based on optical fibers.

Effect of applying carbodiimide combined with a two-step self-etch adhesive durability.

BACKGROUND: This study investigated the effect of carbodiimide (EDC) combined with Clearfil SE self-etch adhesive on the shear bond strength (SBS), crosslinking degree, denaturation temperature, and enzyme activity of dentin in vitro. MATERIALS AND METHODS: Collected human sound third molars were randomly divided into different groups with or without EDC treatment (0.01-1 M). The specimens (n = 16)were stored for 24 h (immediate) or 12 months (aging) before testing the SBS. Fine dentin powder was obtained and treated with the same solutions. Then the crosslinking degree, denaturation temperature (Td), and enzyme activity were tested. Statistical analysis was performed using a one-way analysis of variance (ANOVA) to compare the differences of data between groups (α = 0.05). RESULTS: There was a significant drop in immediate SBS and more adhesive fracture of 1.0 M EDC group, while there were no significant differences among the other groups. SEM showed a homogeneous interface under all treatments. After 12 months of aging, the SBS significantly decreased. Less decreases of SBS in the 0.3 and 0.5 M groups were found. Due to thermal and enzymatical properties consideration, the 0.3 and 0.5 M treatments also showed higher cross-link degree and Td with lower enzyme activity. CONCLUSION: 0.3 and 0.5 M EDC may be favorable for delaying the aging of self-etch bond strength for 12 months. But it is still needed thoroughly study.

Comparison of various methods of restoring adhesion to recently bleached enamel.

AIM: This study compared the effectiveness of several techniques in restoring compromised bonding to recently bleached enamel. METHODS: Seventy-five healthy bovine incisors were divided into five groups (n = 15). Fifteen teeth (Group 1) remained intact, whereas 60 (Groups 2 to 5) underwent at-home bleaching with 16% carbamide peroxide. The bonding procedures were as follows: Group 1: Bonding of resin composite to unbleached enamel; Group 2: Bonding immediately after bleaching; Group 3: Application of a 10% sodium ascorbate solution for 10 min before bonding; Group 4: Enamel removal to the depth of 0.5 mm; and Group 5: Increased curing time of the bonding agent to 80 instead of 20 s. After 24 h, the specimens were subjected to micro-shear testing, and the failure mode was determined. RESULTS: ANOVA revealed a significant difference in bond strength among the groups (P < 0.001). The mean bond strength was significantly lower in group 2 than in other groups (P < 0.05), which showed comparable bond strength to each other (P > 0.05). Adhesive failure was the most predominant failure type in all groups. The mixed failure occurred with a frequency of 26.7% in groups 3 and 5. The Fisher's exact test revealed a significant difference in failure modes among the groups (P = 0.047). CONCLUSIONS: The three experimental procedures used in this study, including the application of 10% sodium ascorbate before bonding, enamel removal to the depth of 0.5 mm, and increasing the curing time of the bonding agent to 80 s, were effective in restoring the compromised bonding to recently bleached enamel.

Influence of etchant type on the shear bond strength of orthodontic brackets to enamel.

The aim of this study was to evaluate the influence of the type of etchant on the shear bond strength (SBS) of metallic brackets to enamel and the Adhesive Remnant Index (ARI) after debonding. A total of 30 mandibular and maxillary premolars were randomly distributed into groups (n = 10) treated with 1 of 3 enamel surface-conditioning agents: 35% phosphoric acid (PA), 35% glycolic acid (GA), or 35% ferulic acid (FA). The designated acid was applied to the buccal enamel surface of the tooth for 20 seconds, and the tooth was then rinsed with distilled water for 20 seconds and air dried for 5 seconds. A metal bracket was bonded to the prepared surface with light-cured orthodontic resin. After 24 hours, the bracket-tooth interface was submitted to SBS testing in a universal testing machine at a speed of 0.5 mm/min. After debonding, the enamel surface was observed under a stereomicroscope (×20 magnification) to determine the ARI. The generalized linear models showed that the PA and GA groups presented significantly higher SBSs than the FA group (P = 0.0003). The ARI was significantly higher in specimens treated with PA than with the other acids (P < 0.05; Kruskal-Wallis and Dunn tests), with a larger quantity of adhesive remaining adhered to the tooth. Both PA and GA are effective for bonding brackets, but GA resulted in a lower percentage of adhesive remnant adhered to the enamel.

Results of the cyclic triaxial testing on mechanically-biologically treated waste.

Accurate assessment of the dynamic strength characteristics of mechanically-biologically treated (MBT) waste is crucial for the construction and safe operation of landfill sites. Herein, samples of MBT waste from the Hangzhou Tianziling landfill were collected and subjected to consolidated undrained cyclic triaxial tests under four confinement levels and six cyclic stress ratios (CSRs). Under cyclic loading, the MBT waste exhibited a critical CSR. If the CSR exceeds the critical value, the MBT waste specimen rapidly undergoes deformation and failure. Dynamic strength of MBT waste decreases with an increase in the number of cyclic vibrations and increases with an increase in confining pressure. Considering the influence of cyclic vibrations and confining pressure, a formula for dynamic strength in terms of cyclic vibrations and confining pressure has been established. The dynamic shear strength parameter ranges for MBT waste were obtained under different seismic magnitudes. We compared the dynamic and static shear strength parameters of MBT waste and municipal solid waste. These study findings can serve as a reference for the dynamic stability analysis of MBT waste landfills.

Effect of various Er:YAG laser conditioning energies on dentin surface: micromorphological investigation and dentin-resin shear bond strength test.

The aim of this study is to assess the influence of various Er:YAG laser energies on dentin surface micromorphology and dentine-resin shear bond strength (SBS). Eighty dentin specimens were prepared and divided randomly into ten groups: control group (CG), phosphoric acid-etched group (AG), four laser-conditioned groups treated with various pulse energies of 40, 60, 80, and 100 mJ (L40, L60, L80, L100), and four laser-conditioned acid-etched groups (LA40, LA60, LA80, LA100). Two specimens from each group underwent scanning electron microscopy examination, while the remaining six were subjected to the dentin-resin SBS test. Statistical analyses included Welch's analysis of variance (ANOVA), followed by post hoc Tamhane's T2 multiple comparisons test, Pearson's correlation, and Fisher's exact test. Pulse energies of 60, 80, and 100 mJ fully exposed the dentin tubule orifices, although 100 mJ lead to microcracks. Laser-conditioned surfaces exhibited smaller tubule diameters compared to acid-etched surfaces, and tubule diameters positively correlated with dentin-resin SBS. Laser-conditioned groups showed lower SBS values, while laser-conditioned acid-etched groups demonstrated higher SBS values. No significant relationship was observed between dentin surface roughness and SBS. The range of laser energies used for dentin conditioning had limited effects on SBS or failure modes. Laser conditioning with energies ranging from 40 to 100 mJ effectively removes the smear layer from the dentin surface. However, to enhance dentin-resin bond strength, further acid etching of the laser-conditioned surface is necessary.

Repair bond strength of different CAD-CAM ceramics after various surface treatments combined with laser irradiation.

The aim of this study was to evaluate the effect of different surface treatments combined with laser irradiation on the shear bond strength of different CAD-CAM ceramics to composite resin. A total of hundred forty-seven ceramic specimens with thicknesses of 2.5 mm were prepared from three different CAD-CAM ceramics (an yttrium oxide partially stabilized tetragonal zirconia polycrystal (Y-TZP); a zirconia-reinforced lithium silicate glass ceramic (ZLS); and a lithium disilicate-strengthened lithium aluminosilicate glass ceramic (LD-LAS)) and subjected to seven groups of treatment (n = 7): (1) control (no treatment), (2) Er:YAG laser irradiation, (3) Nd:YAG laser irradiation, (4) etching with hydrofluoric acid (HFA), (5) Er:YAG + HFA, (6) Nd:YAG + HFA, and (7) sandblasting. After surface treatment procedures, a ceramic primer (Clearfil Ceramic Primer Plus, Kuraray, Japan) was applied to the ceramics. Bonding agent (Single Bond Universal Adhesive, 3 M ESPE, USA) was then applied, and the composite resin (Estelite Sigma Quick, Kuraray, Japan) was layered on the ceramic surfaces. The shear bond strength test was performed using a universal testing machine at a load of 0.5 mm/min. Data were analyzed by 2-way analysis of variance (ANOVA), and the Bonferroni correction was used for pairwise comparisons (α = 0.05). Compared to the bond strength of the control group, irradiation by Er:YAG and Nd:YAG lasers alone improved the bond strength of the composite resin to the Y-TZP (P < 0.001) but did not change the bond strength of composite resin to the ZLS and LD-LAS (P > 0.05). Compared to the bond strength of the control group, etching with HFA alone increased the bond strength of the composite resin to the ZLS and LD-LAS (P < 0.001) but did not affect the bond strength of the composite resin to the Y-TZP (P > 0.05). The highest bond strength of ZLS was obtained using HFA + Er:YAG, and the highest bond strength for LD-LAS was obtained using HFA + Nd:YAG. It was concluded that Er:YAG and Nd:YAG laser treatments presented the highest repair bond strength between the composite resin and Y-TZP ceramics. Er:YAG and Nd:YAG laser treatments in conjuction with HFA presented the highest repair bond strength between the composite resin and the glassy ceramics, ZLS, and LD + LAS.

Investigating the Shear Strength of Granitic Gneiss Residual Soil Based on Response Surface Methodology.

The shear strength of granitic gneiss residual soil (GGRS) determines the stability of colluvial landslides in the Huanggang area, China. It depends on several parameters that represent its structure and state as well as their interactions, and therefore requires accurate assessment. For an effective evaluation of shear strength parameters of GGRS based on these factors and their interactions, three parameters, namely, moisture content, bulk density, and fractal dimension of grain size, were selected as influencing factors in this study based on a thorough investigation of the survey data and physical property tests of landslides in the study area. The individual effects and interaction of the factors were then incorporated by implementing a series of direct shear tests employing the response surface methodology (RSM) into the regression model of the shear parameters. The results indicate that the factors affecting shear parameters in the order of greater to lower are bulk density, moisture content, and fractal dimension, and their interactions are insignificant. The proposed model was validated by applying it to soil specimens from other landslide sites with the same parent bedrock, showing the validity of the strength regression model. This study demonstrates that RSM can be applied for parameter estimation of soils and provide reliable performance, and is also significant for conducting landslide investigation, evaluation, and regional risk assessment.

Enhancing Transdermal Delivery: Investigating the Impact of Permeation Promoters on Ibuprofen Release and Penetration from Medical Patches-In Vitro Research.

This study investigated the impact of various enhancers on permeation through the skin and accumulation in the skin from acrylic pressure-sensitive adhesive-based drug-in-adhesives matrix-type transdermal patches. Eleven patches, each containing a 5% enhancer of permeation, encompassing compounds such as salicylic acid, menthol, urea, glycolic acid, allantoin, oleic acid, Tween 80, linolenic acid, camphor, N-dodecylcaprolactam, and glycerin, were developed. Ibuprofen (IBU) was the model active substance, a widely-used non-steroidal anti-inflammatory drug. The results were compared to patches without enhancers and commercial preparations. The study aimed to assess the effect of enhancers on IBU permeability. The adhesive properties of the patches were characterised, and active substance permeability was tested. The findings revealed that patches with 5% allantoin exhibited the highest IBU permeability, approximately 2.8 times greater than patches without enhancers after 24 h. These patches present a potential alternative to commercial preparations, highlighting the significant impact of enhancers on transdermal drug delivery efficiency.

Feasibility of soil oxidation-reduction potential in judging shear behaviour of hydrocarbon-contaminated soil.

This study investigates the indicative role of oxidation-reduction potential (ORP) and pH of hydrocarbon-contaminated soils on their shear characteristics, contributing to safer and more efficient ex-situ remediation and management processes. The presence of hydrocarbons alters the soil's shear strength by affecting the hydration shell thickness, fluid's dielectric properties, and ion/electron exchange, as well as the soil's electrochemical force, which in turn affects the ORP and pH. The relationship between hydrocarbon concentrations in contaminated soils (0.1-15%) and corresponding ORP/pH values could be fitted linearly with a good correlation coefficient r (0.978), highlighting the potential of ORP/pH as an indicator for pollutant occurrence. Furthermore, the relationships between ORP/pH and shear strength, as tested in our study and obtained after processing from relevant literature sources, exhibited a strong fit (r = 0.976-0.995). The Mohr-Coulomb criterion modified using the ORP/pH parameter was established, which could improve the fitting effect of these relationships (r = 0.988-0.996), verifying the reliability of the novel criterion and application feasibility of ORP/pH. In future research, this modified criterion can be employed to conveniently assess the shear strength of contaminated soil by considering the shear behaviour of virgin soil and the ORP/pH values of the contaminated soil.

Effect of different interfacial surface treatments on the shear bond strength of veneering ceramic and zirconia core.

BACKGROUND: Several interfacial surface treatments of zirconia surfaces have been proposed to improve adhesion to ceramic veneering. However, information regarding the durability and effect of such treatments on the bond strength following such treatments is lacking. AIM OF THE STUDY: This study aimed to evaluate the shear bond strength between veneering ceramic and zirconia core after different interfacial surface treatments. MATERIALS AND METHODS: Fifty-two discs (8 mm in diameter and 3 mm in height) were fabricated from zirconia blanks using a microtome cutting machine. Zirconia discs were divided into four groups (n = 13). Group I was subjected to air-borne abrasion using (Al2O3), group II was coated by bioglass, group III was coated with ZirLiner, and group IV was subjected to wash firing (sprinkle technique). A cylinder (4 mm in diameter and 3 mm in height) of veneering ceramic was fired on top of the zirconia core. Shear bond strength (SBS) between zirconia core and veneering ceramic was evaluated by using a universal testing machine. The data was collected and statistically analysed using One-Way ANOVA followed by multiple pairwise comparisons using Bonferroni adjusted significance level. The failure modes were assessed using a stereomicroscope for each group. RESULTS: The highest mean bond strength was recorded in group III (17.98 ± 2.51 MPa), followed by group II (15.10 ± 4.53 MPa), then group I 14.65 ± 2.97 MPa. The lowest mean bond strength was recorded in group IV (13.28 ± 3.55 MPa). CONCLUSIONS: Surface treatments had an effect on the zirconia-veneer shear bond strength. Liner coating revealed the highest shear bond strength values, significantly higher in comparison to wash firing (sprinkle technique) .

PET waste management in Pakistan through use of PET shreds as additive in backfill soil.

The management of waste plastic bottles is one of the major environmental challenges in the world. Plastic bottles are composed of polyethylene terephthalate (PET), which is non-biodegradable, resulting in environmental problems. Various studies have been carried out on the use of waste PET bottles in the form of custom-made strips as a stabilizer. However, no significant research has been carried out on the use of waste PET bottle shreds already available in the market. These shreds do not require any special technology or arrangement for bulk production. In this study, the shear strength of low plastic silty clay was improved using locally available PET shreds, and their prospective application in the backfill soil was investigated. Standard Proctor tests and direct shear tests were conducted on soil stabilized with three different sizes of plastic shreds (2 mm, 6 mm, and 10 mm) in four different percentages (1%, 3%, 5%, and 10%). Findings revealed that adding PET shreds in 1% content improves the shear strength characteristics. However, the shear strength parameters decrease with further increase in PET shred content. Therefore, PET shreds in 1% content can be added in backfill soil to improve its shear strength. Pakistan needs to construct 0.77 million housing units annually to keep up with its population growth. The statistics of seven major cities of Pakistan show that the PET waste management issue of Pakistan can be resolved by using PET shreds as a backfill additive in only 32% of the new houses required to be constructed.

The Effect of Colloidal Silica and Glaze Coatings on the Adhesion of Zirconia with Various Ytrria Concentration.

PURPOSE: This study evaluated the effect of coating traditional and translucent Y-TZP with an industrial nanometric colloidal silica or glaze before or after sintering on the adhesion of zirconia with various ytrria concentration. MATERIALS AND METHODS: Specimens of Y-TZP with 3% and 5% yttria were subdivided into 5 groups (n=10), according to the coating applied and moment of application (before or after Y-TZP sintering): Control (no coating), Colloidal Silica/Sintering, Sintering/Colloidal Silica, Glaze/Sintering, Sintering/ Glaze. Lithium disilicate (LD) was used as positive control. Except for Y-TZP controls, groups were conditioned with silane before cementation with a self-adhesive resin cement. After 24 hours, the shear bond strength and failure analysis were performed. Also, analysis of specimens' surface was accomplished with SEM-EDX. Kruskal-Wallis and Dunn tests were applied to analyze differences between groups (p⟨0.05). RESULTS: Overall, the worst and best values of shear bond strength test were control and glaze after sintering groups. Different morphological and chemical aspects were observed in SEM-EDX analysis. CONCLUSIONS: Coating Y-TZP with colloidal silica showed unsatisfactory results. In 3Y-TZP, the surface treatment associated with the best adhesion values was the application of glaze after zirconia sintering. However, in 5Y-TZP, glaze application can be performed before or after the zirconia sintering to optimize clinical steps.

A Novel Sensor for Undrained Shear Strength Measurement in Very Soft to Soft Marine Sediments Based on Optical Frequency Domain Reflectometry Technology.

Due to the short supply of conventional fill materials, such as sand, land reclamation using dredged marine deposits has recently been proposed, in which marine deposits with high water content are blow-filled into reclaiming areas. The strength development of the filled marine soils is of great importance during the sedimentation and consolidation to guide the filling process and construction of reclamation. In this study, a novel sensor based on optical frequency domain reflectometry (OFDR) technology with a simple design was developed for undrained shear strength measurement. The novel sensor consists of an optical fiber and a series of polyoxymethylene coins. Owing to the merits of OFDR technology on high resolution, fully distributed sensing, and immunity to electromagnetic interference, the novel sensor can be used to determine undrained shear strength profiles of very soft to soft marine sediments/soils with good accuracy. The sensor was calibrated in remolded marine deposits with different water contents. The good feasibility and performance of the novel sensor for undrained shear strength measurement were well validated in two physical model tests on marine deposits treated by horizontal drains with vacuum preloading.

Evaluation of the Structural Modification of Ibuprofen on the Penetration Release of Ibuprofen from a Drug-in-Adhesive Matrix Type Transdermal Patch.

This study aimed to evaluate the effect of chemical modifications of the structure of active compounds on the skin permeation and accumulation of ibuprofen [IBU] from the acrylic pressure-sensitive adhesive used as a drug-in-adhesives matrix type transdermal patch. The active substances tested were ibuprofen salts obtained by pairing the ibuprofen anion with organic cations, such as amino acid isopropyl esters. The structural modification of ibuprofen tested were Ibuprofen sodium salt, [GlyOiPr][IBU], [AlaOiPr][IBU], [ValOiPr][IBU], [SerOiPr][IBU], [ThrOiPr][IBU], [(AspOiPr)2][IBU], [LysOiPr][IBU], [LysOiPr][IBU]2, [PheOiPr][IBU], and [ProOiPr][IBU]. For comparison, the penetration of unmodified ibuprofen and commercially available patches was also investigated. Thus, twelve transdermal patches with new drug modifications have been developed whose adhesive carrier is an acrylate copolymer. The obtained patches were characterized for their adhesive properties and tested for permeability of the active substance. Our results show that the obtained ibuprofen patches demonstrate similar permeability to commercial patches compared to those with structural modifications of ibuprofen. However, these modified patches show an increased drug permeability of 2.3 to even 6.4 times greater than unmodified ibuprofen. Increasing the permeability of the active substance and properties such as adhesion, cohesion, and tack make the obtained patches an excellent alternative to commercial patches containing ibuprofen.

Hydraulic performance, consolidation characteristics and shear strength analysis of bentonites in the presence of fly-ash, sewage sludge and paper-mill leachates for landfill application.

A rapid upsurge in urban and industrial developments leads to increased generations of solid wastes. The most accepted technique of waste discarding around the world is landfilling. Leaching chemicals from municipal dumping grounds can pollute the groundwater source and the surrounding environment without appropriate precautionary measures. Bentonite is a low-cost constituent used as a liner material in landfills due to its low permeability, high sealing ability, high specific surface area, and the ability to hold up the impurity migration through adsorption. However, leachate interaction with bentonite may alter its properties and reduce its usefulness as a barrier material in the long term. Also, bentonite having different chemical and mineralogical compositions will behave differently due to the leachate interaction. Therefore, it is necessary to compare the performance of various bentonites in the presence of leachates. In the present investigation, two Indian bentonites of different mineralogical compositions were studied for their change in the index properties, swelling, swelling potential, swelling pressure, hydraulic conductivity, consolidation parameters and shear strength properties in the presence of fly ash, sewage sludge and paper mill leachates. The outcomes showed that in the presence of all the leachates, liquid limit, free swell, compression index, swelling potential, swelling pressure, time to complete 90% of consolidation and shear strength dropped; whereas, hydraulic conductivity and coefficient of consolidation increased. Besides, the quality of bentonite prominently influenced the hydraulic, strength and swelling behaviour. The bentonite having a higher cation exchange capacity, liquid limit, specific surface area, and swelling capability undergoes a higher variability in the free swell (80.0, 73.8 and 76.9% decline), liquid limit (73.5, 61.7 and 69.2% decline), swelling potential (61.3, 55.7 and 51.0% decline), swelling pressure (53.3 and 56.4% decrease), and hydraulic conductivity (57.5, 8.6 and 41.1 times increase at a void ratio of 1.2) values when infused with fly ash, sewage sludge and paper mill leachates, respectively. The study also showed that the fly ash leachate interaction causes a higher variation in bentonite behaviour than sewage sludge and paper mill leachates. The study's findings would prove beneficial to design engineers for selecting bentonite types for landfill liners.