bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Characterization of a Mckibben Pneumatic Muscle Prototype with an Embedded Capacitive Length Transducer
Authors: Antonelli Michele Gabrio , Beomonte Zobel Pierluigi , De Marcellis Andrea , Palange Elia
Published: December 2022

The McKibben muscle types are pneumatic actuators known to be intrinsically safe for their high power-to-weight ratio. For these reasons, they are suitable for robotic, biomechanical, and medical applications. In these application fields and, above all, in collaborative robotics, where safety must be ensured for human–robot interactions, the values of pressure, force, and length are necessary and must be continuously monitored and controlled. Force and pressure transducers are commercially available to be integrated into a McKibben muscle type. On the contrary, no commercial-length transducers can be adopted. This work presents a novel McKibben muscle prototype with an embedded capacitive-length transducer. The latter is a cylindrical capacitor made of a telescopic system composed of two tubes: one of its ends is connected to the muscle. A change in the length of the muscle causes a proportional change in the transducer capacitance. The paper reports in detail on the working principle of McKibben’s muscle, its fabrication, characterization, and validation of four prototype capacitive transducers. The results achieved from the experimental activities demonstrate that it is possible to control the variations of the muscle length relative to its elongation and compression for values less than 1 mm. This is the consequence of the ability to measure the transducer capacitance with a typical statistical relative indetermination better than 0.25%, which is a figure of merit for the reliability and mechanical and electrical stability of the proposed McKibben muscle prototype. Moreover, it has been demonstrated that the transducer capacitance as a function of the muscle length is linear, with maximum deviations from linearity equal to 2.44% and 5.22% during the muscle elongation and compression, respectively.
The Heavy-Tailed Gleser Model: Properties, Estimation, and Applications
Authors: Olmos Neveka M. , Gómez-Déniz Emilio , Venegas Osvaldo
Published: December 2022

In actuarial statistics, distributions with heavy tails are of great interest to actuaries, as they represent a better description of risk exposure through a type of indicator with a certain probability. These risk indicators are used to determine companies’ exposure to a particular risk. In this paper, we present a distribution with heavy right tail, studying its properties and the behaviour of the tail. We estimate the parameters using the maximum likelihood method and evaluate the performance of these estimators using Monte Carlo. We analyse one set of simulated data and another set of real data, showing that the distribution studied can be used to model income data.
Convolution Based Graph Representation Learning from the Perspective of High Order Node Similarities
Authors: Li Xing , Li Qingsong , Wei Wei , Zheng Zhiming
Published: December 2022

Nowadays, graph representation learning methods, in particular graph neural network methods, have attracted great attention and performed well in many downstream tasks. However, most graph neural network methods have a single perspective since they start from the edges (or adjacency matrix) of graphs, ignoring the mesoscopic structure (high-order local structure). In this paper, we introduce HS-GCN (High-order Node Similarity Graph Convolutional Network), which can mine the potential structural features of graphs from different perspectives by combining multiple high-order node similarity methods. We analyze HS-GCN theoretically and show that it is a generalization of the convolution-based graph neural network methods from different normalization perspectives. A series of experiments have shown that by combining high-order node similarities, our method can capture and utilize the high-order structural information of the graph more effectively, resulting in better results.
A Comparison of Several AI Techniques for Authorship Attribution on Romanian Texts
Authors: Avram Sanda-Maria , Oltean Mihai
Published: December 2022

Determining the author of a text is a difficult task. Here, we compare multiple Artificial Intelligence techniques for classifying literary texts written by multiple authors by taking into account a limited number of speech parts (prepositions, adverbs, and conjunctions). We also introduce a new dataset composed of texts written in the Romanian language on which we have run the algorithms. The compared methods are artificial neural networks, multi-expression programming, k-nearest neighbour, support vector machines, and decision trees with C5.0. Numerical experiments show, first of all, that the problem is difficult, but some algorithms are able to generate acceptable error rates on the test set.
Randomized Average Kaczmarz Algorithm for Tensor Linear Systems
Authors: Bao Wendi , Zhang Feiyu , Li Weiguo , Wang Qin , Gao Ying
Published: December 2022

For solving tensor linear systems under the tensor–tensor t-product, we propose the randomized average Kaczmarz (TRAK) algorithm, the randomized average Kaczmarz algorithm with random sampling (TRAKS), and their Fourier version, which can be effectively implemented in a distributed environment. We analyzed the relationships (of the updated formulas) between the original algorithms and their Fourier versions in detail and prove that these new algorithms can converge to the unique least F-norm solution of the consistent tensor linear systems. Extensive numerical experiments show that they significantly outperform the tensor-randomized Kaczmarz (TRK) algorithm in terms of both iteration counts and computing times and have potential in real-world data, such as video data, CT data, etc.
New Applications of Perov’s Fixed Point Theorem
Authors: Mureşan Sorin , Iambor Loredana Florentina , Bazighifan Omar
Published: December 2022

The goal of this paper is to consider a differential equation system written as an interesting equivalent form that has not been used before. Using Perov’s fixed point theorem in generalized metric spaces, the existence and uniqueness of the solution are obtained for the proposed system. The approximation of the solution is given, and as a novelty, the approximation of its derivative is also obtained using the same iteration steps.
Deep Learning Activation Layer-Based Wall Quality Recognition Using Conv2D ResNet Exponential Transfer Learning Model
Authors: Kim Bubryur , Natarajan Yuvaraj , Munisamy Shyamala Devi , Rajendran Aruna , Sri Preethaa K. R. , Lee Dong-Eun , Wadhwa Gitanjali
Published: December 2022

Crack detection is essential for observing structural health and guaranteeing structural safety. The manual crack and other damage detection process is time-consuming and subject to surveyors’ biased judgments. The proposed Conv2D ResNet Exponential model for wall quality detection was trained with 5000 wall images, including various imperfections such as cracks, holes, efflorescence, damp patches, and spalls. The model was trained with initial weights to form the trained layers of the base model and was integrated with Xception, VGG19, DenseNet, and ResNet convolutional neural network (CNN) models to retrieve the general high-level features. A transfer deep-learning-based approach was implemented to create a custom layer of CNN models. The base model was combined with custom layers to estimate wall quality. Xception, VGG19, DenseNet, and ResNet models were fitted with different activation layers such as softplus, softsign, tanh, selu, elu, and exponential, along with transfer learning. The performance of Conv2D was evaluated using model loss, precision, accuracy, recall, and F-score measures. The model was validated by comparing the performances of Xception, VGG19, DenseNet, ResNet, and Conv2D ResNet Exponential. The experimental results show that the Conv2D ResNet model with an exponential activation layer outperforms it with an F-score value of 0.9978 and can potentially be a viable substitute for classifying various wall defects.
LDA-CNN: Linear Discriminant Analysis Convolution Neural Network for Periocular Recognition in the Wild
Authors: Alahmadi Amani , Hussain Muhammad , Aboalsamh Hatim
Published: December 2022

Due to the COVID-19 pandemic, the necessity for a contactless biometric system able to recognize masked faces drew attention to the periocular region as a valuable biometric trait. However, periocular recognition remains challenging for deployments in the wild or in unconstrained environments where images are captured under non-ideal conditions with large variations in illumination, occlusion, pose, and resolution. These variations increase within-class variability and between-class similarity, which degrades the discriminative power of the features extracted from the periocular trait. Despite the remarkable success of convolutional neural network (CNN) training, CNN requires a huge volume of data, which is not available for periocular recognition. In addition, the focus is on reducing the loss between the actual class and the predicted class but not on learning the discriminative features. To address these problems, in this paper we used a pre-trained CNN model as a backbone and introduced an effective deep CNN periocular recognition model, called linear discriminant analysis CNN (LDA-CNN), where an LDA layer was incorporated after the last convolution layer of the backbone model. The LDA layer enforced the model to learn features so that the within-class variation was small, and the between-class separation was large. Finally, a new fully connected (FC) layer with softmax activation was added after the LDA layer, and it was fine-tuned in an end-to-end manner. Our proposed model was extensively evaluated using the following four benchmark unconstrained periocular datasets: UFPR, UBIRIS.v2, VISOB, and UBIPr. The experimental results indicated that LDA-CNN outperformed the state-of-the-art methods for periocular recognition in unconstrained environments. To interpret the performance, we visualized the discriminative power of the features extracted from different layers of the LDA-CNN model using the t-distributed Stochastic Neighboring Embedding (t-SNE) visualization technique. Moreover, we conducted cross-condition experiments (cross-light, cross-sensor, cross-eye, cross-pose, and cross-database) that proved the ability of the proposed model to generalize well to different unconstrained conditions.
Cryptanalysis of Two Recent Ultra-Lightweight Authentication Protocols
Authors: Servati Mohammad Reza , Safkhani Masoumeh , Ali Saqib , Malik Mazhar Hussain , Ahmed Omed Hassan , Hosseinzadeh Mehdi , Mosavi Amir H.
Published: December 2022

Radio Frequency Identification (RFID) technology is a critical part of many Internet of Things (IoT) systems, including Medical IoT (MIoT) for instance. On the other hand, the IoT devices’ numerous limitations (such as memory space, computing capability, and battery capacity) make it difficult to implement cost- and energy-efficient security solutions. As a result, several researchers attempted to address this problem, and several RFID-based security mechanisms for the MIoT and other constrained environments were proposed. In this vein, Wang et al. and Shariq et al. recently proposed CRUSAP and ESRAS ultra-lightweight authentication schemes. They demonstrated, both formally and informally, that their schemes meet the required security properties for RFID systems. In their proposed protocols, they have used a very lightweight operation called Cro(·) and Rank(·), respectively. However, in this paper, we show that those functions are not secure enough to provide the desired security. We show that Cro(·) is linear and reversible, and it is easy to obtain the secret values used in its calculation. Then, by exploiting the vulnerability of the Cro(·) function, we demonstrated that CRUSAP is vulnerable to secret disclosure attacks. The proposed attack has a success probability of "1" and is as simple as a CRUSAP protocol run. Other security attacks are obviously possible by obtaining the secret values of the tag and reader. In addition, we present a de-synchronization attack on the CRUSAP protocol. Furthermore, we provide a thorough examination of ESRAS and its Rank(·) function. We first present a de-synchronization attack that works for any desired Rank(·) function, including Shariq et al.’s proposed Rank(·) function. We also show that Rank(·) does not provide the desired confusion and diffusion that is claimed by the designers. Finally, we conduct a secret disclosure attack against ESRAS.
Important Arguments Nomination Based on Fuzzy Labeling for Recognizing Plagiarized Semantic Text
Authors: Osman Ahmed Hamza , Aljahdali Hani Moaiteq
Published: December 2022

Plagiarism is an act of intellectual high treason that damages the whole scholarly endeavor. Many attempts have been undertaken in recent years to identify text document plagiarism. The effectiveness of researchers’ suggested strategies to identify plagiarized sections needs to be enhanced, particularly when semantic analysis is involved. The Internet’s easy access to and copying of text content is one factor contributing to the growth of plagiarism. The present paper relates generally to text plagiarism detection. It relates more particularly to a method and system for semantic text plagiarism detection based on conceptual matching using semantic role labeling and a fuzzy inference system. We provide an important arguments nomination technique based on the fuzzy labeling method for identifying plagiarized semantic text. The suggested method matches text by assigning a value to each phrase within a sentence semantically. Semantic role labeling has several benefits for constructing semantic arguments for each phrase. The approach proposes nominating for each argument produced by the fuzzy logic to choose key arguments. It has been determined that not all textual arguments affect text plagiarism. The proposed fuzzy labeling method can only choose the most significant arguments, and the results were utilized to calculate similarity. According to the results, the suggested technique outperforms other current plagiarism detection algorithms in terms of recall, precision, and F-measure with the PAN-PC and CS11 human datasets.
Cosmetic Application of Cyanobacteria Extracts with a Sustainable Vision to Skincare: Role in the Antioxidant and Antiaging Process
Authors: Morone Janaína , Lopes Graciliana , Morais João , Neves Jorge , Vasconcelos Vítor , Martins Rosário
Published: December 2022

Nature-based and sustainably sourced cosmetics have been dominating the area of skincare products worldwide. Due to their antioxidant and antiaging properties, compounds from cyanobacteria, such as carotenoids and phycobiliproteins, may replace synthetic ingredients in cosmetic formulations and may be used in products such as sunscreens, skincare creams, and makeup. In this study, we evaluated the potential of acetonic and aqueous extracts from cyanobacteria strains of the genera Cyanobium and Leptothoe and from strains within Synechococcales and Oscillatoriales orders, for use in cosmetics. Extractions were sequentially performed with acetone and water. Extracts were firstly analyzed for their toxicity to keratinocytes, fibroblasts, and endothelial cells (HaCAT, 3T3L1 and hCMEC/D3, respectively). The non-cytotoxic extracts were characterized in terms of total proteins, carotenoids, chlorophyll, phenols, phycobiliproteins, and analyzed for their antioxidant potential against the superoxide anion radical (O2•−), and for their ability to inhibit key enzymes associated with the skin aging process. Aqueous extracts were richer in total proteins and phycobiliproteins. The aqueous extracts of Synechococcales cyanobacterium LEGE 181157 and Synechococcales cyanobacterium LEGE 181150 showed the highest value for total proteins (760.81 and 695.25 μg BSA mL−1dry extract, respectively) and the best values regarding O2•− scavenging (IC50 = 63.24 and 112.18 μg mL−1dry extract, respectively) with a significant negative correlation observed (p < 0.01). Moreover, aqueous extracts of Synechococcales cyanobacterium LEGE 181150 and Synechococcales cyanobacterium LEGE 181157 inhibited hyaluronidase, (IC50 of 483.86 and 645.06 μg mL−1dry extract, respectively), with a significant negative correlation with total proteins (p < 0.05), pointing out the contribution of these compounds to the biological activities observed. Acetonic extracts were richer in carotenoids and phenols. Zeaxanthin and β-carotene were predominant among all strains, being present in higher amount in Cyanobium sp. LEGE 07175 (53.08 μg mg−1) and Leptothoe sp. LEGE 181156 (47.89 μg mg−1), respectively. The same strains also showed the highest values for collagenase inhibition at 750 μg mL−1dry extract (32.88 and 36.61%, respectively). Furthermore, Leptothoe sp. LEGE 181156 exhibited the lowest IC50 value for tyrosinase inhibition (465.92 μg mL−1dry extract) and Synechococcales cyanobacterium LEGE 181157 presented the best values for elastase inhibition (IC50 of 380.50 and IC25 of 51.43 μg mL−1dry extract). In general, cyanobacteria extracts demonstrated potential for being used for antiaging purposes, with aqueous extracts being more efficient at free radicals scavenging and acetonic ones at avoiding degradation of dermal matrix components.
Suboccipital Muscles, Forward Head Posture, and Cervicogenic Dizziness
Authors: Sung Yun-Hee
Published: December 2022

Dizziness or vertigo can be caused by dysfunction of the vestibular or non-vestibular systems. The diagnosis, treatment, and mechanism of dizziness or vertigo caused by vestibular dysfunction have been described in detail. However, dizziness by the non-vestibular system, especially cervicogenic dizziness, is not well known. This paper explained the cervicogenic dizziness caused by abnormal sensory input with references to several studies. Among head and neck muscles, suboccipital muscles act as stabilizers and controllers of the head. Structural and functional changes of the suboccipital muscles can induce dizziness. Especially, myodural bridges and activation of trigger point stimulated by abnormal head posture may be associated with cervicogenic dizziness.
Microstructure and Mechanical Properties of Novel Heat Resistant Cast Al-Cu-Yb(Gd)-Mg-Mn-Zr Alloys
Authors: Mamzurina Olga I. , Amer Sayed M. , Glavatskikh Maria V. , Barkov Ruslan Yu. , Loginova Irina S. , Pozdniakov Andrey V.
Published: December 2022

The present study focused on the development of the novel heat resistant cast Al-Cu-Yb(Gd)-Mg-Mn-Zr alloys based on the prevue investigations. Microstructures and mechanical properties were investigated by optical, scanning and transmission electron microscopy, hardness measurements, and tensile and creep tests at room and elevated temperatures. Ytterbium in combination with Zr and Ti provide greater Al grain refining than gadolinium. The L12-Al3(Zr,Yb) or L12-Al3(Zr,Gd) and Al20Cu2Mn3 phase precipitates were nucleated during solution treatment. The average sizes of L12-Al3(Zr,Yb) and L12-Al3(Zr,Gd) are 28 ± 6 nm and 32 ± 4 nm, respectively. Al20Cu2Mn3 phase precipitates formed with a more coarse size of 100–200 nm. The highest hardening effect was achieved after 3 h of aging at 210 °C in both alloys due to S’(Al2CuMg) precipitates. The ultimate tensile strengths (UTS) of the AlCuYbMg and AlCuGdMg alloys at room temperature are 338 and 299 MPa, respectively. The UTS decreases to 220–272 MPa when increasing the temperature of the tensile test to 200–250 °C. The rupture stress at 250 °C for 100 h under stress is 111–113 MPa. The contribution from different structure parts in the yield strength was calculated. The main strengthening effects of 54–60 MPa and 138–153 MPa were achieved from L12 and S’ precipitates, respectively. The calculated values of yield strength (YS) are consistent with the experimental data. Novel AlCuYbMg and AlCuGdMg alloys are a potential option for castings for high temperature application.
Multiple Glass Transitions in Bismuth and Tin beyond Melting Temperatures
Authors: Tournier Robert
Published: December 2022

Liquid-liquid transitions were discovered above the melting temperature (Tm) in Bi and Sn up to 2 Tm, viewed as glass transitions at Tg = Tn+ > Tm of composites nucleated at Tx < Tm and fully melted at Tn+. A glassy fraction (f) disappeared at 784 K in Sn. (Tn+) increases with singular values of (f) depending on Tx with (f) attaining 100% at Tg = Tn+ = 2 Tm. The nonclassical model of homogeneous nucleation is used to predict Tx, Tn+ and the specific heat. The singular values of (f) leading to (Tn+) correspond to percolation thresholds of configurons in glassy phases. A phase diagram of glassy fractions occurring in molten elements is proposed. The same value of (Tx) can lead to multiple (Tg). Values of (Tg = Tn+) can be higher than (2 Tm) for Tx/Tm < 0.7069. A specific heat equal to zero is predicted after cooling from T ≤ 2 Tm and would correspond to a glassy phase. Weak glassy fractions are nucleated near (Tn+) after full melting at (Tm) without transition at (Tx). Resistivity decreases were observed after thermal cycling between solid and liquid states with weak and successive values of (f) due to Tx/Tm < 0.7069.
Structure Design of Polymer-Based Films for Passive Daytime Radiative Cooling
Authors: Du Mu , Huang Maoquan , Yu Xiyu , Ren Xingjie , Sun Qie
Published: December 2022

Passive daytime radiative cooling (PDRC), a cooling method that needs no additional energy, has become increasingly popular in recent years. The combination of disordered media and polymeric photonics will hopefully lead to the large-scale fabrication of high-performance PDRC devices. This work aims to study two typical PDRC structures, the randomly distributed silica particle (RDSP) structure and the porous structure, and systematically investigates the effects of structural parameters (diameter D, volume fraction fv, and thickness t) on the radiative properties of the common plastic materials. Through the assistance of the metal-reflective layer, the daytime cooling power Pnet of the RDSP structures is slightly higher than that of the porous structures. Without the metal-reflective layer, the porous PC films can still achieve good PDRC performance with Pnet of 86 W/m2. Furthermore, the effective thermal conductivity of different structures was evaluated. The single-layer porous structure with optimally designed architecture can achieve both good optical and insulating performance, and it is the structure with the most potential in PDRC applications. The results can provide guidelines for designing high-performance radiative cooling films.
An Intelligent Logic-Based Mold Breakout Prediction System Algorithm for the Continuous Casting Process of Steel: A Novel Study
Authors: Ansari Md Obaidullah , Ghose Joyjeet , Chattopadhyaya Somnath , Ghosh Debasree , Sharma Shubham , Sharma Prashant , Kumar Abhinav , Li Changhe , Singh Rajesh , Eldin Sayed M.
Published: December 2022

Mold breakout is one of the significant problems in a continuous casting machine (caster). It represents one of the key areas within the steel production facilities of a steel plant. A breakout event on a caster will always cause safety hazards, high repair costs, loss of production, and shutdown of the caster for a short while. In this paper, a logic-judgment-based mold breakout prediction system has been developed for a continuous casting machine. This system developed new algorithms to detect the different sticker behaviors. With more algorithms running, each algorithm is more specialized in the other behaviors of stickers. This new logic-based breakout prediction system (BOPS) not only detects sticker breakouts but also detects breakouts that takes place due to variations in casting speed, mold level fluctuation, and taper/mold problems. This system also finds the exact location of the breakout in the mold and reduces the number of false alarms. The task of the system is to recognize a sticker and prevent a breakout. Moreover, the breakout prediction system uses an online thermal map of the mold for process visualization and assisting breakout prediction. This is done by alerting the operating staff or automatically reducing the cast speed according to the location of alarmed thermocouples, the type of steel, the tundish temperature, and the size of the cold slab width. By applying the proposed model in an actual steel plant, field application results show that it could timely detect all 13 breakouts with a detection ratio of 100%, and the frequency of false alarms was less than 0.056% times/heat. It has the additional advantage of not needing a lot of learning data, as most neural networks do. Thus, this new logical BOPS system should not only detect the sticker breakouts but also detect breakouts taking place due to variations in casting speed and mold level fluctuation.
Deep Eutectic Solvents as à-la-Carte Medium for Transition-Metal-Catalyzed Organic Processes
Authors: Marset Xavier , Guillena Gabriela
Published: December 2022

Our society is facing a tremendous challenge to become more sustainable in every sphere of life. Regarding the chemical industry, one of the most significant issues to be addressed is the use of volatile organic compounds (VOCs) as solvents because they are petrol-derived and most of them are toxic and flammable. Among the possible solutions, deep eutectic solvents (DESs) have emerged as sustainable alternatives to VOCs in organic catalyzed transformations and other fields. The advantages of these new reaction media are not only related to their more benign physical and chemical properties and, for most of them, their renewable sources but also due to the possibility of being recycled after their use, increasing the sustainability of the catalyzed process in which they are involved. However, their use as media in catalytic transformations introduces new challenges regarding the compatibility and activity of known catalysts. Therefore, designed catalysts and “à-la-carte” DESs systems have been developed to overcome this problem, to maximize the reaction outcomes and to allow the recyclability of the catalyst/media system. Over the last decade, the popularity of these solvents has steadily increased, with several examples of efficient metal-catalyzed organic transformations, showing the efficiency of the catalysts/DES system, compared to the related transformations carried out in VOCs. Additionally, due to the inherent properties of the DES, unknown transformations can be carried out using the appropriated catalyst/DES system. All these examples of sustainable catalytic processes are compiled in this review.
Fluorinated and Non-Fluorinated 1,4-Diarylpyrazoles via MnO2-Mediated Mechanochemical Deacylative Oxidation of 5-Acylpyrazolines
Authors: Utecht-Jarzyńska Greta , Kowalczyk Anna , Jasiński Marcin
Published: December 2022

A solvent-free two-step synthesis of polyfunctionalized pyrazoles under ball-milling mechanochemical conditions was developed. The protocol comprises (3 + 2)-cycloaddition of in situ generated nitrile imines and chalcones, followed by oxidation of the initially formed 5-acylpyrazolines with activated MnO2. The second step proceeds via an exclusive deacylative pathway, to give a series of 1,4-diarylpyrazoles functionalized with a fluorinated (CF3) or non-fluorinated (Ph, COOEt, Ac) substituent at C(3) of the heterocyclic ring. In contrast, MnO2-mediated oxidation of a model isomeric 4-acylpyrazoline proceeded with low chemoselectivity, leading to fully substituted pyrazole as a major product formed via dehydrogenative aromatization. The presented approach extends the scope of the known methods carried out in organic solvents and enables the preparation of polyfunctionalized pyrazoles, which are of general interest in medicine and material sciences.
Biological Investigation and Chemical Study of Brassica villosa subsp. drepanensis (Brassicaeae) Leaves
Authors: Malfa Giuseppe Antonio , De Leo Marinella , Tundis Rosa , Braca Alessandra , Loizzo Monica Rosa , Di Giacomo Claudia , Raimondo Francesco Maria , Bucchini Anahi Elena Ada , Acquaviva Rosaria
Published: December 2022

Brassica villosa subsp. drepanensis (Caruel) Raimondo & Mazzola, belonging to the Brassica oleracea complex, is a wild edible plant endemic to western Sicily and a relative of modern cultivated Brassica crops. In this study, the antioxidant properties, anti-inflammatory activities, enzymatic inhibition, and cytotoxicity in cancer cells of B. villosa subsp. drepanensis leaf ethanolic extract were analysed for the first time. In addition, its chemical profile was investigated partitioning the total 70% ethanol extract among ethyl acetate, n-butanol, and water to obtain three residues that were subjected to chromatographic separation. Two flavonol glycosides, a phenol glucoside, two amino acids, and purine/pyrimidine bases were obtained. The presence of the glucosinolate glucoiberin was detected in the water extract by UHPLC-MS analysis. The total polyphenol and flavonoid content of the 70% ethanol extract showed good antioxidant capacities and anti-inflammatory properties by reducing nitric oxide release and reactive oxygen species levels and increasing glutathione in lipopolysaccharide-stimulated RAW 264.7 cells. The extract inhibited the enzymatic activity of α-amylase, α-glucosidase, and, significantly, of lipase. The MTT assay showed that the extract did not affect the viability of normal HFF-1 and RAW 264.7 cells. Among the cancer cell lines tested, an antiproliferative action was only observed in CaCo-2. The cytotoxicity of the extract was further confirmed by LDH release assay and by the destabilization of the oxidative balance. Results confirmed the antioxidant properties of the crude extract responsible for the anti-inflammatory effect on healthy cells and cytotoxicity in cancer cells.
Tetrel Bonding in Anion Recognition: A First Principles Investigation
Authors: Varadwaj Pradeep R.
Published: December 2022

Twenty-five molecule–anion complex systems [I4Tt···X−] (Tt = C, Si, Ge, Sn and Pb; X = F, Cl, Br, I and At) were examined using density functional theory (ωB97X-D) and ab initio (MP2 and CCSD) methods to demonstrate the ability of the tetrel atoms in molecular entities, I4Tt, to recognize the halide anions when in close proximity. The tetrel bond strength for the [I4C···X−] series and [I4Tt···X−] (Tt = Si, Sn; X = I, At), was weak-to-moderate, whereas that in the remaining 16 complexes was dative tetrel bond type with very large interaction energies and short Tt···X close contact distances. The basis set superposition error corrected interaction energies calculated with the highest-level theory applied, [CCSD(T)/def2-TZVPPD], ranged from −3.0 to −112.2 kcal mol−1. The significant variation in interaction energies was realized as a result of different levels of tetrel bonding environment between the interacting partners at the equilibrium geometries of the complex systems. Although the ωB97X-D computed intermolecular geometries and interaction energies of a majority of the [I4Tt···X−] complexes were close to those predicted by the highest level of theory, the MP2 results were shown to be misleading for some of these systems. To provide insight into the nature of the intermolecular chemical bonding environment in the 25 molecule–anion complexes investigated, we discussed the charge-density-based topological and isosurface features that emanated from the application of the quantum theory of atoms in molecules and independent gradient model approaches, respectively.
Identification of Novel Antifungal Skeleton of Hydroxyethyl Naphthalimides with Synergistic Potential for Chemical and Dynamic Treatments
Authors: Zhang Pengli , Tangadanchu Vijai Kumar Reddy , Zhou Chenghe
Published: December 2022

The invasion of pathogenic fungi poses nonnegligible threats to the human health and agricultural industry. This work exploited a family of hydroxyethyl naphthalimides as novel antifungal species with synergistic potential of chemical and dynamic treatment to combat the fungal resistance. These prepared naphthalimides showed better antifungal potency than fluconazole towards some tested fungi including Aspergillus fumigatus, Candida tropicalis and Candida parapsilosis 22019. Especially, thioether benzimidazole derivative 7f with excellent anti-Candida tropicalis efficacy (MIC = 4 μg/mL) possessed low cytotoxicity, safe hemolysis level and less susceptibility to induce resistance. Biochemical interactions displayed that 7f could form a supramolecular complex with DNA to block DNA replication, and constitute a biosupermolecule with cytochrome P450 reductase (CPR) from Candida tropicalis to hinder CPR biological function. Additionally, 7f presented strong lipase affinity, which facilitated its permeation into cell membrane. Moreover, 7f with dynamic antifungal potency promoted the production and accumulation of reactive oxygen species (ROS) in cells, which destroyed the antioxidant defence system, led to oxidative stress with lipid peroxidation, loss of glutathione, membrane dysfunction and metabolic inactivation, and eventually caused cell death. The chemical and dynamic antifungal synergistic effect initiated by hydroxyethyl naphthalimides was a reasonable treatment window for prospective development.
Ligandless Palladium-Catalyzed Direct C-5 Arylation of Azoles Promoted by Benzoic Acid in Anisole
Authors: Rosadoni Elisabetta , Banchini Federico , Bellini Sara , Lessi Marco , Pasquinelli Luca , Bellina Fabio
Published: December 2022

The palladium-catalyzed direct arylation of azoles with (hetero)aryl halides is nowadays one of the most versatile and efficient procedures for the selective synthesis of heterobiaryls. Although this procedure is, due to its characteristics, also of great interest in the industrial field, the wide use of a reaction medium such as DMF or DMA, two polar aprotic solvents coded as dangerous according to environmental, health, safety (EHS) parameters, strongly limits its actual use. In contrast, the use of aromatic solvents as the reaction medium for direct arylations, although some of them show good EHS values, is poorly reported, probably due to their low solvent power against reagents and their potential involvement in undesired side reactions. In this paper we report an unprecedented selective C-5 arylation procedure involving anisole as an EHS green reaction solvent. In addition, the beneficial role of benzoic acid as an additive was also highlighted, a role that had never been previously described.
In vitro Antitumor Properties of Fucoidan-Coated, Doxorubicin-Loaded, Mesoporous Polydopamine Nanoparticles
Authors: Xu Hongping , Ling Junhong , Zhao Han , Xu Xinyi , Ouyang Xiao-kun , Song Xiaoyong
Published: December 2022

Chemotherapy is a common method for tumor treatment. However, the non-specific distribution of chemotherapeutic drugs causes the death of normal cells. Nanocarriers, particularly mesoporous carriers, can be modified to achieve targeted and controlled drug release. In this study, mesoporous polydopamine (MPDA) was used as a carrier for the antitumor drug doxorubicin (DOX). To enhance the release efficiency of DOX in the tumor microenvironment, which contains high concentrations of glutathione (GSH), we used N,N-bis(acryloyl)cysteamine as a cross-linking agent to encapsulate the surface of MPDA with fucoidan (FU), producing MPDA-DOX@FU-SS. MPDA-DOX@FU-SS was characterized via transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy (XPS), and its antitumor efficacy in vitro was investigated. The optimal conditions for the preparation of MPDA were identified as pH 12 and 20 °C, and the optimal MPDA-to-FU ratio was 2:1. The DOX release rate reached 47.77% in an in vitro solution containing 10 mM GSH at pH 5.2. When combined with photothermal therapy, MPDA-DOX@FU-SS significantly inhibited the growth of HCT-116 cells. In conclusion, MPDA-DOX@FU-SS may serve as a novel, highly effective tumor suppressor that can achieve targeted drug release in the tumor microenvironment.
Green and Efficient Construction of Chromeno[3,4-c]pyrrole Core via Barton–Zard Reaction from 3-Nitro-2H-chromenes and Ethyl Isocyanoacetate
Authors: Kochnev Ivan A. , Barkov Alexey Y. , Zimnitskiy Nikolay S. , Korotaev Vladislav Y. , Sosnovskikh Vyacheslav Y.
Published: December 2022

A regioselective one-pot method for the synthesis of 1-ethyl 2,4-dihydrochromene[3,4-c]pyrroles in 63–94% yields from available 2-phenyl-, 2-trifluoro(trichloro)methyl- or 2-phenyl-2-(trifluoromethyl)-3-nitro-2H-chromenes and ethyl isocyanoacetate through the Barton–Zard reaction in ethanol at reflux for 0.5 h, using K2CO3 as a base, has been developed.
Selection of Enzymatic Treatments for Upcycling Lentil Hulls into Ingredients Rich in Oligosaccharides and Free Phenolics
Authors: Bautista-Expósito Sara , Vandenberg Albert , Dueñas Montserrat , Peñas Elena , Frias Juana , Martínez-Villaluenga Cristina
Published: December 2022

In this study, the comprehensive chemical characterization of red lentil hulls obtained from the industrial production of football and split lentils was described. The lentil hulls were rich in dietary fiber (78.43 g/100 g dry weight with an insoluble to soluble fiber ratio of 4:1) and polyphenols (49.3 mg GAE/g dry weight, of which 55% was bound phenolics), which revealed the suitability of this lentil by-product as a source of bioactive compounds with recognized antioxidant and prebiotic properties. The release of oligosaccharides and phenolic compounds was accomplished by enzymatic hydrolysis, microwave treatment and a combination of both technologies. The key role played by the selection of a suitable enzymatic preparation was highlighted to maximize the yield of bioactive compounds and the functional properties of the lentil hull hydrolysates. Out of seven commercial preparations, the one with the most potential for use in a commercial context was Pectinex® Ultra Tropical, which produced the highest yields of oligosaccharides (14 g/100 g lentil hull weight) and free phenolics (45.5 mg GAE/100 g lentil hull weight) and delivered a four-fold increase in terms of the original antioxidant activity. Finally, this enzyme was selected to analyze the effect of a microwave-assisted extraction pretreatment on the yield of enzymatic hydrolysis and the content of free phenolic compounds and oligosaccharides. The integrated microwave and enzymatic hydrolysis method, although it increased the solubilization yield of the lentil hulls (from 25% to 34%), it slightly decreased the content of oligosaccharides and proanthocyanidins and reduced the antioxidant activity. Therefore, the enzymatic hydrolysis treatment alone was more suitable for producing a lentil hull hydrolysate enriched in potential prebiotics and antioxidant compounds.
The Use of Aryl-Substituted Homophthalic Anhydrides in the Castagnoli–Cushman Reaction Provides Access to Novel Tetrahydroisoquinolone Carboxylic Acid Bearing an All-Carbon Quaternary Stereogenic Center
Authors: Moshnenko Nazar , Kazantsev Alexander , Bakulina Olga , Dar’in Dmitry , Krasavin Mikhail
Published: December 2022

Novel aryl-substituted homophthalic acids were cyclodehydrated to the respective homophthalic anhydrides for use in the Castagnoli–Cushman reaction. With a range of imines, this reaction proceeded smoothly and delivered hitherto undescribed 4-aryl-substituted tetrahydroisoquinolonic acids with remarkable diastereoselectivity, good yields and no need for chromatographic purification. These findings significantly extend the range of cyclic anhydrides employable in the Castagnoli–Cushman reaction and signify access to a novel substitution pattern around the medicinally relevant tetrahydroisoquinolonic acid scaffold.
Exploring the Optoelectronic Properties of D-A and A-D-A 2,2′-bi[3,2-b]thienothiophene Derivatives
Authors: Gabrian Levi , Giurgi Gavril-Ionel , Stroia Ioan , Bogdan Elena , Crişan Andreea Petronela , Hădade Niculina Daniela , Grosu Ion , Terec Anamaria
Published: December 2022

The synthesis of some novel donor-acceptor and acceptor-donor-acceptor systems containing a 2,2′-bi[3,2-b]thienothiophene donor block and various electron-accepting units is described alongside their photophysical properties studied using electrochemistry, optical spectroscopy and theoretical calculations. The obtained results show that the energy levels can be modulated by changing the strength of the acceptor unit. Among the three investigated end-groups, 1,1-dicyanomethylene-3-indanone exhibited the largest bathochromic shift and the lowest band gap suggesting the strongest electron-withdrawing character. Moreover, the emissive properties of the investigated systems vary greatly with the nature of the terminal group and are generally lower compared to their precursor aldehyde derivatives.
A Comparative Study of Cellulose Ethers as Thermotropic Materials for Self-Tracking Solar Concentrators
Authors: Galeotti Francesco , Scatena Lorenzo , Trespidi Franco , Pasini Mariacecilia
Published: December 2022

The continuous growth in energy demand requires researchers to find new solutions to enlarge and diversify the possible ways of exploiting renewable energy sources. Our idea is the development of a solar concentrator based on trapping the luminous radiation with a smart window. This system is able to direct light towards the photovoltaic cells placed on window borders and produce electricity, without any movable part and without changing its transparency. Herein, we report a detailed study of cellulose ethers, a class of materials of natural origin capable of changing their state, from transparent aqueous solution to scattering hydrogel, in response to a temperature change. Cellulose thermotropism can be used to produce a scattering spot in a window filled with the thermotropic fluid to create a new kind of self-tracking solar concentrator. We demonstrate that the properties of the thermotropic fluid can be finely tuned by selecting the cellulose functionalization, the co-dissolved salt, and by regulating their dosage. Lastly, the results of our investigation are tested in a proof-of-concept demonstration of solar concentration achieved by thermotropism-based light trapping.
Fused Pyrroles in Cholestane and Norcholestane Side Chains: Acaricidal and Plant Growth-Promoting Effects
Authors: De los Santos María G. , Cua-Basulto Marcos , Huepalcalco Anallely , Delit Wendy , Sandoval-Ramírez Jesús , López-Torres Adolfo , Ruiz-Sánchez Esaú , Fernández-Herrera María A.
Published: December 2022

Herein, we describe the synthesis and characterization of fused pyrroles in cholestane and norcholestane side chains derived from kryptogenin and diosgenin, respectively. Both conventional and microwave heating techniques were used to synthesize the steroidal pyrroles from primary amines, with the microwave method producing the highest yields. In particular, the norcholestane pyrroles were tested as acaricides against the two-spotted spider mite (Tetranychus urticae Koch) under laboratory conditions and as plant growth promoters on habanero pepper (Capsicum chinense Jacq) under greenhouse conditions.
Synthesis of 1,5-Substituted Pyrrolidin-2-ones from Donor–Acceptor Cyclopropanes and Anilines/Benzylamines
Authors: Boichenko Maksim A. , Plodukhin Andrey Yu. , Shorokhov Vitaly V. , Lebedev Danyla S. , Filippova Anastasya V. , Zhokhov Sergey S. , Tarasenko Elena A. , Rybakov Victor B. , Trushkov Igor V. , Ivanova Olga A.
Published: December 2022

We developed a straightforward synthetic route to pharmacologically important 1,5-substituted pyrrolidin-2-ones from donor–acceptor cyclopropanes bearing an ester group as one of the acceptor substituents. This method includes a Lewis acid-catalyzed opening of the donor–acceptor cyclopropane with primary amines (anilines, benzylamines, etc.) to γ-amino esters, followed by in situ lactamization and dealkoxycarbonylation. The reaction has a broad scope of applicability; a variety of substituted anilines, benzylamines, and other primary amines as well as a wide range of donor–acceptor cyclopropanes bearing (hetero)aromatic or alkenyl donor groups and various acceptor substituents can be involved in this transformation. In this process, donor–acceptor cyclopropanes react as 1,4-C,C-dielectrophiles, and amines react as 1,1-dinucleophiles. The resulting di- and trisubstituted pyrrolidin-2-ones can be also used in subsequent chemistry to obtain various nitrogen-containing polycyclic compounds of interest to medicinal chemistry and pharmacology, such as benz[g]indolizidine derivatives.
Influence of Block Ratio on Thermal, Optical, and Photovoltaic Properties of Poly(3-hexylthiophene)-b-poly(3-butylthiophene)-b-poly(3-octylthiophene)
Authors: Nguyen Van Hai , Nguyen Thanh Danh , Song Jongwoo , An Jongdeok , Im Chan
Published: December 2022

Efforts to improve the solar power conversion efficiencies of binary bulk heterojunction-type organic photovoltaic devices using an active layer consisting of a poly-(3-alkylthiophene) (P3AT) homopolymer and a suitable fullerene derivative face barriers caused by the intrinsic properties of homopolymers. To overcome such barriers, researchers might be able to chemically tailor homopolymers by means of monomer ratio-balanced block copolymerization to obtain preferable properties. Triblock copolymers consisting of three components—3-hexylthiophene (HT), 3-butylthiophene (BT), and 3-octylthiophene (OT)—were synthesized via Grignard metathesis (GRIM) polymerization. The component ratios of the synthesized block copolymers were virtually the same as the feeding ratios of the monomers, a fact which was verified using 1H-NMR spectra. All the copolymers exhibited comparable crystalline and melting temperatures, which increased when one type of monomer became dominant. In addition, their power conversion efficiencies and photoluminescence properties were governed by the major components of the copolymers. Interestingly, the HT component-dominated block copolymer indicated the highest power conversion efficiency, comparable to that of its homopolymer, although its molecular weight was significantly shorter.
Enantioselective Recognition of Lysine and Phenylalanine Using an Imidazole Salt-Type Fluorescent Probe Based on H8-BINOL
Authors: Wei Zhaoqin , Tang Shi , Sun Xiaoxia , Hu Yu
Published: December 2022

An imidazole bromide fluorescent probe (R)-1 based on chiral H8-BINOL was synthesized with a high yield; it was found to have good enantioselective recognition of lysine and phenylalanine using fluorescence analysis. When L-lysine was recognized, the enantioselective fluorescence enhancement ratio was 2.7 (ef = IL − I0/ID − I0, ef = 2.7, 20 eq Lys); as the amount of L-Lys increased, a distinct red shift was observed (the wavelength varied by 55.6 nm, 0–100 eq L-Lys), whereas D-Lys had a minimal red shift. The generation of this red shift phenomenon was probably due to the ICT effect; the probe’s intramolecular charge transfer was affected after (R)-1 bound to L-Lys, and this charge transfer was enhanced, leading to a red shift in fluorescence. In addition to the enantioselective recognition of lysine, phenylalanine was also recognized; the enantioselective fluorescence enhancement ratio was 5.1 (ef = IL − I0/ID − I0, ef = 5.1, 20 eq Phe).