bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Optical Saturable Absorption Properties of 2D VP Nanosheets and Application as SA in a Passively Q-Switched Nd:YVO4 Laser
Authors: Guo Haowen , Jia Chunyan , Yao Yongping , Bai Meng , Ma Tiejun , Zhang Jiayu , Xia Jinbao , Nie Hongkun , Yao Bo , He Jingliang , Zhang Baitao
Published: May 2024

Two-dimensional (2D) violet phosphorus (VP) plays a significant role in the applications of photonic and optoelectronic devices due to its unique optical and electrical properties. The ultrafast carrier dynamics and nonlinear optical absorption properties were systematically investigated here. The intra- and inter-band ultrafast relaxation times of 2D VP nanosheets were measured to be ~6.83 ps and ~62.91 ps using the pump–probe method with a probe laser operating at 1.03 μm. The nonlinear absorption coefficient βeff, the saturation intensity Is, the modulation depth ΔR, and the nonsaturable loss were determined to be −2.18 × 104 cm/MW, 329 kW/cm2, 6.3%, and 9.8%, respectively, by using the Z-scan and I-scan methods, indicating the tremendous saturable absorption property of 2D VP nanosheets. Furthermore, the passively Q-switched Nd:YVO4 laser was realized with the 2D VP nanosheet-based SA, in which the average output power of 700 mW and the pulse duration of 478 ns were obtained. These results effectively reveal the nonlinear optical absorption characteristics of VP nanosheets, demonstrating their outstanding light-manipulating capabilities and providing a basis for the applications of ultrafast optical devices. Our results verify the excellent saturable absorption properties of 2D VP, paving the way for its applications in pulsed laser generation.
Effect of Si3N4 Additive on Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Cutting Tools
Authors: Elgazzar Ali , Zhou Sheng-Jian , Ouyang Jia-Hu , Peng Zi-Jian , Yao Jun-Teng , Liu Zhan-Guo , Wang Yu-Jin , Wang Ya-Ming
Published: May 2024

Development of high-performance cutting tool materials is one of the critical parameters enhancing the surface finishing of high-speed machined products. Ti(C,N)-based cermets reinforced with and without different contents of silicon nitride were designed and evaluated to satisfy the requirements. In fact, the effect of silicon nitride addition to Ti(C,N)-based cermet remains unclear. The purpose of this study is to investigate the influence of Si3N4 additive on microstructure, mechanical properties, and thermal stability of Ti(C,N)-based cermet cutting tools. In the present work, α-Si3N4 “grade SN-E10” was utilized with various fractions up to 6 wt.% in the designed cermets. A two-step reactive sintering process under vacuum was carried out for the green compact of Ti(C,N)-based cermet samples. The samples with 4 wt.% Si3N4 have an apparent solid density of about 6.75 g/cm3 (relative density of about 98 %); however, the cermet samples with 2 wt.% Si3N4 exhibit a superior fracture toughness of 10.82 MPa.m1/2 and a traverse rupture strength of 1425.8 MPa. With an increase in the contents of Si3N4, the Vickers hardness and fracture toughness of Ti(C,N)-based cermets have an inverse behavior trend. The influence of Si3N4 addition on thermal stability is clarified to better understand the relationship between thermal stability and mechanical properties of Ti(C,N)-based cermets.
Fe(Se,Te) Thin Films Deposited through Pulsed Laser Ablation from Spark Plasma Sintered Targets
Authors: Iebole Michela , Braccini Valeria , Bernini Cristina , Malagoli Andrea , Manca Nicola , Martinelli Alberto , Cialone Matteo , Putti Marina , Singh Shiv J. , Latronico Giovanna , Mele Paolo
Published: May 2024

Iron-based superconductors are under study for their potential for high-field applications due to their excellent superconducting properties such as low structural anisotropy, large upper critical fields and low field dependence of the critical current density. Between them, Fe(Se,Te) is simple to be synthesized and can be fabricated as a coated conductor through laser ablation on simple metallic templates. In order to make all the steps simple and fast, we have applied the spark plasma sintering technique to synthesize bulk Fe(Se,Te) to obtain quite dense polycrystals in a very short time. The resulting polycrystals are very well connected and show excellent superconducting properties, with a critical temperature onset of about 16 K. In addition, when used as targets for pulsed laser ablation, good thin films are obtained with a critical current density above 105 A cm−2 up to 16 T.
Experimental and Numerical Simulation of Reinforced Concrete-Filled Square GFRP Tubular Columns under Axial Compression
Authors: Jing Chenggui , Zhao Lin , Wu Tong , Li Weizhao
Published: May 2024

To investigate the axial compressive behavior of reinforced concrete-filled square glass-fiber-reinforced polymer(GFRP) tubular (RCFSGT) columns, 17 specimens were designed with variations in GFRP tube wall thickness, spiral reinforcement yield strength, and spiral reinforcement ratio. A detailed model was developed using the finite element software ABAQUS, enabling in-depth mechanistic analysis and expanded parameter studies. The results indicate that the failure types of the specimens are all manifested as GFRP square tube cracking, and the core concrete is subjected to crushing or shear failure. The inclusion of a reinforcement cage can significantly enhance the load-bearing capacity and ductility of the specimen. Furthermore, as the yield strength and reinforcement ratio of the spiral reinforcement increase, so does the load-bearing capacity of the specimen. The finite element simulation results align well with the experimental findings. As the wall thickness of the GFRP square tube increases from 2 mm to 6 mm, the load-bearing capacity improves by approximately 19.69%. With the yield strength of the spiral reinforcement rising from 200 MPa to 400 MPa, the specimen’s load-bearing capacity shows an increase of approximately 7.55%. However, as its yield strength continues to increase, there is minimal change in the load-bearing capacity. When the stirrup ratio of spiral reinforcement rises from 0.33% to 2.26%, the specimen’s load-bearing capacity experiences an increase of approximately 56.90%.
Cutting Efficiency of Diamond Grinders on Composite and Zirconia
Authors: Rosentritt Martin , Strasser Thomas , Mueller Maerit-Martha , Schmidt Michael Benno
Published: May 2024

This in vitro study was carried out to compare the cutting efficiency of diamond grinders on zirconia and resin-based composite materials. Grinders were employed with a special holder for the handpiece to apply a constant load (160 g) for resin-based composite (8 cuts, 40 s each) and zirconia materials (4 cuts, 5 min each; n = 10 for each material and grinder). To assess the efficiency of the grinders, weight measurements of the material were taken before and after the grinding process. Scanning electron micrographs were captured for instrument surfaces before and after testing and for the resulting surface of the materials. In the resin-based composite group, there were significant differences in weight removal between the burs for both the baseline (first cut; p = 0.009) and removal after the eighth cut (p = 0.049). Statistically significant decreases in weight removal compared to the baseline values were noted for the third, fourth, sixth, and seventh steps (p ≤ 0.046). For the zirconia group, significant differences existed in weight removal between the burs for the baseline (first cut; p < 0.001) and removal after the fourth cut (p < 0.001). A significant positive correlation was observed between removal and the number of cuts (Pearson: 0.673; p < 0.001). A statistically significant decrease in removal compared to the respective baseline value was found for the fourth step (p = 0.006). The initial wear removal and durability significantly differed between the grinders used on resin-based composite and zirconia. Achieving comparable weight removal took five times longer when grinding zirconia compared to the resin-based composite.
Enhancing Tribological Performance of Self-Lubricating Composite via Hybrid 3D Printing and In Situ Spraying
Authors: Ralls Alessandro M. , Monette Zachary , Kasar Ashish K. , Menezes Pradeep L.
Published: May 2024

In this work, a self-lubricating composite was manufactured using a novel hybrid 3D printing/in situ spraying process that involved the printing of an acrylonitrile butadiene styrene (ABS) matrix using fused deposition modeling (FDM), along with the in situ spraying of alumina (Al2O3) and hexagonal boron nitride (hBN) reinforcements during 3D printing. The results revealed that the addition of the reinforcement induced an extensive formation of micropores throughout the ABS structure. Under tensile-loading conditions, the mechanical strength and cohesive interlayer bonding of the composites were diminished due to the presence of these micropores. However, under tribological conditions, the presence of the Al2O3 and hBN reinforcement improved the frictional resistance of ABS in extreme loading conditions. This improvement in frictional resistance was attributed to the ability of the Al2O3 reinforcement to support the external tribo-load and the shearing-like ability of hBN reinforcement during sliding. Collectively, this work provides novel insights into the possibility of designing tribologically robust ABS components through the addition of in situ-sprayed ceramic and solid-lubricant reinforcements.
Multi-Force Bio-Active™ Archwires and Various Contemporary NiTi Multi-Force Archwires: Properties and Characteristics—A Review
Authors: Stoyanova-Ivanova Angelina , Petrov Valeri , Martins Jorge N. R. , Andreeva Laura , Georgiev Velizar
Published: May 2024

The manufacturing of orthodontic archwires made from NiTi alloy has undergone numerous changes from the second half of the last century to modern times. Initially, superelastic-active austenitic NiTi alloys were predominant, followed by thermodynamic-active martensitic NiTi alloys, and, finally, the most recent development was graded thermodynamic alloys. These advancements have been the subject of extensive investigation in numerous studies, as they necessitated a deeper understanding of their properties. Furthermore, it is imperative that we validate the information provided by manufacturers regarding these archwires through independent studies. This review evaluates existing studies on the subject with a specific focus on the Bio-active multi-force NiTi archwire, by examining its mechanical, thermal, and physicochemical properties before and after clinical use. This archwire consists primarily of Ni and Ti, with traces of Fe and Cr, which release graduated, biologically tolerable forces which increase in a front-to-back direction and are affected by the temperature of the environment they are in. The review provides information to practicing orthodontists, facilitating informed decisions regarding the selection and use of Bio-active™ archwires for individual patient treatments.
Multi-Faceted Analysis of Phase-Change Composite Intended for Autonomous Buildings
Authors: Musiał Michał , Lichołai Lech
Published: May 2024

This paper presents the long-term, holistic results of research into an innovative heat accumulator based on an organic phase-change material in the form of a mixture of aliphatic alkanes, molecular silica sieves, carbon recyclate and epoxy and cement matrices. The research included chemical testing of vacuum soaking of molecular silica sieves with a liquid phase-change material. The results proved an improvement in the heat storage efficiency of the heat accumulators due to the addition of carbon recyclate by 28%, while increasing the heat storage time by 134 min, and a reduction in PCM leakage due to the use of molecular silica sieves. In addition to its cognitive scientific value, another research objective of the work achieved was to obtain response functions in the form of approximating polynomials. They provide a useful, validated and verified tool to predict the physical and chemical characteristics of heat accumulators with different contents of individual components. As part of the ongoing research, technical problems related to leak-proofing assurance and matrix selection for organic phase-change materials were also solved. The solution presented is in line with the issues of efficient use of renewable energy, low-carbon and energy-efficient circular economy.
Deep Desulfurization of High-Sulfur Petroleum Coke via Alkali Catalytic Roasting Combined with Ultrasonic Oxidation
Authors: Luo Pen , Chen Zhengjie , Chen Xiuhua , Ma Wenhui
Published: May 2024

The sulfur in petroleum coke is harmful to carbon products, underscoring the importance of desulfurization for high-sulfur petroleum coke. This paper proposes a method combining alkaline catalytic roasting with ultrasonic oxidation for the deep desulfurization of high-sulfur petroleum coke. The results show that the desulfurization rate reaches 88.99% and the sulfur content is reduced to 0.83 wt.% under a coke particle size of 96–75 μm, sodium-hydroxide-to-petroleum-coke ratio of 50%, roasting temperature of 700 °C, and holding time of 2 h. The alkali-calcined petroleum coke is ultrasonically oxidized and desulfurized in peracetic acid. The results show that, under a hydrogen peroxide content of 10%, hydrogen-peroxide-(liquid)-to-petroleum-coke (solid) ratio of 20 mL/g, acetic acid content of 5 mL, ultrasonic power of 300 W, reaction temperature of 60 °C, and reaction duration of 4 h, the sulfur content is reduced to 0.15 wt.% and the total desulfurization reaches 98.01%. Through a series of characterizations, the proposed desulfurization mechanism is verified. Alkali roasting effectively removes a significant portion of sulfur in petroleum coke. However, the elimination of certain sulfur compounds, such as the more complex thiophene, presents challenges. The thiophene content is subsequently removed via ultrasonic oxidation.
Adaptive Iterative Learning Constrained Control for Linear Motor-Driven Gantry Stage with Fault-Tolerant Non-Repetitive Trajectory Tracking
Authors: Yu Chaohai
Published: May 2024

This article introduces an adaptive fault-tolerant control method for non-repetitive trajectory tracking of linear motor-driven gantry platforms under state constraints. It provides a comprehensive solution to real-world issues involving state constraints and actuator failures in gantry platforms, alleviating the challenges associated with precise modeling. Through the integration of iterative learning and backstepping cooperative design, this method achieves system stability without requiring a priori knowledge of system dynamic models or parameters. Leveraging a barrier composite energy function, the proposed controller can effectively regulate the stability of the controlled system, even when operating under state constraints. Instability issues caused by actuator failures are properly addressed, thereby enhancing controller robustness. The design of a trajectory correction function further extends applicability. Experimental validation on a linear motor-driven gantry platform serves as empirical evidence of the effectiveness of the proposed method.
Using Rotations to Control Observable Relativistic Effects
Authors: Brezov Danail
Published: May 2024

This paper examines the possibility of controlling the outcome of measured (flat space-time) relativistic effects, such as time dilation or length contractions, using pure rotations and their nontrivial interactions with Lorentz boosts in the isometry group SO+(3,1). In particular, boost contributions may annihilate leaving only a geometric phase (Wigner rotation), which we see in the complex solutions of the generalized Euler decomposition problem in R3. We consider numerical examples involving specific matrix factorizations, along with possible applications in special relativity, electrodynamics and quantum scattering. For clearer interpretation and simplified calculations we use a convenient projective biquaternion parametrization which emphasizes the geometric phases and for a large class of problems allows for closed-form solutions in terms of only rational functions.
A Stock Index Futures Price Prediction Approach Based on the MULTI-GARCH-LSTM Mixed Model
Authors: Pan Haojun , Tang Yuxiang , Wang Guoqiang
Published: May 2024

As a type of financial derivative, the price fluctuation of futures is influenced by a multitude of factors, including macroeconomic conditions, policy changes, and market sentiment. The interaction of these factors makes the future trend become complex and difficult to predict. However, for investors, the ability to accurately predict the future trend of stock index futures price is directly related to the correctness of investment decisions and investment returns. Therefore, predicting the stock index futures market remains a leading and critical issue in the field of finance. To improve the accuracy of predicting stock index futures price, this paper introduces an innovative forecasting method by combining the strengths of Long Short-Term Memory (LSTM) networks and various Generalized Autoregressive Conditional Heteroskedasticity (GARCH)-family models namely, MULTI-GARCH-LSTM. This integrated approach is specifically designed to tackle the challenges posed by the nonstationary and nonlinear characteristics of stock index futures price series. This synergy not only enhances the model’s ability to capture a wide range of market behaviors but also significantly improves the precision of future price predictions, catering to the intricate nature of financial time series data. Initially, we extract insights into the volatility characteristics, such as the aggregation of volatility in futures closing prices, by formulating a model from the GARCH family. Subsequently, the LSTM model decodes the complex nonlinear relationships inherent in the futures price series and incorporates assimilated volatility characteristics to predict future prices. The efficacy of this model is validated by applying it to an authentic dataset of gold futures. The empirical findings demonstrate that the performance of our proposed MULTI-GARCH-LSTM hybrid model consistently surpasses that of the individual models, thereby confirming the model’s effectiveness and superior predictive capability.
Process Capability Evaluation Using Capability Indices as a Part of Statistical Process Control
Authors: Benková Marta , Bednárová Dagmar , Bogdanovská Gabriela
Published: May 2024

This study aims to highlight the importance of a systematic approach to process capability assessment and the importance of following a sequence of steps. Statistical process control provides several different ways of assessing process capability. This study evaluates the process capability of crown cap manufacturing through capability indices. In addition to calculating the indices, the evaluation involves extensive data analysis. Before calculating the capability indices, the assumptions for their correct selection and use were also verified. Several statistical tests were used to verify each assumption. The research value of the study lies in pointing out that not all tests led to the same conclusions. It highlights the importance of selecting the appropriate test type for the evaluated process quality characteristics.
Entry-Wise Eigenvector Analysis and Improved Rates for Topic Modeling on Short Documents
Authors: Ke Zheng Tracy , Wang Jingming
Published: May 2024

Topic modeling is a widely utilized tool in text analysis. We investigate the optimal rate for estimating a topic model. Specifically, we consider a scenario with n documents, a vocabulary of size p, and document lengths at the order N. When N≥c·p, referred to as the long-document case, the optimal rate is established in the literature at p/(Nn). However, when N=o(p), referred to as the short-document case, the optimal rate remains unknown. In this paper, we first provide new entry-wise large-deviation bounds for the empirical singular vectors of a topic model. We then apply these bounds to improve the error rate of a spectral algorithm, Topic-SCORE. Finally, by comparing the improved error rate with the minimax lower bound, we conclude that the optimal rate is still p/(Nn) in the short-document case.
Optimizing Phycocyanin Extraction from Cyanobacterial Biomass: A Comparative Study of Freeze–Thaw Cycling with Various Solvents
Authors: Pispas Konstantinos , Manthos Georgios , Sventzouri Eirini , Geroulia Maria , Mastropetros Savvas Giannis , Ali Sameh Samir , Kornaros Michael
Published: May 2024

Cyanobacterial phycocyanin pigment is widely utilized for its properties in various industries, including food, cosmetics, and pharmaceuticals. Despite its potential, challenges exist, such as extraction methods impacting yield, stability, and purity. This study investigates the impact of the number of freeze–thaw (FT) cycles on the extraction of phycocyanin from the wet biomass of four cyanobacteria species (Arthrospira platensis, Chlorogloeopsis fritschii, Phormidium sp., and Synechocystis sp.), along with the impact of five extraction solutions (Tris-HCl buffer, phosphate buffer, CaCl2, deionized water, and tap water) at various pH values. Synechocystis sp. exhibited the highest phycocyanin content among the studied species. For A. platensis, Tris-HCl buffer yielded maximum phycocyanin concentration from the first FT cycle, while phosphate buffer provided satisfactory results from the second cycle. Similarly, Tris-HCl buffer showed promising results for C. fritschii (68.5% of the maximum from the first cycle), with the highest concentration (~12% w/w) achieved during the seventh cycle, using phosphate buffer. Phormidium sp. yielded the maximum pigment concentration from the first cycle using tap water. Among species-specific optimal extraction solutions, Tris-HCl buffer demonstrated sufficient extraction efficacy for all species, from the first cycle. This study represents an initial step toward establishing a universal extraction method for phycocyanin from diverse cyanobacteria species.
Antiviral Potential of Fucoxanthin, an Edible Carotenoid Purified from Sargassum siliquastrum, against Zika Virus
Authors: Kang Nalae , Kim Eun-A , Park Areumi , Heo Seong-Yeong , Heo Jun-Ho , Heo Soo-Jin
Published: May 2024

Considering the lack of antiviral drugs worldwide, we investigated the antiviral potential of fucoxanthin, an edible carotenoid purified from Sargassum siliquastrum, against zika virus (ZIKV) infection. The antiviral activity of fucoxanthin was assessed in ZIKV-infected Vero E6 cells, and the relevant structural characteristics were confirmed using molecular docking and molecular dynamics (MD) simulation. Fucoxanthin decreased the infectious viral particles and nonstructural protein (NS)1 mRNA expression levels at concentrations of 12.5, 25, and 50 µM in ZIKV-infected cells. Fucoxanthin also decreased the increased mRNA levels of interferon-induced proteins with tetratricopeptide repeat 1 and 2 in ZIKV-infected cells. Molecular docking simulations revealed that fucoxanthin binds to three main ZIKV proteins, including the envelope protein, NS3, and RNA-dependent RNA polymerase (RdRp), with binding energies of −151.449, −303.478, and −290.919 kcal/mol, respectively. The complex of fucoxanthin with RdRp was more stable than RdRp protein alone based on MD simulation. Further, fucoxanthin bonded to the three proteins via repeated formation and disappearance of hydrogen bonds. Overall, fucoxanthin exerts antiviral potential against ZIKV by affecting its three main proteins in a concentration-dependent manner. Thus, fucoxanthin isolated from S. siliquastrum is a potential candidate for treating zika virus infections.
Evaluation of the Biological Activities of Peptides from Epidermal Mucus of Marine Fish Species from Chilean Aquaculture
Authors: Álvarez Claudio A. , Toro-Araneda Teresa , Cumillaf Juan Pablo , Vega Belinda , Tapia María José , Roman Tanya , Cárdenas Constanza , Córdova-Alarcón Valentina , Jara-Gutiérrez Carlos , Santana Paula A. , Guzmán Fanny
Published: May 2024

The skin of fish is a physicochemical barrier that is characterized by being formed by cells that secrete molecules responsible for the first defense against pathogenic organisms. In this study, the biological activity of peptides from mucus of Seriola lalandi and Seriolella violacea were identified and characterized. To this purpose, peptide extraction was carried out from epidermal mucus samples of juveniles of both species, using chromatographic strategies for purification. Then, the peptide extracts were characterized to obtain the amino acid sequence by mass spectrometry. Using bioinformatics tools for predicting antimicrobial and antioxidant activity, 12 peptides were selected that were chemically produced by simultaneous synthesis using the Fmoc-Tbu strategy. The results revealed that the synthetic peptides presented a random coil or extended secondary structure. The analysis of antimicrobial activity allowed it to be discriminated that four peptides, named by their synthesis code 5065, 5069, 5070, and 5076, had the ability to inhibit the growth of Vibrio anguillarum and affected the copepodite stage of C. rogercresseyi. On the other hand, peptides 5066, 5067, 5070, and 5077 had the highest antioxidant capacity. Finally, peptides 5067, 5069, 5070, and 5076 were the most effective for inducing respiratory burst in fish leukocytes. The analysis of association between composition and biological function revealed that the antimicrobial activity depended on the presence of basic and aromatic amino acids, while the presence of cysteine residues increased the antioxidant activity of the peptides. Additionally, it was observed that those peptides that presented the highest antimicrobial capacity were those that also stimulated respiratory burst in leukocytes. This is the first work that demonstrates the presence of functional peptides in the epidermal mucus of Chilean marine fish, which provide different biological properties when the fish face opportunistic pathogens.
Twinning–Detwinning-Dominated Cyclic Deformation Behavior of a High-Strength Mg-Al-Sn-Zn Alloy during Loading Reversals: Experiment and Modeling
Authors: Wang Huai , Yu Yongze , Lv Binjiang , Song Ming , Xie Xuefang
Published: May 2024

The deformation behavior of a high-strength Mg-Al-Sn-Zn alloy under loading reversals has been thoroughly examined through a combination of experimental measurements and crystal plasticity modeling. We focused on an age-treated alloy fortified by distributed Mg2Sn particles and Mg17Al12 precipitates, which underwent two distinct loading cycles: tension-compression-tension (TCT) and compression-tension-compression (CTC), aligned with the extrusion direction (ED). The initial and deformed microstructures of the alloy were analyzed using the electron backscattering diffraction (EBSD) technique. Notably, the alloy displays tensile and compressive yield strengths (YS) of 215 MPa and 160 MPa, respectively, with pronounced anelastic behavior observed during unloading and reverse loading phases. Utilizing the elasto-viscoplastic self-consistent model incorporating a twinning–detwinning scheme (EVPSC-TDT), the cyclic stress–strain responses and resultant textures of the alloy were accurately captured. The predicted alternation between various slip and twinning modes during plastic deformation was used to interpret the observed behaviors. It was found that prismatic  slip plays an important role during the plastic deformation of the studied alloy, and its relative activity in tensile loading processes accounts for up to ~66% and ~67% in the TCT and CTC cases, respectively. Moreover, it was discerned that detwinning and twinning behaviors are predominantly governed by stresses within the parent grain, and they can concurrently manifest during the reverse tensile loading phase in the TCT case. After cyclic deformation, the area fractions of residual twins were determined to be 7.51% and 0.93% in the TCT and CTC cases, respectively, which is a result of the varied twinning–detwinning behavior of the alloy in different loading paths.
Fungal Melanonychia: A Systematic Review
Authors: Rodríguez-Cerdeira Carmen , Martínez-Herrera Erick , Cortés-López Paulina Nundehui , Guzmán-Montijo Estefanía , Sánchez-Cárdenas Carlos Daniel , Arenas Roberto , Fuentes-Venado Claudia Erika , Vega-Sánchez Diana Carolina , Pinto-Almazán Rodolfo ,   Members of Mycology Task Force Group of CILAD
Published: May 2024

Fungal melanonychia is an uncommon condition, most typically caused by opportunistic melanin-producing pigmented filamentous fungi in the nail plate. In the present study, the clinical characteristics of patients diagnosed with fungal melanonychia were analyzed through a systematic review of cases reported in the literature. The MESH terms used for the search were “melanonychia” AND “fungal” OR “fungi” through four databases: PubMed, SciELO, Google scholar and SCOPUS. After discarding inadequate articles using the exclusion criteria, 33 articles with 133 cases were analyzed, of which 44% were women, 56% were men and the age range was between 9 and 87 years. The majority of cases were reported in Turkey followed by Korea and Italy. Frequent causal agents detected were Trichophyton rubrum as non-dematiaceous in 55% and Neoscytalidium dimidiatum as dematiaceous in 8%. Predisposing factors included nail trauma, migration history, employment and/or outdoor activities. Involvement in a single nail was presented in 45% of the cases, while more than one affected nail was identified in 21%, with a range of 2 to 10 nails. Regarding the clinical classification, 41% evidenced more than one type of melanonychia, 21% corresponded to the longitudinal pattern and 13% was of total diffuse type. Likewise, the usual dermoscopic pattern was multicolor pigmentation. It is concluded that fungal melanonychia is an uncommon variant of onychomycosis and the differential diagnosis is broad, which highlights the complexity of this disease.
Chemical Constituents with Anti-Proliferative Activity on Pulmonary Arterial Smooth Muscle Cells from the Roots of Anthriscus sylvestris (L.) Hoffm.
Authors: Liu Yanling , Cao Yangang , Zheng Yajuan , Niu Ying , Chen Lan , Chen Xu , Ma Xinyi , Li Xiangda , Zheng Xiaoke , Feng Weisheng
Published: May 2024

A chemical investigation of Anthriscus sylvestris roots led to the isolation and characterization of two new nitrogen-containing phenylpropanoids (1–2) and two new phenol glycosides (8–9), along with fifteen known analogues. Structure elucidation was based on HRESIMS, 1D and 2D NMR spectroscopy, and electronic circular dichroism (ECD). In addition, compounds 3, 6, 9–10, 12, and 17 exhibited inhibitory effects against the abnormal proliferation of pulmonary arterial smooth muscle cells with IC50 values ranging from 10.7 ± 0.6 to 57.1 ± 1.1 μM.
Effect of Spirulina Nigrita® Supplementation on Indices of Exercise-Induced Muscle Damage after Eccentric Protocol of Upper Limbs in Apparently Healthy Volunteers
Authors: Krokidas Anastasios , Gakis Athanasios G. , Aktypi Ourania , Antonopoulou Smaragdi , Nomikos Tzortzis
Published: May 2024

Spirulina is a supplement with antioxidant and anti-inflammatory properties that may enhance performance and recovery after intense exercise. The present study aimed to investigate the effects of Spirulina Nigrita® on physical performance, and recovery markers after intense eccentric exercise in healthy moderately physically active volunteers. In a double-blind crossover design, participants were supplemented either with spirulina (42 mg Kg−1 BW per day) or a placebo for 15 days before conducting an eccentric exercise protocol using the non-dominant arm. A six-week washout period was required between conditions. Performance and mobility markers such as isometric peak torque (PTQ), ligament range of motion (ROM), and perceived muscle discomfort (VAS) were assessed and blood samples (CK, LDH) were obtained at 1, 24, 48, and 72 h post-exercise. No significant differences were noticed between the two conditions on any of the investigated markers, indicating that spirulina supplementation has no positive effect on isometric muscle performance or alleviation of exercise-induced muscle damage (EIMD) symptoms in the specific population.
Extended Treatment with Micron-Size Oral Palmitoylethanolamide (PEA) in Chronic Pain: A Systematic Review and Meta-Analysis
Authors: Schweiger Vittorio , Schievano Carlo , Martini Alvise , Polati Luca , Del Balzo Giovanna , Simari Salvatore , Milan Beatrice , Finco Gabriele , Varrassi Giustino , Polati Enrico
Published: May 2024

Palmitoylethanolamide (PEA) emerged over the years as a promising approach in the management of chronic pain. Despite the fact that the efficacy of micron-size PEA formulations appears to be time-dependent, the optimal timing has not yet been elucidated. This systematic review and meta-analysis aim to estimate the possible advantage of an extended treatment in the relief of chronic pain. The literature search was conducted consulting scientific databases, to identify clinical trials in which micron-size PEA was administered for at least 60 days, and pain assessed by the Visual Analogue Scale (VAS) or Numeric Rating Scale (NRS). Nine studies matched the required criteria, for a total of 742 patients involved. The meta-analysis showed a statistically and clinically significant pain intensity reduction after 60 days of micron-size PEA supplementation, compared to 30 days (1.36 points, p < 0.01). The secondary analysis revealed a weighted NRS/VAS score decrease of 2.08 points within the first month of treatment. These two obtained scores corresponded to a 35.1% pain intensity reduction within the first month, followed by a further 35.4% during the second month. Overall, these results confirm the clinically relevant and time-depended pain-relieving effect of micron-size PEA and therefore the advantage of an extended treatment, especially in patient with incomplete pain management.
TEOS-10 Equations for Determining the Lifted Condensation Level (LCL) and Climatic Feedback of Marine Clouds
Authors: Feistel Rainer , Hellmuth Olaf
Published: May 2024

At an energy flux imbalance of about 1 W m−2, the ocean stores 90% of the heat accumulating by global warming. However, neither the causes of this nor the responsible geophysical processes are sufficiently well understood. More detailed investigations of the different phenomena contributing to the oceanic energy balance are warranted. Here, the role of low-level marine clouds in the air–sea interaction is analysed. TEOS-10, the International Thermodynamic Equation of State of Seawater—2010, is exploited for a rigorous thermodynamic description of the climatic trends in the lifted condensation level (LCL) of the marine troposphere. Rising sea surface temperature (SST) at a constant relative humidity (RH) is elevating marine clouds, cooling the cloud base, and reducing downward thermal radiation. This LCL feedback effect is negative and counteracts ocean warming. At the current global mean SST of about 292 K, the net radiative heat flux from the ocean surface to the LCL cloud base is estimated to be 24 W m−2. Per degree of SST increase, this net flux is expected to be enhanced by almost 0.5 W m−2. The climatic LCL feedback effect is relevant for the ocean’s energy balance and may be rigorously thermodynamically modelled in terms of TEOS-10 equations. LCL height may serve as a remotely measured, sensitive estimate for the sea surface’s relative fugacity, or conventional relative humidity.
Comparative Efficacy and Safety of Potassium-Competitive Acid Blockers vs. Proton Pump Inhibitors for Peptic Ulcer with or without Helicobacter pylori Infection: A Systematic Review and Network Meta-Analysis
Authors: Ouyang Mengling , Zou Shupeng , Cheng Qian , Shi Xuan , Zhao Yazheng , Sun Minghui
Published: May 2024

Novel potassium-competitive acid blockers (P-CABs) have emerged as effective acid-suppressive drugs in recent years, replacing proton pump inhibitors (PPIs). We aim to compare the efficacy and safety of P-CABs versus PPIs in the treatment of peptic ulcers with or without Helicobacter pylori (H. pylori) infection. We searched in PubMed, Embase, WOS, Cochrane Library, ClinicalTrials.gov, CNKI, and Wanfang databases (all years up to January 2024). Efficacy and safety outcomes were evaluated using odds ratio (OR) and 95% confidence intervals (CI). The Surface Under the Cumulative Ranking (SUCRA) probabilities were used to rank each intervention. Among 14,056 studies screened, 56 studies involving 9792 participants were analyzed. Vonoprazan demonstrated the best efficacy in ulcer healing rate and H. pylori eradication rate (SUCRA = 86.4% and 90.7%, respectively). Keverprazan ranked second in ulcer healing rates (SUCRA = 76.0%) and was more effective in pain remission rates (SUCRA = 91.7%). The risk of adverse events was low for keverprazan (SUCRA = 11.8%) and tegoprazan (SUCRA = 12.9%), and moderate risk for vonoprazan (SUCRA = 44.3%) was demonstrated. Compared to lansoprazole, vonoprazan exhibited a higher risk of drug-related adverse events (OR: 2.15; 95% CI: 1.60–2.89) and serious adverse events (OR: 2.22; 95% CI: 1.11–4.42). Subgroup analysis on patients with H. pylori-positive peptic ulcers showed that vonoprazan was at the top of the SUCRA rankings, followed by keverprazan. Vonoprazan showed superior performance in peptic ulcers, especially for patients with H. pylori-positive peptic ulcers. However, the risk of adverse events associated with vonoprazan should be noted. Keverprazan has also shown good therapeutic outcomes and has performed better in terms of safety.
Exploring the Comprehensive Neuroprotective and Anticancer Potential of Afzelin
Authors: Kciuk Mateusz , Garg Nitika , Dhankhar Sanchit , Saini Monika , Mujwar Somdutt , Devi Sushma , Chauhan Samrat , Singh Thakur Gurjeet , Singh Randhir , Marciniak Beata , Gielecińska Adrianna , Kontek Renata
Published: May 2024

Neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and others) and cancer, seemingly disparate in their etiology and manifestation, exhibit intriguing associations in certain cellular and molecular processes. Both cancer and neurodegenerative diseases involve the deregulation of cellular processes such as apoptosis, proliferation, and DNA repair and pose a significant global health challenge. Afzelin (kaempferol 3-O-rhamnoside) is a flavonoid compound abundant in various plant sources. Afzelin exhibits a diverse range of biological activities, offering promising prospects for the treatment of diseases hallmarked by oxidative stress and deregulation of cell death pathways. Its protective potential against oxidative stress is also promising for alleviating the side effects of chemotherapy. This review explores the potential therapeutic implications of afzelin, including its capacity to mitigate oxidative stress, modulate inflammation, and promote cellular regeneration in neurodegenerative and cancer diseases.
Patterns of Genetic Variation of Nepeta nuda L. from the Central Balkans: Understanding Drivers of Chemical Diversity
Authors: Petrović Luka , Skorić Marijana , Šiler Branislav , Banjanac Tijana , Gašić Uroš , Matekalo Dragana , Lukić Tamara , Nestorović Živković Jasmina , Dmitrović Slavica , Aničić Neda , Milutinović Milica , Božunović Jelena , Filipović Biljana , Todorović Miloš , Mišić Danijela
Published: May 2024

Nepeta nuda L., a notable medicinal species in the tradition of the Balkan region, is a rich source of bioactive iridoids and phenolics previously described as high-resolution taxonomical classifiers for the genus Nepeta. However, their potential in investigating intra-species differentiation is here described for the first time. The aim was to recognize the sources of natural chemical diversity and their association with the genetic variability both within and among N. nuda populations in the Central Balkans. Chemical diversity was assessed from methanol extracts and essential oils through untargeted and targeted metabolomics using state-of-the-art analytical tools, covering a broad spectrum of compounds that represent the N. nuda metabolome. We found that chemodiversity primarily resides within populations of N. nuda, and similar results were obtained at the DNA level using microsatellite markers. The low genetic and chemical differentiation of the studied N. nuda populations implies that their metabolomic profiles may be less influenced by geographic distance and variable environmental conditions within the Central Balkans, as they are under the pivotal control of their genetic backgrounds. Screening the distribution of the major bioactive compounds belonging to phenolics (phenolic acids and flavonoids) and iridoids (both aglycones and glycosylated forms), within and among N. nuda populations, is able to guarantee mass spectrometry-based tools for the selection of elite representative genotypes with practical importance. The knowledge acquired will allow us to delve deeper into the molecular background of N. nuda chemical diversity, which is the course of our further work.
Genetic Differentiation and Relationship among Castanopsis chinensis, C. qiongbeiensis, and C. glabrifolia (Fagaceae) as Revealed by Nuclear SSR Markers
Authors: Wu Yang , Yang Kai , Wen Xiangying , Sun Ye
Published: May 2024

Castanopsis chinensis (Spreng.) Hance is widespread in the subtropical forests of China. Castanopsis qiongbeiensis G.A. Fu and Castanopsis glabrifolia J. Q. Li & Li Chen are limited to the coastal beaches of Wenchang county in the northeast of Hainan Island, and have similar morphological characteristics to C. chinensis. It is supposed that C. qiongbeiensis and C. glabrifolia are closely related to C. chinensis. In the present study, the genetic differentiation, gene flow, and genetic relationship of C. chinensis, C. qiongbeiensis, and C. glabrifolia were investigated by using 15 nuclear microsatellite markers; a total of 308 individuals from 17 populations were sampled in the three species. The allelic variation of nuclear microsatellites revealed moderate but significant genetic differentiation (FCT = 0.076) among C. chinensis, C. qiongbeiensis, and C. glabrifolia, and genetic differentiation between C. chinensis and C. glabrifolia was larger than that between C. chinensis and C. qiongbeiensis. Demographic simulations revealed unidirectional gene flow from C. chinensis to C. glabrifolia and C. qiongbeiensis, which highlight dispersal from mainland to island. The isolation effect of Qiongzhou Strait increased the genetic differentiation of species on both sides of the strait; however, the differentiation was diminished by gene flow that occurred during the historical period when Hainan Island was connected to mainland China. Our results supported the argument that C. glabrifolia should be considered an independent species and argued that C. qiongbeiensis should be regarded as an incipient species and independent conservation unit.
Phenotype, Biomass, Carbon and Nitrogen Assimilation, and Antioxidant Response of Rapeseed under Salt Stress
Authors: Wang Long , Lin Guobing , Li Yiyang , Qu Wenting , Wang Yan , Lin Yaowei , Huang Yihang , Li Jing , Qian Chen , Yang Guang , Zuo Qingsong
Published: May 2024

Salt stress is one of the major adverse factors affecting plant growth and crop production. Rapeseed is an important oil crop, providing high-quality edible oil for human consumption. This experiment was conducted to investigate the effects of salt stress on the phenotypic traits and physiological processes of rapeseed. The soil salinity was manipulated by setting three different levels: 0 g NaCl kg−1 soil (referred to as S0), 1.5 g NaCl kg−1 soil (referred to as S1), and 3.0 g NaCl kg−1 soil (referred to as S2). In general, the results indicated that the plant height, leaf area, and root neck diameter decreased with an increase in soil salinity. In addition, the biomass of various organs at all growth stages decreased as soil salinity increased from S0 to S2. The increasing soil salinity improved the distribution of biomass in the root and leaf at the seedling and flowering stages, indicating that rapeseed plants subjected to salt stress during the vegetative stage are capable of adapting their growth pattern to sustain their capacity for nutrient and water uptake, as well as leaf photosynthesis. However, as the soil salinity increased, there was a decrease in the distribution of biomass in the pod and seed at the maturity stage, while an increase was observed in the root and stem, suggesting that salt stress inhibited carbohydrate transport into reproductive organs. Moreover, the C and N accumulation at the flowering and maturity stages exhibited a reduction in direct correlation with the increase in soil salinity. High soil salinity resulted in a reduction in the C/N, indicating that salt stress exerted a greater adverse effect on C assimilation compared to N assimilation, leading to an increase in seed protein content and a decrease in oil content. Furthermore, as soil salinity increased from S0 to S2, the activity of superoxide dismutase (SOD) and catalase (CAT) and the content of soluble protein and sugar increased by 58.39%, 33.38%, 15.57%, and 13.88% at the seedling stage, and 38.69%, 22.85%, 12.04%, and 8.26% at the flowering stage, respectively. In summary, this study revealed that salt stress inhibited C and N assimilation, leading to a suppressed phenotype and biomass accumulation. The imbalanced C and N assimilation under salt stress contributed to the alterations in the seed oil and protein content. Rapeseed had a certain degree of salt tolerance by improving antioxidants and osmolytes.
Effects of Organic Fertilizer Addition to Vegetation and Soil Bacterial Communities in Saline–Alkali-Degraded Grassland with Photovoltaic Panels
Authors: Jia Aomei , Bai Zhenyin , Gong Liping , Li Haixian , Bai Zhenjian , Wang Mingjun
Published: May 2024

The Songnen grassland is an important resource for livestock production in China. Due to the intensification of anthropogenic activities in recent years, vegetation degradation has worsened, and the salinization of grassland has become increasingly serious, which severely affects the sustainable development of grassland animal husbandry. In this study, organic fertilizer addition was carried out at saline-and-alkaline-degraded Songnen grassland sites with photovoltaic panels, and we investigated the effects of organic fertilizer treatments on the vegetation and soil bacteria in these areas. The results showed that both organic fertilizer treatments increased the community composition and diversity indices of plants (p < 0.05); they also had significant effects on soil electrical conductivity and rapidly available potassium (p < 0.05). In the dominant phylum of bacteria, the relative abundance of Firmicutes increased without adding organic fertilizer under the photovoltaic panel; the addition of organic fertilizer had a significant effect on the relative abundance of Firmicutes and Desulfobacterota (p < 0.05), reducing their relative abundance, respectively. There were differences in the number of bacteria at the genus level under different treatments compared to the control, with the highest enrichment of bacteria occurring at the OFE position, and a significant difference (p < 0.05) being found between the control and the other four groups at the genus level of g_norank_f_norank_o_Actinomarinales. Organic fertilizer had a significant effect on the bacterial Simpson diversity index, with the most significant increasing trend found in OFE (the front eaves of the photovoltaic panel in fertilization area). The results of a correlation analysis showed that pH, electrical conductivity, and total nitrogen were the main factors affecting the soil bacterial community.