Tag Length Research Articles

Effect of Dentin Bio-Modifiers Grape Seed Extract, Hesperidin on Shear Bond Strength and Microleakage: AScanning Electron Microscopic Assessment.

Investigation of different collagen cross-linking (CCL) agents, grape seed extract (GSE), Hesperidin (Hes), and rose bengal photosensitizer (RBP) on shear bond strength (SBS) and marginal leakage (ML) of composite bonded to carious affected dentin (CAD). Sixty-eight human molars in which carious lesions up to the middle third of the dentin were included. CAD was made flat followed by acid etching. Teeth were allocated randomly into four groups based on the application of CCL agents. Group 1: no CCL agent, Groups 2-4 samples treated with CCL agents. Bonding of adhesive and composite was performed followed by artificial aging. ML assessment was performed using a dye penetration test. SBS was evaluated using a universal testing machine followed by failure mode analysis. Analysis of the resin CAD interface with SEM was performed to identify the resin tag. For group comparisons, one-way ANOVA and post hoc Tukey test were used. The length and number of resin tags in GSE and Hes groups were greater than in the control and RBP. Furthermore, samples treated with GSE presented the highest scores of SBS and lowest ML. The control group presented the lowest bond integrity and highest ML. GSE and Hes positively influenced both SBS and ML.

Caries affected Dentin biomodification using Bromelain, Riboflavin photosensitizer via UVA, and Chitosan Nanoparticles on shear bond strength and microleakage scores: A SEM evaluation.

Assessment of the impact of different dentin bio-modifiers i.e., Bromelain, Riboflavin photosensitizer (RFP/Ultraviolet-A), and Chitosan nanoparticles (CHNPs) on the shear bond strength (SBS) and microleakage of composite bonded to acid etched carious affected dentin (CAD). Sixty-four human molars in which carious lesions extend till the middle third of the dentin were included. The infected dentin was removed and CAD was exposed. All specimens were categorized into four groups based on the application of dentin bio-modifier (n=16) Group 1 (No dentin modifier), Group 2 (Bromelain), Group 3 (RFP/UVA), and Group 4 (CHNPs). Dental adhesive application and composite buildup were performed. A dye penetration test was used to assess marginal leakage. Resin CAD interface assessment was performed using SEM. For SBS and failure pattern analysis, a universal testing machine and stereomicroscope were used respectively. One-way ANOVA followed by Bonferroni's posthoc test was employed to analyze the differences among various groups (p ≤ 0.05) RESULTS: The lowest microleakage (13.27 ± 0.10) and highest SBS (11.64 ± 0.16 MPa) were observed in Group 2 (Bromelain). However, the maximum values of marginal leakage (37.21 ± 0.21) and minimum SBS (7.34 ± 0.07 MPa) were detected in Group 1 samples. The length of resin tags in the Group 2 specimens (Bromelain) was found to be the highest (102.11 ± 5.12μm). However, Group 1 (No modifier) exhibited the lowest resin tag length (50.45 ± 2.37 μm). Caries-affected dentin modified with Bromelain resulted in satisfactory SBS with minimal microleakage scores. Chitosan nanoparticles and RFP/Ultraviolet-A also presented better outcomes in terms of microleakage and SBS than the control.

A blockchain-assisted lightweight UAV network authentication mechanism via covert communication

The increasing importance of terminal privacy in the Unmanned Aerial Vehicle (UAV) network has led to a growing recognition of the crucial role of authentication technology in UAV network security. However, traditional authentication approaches are vulnerable due to the transmission of identity information between UAVs and cryptographic paradigm management centers over a public channel. These vulnerabilities include brute-force attacks, single point of failure, and information leakage. Blockchain, as a decentralized distributed ledger with blockchain storage, tamper-proof, secure, and trustworthy features, can solve problems such as single-point-of-failure and trust issues, while the hidden communication in the physical layer can effectively resist information leakage and violent attacks. In this paper, we propose a lightweight UAV network authentication mechanism that leverages blockchain and covert communication, where the identity information is transmitted as covert tags carried by normal modulated signals. In addition, a weight-based Practical Byzantine Fault-Tolerant (wPBFT) consensus protocol is devised, where the weights are determined by the channel states of UAVs and the outcomes of past authentication scenarios. Simulation results demonstrate that the proposed mechanism outperforms traditional benchmarks in terms of security and robustness, particularly under conditions of low Signal-to-Noise Ratio (SNR) and short tag length.

In vitro Investigation of Resin Tag Lengths of Three Commercially Available Pit and Fissure Sealants.

The aim of this in vitro study was to perform a comparative evaluation of the length of resin tags produced by three different types of pit and fissure sealants (Embrace WetBond, Helioseal Clear, and Fuji VII) using scanning electron microscopy. Thirty extracted mandibular premolars were randomly divided into three groups of ten. Each group was treated with one of the sealants - Embrace WetBond, Helioseal Clear, or Fuji VII. Following cleaning and preparation, the sealants were applied according to the manufacturer's instructions. Teeth were then sectioned and prepared for SEM investigation, and the length of resin tags was measured. Scanning electron microscopy revealed Embrace WetBond produced significantly longer resin tags than Helioseal Clear and Fuji VII. The study concludes that Embrace WetBond sealant exhibited the longest resin tags, which may suggest a stronger mechanical bond to enamel.

CCA Security with Short AEAD Tags

The size of the authentication tag represents a significant overhead for applications that are limited by bandwidth or memory. Hence, some authenticated encryption designs have a smaller tag than the required privacy level, which was also suggested by the NIST lightweight cryptography standardization project. In the ToSC 2022, two papers have raised questions about the IND-CCA security of AEAD schemes in this situation. These papers show that (a) online AE cannot provide IND-CCA security beyond the tag length, and (b) it is possible to have IND-CCA security beyond the tag length in a restricted Encode-then-Encipher framework. In this paper, we address some of the remaining gaps in this area. Our main result is to show that, for a fixed stretch, Pseudo-Random Injection security implies IND-CCA security as long as the minimum ciphertext size is at least as large as the required IND-CCA security level. We also show that this bound is tight and that any AEAD scheme that allows empty plaintexts with a fixed stretch cannot achieve IND-CCA security beyond the tag length. Next, we look at the weaker notion of MRAE security, and show that two-pass schemes that achieve MRAE security do not achieve IND-CCA security beyond the tag size. This includes SIV and rugged PRPs.

Evaluation of the Dentinal Shear Bond Strength and Resin Interface in Primary Molars after Pre-Treatment with Various Dentin Bio-Modifiers: An In Vitro Study.

Dentine adhesives have demonstrated great success with permanent teeth. Though the results in primary teeth are not well documented, some studies have demonstrated lower values of bond strength in primary teeth than those found in permanent teeth. The aim of this study was to compare and evaluate the effect of grape seed extract (6.5%) (Herbal Bio Solutions, Delhi, India), glutaraldehyde (5%) (Loba Chemie PVT. LTD., Mumbai), hesperidin (0.5%) (Herbal Bio Solutions, Delhi, India), and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) (GC Corporation, Alsip, IL, USA) on the shear bond strength of dentine of primary teeth and to evaluate the resin tags at the resin tooth interface. Seventy-five caries-free human primary molars were collected, and their occlusal surfaces were ground flat. Dentin surfaces were etched using phosphoric acid. Then teeth were randomly assigned in sequential order to five groups according to the dentinal treatment method: Group I (Control group) (no treatment), Group II (5% glutaraldehyde), Group III (6.5% grape seed extract), Group IV (0.5% hesperidin), and Group V (CPP-ACP). Ten teeth from each group were assigned for Shear Bond Strength and five for SEM analysis. ANOVA and a post hoc least significant difference test (p < 0.05) were used for statistical analysis of the collected data. The grape seed extract group showed significantly increased shear bond strength than the control group (p < 0.05), and the mean length of resin tags in different dentine bio modifiers groups was also statistically significant (p < 0.05). The use of dentin bio modifiers such as 5% glutaraldehyde, 6.5% grape seed extract, 0.5% hesperidin, and CPP-ACP in the bonding process for primary teeth did not improve the dentinal bond strength.

Polyvinylpyrrolidone as a primer for resin-dentin bonding

ObjectiveThis study aimed to investigate the effects of polyvinylpyrrolidone (PVP)-containing primer (PCP) on dentin bonding. MethodsPVP and anhydrous ethanol were used to prepare the PCPs, which were prepared at concentrations of 0.5%, 1%, and 2% (w/v). These PCPs were subsequently applied to the dentin surface, denoted as E1, E2, and E3, respectively. In the control group, no primer was applied. Following the treatment, the dentin surfaces were subjected to analysis using Fourier-transform infrared spectroscopy (FTIR), and the micro-tensile bond strength (MTBS) was evaluated. The failure mode, nanoleakage, and bonding longitudinal section were observed utilizing scanning electron microscopy (SEM). Additionally, the effect of PCPs on matrix metalloproteinases (MMPs) activity was analyzed through an in situ zymography test. Data were subjected to statistical analysis using ANOVA tests (α = 0.05). ResultsSignificant alterations in the infrared resonances associated with collagen cross-linking within the collagen matrix were observed across all PCP groups. The application of PCP demonstrated a noteworthy enhancement in micro-tensile bond strength (MTBS) compared to group C (p < 0.05). Notably, group C exhibited the lowest MTBS (41 ± 7.7 MPa), whereas group E2 demonstrated the highest MTBS (66 ± 11.9 MPa). Even after undergoing aging, the MTBS of the PCP groups remained superior to that of group C (p < 0.05). The resin tag length in the PCP groups was found to be greater than that of group C, and the occurrence of nanoleakage was comparatively lower in the PCP groups, both before and after aging. Additionally, PCP exhibited a dose-dependent inhibition of matrix metalloproteinases (MMPs) activity, which was statistically significant (p < 0.05). ConclusionsThe utilization of PCP Primer exhibits notable enhancements in bond strength, mitigates nano-leakage, and suppresses enzyme activity within the hybrid layer.

In Vitro Evaluation of Viscosity, Depth of Penetration, Microleakage, and Shear Bond Strength of Conventional and Hydrophilic Sealants.

Sealants are effective in preventing and arresting pit and fissure caries. Newer brands of sealants continue to be developed despite the lack of scientifically based information addressing the caries-preventive properties of these materials. Hence, laboratory in vitro tests play a vital role in providing the necessary information regarding the efficacy of new products in a short period of time. To compare and evaluate the viscosity, resin tag length, microleakage, and shear bond strength between conventional and hydrophilic sealants. A total of 40 extracted third molars were selected. Only 20 were evaluated for microleakage and resin tag length and another 20 for shear bond strength evaluation between group I-ClinPro and group II-UltraSeal XT hydro. After sealant placement, specimens were immersed in 0.1% rhodamine dye, followed by thermocycling. Microleakage testing was done using a confocal laser scanning microscope and resin tag length evaluation using a scanning electron microscope (SEM) and shear bond strength using an Universal Instron machine. Viscosity was assessed using an Anton Paar viscometer. Results were subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) software version 20. Viscosity and mean microleakage scores for group I (0.92 MPa and 1.50) were found to be higher than for group II (0.72 MPa and 0.60). Mean resin tag length and mean shear bond strength for group I (7.46 ± 0.95 μm and 13.71 ± 0.94 MPa) were found to be less compared to group II (10.03 ± 1.00 μm and 20.39 ± 0.98 MPa). The results were found to be statistically significant (p < 0.05). Group II was found to be less viscous, which resulted in the formation of resin tags of sufficient length and showed less microleakage and higher shear bond strength than group I. Prabakar J, Jeevanandan G, Kengadaran S. In Vitro Evaluation of Viscosity, Depth of Penetration, Microleakage, and Shear Bond Strength of Conventional and Hydrophilic Sealants. Int J Clin Pediatr Dent 2023;16(5):745-750.

Positive Correlation of Body Length with Innate Immune Status and Resistance to &lt;i&gt;Aeromonas hydrophila&lt;/i&gt; Infection In Rohu, &lt;i&gt;Labeo rohita&lt;/i&gt;

Full-sib families of rohu (Labeo rohita) of four year-classes viz., 2003 (906 numbers of fish), 2004 (1208 nos.), 2008 (2000 nos.) and 2009 (1355 nos.) were subjected to intraperitoneal Aeromonas hydrophila challenge. The fingerlings were tagged individually with passive integrated transponder (PIT) tag and total length was measured prior to challenge. The mortality was recorded on an hourly basis for up to 24 h and later over a period of 10 days post-challenge. Mean body length of survived and dead fish were significantly different (p&lt;0.05) in the year-classes 2004, 2008 and 2009, whereas for 2003 there was no marked difference. Positive correlations of 0.004, 0.115 and 0.108 were found between length and survival for 2004, 2008 and 2009 year-classes, respectively. However, the length of 2003 year-class showed a negligible negative correlation (-0.065) with survival. The serum immune parameters viz., haemolysin titre, ceruloplasmin and myeloperoxidase activities analyzed from naïve individuals of each family showed positive correlations with body length of the same family (0.135, 0.290 and 0.109, respectively) in three year-classes i.e., 2003, 2004 and 2009. The positive correlation of length with survival and immune response indicated its possibility to be used as a co-trait for selection for improved resistance to A. hydrophila infection.

SEM study of resin tags depth for filled pit and fissure sealants using subpressure and adhesive system - An experimental analysis

Background: Pit and fissure caries account for about 90% of the caries of permanent posterior teeth and 44% of caries within the first teeth in children and adolescents. Sealant application may be a preventive conservative approach. However, it is still challenging to bolster the retention of the filled sealant and to chop back the microleakage. Aims and Objectives: To evaluate and compare the depth of resin tags of three filled pit and fissure sealants (PFS) using subpressure and adhesive system under scanning electron microscope (SEM). Materials and Methods: This study was in vitro experimental study. Forty-five orthodontically extracted premolars were prepared for resin tag depth measurement and divided according to materials and subgroups. Group A- Resin-based filled PFS, Group B- Resin modified glass ionomer-based filled PFS, Group C- Giomer based filled PFS. Subgroup 1- Only sealant application, Subgroup 2- Subpressure application, Subgroup 3-Adhesive system + Subpressure application. Samples were subjected to thermocycling. The sectioned tooth fragments were polished using a carbide stone and then mounted under SEM for analysis. Photographs of the sections were obtained and the resin tag lengths were measured. Unpaired t-test and one-way analysis of variance test used for analysis. Results were considered significant when P&lt;0.05. Results: The depth of resin tags of the tested materials differed significantly for Giomer-based and resin-modified glass ionomer-based filled PFS group with P&lt;0.05. Whereas Resin-based filled PFS group was not found significant P&gt;0.05 for the depth of resin tags. Conclusion: This study concludes that Giomer based filled PFS group and Resin-modified glass ionomer-based filled PFSs showed the highest Resin tag depth respectively when compared with Resin-based filled PFSs. The Subpressure application group was more effective followed by Adhesive+subpressure application group and Control group.

A Review of Tags Anti-Collision Identification Methods Used in RFID Technology

With radio frequency identification (RFID) becoming a popular wireless technology, more and more relevant applications are emerging. Therefore, anti-collision algorithms, which determine the time to tag identification and the accuracy of identification, have become very important in RFID systems. This paper presents the algorithms of ALOHA for randomness, the binary tree algorithm for determinism, and a hybrid anti-collision algorithm that combines these two algorithms. To compensate for the low throughput of traditional algorithms, RFID anti-collision algorithms based on blind source separation (BSS) are described, as the tag signals of RFID systems conform to the basic assumptions of the independent component analysis (ICA) algorithm. In the determined case, the ICA algorithm-based RFID anti-collision method is described. In the under-determined case, a combination of tag grouping with a blind separation algorithm and constrained non-negative matrix factorization (NMF) is used to separate the multi-tag mixing problem. Since the estimation of tag or frame length is the main step to solve the RFID anti-collision problem, this paper introduces an anti-collision algorithm based on machine learning to estimate the number of tags.

Micromorphology and analysis of dentin surfaces after preparation with Er:YAG laser and application of self-etch adhesive system with 10-MDP. A confocal laser scanning microscope study.

The purpose of this study was to analyze and compare the micromorphology of the hybrid layer and the dentinal surface when the dentin was prepared with an Er:YAG laser or burs, and to find if there was any difference if the time of application of the self-etching primer on the dentin prepared with an Er:YAG laser was doubled.

Effects of His-Tag Length on the Soluble Expression and Selective Immobilization of D-Amino Acid Oxidase from Trigonopsis variabilis: A Preliminary Study

His-tags are widely used for the purification of recombinant proteins. High-cost carriers functionalized with nickel ions are commonly required for the selective immobilization of His-tagged enzymes. In this study, His-tags of varying lengths were fused to the N-terminus of D-amino acid oxidase (DAO) from Trigonopsis variabilis. The attachment of a His6 tag significantly improved the solubility of the recombinant DAO expressed in Escherichia coli. By modulating the tag lengths, a better balance between cell growth and protein solubility was achieved, resulting in a higher volume activity (His3). Furthermore, the fusion of longer tags (His6 and His9) facilitated the rapid immobilization of DAOs onto a commercial epoxy carrier without metal bearing, resulting in more selective immobilization. In conclusion, the modulation of His-tag length was preliminarily demonstrated as a simple and cost-effective approach to achieve efficient expression, as well as fast and selective immobilization of DAO.

In Vitro Analysis of Hydrophilic and Conventional sealants - A comparative study

Background: According to the World Health Organization, filling up the pits and fissures is one of the most efficient, least invasive ways to completely protect the occlusal surface from the carious phenomena. In vitro tests are essential for quickly delivering the knowledge required about the effectiveness of more recent sealant brands. Consequently, the objective of the current study was to assess and contrast the viscosity and length of resin tags on permanent molars of conventional and hydrophilic sealants. Materials and Methods: Twenty extracted third molars were split into two groups at random, one receiving conventional sealant (Clinpro 3M ESPE), and the other receiving hydrophilic sealant (UltraSeal XT Hydro). Each tooth's occlusal surfaces underwent an acid etchant pretreatment before the appropriate sealants were applied. Afterwards thermocycling and longitudinal sectioning were applied to both groups. For the purpose of measuring the length of the resin tag, the sectioned tooth specimens were examined under a scanning electron microscope. An Anton Paar viscometer was used to measure viscosities. The difference between the mean resin tag length of Group I and Group II sealants was compared using an independent t-test. Results: The mean resin tag length of Group II (10.07+/- 1.01m) was found to be higher than Group I (7.49+/- 0.94m), and this difference was statistically significant (P = 0.001). The viscosity measurements of Groups I and II were determined to be 0.8 mega Pascal (MPa) and 0.6 MPa, respectively. Conclusion: Based on the findings of the current investigation, it can be said that Group II sealants generated resin tags of sufficient length and had lower viscosities than Group I sealants. Thus, a hydrophilic sealant outperformed a conventional sealant in terms of performance.

Sponge-Based Parallel Authenticated Encryption With Variable Tag Length and Side-Channel Protection

Authenticated Encryption (AE) protects confidentiality and integrity at the same time. The sponge construction is based on an iterated permutation or transformation that can be used to implement hashing, and AE schemes, among others. Sponge-based AE schemes offer desirable characteristics like parallelizability and incrementality. In addition, they provide security features such as protection against Chosen Plaintext Attacks, Chosen-Ciphertext Attacks, and Side-Channel Attacks (SCAs). Traditionally AE schemes assume the tag length, also called the stretch, as a fixed parameter per key, and the security is proved according to that assumption. However, the variable tag length per key could happen due to misconfiguration or misuse. In that case, the security would be violated, so it is vital to accommodate variable tag length without sacrificing other desirable features. Reyhanitabar et al. proposed Key Equivalent Separation by Stretch feature and concretized it for protection against tag length misuse attacks in block cipher-based AE schemes. However, the problem remains unresolved for sponge-based constructions, where current sponge-based schemes are vulnerable to tag length variation under the same key attacks. This work aims to bridge this gap by proposing a parallel, sponge-based AE scheme with a variable tag length per key that protects against SCAs and suggesting a lower bound for the recommended tag length. Finally, the security of the proposed scheme is discussed, and its performance is analyzed after implementing the proposed AE scheme in the C programming language.

Physical Layer Authentication With High Compatibility Using an Encoding Approach

This paper concerns the problem of improving compatibility in the tag-based Physical-Layer Authentication (PLA) without sacrificing robustness of the PLA schemes. The prior PLA schemes for improving compatibility often sacrifice robustness or introduce extra communication overhead and security vulnerabilities. The main objective of our approach is to reduce the modification ratio of the source message given the tag length via an encoding approach. Based on a tag-encoding function, we propose two encoded tag-based schemes for the scenario of a single block and the scenario of multiple blocks, respectively, which are named as the Encoded Tag-based PLA scheme for Single Block (ET-SB) and the Encoded Tag-based PLA scheme for Multiple Blocks (ET-MB), respectively. We theoretically analyze the performance of the proposed schemes over fading channels and derive the closed-form expressions of the performance analyses. We implement the proposed schemes and conduct extensive performance comparisons through simulations. Our simulation results show that the closed-form expressions of the theoretical results of the proposed schemes perfectly match the corresponding simulation results. When the SNR is 10 dB, the compatibility of the ET-SB and ET-MB schemes improves to 15.63% and 23.45%, respectively, compared to the prior scheme.

Structural and biochemical insights into His-tag-induced higher-order oligomerization of membrane proteins by cryo-EM and size exclusion chromatography

Structural and functional characterization of proteins as well as the design of targeted drugs heavily rely on recombinant protein expression and purification. The polyhistidine-tag (His-tag) is among the most prominent examples of affinity tags used for the isolation of recombinant proteins from their expression hosts. Short peptide tags are commonly considered not to interfere with the structure of the tagged protein and tag removal is frequently neglected. This study demonstrates the formation of higher-order oligomers based on the example of two His-tagged membrane proteins, the dimeric arginine-agmatine antiporter AdiC and the pentameric light-driven proton pump proteorhodopsin. Size exclusion chromatography revealed the formation of tetrameric AdiC and decameric as well as pentadecameric proteorhodopsin through specific interactions between their His-tags. In addition, single particle cryo-electron microscopy (cryo-EM) allowed structural insights into the three-dimensional arrangement of the higher-order oligomers and the underlying His-tag-mediated interactions. These results reinforce the importance of considering the length and removal of affinity purification tags and illustrate how neglect can lead to potential interference with downstream biophysical or biochemical characterization of the target protein.

Effects of carbodiimide combined with ethanol-wet bonding pretreatment on dentin bonding properties: an in vitro study.

PurposeThis study evaluated the combined effects of Carbodiimide (EDC) and ethanol–wet bonding (EWB) pretreatment on the bond strength and resin–dentin surface.MethodsPhosphoric acid-etched dentin specimens were randomly divided into five groups based on the following pretreatments: deionized water (control), EWB, 0.3M EDC in water (EDCw), EDC water solution combined EWB (EDCw + EWB), and 0.3M EDC in ethanol (EDCe). A scanning electron microscope (SEM) was used to observe the morphology of collagen fibrils on the demineralized dentin matrix in each group after pretreatment. The adhesives Prime & Bond NT (PB) (Dentsply De trey, Konstanz, Germany) or Single bond 2 (SB) (3M ESPE, St. Paul, MN, USA) was applied after pretreatments, and a confocal laser scanning microscope (CLSM) was used to evaluate the quality of resin tags. The degree of conversion (DC) of the adhesive was investigated by Fourier transform infrared spectroscopy (ATR-FTIR). The dentin was first bonded with resin and bathed in water at 37 °C for 24 h. Half of them were subjected to 10, 000 cycles in a thermocycler between 5 °C and 55 °C before a microshear bond strength (µSBS) test. The statistical methods were Analysis of Variance (ANOVA) and a Tukey post hoc test at α = 0.05.ResultsThe µSBS was significantly affected by pretreatments (p < 0.001), adhesives (p < 0.001), and aging conditions (p < 0.001) as revealed by the three-way ANOVA. The EDCw, EDCw + EWB, and EDCe groups significantly increased the µSBS; the EDCw + EWB and EDCe groups produced the highest µSBS. In the EDC-containing groups, the SEM showed at the collagen fibrils in the dentin matrix formed a three-dimensional network structure in the tubules after cross-linking into sheets, and the hybrid layer formed thicker resin tags under a CLSM. In the EDC-containing groups, the CLSM observed an increase in the length of resin tags. PB showed a higher DC and bonding strength than SB, and the five pretreatment groups tested did not affect the DC of the two adhesives.ConclusionsIn etch–and–rinse bonding system, EDC combined with EWB pretreatment can improve the quality of the hybrid layer and enhance the mechanical properties of demineralized dentin matrix. Pretreatment with EDC–ethanol solution may be a new clinically friendly option for enhancing dentin bonding durability.

Evaluation of six different one-step universal adhesive systems in terms of dentin bond strength, adhesive interface characterization, surface tension, contact angle, degree of conversion and solvent evaporation after immediate and delayed use.

In this study, it was aimed to investigate the effects of different waiting periods on resin-dentin bond strength (BS), degree of conversion (DC), contact angle (CA), surface tension (ST), solvent evaporation (weight loss) and the characteristics of adhesive interfaces of the current six universal adhesive resins (ARs). A total of 216 caries-free human lower third molar teeth were used. Composite resin restorations were performed by applying six universal ARs in etch-and-rinse and self-etch mode on standardized dentin surfaces after 0, 5, and 30 min waiting time. Then, a micro-shear BS test, SEM examination and characterization of the adhesive interface were performed. In addition, DC, CA, ST, solvent evaporation of all tested ARs were evaluated. The obtained data were statistically anaIyzed. The tested ARs did not show any statistical difference between 0 and 5min evaluations in all parameters evaluated except for weight loss (p > 0.05). While the weight loss, ST and CA of all ARs increased in 30 min (p < 0.05), the BS, DC, thickness of the adhesive layer and the hybrid layer, resin tag length and number of resin tags varied according to the ARs used. When the ARs were used in etch-and-rinse mode, all the parameters evaluated also varied according to the AR used. Higher adhesive layer thickness and lower hybrid layer thickness were found in the self-etch mode (p < 0.05). All of the adhesives tested can be safely used up to 30 min. This could also prevent economical loss caused by waste adhesive material. It is important to know how the bond strength, degree of conversion, adhesion, contact angle and surface tension properties of the adhesive resin waiting in the dispensing cup for a long time during clinical use are affected to make ideal restorations.

On the security of TrCBC

TrCBC is a variant of CBC-MAC which appeared in Zhang et al. (2012) [9]. The authors claimed TrCBC to be a secure message authentication code (MAC) with some interesting properties. If TrCBC is instantiated with a block cipher with block length n, then it requires ⌈λ/n⌉ block cipher calls for authenticating a λ-bit message and requires a single key, which is the block cipher key. The authors state that TrCBC can have tag lengths of size less than n/2. We show that with high probability, an adversary can forge TrCBC with tag length n/2−1 with just three queries. The attack that we show can be applied to forge a large class of messages. The authors proved TrCBC to be a pseudorandom function (PRF). A scrutiny of the claimed PRF bound shows that for some recommended values of tag lengths, the bound turns out to be quite large. Thus, the security theorem does not imply security of TrCBC for all recommended tag lengths.