Length Of Tag Research Articles

Using the length of pleural tag to predetermine pleural invasion by lung adenocarcinomas.

Pleural contact is present when the underlying pathology of the pleural tag (PT) involves the pleura. This study aimed to preoperatively predict PI by lung adenocarcinomas (ACCs) with PT, exploring CT imaging parameters indicative of PT consisting of pleura and tumor invasiveness. This single-center, retrospective study included 84 consecutive patients diagnosed with solid ACCs with PT, who underwent resection at our hospital between May 2019 and July 2023. CT imaging parameters analyzed included: LPT (the length of PT), defined as the shortest distance from the tumor edge to the retracted pleura. Patients were divided into PI -ve group and PI +ve group according to PI status. Regression analyses were used to determine predictive factors for PI. The study evaluated 84 patients (mean age, 62.0 ± 13.8 years; 45 females) pathologically diagnosed with ACCs with PT on CT. Multivariate regression analysis identified tumor size (OR 1.18, 95% CI 1.09-1.29, p = 0.000), LPT (OR 0.48, 95% CI 0.25-0.91, p = 0.03) and multiple PTs to multiple types of pleura (OR 3.58, 95% CI 1.13-11.20, p = 0.03) as independent predictors for PI. The combination of these CT features improved the predictive performance for preoperatively identifying PI, achieving high specificity and moderate accuracy. The sensitivity of predicting PI with only LPT < 3 mm was 96.9%. This study determined that LPT is effective for predetermining PI in ACCs with PT.

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.

Power Yoga: Variable-Stretch Security of CCM for Energy-Efficient Lightweight IoT

The currently ongoing NIST LWC project aims at identifying new standardization targets for lightweight authenticated encryption with associated data (AEAD) and (optionally) lightweight cryptographic hashing. NIST has deemed it important for performance and cost to be optimized on relevant platforms, especially for short messages. Reyhanitabar, Vaudenay and Vizár (Asiacrypt 2016) gave a formal treatment for security of nonce-based AEAD with variable stretch, i.e., when the length of the authentication tag is changed between encryptions without changing the key. They argued that AEAD supporting variable stretch is of practical interest for constrained applications, especially low-power devices operated by battery, due to the ability to flexibly trade communication overhead and level of integrity.In this work, we investigate this hypothesis with affirmative results. We present vCCM, a variable-stretch variant of the standard CCM and prove it is secure when used with variable stretch. We then experimentally measure the energy consumption of a real-world wireless sensor node when encrypting and sending messages with vCCM and CCM, respectively. Our projections show that the flexible trade of integrity level and ciphertext expansion can lead up to 21% overall energy consumption reduction in certain scenarios. As vCCM is obtained from the widely-used CCM by a black-box transformation, allowing any existing CCM implementations to be reused as-is, our results can be immediately put to use in practice. vCCM is all the more relevant because neither the NIST LWC project, nor any of the candidates give a consideration for the support of variable stretch and the related integrity-overhead trade-off.

Surface crack detection and monitoring in metal structure using RFID tag

PurposeRFID tags for sensing are available to operate and transmit sensing data to measurement equipment without battery and wires, which is a great advantage in establishing IoT environment. For crack sensing tags, however, the short service life of tags restricted their application. This paper aims to introduce a method of surface crack detection and monitoring based on RFID tag, which makes it possible for tags to be reused.Design/methodology/approachMetal plate to be monitored, acting as the ground plane of microstrip patch antenna, is underneath the crack sensing tag. The propagating surface crack in metal plate will change the electric length of tag’s antenna that is directly proportional to the crack depth and length. Thus, the deformation of sensing tag introduced by the load on metal structure is no longer a prerequisite for crack sensing.FindingsThe simulated and experimental results show that the proposed crack sensing tag can sense the change of surface crack with mm-resolution and sense surface crack propagation without a deformation, which means the proposed crack sensing tag can be reused.Originality/valueThe key advantage of the proposed method is the reusability of the RFID tags.

Deterministic Dual-stack Query Tree RFID tag anti-collision algorithm

Tag collision problems are a major issue affecting the performance of RFID systems. The probabilistic tag anti-collision algorithm has tag starvation and cannot identify some tags. This paper proposes a deterministic dual-stack query tree algorithm (DDQT). It successfully implements the anti-collision algorithm of tags by generating new query codes and tag identification functions. At the same time, the DDQT algorithm greatly saves memory space by adding a prefix code stack and a suffix code stack. The DDQT algorithm is simple, and there is no limit on the length of the electronic tag to be queried. Compared with the previous query-tree algorithms, the DDQT algorithm has obvious improvements in query comparison times, empty query times, and occupied memory space. It can effectively remove idle nodes, shorten recognition time and save memory resources, thus improving the speed and accuracy of label recognition to some extent.

Engineering peroxiredoxin 3 to facilitate control over self-assembly

Oligomeric proteins are abundant in nature and are useful for a range of nanotechnological applications; however, a key requirement in using these proteins is controlling when and how they form oligomeric assemblies. Often, protein oligomerisation is triggered by various cellular signals, allowing for controllable oligomerisation. An example of this is human peroxiredoxin 3 (Prx), a stable protein that natively forms dimers, dodecameric rings, stacks, and tubes in response to a range of environmental stimuli. Although we know the key environmental stimuli for switching between different oligomeric states of Prx, we still have limited molecular knowledge and control over the formation and size of the protein's stacks and tubes. Here, we have generated a range of Prx mutants with either a decreased or knocked out ability to stack, and used both imaging and solution studies to show that Prx stacks through electrostatic interactions that are stabilised by a hydrogen bonding network. Furthermore, we show that altering the length of the polyhistidine tag will alter the length of the Prx stacks, with longer polyhistidine tags giving longer stacks. Finally, we have analysed the effect a variety of heavy metals have on the oligomeric state of Prx, wherein small transition metals like nickel enhances Prx stacking, while larger positively charged metals like tungstate ions can prevent Prx stacking. This work provides further structural characterisation of Prx, to enhance its use as a platform from which to build protein nanostructures for a variety of applications.

CMCC: Misuse Resistant Authenticated Encryption with Minimal Ciphertext Expansion

In some wireless environments, minimizing the size of messages is paramount due to the resulting significant energy savings. We present CMCC (CBC-MAC-CTR-CBC), an authenticated encryption scheme with associated data (AEAD) that is also nonce misuse resistant. The main focus for this work is minimizing ciphertext expansion, especially for short messages including plaintext lengths less than the underlying block cipher length (e.g., 16 bytes). For many existing AEAD schemes, a successful forgery leads directly to a loss of confidentiality. For CMCC, changes to the ciphertext randomize the resulting plaintext, thus forgeries do not necessarily result in a loss of confidentiality which allows us to reduce the length of the authentication tag. For protocols that send short messages, our scheme is similar to Synthetic Initialization Vector (SIV) mode for computational overhead but has much smaller expansion. We prove both a misuse resistant authenticated encryption (MRAE) security bound and an authenticated encryption (AE) security bound for CMCC. We also present a variation of CMCC, CWM (CMCC With MAC), which provides a further strengthening of the security bounds.

Comparative Evaluation of the Viscosity and Length of Resin Tags of Conventional and Hydrophilic Pit and Fissure Sealants on Permanent Molars: An In vitro Study.

Background:The World Health Organization considers sealing the pit and fissures as a primary preventive measure and is one of the most effective, least invasive means to ensure the complete protection of the occlusal surface from the carious phenomenon. In vitro tests play a vital role in providing the necessary information regarding the efficacy of newer brands of sealants in a short period. Therefore, the aim of the present study was to evaluate and compare the viscosity and length of resin tag of conventional and hydrophilic sealant on permanent molars.Materials and Methods:Twenty extracted third molars were randomly divided into two groups: Group I: Conventional sealant (Clinpro 3M ESPE) and Group II: Hydrophilic sealant (UltraSeal XT Hydro). Occlusal surfaces of each tooth were pretreated with the acid etchant, and the respective sealants were placed. Both the groups were then subjected to thermocycling and sectioned longitudinally. The sectioned tooth specimens were examined under scanning electron microscope for resin tag length measurements. Viscosities were evaluated using an Anton Paar viscometer. Independent t-test was used to compare the difference in mean resin tag length of Group I and Group II sealants.Results:Viscosity measurements of Group I and Group II were found to be 0.9 mega Pascal (MPa) and 0.7 MPa and the mean resin tag length of Group II (10.03 ± 1.00 μm) was found to be higher than Group I (7.46 ± 0.95 μm) and was found to be significant statistically (P = 0.001).Conclusion:Based on the results of the present study, it can be concluded that Group II sealant exhibited lower viscosity and formed resin tag of sufficient length than that of Group I sealants. Therefore, hydrophilic sealant showed better results as compared to a conventional sealant.

Electrochemical CO2 reduction on EC Tag (Cu) Supported Carbon Electrode

Increase in greenhouse gases, such as carbon dioxide is global issue on the warming of our planet. CO2 reduction is an approach to solving the issue, and studied with various methodologies. We have developed an electrochemical method with metal supported carbon electrodes. Catalytic metal supported electrode could reduce CO2 into valuable substances, such as CO, CH4, C2H6, C2H4, CH3OH, C2H5OH, HCOOH, and etc. Electrochemical CO2 reduction is the one of the efficient chemical process. But both efficiency and reduced products of CO2electrochemical reduction are very much depended on a supported material and its state of support on an electrode. We have developed EC tag method in order to electrochemical support a catalytic nano metal on economical non-catalytic electrode, such as carbon. EC tag method is our originated method to support metal-peptidic tag complex on solid surface electrochemically [1-3]. EC tag method has been employed to support metal on carbon electrode electrochemically. EC tag method is an unique method to electrical deposition of metal. EC tag-metal complex can be supported through electrochemical reduction. In the EC tag method Cu support, the deposited Cu doesn’t growth much because the metal crystal growth is affected with complexed EC tag. So that means that the EC tag (Cu) can be support in nano size metal on glassy carbon. The supported metal (Cu) shows catalytic activity on CO2reduction and electrolysis of water. We assumed that EC tag method could support nano metal on electrode, so reaction efficiency and product selectivity improved. Therefore, in this study, the supported metal (Cu) was employed EC tag method. We have objective to clarify alternation of CO2reduction products with the carbon electrode with different condition of metal support. Electrochemical support of EC tag (Cu) on glassy carbon has been done as follow; electrochemical supporting reaction mixture was containing EC tag (Cu2+) (0.1mM) and KNO3 (0.1mM) and was adjusted of several different pH. Electrochemical EC tag (Cu) supporting was performed in three-electrode system (WE: glassy carbon electrode, CE: Pt electrode, RE: Ag/AgCl electrode) with constant potential application at -200mV, -400mV, or -600mV for max, 30min. Electrochemical reduction of CO2 was performed with the EC tag (Cu) supported glassy carbon electrodes. The CO2 reduction had been done with three electrode system with -600mV constant potential application. CO2 reduced products were changed depending on the pH of EC tag (Cu) supporting reaction mixture. The reaction time length of EC tag (Cu) and Cu supporting have also effect on the CO2reduction products which were vary. These observations suggest that the state of supported EC tag (Cu) is different among the condition of supporting reaction, e.g. pH, supporting potential. We are starting to observe EC tag (Cu)/glassy carbon electrode by atomic force microscopy (AFM) and scanning electron microscope. In our current results, methane and ethylene was produced by electrochemical CO2 reduction by EC tag (Cu)/glassy carbon electrode which was prepared through specific condition. EC tag metal support modified carbon electrode shows a typical catalytic action in electrochemical CO2 reduction. It suggests potential to apply the EC tag metal support modified carbon electrode for CO2conversion. [1] T. Haruyama, T. Sakai, K. Matsuno, Biomaterials, 26/24, 4944-4947 (2005) [2] H. Sakamoto and T. Haruyama et al., Analytica Chimica Acta, 26;604(1):76-80 (2007) [3] H. Sakamoto and T. Haruyama, Colloids and Surfaces B: 79, 83-87 (2010)

Application of volcanic ash particles for protein affinity purification with a minimized silica-binding tag

We recently reported that the spore coat protein, CotB1 (171 amino acids), from Bacillus cereus mediates silica biomineralization and that the polycationic C-terminal sequence of CotB1 (14 amino acids), designated CotB1p, serves as a silica-binding tag when fused to other proteins. Here, we reduced the length of this silica-binding tag to only seven amino acids (SB7 tag: RQSSRGR) while retaining its affinity for silica. Alanine scanning mutagenesis indicated that the three arginine residues in the SB7 tag play important roles in binding to a silica surface. Monomeric l-arginine, at concentrations of 0.3-0.5M, was found to serve as a competitive eluent to release bound SB7-tagged proteins from silica surfaces. To develop a low-cost, silica-based affinity purification procedure, we used natural volcanic ash particles with a silica content of ∼70%, rather than pure synthetic silica particles, as an adsorbent for SB7-tagged proteins. Using green fluorescent protein, mCherry, and mKate2 as model proteins, our purification method achieved 75-90% recovery with ∼90% purity. These values are comparable to or even higher than that of the commonly used His-tag affinity purification. In addition to low cost, another advantage of our method is the use of l-arginine as the eluent because its protein-stabilizing effect would help minimize alteration of the intrinsic properties of the purified proteins. Our approach paves the way for the use of naturally occurring materials as adsorbents for simple, low-cost affinity purification.

Evaluation of hybrid layer thickness and resin tag length of self-etch adhesives with different ph using confocal laser scanning microscope: an in vitro study

The aim of this in vitro study is to evaluate the hybrid layer thickness and resin tag length of self-etches adhesives with different pH using Confocal Laser Scanning Microscope (CLSM). Total 40 teeth was prepared and divided into four groups. Group-I (Prime and Bond NT), group-II: (Xeno III), group-III: (Xeno V) and group-IV: (Xeno IV). Each group contains 10 teeth. The samples were mounted on Borosilicate cover glass with cover slip. The excitation laser light was generated with a wavelength 514nm. The image was recorded in fluorescent mode and hybrid layer and resin tag length were visualized as green. They were analyzed, and thickness of hybrid layer and length of resin tag were measured by means of Image Browser software (zeiss, Germany) in micrometers. Results were tabulated and mean obtained. Group-I (Prime and Bond NT) showed the maximum values for hybrid layer thickness & resin tag length compared to group-II (Xeno III), group-III (Xeno V) and group-IV (Xeno IV). Among the self-etching primer group-II (Xeno III) with strong pH (<1) gave higher values for hybrid layer thickness and resin tag length. Among the self-etching adhesives, strong self-etch adhesive showed the maximum hybrid layer thickness and resin tag length. Further studies with more parameters must be conducted to evaluate the resin-dentin interface.

WITHDRAWN: Reprint of: Effective high-throughput overproduction of membrane proteins in Escherichia coli

Structural biology is increasingly reliant on elevated throughput methods for protein production. In particular, development of efficient methods of heterologous production of membrane proteins is essential. Here, we describe the heterologous overproduction of 24 membrane proteins from the human pathogen Legionella pneumophila in Escherichia coli. Protein production was performed in 0.5ml cultures in standard 24-well plates, allowing increased throughput with minimal effort. The effect of the location of a histidine purification tag was analyzed, and the effect of decreasing the length of the N- and C-terminal extensions introduced by the Gateway cloning strategy is presented. We observed that the location and length of the purification tag significantly affected protein production levels. In addition, an auto-induction protocol for membrane protein expression was designed to enhance the overproduction efficiency such that, regardless of the construct used, much higher expression was achieved when compared with standard induction approaches such as isopropyl-β-d-thiogalactopyranoside (IPTG). All 24 targets were produced at levels exceeding 2mg/l, with 18 targets producing at levels of 5mg/l or higher. In summary, we have designed a fast and efficient process for the production of medically relevant membrane proteins with a minimum number of screening parameters.

Design of Novel Affinity Tags to Increase Recovery of Recombinant Proteins in Ther Soluble Forms

One major challenge in the expression and purification of recombinant proteins is preventing proteins from entering inclusion bodies. While some proteins can be extracted and refolded from the insoluble inclusion bodies others cannot, such as those proteins containing a protein affinity tag. This study will examine those specific challenges and will explore potential solutions to those problems. We aim to exploit properties of osmolytes like betaine, sarcosine, arginine, and proline to design affinity tags that prevent the formation of inclusion bodies during over-expression of proteins in bacterial hosts. Results of the interactions of the designed affinity tag(s) with transition metals, like nickel and cobalt, will be presented. In addition, correlation between recombinant protein expression yields and the length of the affinity tag(s) will also be discussed.

Effective high-throughput overproduction of membrane proteins in Escherichia coli

Structural biology is increasingly reliant on elevated throughput methods for protein production. In particular, development of efficient methods of heterologous production of membrane proteins is essential. Here, we describe the heterologous overproduction of 24 membrane proteins from the human pathogen Legionella pneumophila in Escherichia coli. Protein production was performed in 0.5 ml cultures in standard 24-well plates, allowing increased throughput with minimal effort. The effect of the location of a histidine purification tag was analyzed, and the effect of decreasing the length of the N- and C-terminal extensions introduced by the Gateway cloning strategy is presented. We observed that the location and length of the purification tag significantly affected protein production levels. In addition, an auto-induction protocol for membrane protein expression was designed to enhance the overproduction efficiency such that, regardless of the construct used, much higher expression was achieved when compared with standard induction approaches such as isopropyl-β- d-thiogalactopyranoside (IPTG). All 24 targets were produced at levels exceeding 2 mg/l, with 18 targets producing at levels of 5 mg/l or higher. In summary, we have designed a fast and efficient process for the production of medically relevant membrane proteins with a minimum number of screening parameters.

Influence of tryptophan tags on the purification of cutinase, secreted by a recombinant Saccharomyces cerevisiae, using cationic expanded bed adsorption and hydrophobic interaction chromatography

During cationic bed adsorption (EBA), with cutinase with varying length tryptophan tags (WP)(2)and (WP)(4), 33% and 10% of adsorption capacity and 80% and 32% eluted specific activity were observed in relation to wild type (wt)-cutinase in the conventional process. Therefore, as the hydrophobicity of the protein increases, it is important to integrate the EBA step with a hydrophobic interaction chromatography (HIC) process. As the length of the hydrophobic tag-(WP) increases from n = 2 to n = 4, the purification factor obtained by HIC was 1.8 and 2.2-fold higher than wt-cutinase. However, the recovery yield obtained in HIC decreases substantially as the length of hydrophobic tag increases (97%, 84% and 70% for wt-cutinase, cutinase-(WP)(2) and cutinase-(WP)(4)). The integration of two purification steps, EBA followed by HIC, resulted in the highest overall purity level for cutinase-(WP)(2), and the highest overall recovery yield for wt-cutinase. When optimizing the design of a hydrophobic tag fused to a protein secreted by Saccharomyces cerevisiae it must be considered that the cultivation parameters could impair the downstream process, and consequently the optimum tag is not necessarily the one that presents the highest purification factor in HIC.

Unconditionally secure chaffing and winnowing with short authentication tags

Rivest proposed the idea of a chaffing-and-winnowing scheme, inwhich confidentiality is achieved through the use of an authentication code. Thus it would still be possible to have confidential communications even if conventional encryption schemes were outlawed. Hanaoka et al. constructedunconditionally secure chaffing-and-winnowing schemes which achieve perfect secrecy in the sense of Shannon. Their schemes are constructed from unconditionally secure authentication codes. In this paper, we construct unconditionally secure chaffing-and-winnowing schemes from unconditionally secure authentication codes in which the authentication tags are very short. This could be a desirable feature, because certain types of unconditionally secure authentication codes can provide perfect secrecy if the length of an authentication tag is at least as long as the length of the plaintext. The use of such a code might be prohibited if encryption schemes are made illegal, so it is of interest to construct chaffing-and-winnowing schemes based on ''short'' authentication tags.

A comparative analysis of the information content in long and short SAGE libraries

BackgroundSerial Analysis of Gene Expression (SAGE) is a powerful tool to determine gene expression profiles. Two types of SAGE libraries, ShortSAGE and LongSAGE, are classified based on the length of the SAGE tag (10 vs. 17 basepairs). LongSAGE libraries are thought to be more useful than ShortSAGE libraries, but their information content has not been widely compared. To dissect the differences between these two types of libraries, we utilized four libraries (two LongSAGE and two ShortSAGE libraries) generated from the hippocampus of Alzheimer and control samples. In addition, we generated two additional short SAGE libraries, the truncated long SAGE libraries (tSAGE), from LongSAGE libraries by deleting seven 5' basepairs from each LongSAGE tag.ResultsOne problem that occurred in the SAGE study is that individual tags may have matched to multiple different genes – due to the short length of a tag. We found that the LongSAGE tag maps up to 15 UniGene clusters, while the ShortSAGE and tSAGE tags map up to 279 UniGene clusters. Both long and short SAGE libraries exhibit a large number of orphan tags (no gene information in UniGene), implying the limitation of the UniGene database. Among 100 orphan LongSAGE tags, the complete sequences (17 basepairs) of nine orphan tags match to 17 genomic sequences; four of the orphan tags match to a single genomic sequence. Our data show the potential to resolve 4–9% of orphan LongSAGE tags. Finally, among 400 tSAGE tags showing significant differential expression between AD and control, 79 tags (19.8%) were derived from multiple non-significant LongSAGE tags, implying the false positive results.ConclusionOur data show that LongSAGE tags have high specificity in gene mapping compared to ShortSAGE tags. LongSAGE tags show an advantage over ShortSAGE in identifying novel genes by BLAST analysis. Most importantly, the chances of obtaining false positive results are higher for ShortSAGE than LongSAGE libraries due to their specificity in gene mapping. Therefore, it is recommended that the number of corresponding UniGene clusters (gene or ESTs) of a tag for prioritizing the significant results be considered.

New Data Base-independent, Sequence Tag-based Scoring of Peptide MS/MS Data Validates Mowse Scores, Recovers Below Threshold Data, Singles Out Modified Peptides, and Assesses the Quality of MS/MS Techniques

The Mascot score (M-score) is one of the conventional validity measures in data base identification of peptides and proteins by MS/MS data. Although tremendously useful, M-score has a number of limitations. For the same MS/MS data, M-score may change if the protein data base is expanded. A low M-value may not necessarily mean poor match but rather poor MS/MS quality. In addition M-score does not fully utilize the advantage of combined use of complementary fragmentation techniques collisionally activated dissociation (CAD) and electron capture dissociation (ECD). To address these issues, a new data base-independent scoring method (S-score) was designed that is based on the maximum length of the peptide sequence tag provided by the combined CAD and ECD data. The quality of MS/MS spectra assessed by S-score allows poor data (39% of all MS/MS spectra) to be filtered out before the data base search, speeding up the data analysis and eliminating a major source of false positive identifications. Spectra with below threshold M-scores (poor matches) but high S-scores are validated. Spectra with zero M-score (no data base match) but high S-score are classified as belonging to modified sequences. As an extension of S-score, an extremely reliable sequence tag was developed based on complementary fragments simultaneously appearing in CAD and ECD spectra. Comparison of this tag with the data base-derived sequence gives the most reliable peptide identification validation to date. The combined use of M- and S-scoring provides positive sequence identification from >25% of all MS/MS data, a 40% improvement over traditional M-scoring performed on the same Fourier transform MS instrumentation. The number of proteins reliably identified from Escherichia coli cell lysate hereby increased by 29% compared with the traditional M-score approach. Finally S-scoring provides a quantitative measure of the quality of fragmentation techniques such as the minimum abundance of the precursor ion, the MS/MS of which gives the threshold S-score value of 2.

A secure and flexible authentication system for digital images

Authentication of image data is a challenging task. Unlike data authentication systems that detect a single bit change in the data, image authentication systems must remain tolerant to changes resulting from acceptable image processing or compression algorithms while detecting malicious tampering with the image. Tolerance to the changes due to lossy compression systems is particularly important because in the majority of cases images are stored and transmitted in compressed form, and so it is important for verification to succeed if the compression is within the allowable range. In this paper we consider an image authentication system that generates an authentication tag that can be appended to an image to allow the verifier to verify the authenticity of the image. We propose a secure, flexible, and efficeint image authentication algorithm that is tolerant to image degradation due to JPEG lossy compression within designed levels. (JPEG is the most widely used image compression system and is the de facto industry standard.) By secure we mean that the cost of the best known attack againt the system is high, by flexible we mean that the level of protection can be adjusted so that higher security can be obtained with increased length of the authentication tag, and by efficient we mean that the computation can be performed largely as part of the JPEG compression, allowing the generation of the authentication tag to be efficiently integrated into the compression system. The authentication tag consists of a number of feature codes that can be computed in parallel, and thus computing the tag is effectively equivalent to computing a single feature code. We prove the soundness of the algorithm and show the security of the system. Finally, we give the results of our experiments.

Efficient enantiomeric resolution via introduction of a fluorous tag as a resolving reagent with β-cyclodextrin columns: model study on fluorinated O-acetylmandelate and ibuprofen amide

Efficient enantiomeric resolution of racemates is performed by introduction of fluorous tags using β-cyclodextrin columns. Selection of appropriate length of tag and mobile phase leads to an efficient resolution of racemates (fluorinated O-acetylmandelate and ibuprofen amide) by those columns.