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In the present study, the tautomeric process, intramolecular hydrogen bonding (IMHB), and π-electron delocalization (π-ED) of 2-selenoformyl-3-thioxo-propionaldehyde (STP) in the first singlet and triplet excited states were investigated by CIS and TD-DFT methods. The relative energies of hydrogen-bonded tautomers in both excited states indicate that the thiol/enol conformers are the most/least stable forms. In this regard, a detailed analysis of various tautomeric equilibriums, different types of hydrogen bonds, and π-electron delocalization was performed. The electronic energies of different tautomers indicate the thermodynamic preference of thiol with respect to the other forms. Furthermore, the low activation energy barriers of thione⇄thiol equilibrium also show the kinetic preference of thiol. On the other hand, the estimation of different hydrogen bond energies emphasizes the stronger IMHB of enol. Moreover, the evaluation of π-ED by the structural parameter of Gilli (λ) represents the significance of electron mobility in the enol conformers. Consequently, the duality between the IMHB and π-ED with the thermodynamic stability order of tautomers indicates that the tautomeric phenomenons play a dominant role in determining the stability of the benchmark structures in both singlet and triplet excited states. [ABSTRACT FROM AUTHOR]

Prostate-specific membrane antigen (PSMA), also called glutamate carboxypeptidase II (GCP(II)), is a Zn-dependent metalloprotease that is known as a well prostate cancer indication and a potential targeting towards anti-cancer medicines and drug delivery. Because of its centrality in the diagnostics and treatment of prostate cancer, several types of inhibitors are designed with particular scaffolds. In this study, important groups of related inhibitors as well as reported experimental and computational studies are being reviewed, in which we examined three functional groups on each group of structures. The importance of computational biochemistry and the necessity of extensive research in this area on PSMA and its effective ligands are recommended. [ABSTRACT FROM AUTHOR]

Parallel execution of multiple threads of a web application will result in server-side races if the web application is not synchronized correctly. Server-side race is susceptible to flaws in the relation between the server and the database. Detecting the race condition in the web applications depends on the business logic of the application. No logic-aware approach has been presented to deal with race conditions. Furthermore, most existing approaches either result in DoS or are not applicable with false positive. In this study, the session puzzling race conditions existing in a web application are classified and described. In addition, we present Business-Layer Session Puzzling Racer, a black-box approach for dynamic application security testing, to detect the business-layer vulnerability of the application against session puzzling race conditions. Experiments on well-known and widely used web applications showed that Business-Layer Session Puzzling Racer is able to detect the business layer vulnerabilities of these applications against race conditions. In addition, the amount of traffic generated to identify the vulnerabilities has been improved by about 94.38% by identifying the business layer of the application. Thus, Business-Layer Session Puzzling Racer does not result in DoS. [ABSTRACT FROM AUTHOR]

The dendritic cell algorithm (DCA) as one of the emerging evolutionary algorithms is based on the behavior of the specific immune agents, known as dendritic cells (DCs). DCA has several potentially beneficial features for binary classification problems. In this paper, we aim at providing a new version of this immune-inspired mechanism acts as a semi-supervised classifier, which can be a defensive shield in network intrusion detection problem. Till now, no strategy or idea has been adopted on the |$Get_{Antigen()}$| function on the detection phase, but random sampling entails the DCA to provide undesirable results in several cycles at each time. This leads to uncertainty. Whereas it must be accomplished by biological behaviors of DCs in peripheral tissues, we have proposed a novel strategy that exactly acts based on its immunological functionalities of dendritic cells. The proposed mechanism focuses on two items: first, to obviate the challenge of needing to have a preordered antigen set for computing danger signal, and the second, to provide a novel immune-inspired idea for nonrandom data sampling. A variable functional migration threshold is also computed cycle by cycle that shows the necessity of the migration threshold flexibility. A significant criterion so-called capability of intrusion detection (CID) is used for tests. All the tests have been performed in a new benchmark dataset named UNSW-NB15. Experimental consequences demonstrate that the present schema as the best version among improved DC algorithms achieves 76.69% CID by 90% accuracy and outperforms its counterpart methods. [ABSTRACT FROM AUTHOR]

A comprehensive theoretical study of the mutual effects of the aerogen bond and cation-π interactions in the several ternary complexes of heterocyclic rings with noble gas elements (Ar, Kr) and cations (Li+, Na+, Be2+, Mg2+) were carried out. The cooperative and diminutive effects are observed when aerogen bond and cation-π interactions coexist in the ternary Ae···π···M complex. The value of cooperative energies (Ecoop) becomes more negative (cooperative) ∖ positive (diminutive) when AlN ∖ Be2+ as π–system ∖ cation are employed. According to the result of molecular electrostatic potential (ΔV) and ΔEint, the relative strength of ternary Ae···π···M complexes interactions as follows: Ae···AlN···M > Ae···BP···M > Ae···BN···M; Ae···>···Be2+ > Ae···>···Mg2+ > Ae···>···Li+ > Ae···>···K+; Kr···π > Ar···π. The interaction energy values are substantially dependent on the cations with respect to the noble gas atoms, that is, when the mono and the divalent cation is added to Ae···π complex, the absolute value interaction energy of the aerogen bond is increased. An energy decomposition analysis shows that polarization and electrostatic effects play an important role in the strength of the ternary Ae···π···M complexes. [ABSTRACT FROM AUTHOR]

A denial‐of‐service (DoS) attack is a serious attack that targets web applications. According to Imperva, DoS attacks in the application layer comprise 60% of all the DoS attacks. Nowadays, attacks have grown into application‐ and business‐layer attacks, and vulnerability‐analysis tools are unable to detect business‐layer vulnerabilities (logic‐related vulnerabilities). This paper presents the business‐layer dynamic application security tester (BLDAST) as a dynamic, black‐box vulnerability‐analysis approach to identify the business‐logic vulnerabilities of a web application against DoS attacks. BLDAST evaluates the resiliency of web applications by detecting vulnerable business processes. The evaluation of six widely used web applications shows that BLDAST can detect the vulnerabilities with 100% accuracy. BLDAST detected 30 vulnerabilities in the selected web applications; more than half of the detected vulnerabilities were new and unknown. Furthermore, the precision of BLDAST for detecting the business processes is shown to be 94%, while the generated user navigation graph is improved by 62.8% because of the detection of similar web pages. [ABSTRACT FROM AUTHOR]

O, S, Se, and P atoms are considered as different proton donor/acceptor moieties in the resonance-inhibited hydrogen bonded (RIHB) interactions to conduct a comparative investigation. In order to study the effects of resonance and σ-skeleton planarity, the corresponding saturated and planar molecules are also computed. Moreover, to provide a broader perspective, all the given systems are compared to their resonance-assisted hydrogen bonded (RAHB) analogues. The natural bond orbital (NBO), the quantum theory of atoms in molecule (QTAIM), and the gauge-independent atomic orbital (GIAO) analyses, are performed to estimate the strength and nature of the intramolecular hydrogen bonds (IMHBs). The strength of IMHBs is also estimated using energy differences between closed and open conformers. According to the results, all the given RIHB systems suggest that resonance can obviously decrease the strength of the IMHBs. However, in the RIHB systems and also in some RAHB ones, the role of π-conjugation in the IMHB formation is less important than that of σ-planarity. In other words, the constraints imposed by σ-skeleton cause both the H-bond acceptor and donor groups to be situated close to each other; these effects outweigh the undesirable results of resonance, which totally lead to the formation of the RIHB. [ABSTRACT FROM AUTHOR]

Web application vulnerability scanners cannot detect business logic vulnerabilities (vulnerabilities related to logic) because they are not able to understand the business logic of the web application. To identify the business logic of the web application, this paper presents BLProM, Business-Layer Process Miner, the black-box approach that identifies business processes of the web application. Detecting business processes of the web applications can be used in dynamic security testing to identify business logic vulnerabilities in web applications. BLProM first extracts the navigation graph of the web application then identifies business processes from the navigation graph. The evaluation conducted on three well-known open-source web applications shows that BLProM can detect business logic processes. Experimental results show that BLProM improves web application scanning because it clusters web application pages and prevents scanning similar pages. The proposed approach is compared to OWASP ZAP, an open-source web scanner. We show that BLProM improves web application scanning about %96. [ABSTRACT FROM AUTHOR]