Search Results (142)

Polyphenolic compounds are key elements in sectors such as pharmaceutics, cosmetics and food; thus, their physicochemical characterization is a vital task. In this work, the thermal behavior of seven polyphenols (trans-resveratrol, trans-polydatin, kaempferol, quercetin, myricetin, hesperidin, and (−)-epicatechin) was investigated with DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis). Melting temperatures, enthalpies of fusion and decomposition temperatures were determined, and heat capacities were measured in the temperature range from 283.15 K to 363.15 K. Results were compared to the scarce experimental data available in the literature, showing a satisfactory agreement. All compounds were found to be thermally stable until melting, upon which they rapidly decomposed. Myricetin was the only polyphenol that presented polymorphic behavior, exhibiting two phase transitions prior to melting. Heat capacities increased minimally with temperature in the studied range. In addition, the group contribution method developed by Marrero and Gani was used to estimate the thermal properties of the polyphenols, achieving high accuracy for melting temperatures. Full article

Peptides occupy a significant share of the pharmaceutical market and are among the top-200 selling drugs in the group of non-insulin drugs with analgesic, antibacterial and cardiovascular effects. The aim of this work is to develop a comprehensive analytical approach for quality control of novel synthetic peptides with non-narcotic types of analgesia and to provide docking simulations of dermorphin complex formation at the μ-opioid receptor (MOR) binding site. The materials and methods used include the pharmaceutical substance dermorphin tetrapeptide (DMTP) (tyrosyl-D-arginyl-phenylalanyl-glycinamide); Fourier transform infrared spectroscopy (FT-IR); static and dynamic laser light scattering (DLS, LALLS); scanning optical microscopy (SEM); X-ray fluorescence elements analysis; polarimetry for optical activity determining; and Spirotox method for sample biotesting. FT-IR-Spectra indicated specific amino acid chemical groups in the tetrapeptide sequence at 3300–2700 cm⁻¹, 1670 cm⁻¹. UV-absorption spectra of aqueous solutions of dermorphin tetrapeptide showed an absorption maximum at 275 nm, which is in good agreement with the presented spectrum of the bovine serum albumin (BSA) standard; the Pearson’s r of calibration line “A-C%” in 0.0125% to 0.0500% concentration range is 0.999; and the calculated specific extinction value E1cm 1% = 18.38 ± 0.23. Of the 11 elements detected by X-rays, the elements copper (Cu) and cobalt (Co) have the highest X-ray intensity. Dispersion characteristics of dermorphin solutions were studied in the submicron and micron range. Conglomerates and druzes were detected by SEM, ranging in size from 2 µm to 100 µm. The specific optical activity index was calculated αD20 = +36.18 ± 2.04 [°·mL·g⁻¹·dm⁻¹], according to Biot’s Law. Additionally, the orientation and conformation of the dermorphin molecule in the active binding site of the 8E0G receptor were predicted using molecular modeling, revealing that the contact area affects the key amino acid residue arginine (ARG 182). This comprehensive approach to analytical methods for qualitative and quantitative analysis of dermorphin tetrapeptide can be applied in pharmacies to enhance the understanding of its biological activity and aid in the development of regulatory documentation for a new, non-narcotic analgesic based on the dermorphin tetrapeptide. Full article

Background: Cellular and humoral immunity are key to the immune response against SARS-CoV-2, but the comparability and correlation across different assays remain underexplored. This study compares three T-cell and three antibody assays in two vaccine groups. Methods: This prospective longitudinal cohort study involved 46 naïve healthcare workers: a total of 11 in the homologous mRNA-1273 group (three doses) and 35 in the heterologous ChAd group (two ChAd doses followed by a BNT booster). Blood samples were collected at five time points. Cellular immunity was assessed using ELISPOT and two commercial interferon-gamma release assays: (IGRA)-QuantiFERON SARS-CoV-2 (QF) and Covi-FERON ELISA (CoVF). Humoral immunity was evaluated using total and IgG antibody assays and a surrogate virus neutralization test. Results: The mRNA-1273 group exhibited stronger and more consistent responses than the ChAd group. The correlations between ELISPOT and IGRA varied from weak to moderate (ρ = 0.300–0.410), while QF-IGRA and CoVF-IGRA showed stronger correlations (ρ = 0.700–0.737). The ELISPOT assay showed substantial agreement with QF [Ag2]-IGRA (k = 0.697–0.774) and CoVF [O-sp]-IGRA (k = 0.641–0.718), and an 80.4% agreement rate (k = 0.608) was found between the QF [Ag2]- and CoVF [O-sp]-IGRA tests. Three antibody assays demonstrated very strong correlations with each other and substantial to near-perfect agreement with ELISPOT (k = 0.866–0.949), QF [Ag2]-IGRA (k = 0.807–0.831), and CoVF [O-sp]-IGRA (k = 0.753–0.777). Conclusions: SARS-CoV-2-specific cellular and antibody responses vary by platform and vaccine type, highlighting the importance of measuring both T-cell and B-cell responses using multiple assays to comprehensively assess immune status. Full article

As participatory mapping becomes more ingrained into participatory practices, it is vital to understand what makes a method effective. Through the employment of a participatory mapping experiment within an ongoing urban greening initiative, this research aims at validating two established aggregation methods of spatially explicit data points in participatory mapping. Utilizing a paper mapping activity with community residents, the collected spatial data points were analyzed using both democratic and weighted aggregation. Subsequently, a follow-up study was employed to validate the perceived feeling of ownership among both of the methods in terms of the stakeholders’ sense of community representation within the visual outputs. This research introduces a novel approach to the evaluation of participatory mapping practices. A key finding includes the development of a comprehensive methodological model that explores various aspects of a participatory process. Additionally, a new criterion was presented, stakeholder representation, in which to evaluate effectiveness. The difference between the methods was not found to be significant, as the mapping results revealed a consistent overlap in the areas of interest across the stakeholder groups, suggesting a general public consensus on the local development priorities. These insights hold considerable value for local decisions makers, as agreement areas provide a stable foundation for planning. Lastly, this research contributes to the ongoing efforts to evaluate and standardize participatory mapping methods, while also addressing the potential of varied aggregation methods to enhance effectiveness. Full article

A Fresnel mirror is introduced at a hollow-core photonic bandgap fiber end by fusion splicing a short single-mode fiber segment, to reflect the light backward to an optical frequency domain reflectometry. The backward Fresnel reflection is used as a probe light to achieve light speed measurement with a high resolution and a high signal-to-noise ratio. Thus, its group velocity is obtained with the round-trip time delay as well as the beat frequency at the reflection peak. Multiple Fresnel peaks are observed from 2180.00 Hz to 13,988.75 Hz, corresponding to fusion-spliced hollow-core fiber segments with different lengths from 0.2595 m to 1.6678 m, respectively. The speed of light in the air guidance is calculated at 2.9753 × 10⁸ m/s, approaching that in vacuum, which is also in good agreement with 2.9672 × 10⁸ m/s given by the numerical analysis with an uncertainty of 10⁻³. Our demonstration promises a key to hollow-core waveguide characterization for future wide-bandwidth and low-latency optical communication. Full article

While kinship care is prevalent and preferred over out-of-family care, there are relatively few measurement tools validated for use with this audience. The Title IV-E Clearinghouse, used to rate Families First Prevention Services such as Kinship Navigator Programs, requires valid tools. Such families face a myriad of needs in supporting children in their care. Previous research has established the significant challenges faced by rural families. Accurate assessment of these needs, particularly for rural families, is an essential component of kinship navigation services. In this study, we examined the face validity of the Family Needs Scale for use with kinship caregivers in rural programs. Methods: The evaluation teams with each respective kinship program conducted four virtual focus groups comprising kinship caregivers (n = 18) in three rural states. Participants were recruited from outside an ongoing Kinship Navigator Program Evaluation sample but had previously received program support as kinship caregivers. All states received IRB approval from their respective universities. Verbal consent was obtained at the time of the focus group. Focus groups lasted approximately 60–90 min and participants received a gift card incentive. Data were transcribed and qualitatively coded by question set and individual questions to identify phenomenological trends. Findings: Across four focus groups, we found four themes: (1) Broad agreement regarding the face validity of most assessment items; (2) Lack of clarity and shared understanding of several terms used within the tool, (3) Responses change with Ages and Stages of kinship family, and (4) Perspective considerations varying when completing the assessment. Discussion: Findings indicate that most assessment items had strong face validity, where there are a few opportunities to clarify key concepts relevant to rural kinship families and assess additional needs to understand the situational scope of the kinship experience. Overall, the needs assessment tool appears to have validity in assessing current kinship needs and outcomes within Kinship Navigator program evaluation. Full article

We present an active attack that targets Ateniese et al.’s authenticated group key agreement, which, as a particular case, includes the well-known multiparty key exchange protocol CLIQUES that allows a group of users to build a common secret using some private values in a collaborative and distributed way, naturally extending the foundational key exchange introduced by Diffie and Hellman between two communicating parties that motivated the birth of public key cryptography. Ateniese et al.’s protocol adds some authentication information, allowing the parties to trust the exchanged information, but we show that it is possible to surpass this as well. The attack allows a malicious party to agree on a secret with the rest of the legal members of the group without their knowledge, so all the distributed information can be accessed using this secret. In addition, this is shown under a well-known cryptographic model that, in principle, requires absolute control of group communications, but, in fact, it only requires malicious control of the communications of a single arbitrary user and only for the duration of the key exchange. This means that after the attack, the malicious party does not have to take any other actions that could reveal a clue that an attack occurred and that the distributed information is being illegally accessed, contrary to a typical man-in-the-middle attack where the attacker has to continue the activity, meaning this could be detected at some point. Full article

The increasing adoption of batteries in a variety of applications has highlighted the necessity of accurate parameter identification and effective modeling, especially for lithium-ion batteries, which are preferred due to their high power and energy densities. This paper proposes a comprehensive framework using the Levenberg–Marquardt algorithm (LMA) for validating and identifying lithium-ion battery model parameters to improve the accuracy of state of charge (SOC) estimations, using only discharging measurements in the N-order Thevenin equivalent circuit model, thereby increasing computational efficiency. The framework encompasses two key stages: model parameter identification and model verification. This framework is validated using experimental measurements on the INR 18650-20R battery, produced by Samsung SDI Co., Ltd. (Suwon, Republic of Korea), conducted by the Center for Advanced Life Cycle Engineering (CALCE) battery group at the University of Maryland. The proposed framework demonstrates robustness and accuracy. The results indicate that optimization using only the discharging data suffices for accurate parameter estimation. In addition, it demonstrates excellent agreement with the experimental measurements. The research underscores the effectiveness of the proposed framework in enhancing SOC estimation accuracy, thus contributing significantly to the reliable performance and longevity of lithium-ion batteries in practical applications. Full article

Notwithstanding the legal milestones observed in the Portuguese child protection system (CPS), several concerns call for political action to ensure the effective guarantee of children’s rights. In this context, it is imperative to discuss proposals for reforming the CPS. Agreement on these proposals by the stakeholders in the system is key to validating and improving the system. Therefore, the main research questions of the present study are (1) what is the level of agreement among stakeholders in the CPS on certain proposals for child protection reform? and (2) what are the positions on those proposals? Mixed methods were conducted based on an online survey (n = 292), supported by Qualtrics, and eight focus groups involving stakeholders as former beneficiaries, families, practitioners and academics (n = 18). Findings show a harmonious alignment with the proposals, justifying an urgent reform of the CPS and the need to strengthen a child-centred system. Three themes emerged: promotion of quality family-based care and promotion of adoption; development of child-friendly terminology; and improvement of the CPS administration. The conclusions highlight implications for policy and practice. Full article

In edge–cloud collaboration scenarios, data sharing is a critical technological tool, yet smart devices encounter significant challenges in ensuring data-sharing security. Attribute-based keyword search (ABKS) is employed in these contexts to facilitate fine-grained access control over shared data, allowing only users with the necessary privileges to retrieve keywords. The implementation of secure data sharing is threatened since most of the current ABKS protocols cannot resist keyword guessing attacks (KGAs), which can be launched by an untrusted cloud server and result in the exposure of sensitive personal information. Using attribute-based encryption (ABE) as the foundation, we build a secure data exchange paradigm that resists KGAs in this work. In our paper, we provide a secure data-sharing framework that resists KGAs and uses ABE as the foundation to achieve fine-grained access control to resources in the ciphertext. To avoid malicious guessing of keywords by the cloud server, the edge layer computes two encryption session keys based on group key agreement (GKA) technology, which are used to re-encrypt the data user’s secret key of the keyword index and keyword trapdoor. The model is implemented using the JPBC library. According to the security analysis, the model can resist KGAs in the random oracle model. The model’s performance examination demonstrates its feasibility and lightweight nature, its large computing advantages, and lower storage consumption. Full article

The interface mechanical performance between aluminum alloy and timber is the key to ensure that the two work together. In this study, 11 group connection performance tests were carried out to investigate the influence of connection type (shear bolt connection, epoxy resin adhesive connection, and mixed connection), number and spacing of bolts, thickness, and length (the area of incidence of the adhesive in the structure) of epoxy resin adhesive on the interface shear-resistant capacity of aluminum–timber composite connections. The shear performance of the three kinds of connections were studied via finite element analysis, and the calculation formula for interface shear-resistant capacity of the aluminum–timber composite connection was proposed based on the bond-slip mechanism of adhesive. The analysis results indicate that the mixed connection can avoid the brittle failure characteristics of the shear bolt connection and the epoxy resin adhesive connection, and the shear-resistant capacity is increased by 45.6% and 14.7%, respectively. The results of the calculation formula for interface shear-resistant capacity are in good agreement with the experimental results, indicating that it is suitable for the aluminum–timber composite connection. Full article

Several pain scoring systems have been validated to measure pain in dogs. However, pain may not be adequately assessed since these tools are associated with high-level inter-observer variation. The aim of this study is to evaluate the agreement of pain assessment using the CMPS-SF between veterinary students, veterinary nurses, veterinary surgeons, and European College of Veterinary Anaesthesia and Analgesia (ECVAA) diplomates. Forty-five client-owned dogs presented to a teaching hospital were enrolled in this prospective, observational study. All dogs were pain-scored in vivo, while a video of the assessment was recorded and subsequently evaluated by twenty assessors, with five per group. Mean scores between groups were compared, and agreement within groups and agreement of the average scores between groups were assessed by calculating the intraclass correlation coefficient (ICC). The intervention point at which dogs were deemed to require additional analgesia was also evaluated. Overall agreement of pain assessment was poor (ICC = 0.494). Nurses had the best inter-observer agreement (ICC = 0.656), followed by ECVAA diplomates (ICC = 0.540), veterinary surgeons (ICC = 0.478), and veterinary students (ICC = 0.432). The best inter-group agreement was between veterinary surgeons and nurses (ICC = 0.951) and between ECVAA diplomates and nurses (ICC = 0.951). Students were more likely to determine that additional analgesia was required compared to other groups. Pain assessment is key for animal welfare, and training in this area should be reinforced to improve consistency. Full article

This article studies some algebraic structures known as twisted-skew group rings in the context of public key cryptography. We first present some background related to these structures to then specifically introduce particular twisted-skew group rings and show how to utilize them as the underlying algebraic structure to build cryptographic protocols. We closely follow an incremental-like methodology to construct these protocols by putting parts together. As as result, we first introduce a key-agreement protocol and then generalize it to a group key-agreement protocol. We then proceed to construct a probabilistic public key encryption from our two-party key agreement and, finally, introduce a key-encapsulation mechanism from a well-known generic construction applied to probabilistic public encryption. Furthermore, we provide an in-depth security analysis for each cryptographic construction under new related algebraic assumptions and supply a proof-of-concept implementation for various candidate chosen groups. Full article

An important feature of Nyberg-Rueppel type digital signature algorithms is message recovery, this signature algorithm can recover the original information from the signature directly by the verifier in the verification phase after signing the message. However, this algorithm is currently vulnerable to quantum attacks and its security cannot be guaranteed. Number Theory Research Unit (NTRU) is an efficient public-key cryptosystem and is considered to be one of the best quantum-resistant encryption schemes. This paper proposes an NTRU-like message recoverable signature algorithm to meet the key agreement requirements in the post-quantum world. This algorithm, designed for the Internet of Things (IoT), constructs a secure system using the Group-Based Message Recoverable Signature Algorithm (NR-GTRU), by integrating a Group-Based NTRU-Like Public-Key Cryptosystem (GTRU) with an efficient Nyberg-Rueppel type of NTRU digital signature algorithm (NR-NTRU). This signature algorithm, resistant to quantum algorithm attacks, offers higher security at the cost of a slight efficiency reduction compared to traditional NTRU signature algorithms, and features Nyberg-Rueppel message recovery, making it well-suited for IoT applications. Full article

This study investigates the clustering patterns of human β-secretase 1 (BACE-1) inhibitors using complex network methodologies based on various distance functions, including Euclidean, Tanimoto, Hamming, and Levenshtein distances. Molecular descriptor vectors such as molecular mass, Merck Molecular Force Field (MMFF) energy, Crippen partition coefficient (ClogP), Crippen molar refractivity (MR), eccentricity, Kappa indices, Synthetic Accessibility Score, Topological Polar Surface Area (TPSA), and 2D/3D autocorrelation entropies are employed to capture the diverse properties of these inhibitors. The Euclidean distance network demonstrates the most reliable clustering results, with strong agreement metrics and minimal information loss, indicating its robustness in capturing essential structural and physicochemical properties. Tanimoto and Hamming distance networks yield valuable clustering outcomes, albeit with moderate performance, while the Levenshtein distance network shows significant discrepancies. The analysis of eigenvector centrality across different networks identifies key inhibitors acting as hubs, which are likely critical in biochemical pathways. Community detection results highlight distinct clustering patterns, with well-defined communities providing insights into the functional and structural groupings of BACE-1 inhibitors. The study also conducts non-parametric tests, revealing significant differences in molecular descriptors, validating the clustering methodology. Despite its limitations, including reliance on specific descriptors and computational complexity, this study offers a comprehensive framework for understanding molecular interactions and guiding therapeutic interventions. Future research could integrate additional descriptors, advanced machine learning techniques, and dynamic network analysis to enhance clustering accuracy and applicability. Full article