Search Results (1,011)

Background/Objective: Cancer stem cells (CSCs) are a self-renewing subpopulation within tumors that contribute to heterogeneity and resistance to conventional cancer therapies, including chemotherapy and radiotherapy. Despite growing interest in CSCs as therapeutic targets, effective compounds against these cells remain limited. This systematic review aims to assess the potential of metal-based coordination complexes as anti-CSC agents in preclinical models. Methods: A systematic literature search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Twenty-seven original in vitro studies were included, all evaluating the cytotoxic effects of metal-based compounds on cancer cell lines enriched with CSC subpopulations. To ensure methodological rigor, all articles underwent a critical appraisal by independent reviewers who resolved discrepancies through consensus, and only studies meeting predefined quality criteria were included. Results: Several metal complexes, particularly copper-based compounds, demonstrated significant cytotoxicity toward CSCs, mainly through the induction of apoptosis. Breast cancer was the most frequently studied tumor type. Many studies reported modulation of CSC-related markers, including EPCAM, CD44, CD133, CD24, SOX2, KLF4, Oct4, NOTCH1, ALDH1, CXCR4, and HES1, suggesting effects on CSC maintenance pathways. Most studies were conducted in the United Kingdom and relied on in vitro models. Conclusions: Metal coordination complexes, especially those containing copper, show promise as therapeutic agents targeting CSCs. However, further in vivo studies and mechanistic investigations are essential to advance their translational potential. Full article

S355NL structural steel is extensively employed in bridges, ships, and power station equipment owing to its excellent tensile strength, weldability, and low-temperature toughness. However, pronounced fluctuations in its Charpy impact energy at low temperatures significantly compromise the reliability and service life of critical components. In this study, vacuum-induction-melted ingots of S355NL steel containing 0–0.086 wt.% rare earth cerium were prepared. The effects of Ce on microstructures, inclusions, and impact toughness were systematically investigated using optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and Charpy V-notch testing. The results indicate that appropriate Ce additions (0.0011–0.0049 wt.%) refine the average grain size from 5.27 μm to 4.88 μm, reduce the pearlite interlamellar spacing from 204 nm to 169 nm, and promote the transformation of large-size Al₂O₃-MnS composite inclusions into fine, spherical, Ce-rich oxysulfides. Charpy V-notch tests at –50 °C reveal that 0.0011 wt.% Ce enhances both longitudinal (269.7 J) and transverse (257.4 J) absorbed energies while minimizing anisotropy (E_t/E_l  =  1.01). Conversely, excessive Ce addition (0.086 wt.%) leads to coarse inclusions and deteriorates impact performance. These findings establish an optimal Ce window (0.0011–0.0049 wt.%) for microstructural and inclusion engineering to enhance the low-temperature impact toughness of S355NL steel. Full article

Due to the structural aspects of the wind turbine, such as wind shear and tower shadow effects, the output power of the wind turbine has periodic fluctuations, known as 3P fluctuations. These fluctuations can reduce overall power generation and deteriorate power quality. In this context, this paper proposes a power smoothing control method that utilizes rotor inertia and a DC-link capacitor as small-scale energy storage devices. First, the typical energy storage capacities of the rotor’s rotational kinetic energy and the DC-link capacitor’s electrostatic energy are analyzed to assess their smoothing potential. Secondly, a control method is presented to apply the rotor and the DC-link capacitor as small-scale energy storage, with the smoothing frequency range allocated according to their respective storage capacities. Finally, the proposed method is compared with the conventional maximum power point tracking (MPPT) method and the 3P-notch filter method. The effectiveness of the proposed algorithm is verified through MATLAB/Simulink simulations, demonstrating its capability to mitigate periodic power fluctuations. The results showed that the proposed control method is applicable, reliable, and effective in mitigating periodic power fluctuations. Full article

Quadcolor cameras with conventional RGB channels were studied. The fourth channel was designed to improve the estimation of the spectral reflectance and chromaticity from the camera signals. The RGB channels of the quadcolor cameras considered were assumed to be the same as those of the Nikon D5100 camera. The fourth channel was assumed to be a silicon sensor with an optical filter (band-pass filter or notch filter). The optical filter was optimized to minimize a cost function consisting of the spectral reflectance error and the weighted chromaticity error, where the weighting factor controls the contribution of the chromaticity error. The study found that using a notch filter is more effective than a band-pass filter in reducing both the mean reflectance error and the chromaticity error. The reason is that the notch filter (1) improves the fit of the quadcolor camera sensitivities to the color matching functions and (2) provides sensitivity in the wavelength region where the sensitivities of RGB channels are small. Munsell color chips under illuminant D65 were used as samples. Compared with the case without the filter, the mean spectral reflectance rms error and the mean color difference (ΔE₀₀) using the quadcolor camera with the optimized notch filter reduced from 0.00928 and 0.3062 to 0.0078 and 0.2085, respectively; compared with the case of using the D5100 camera, these two mean metrics reduced by 56.3%. Full article

This study investigates the coupling mechanism between a parabolic notch and dislocations in one-dimensional (1D) hexagonal piezoelectric quasicrystals (PQCs) based on the theory of complex variable functions. By applying perturbation techniques and the Cauchy integral, analytical solutions for complex potentials are derived, yielding closed-form expressions for the phonon–phason stress field and electric displacement field. Numerical examples reveal several key findings: significant stress concentration occurs at the notch root, accompanied by suppression of electric displacement; interference patterns between dislocation cores and notch-induced stress singularities are identified; the J-integral quantifies distance-dependent forces, size effects, and angular force distributions reflecting notch symmetry; and the energy-driven dislocation slip toward free surfaces leads to the formation of dislocation-free zones. These results provide new insights into electromechanical fracture mechanisms in quasicrystals. Full article

This study proposed a sea cliff stability model that accounted for the coupled effects of sea erosion and rainfall, offering an improved quantitative assessment of the toppling risk. The approach integrated the notch morphology (height and depth) and rainfall infiltration to quantify stability, validated by field data from six toppling sites near Da’ao Bay, where the maximum erosion distance error between model predictions and measurements ranged from 0.81% to 48.8% (with <20% error for Sites S2, S3, and S4). The results indicated that the notch morphology and rainfall exerted significant impacts on the sea cliff stability. Site S4 (the highest site) corresponded to a 17.5% decrease in K per 0.1 m notch depth increment. The rainfall infiltration reduced the maximum stable notch depth, decreasing by 8.86–21.92% during prolonged rainfall. This model can predict sea cliff stability and calculate the critical notch depth (e.g., 0.56–1.22 m for the study sites), providing a quantitative framework for coastal engineering applications and disaster mitigation strategies under climate change scenarios. Full article

A novel approach to estimating the absorbed energy (toughness) in a uniaxial tensile test with only knowledge of the microstructure is presented. The flow behavior of each Dual-Phase (DP) steel grade is predicted using idealized Representative Volume Elements (RVEs) up to uniform elongation. To estimate the flow behavior beyond uniform elongation, the stress-modified fracture strain in a non-local damage model was implemented in Abaqus. Damage parameters were calibrated using Finite Element (FE) simulations of purely ferritic tensile specimens. The damage parameters remained unchanged, except for the coefficient of triaxiality. This coefficient was adjusted based on the average triaxiality of ferrite elements at the instability point of the uniaxially loaded RVEs for each DP steel grade. The proposed approach comprises two steps: micron-sized RVEs to predict the flow behavior up to the point of uniform elongation and the average triaxiality and full-scale tensile-test simulations to predict the rest of the curves. The results show that the damage parameters calibrated for high-strain ferrite effectively estimate the absorbed energy during failure in tension tests. This approach is also geometry-independent; varying the geometry of the tensile specimen, including miniature or notched specimens, still yields predicted absorbed energies that are in good agreement with the experimental results. Full article

Vermipsyllid parasitize the body surface of sheep, feeding on blood and transmitting diseases, causing severe economic losses to the livestock industry. An outbreak of sheep Vermipsyllid fleas in the mountain pastures of Xinjiang’s Altai region showed that several commonly used commercial anthelmintic drugs had poor therapeutic effects on the prevalent flea species. This study first conducted species identification of Vermipsyllid through morphological analysis of 200 female and 40 male specimens collected from the Altai region, followed by molecular biological identification of 6 randomly selected fleas (3 females and 3 males). Finally, pharmacodynamic experiments were performed to screen for highly effective anthelmintic drugs. Ninety Altai multiparous ewes infected with Vermipsyllid were divided into six groups (fifteen sheep per group): an untreated control group (Ctr), avermectin injection group (Group I), ivermectin injection group (Group II), moxidectin pour-on group (Group III), cypermethrin pour-on group (Group IV), and dichlorvos pour-on group (Group V), with a 14-day trial period. On Day 0, each group received a single treatment according to drug instructions and specified dosages. The number of fleas, flea population reduction rates, and cure rates were measured on Day 0, Day 3, Day 7, and Day 14 to screen for effective anthelmintic drugs. Results showed that unfed female and male fleas were grayish-brown. Engorged females reached 14.15 mm in size, appearing pale white or yellow, with their sterna maintaining the original size and shape despite abdominal distension. Female fleas had 20–21 segments on the labium, while males had 16–19 segments. The hind tibiae featured four notches, and each side of the tergite had 13 ± 1 cup-like indentations. Molecular biological identification indicated that the identified fleas belonged to D. ioffi (Vermipsyllidae, Dorcadia Ioff), showing 99.13% sequence similarity with D. ioffi from Xinjiang, China. In pharmacodynamic experiments, the number of D. ioffi in Groups IV and V decreased to zero on both Day 7 and Day 14, which was extremely significantly lower than other groups (p < 0.01). The flea population reduction rates in Groups IV and V reached 100% on both days. By Day 14, the cure rates of Groups I, II, and III were 0%, while those of Groups IV and V were 100%. Avermectin injection, ivermectin injection, and moxidectin pour-on showed poor anthelmintic effects, whereas cypermethrin and dichlorvos pour-on exhibited high anthelmintic activity against this flea species. Full article

Background: Intercellular communication, facilitated by exosomes (Exos) derived from endothelial cells (ECs), significantly influences the regulation of angiogenesis. Leech extract significantly reduces ischemia–reperfusion injury, promotes angiogenesis, and improves neurological function in mice with stroke. However, further investigation is required to determine whether leech promotes angiogenesis through EC-Exo. Objective: This study aims to further explore whether leech regulates Exos to promote the establishment of collateral circulation in mice with ischemic stroke (IS) and the specific mechanisms involved. Methods: Here, we utilized an in vitro co-culture system comprising ECs and pericytes to investigate the impact of Leech-EC-Exo on enhancing the proliferation and migration of mouse brain microvascular pericytes (MBVPs). We further established an in vivo mouse model of middle cerebral artery occlusion/reperfusion (MCAO/R) to investigate the effects and underlying mechanisms of leech on collateral circulation establishment. Results: The findings demonstrated that leech significantly enhanced the in vitro cell migration number and migration number of pericytes. Therefore, it can also enhance the effect of EC-Exo on improving the infarct area and gait of mice, as well as modulating the HIFα-VEGF-DLL4-Notch1 signaling pathway to promote cerebral angiogenesis and facilitating the stable maturation of neovascularization in vivo. Conclusions: These results suggest that leech has the potential to enhance collateral circulation establishment, and its mechanism may involve the modulation of miRNA content in Exos and the promotion of signaling pathways associated with angiogenesis and vascular maturation. Full article

Testing and the estimation methods for predicting the life of crack initiation and crack growth for P92 steel using a circular sharp notched round bar specimen (CNS) under strain-controlled creep and fatigue conditions have been reported previously. A unique estimation method for the cycle-sequential characteristics of tensile and compressive peak stresses is proposed; specifically, the nominal stress range ${∆\sigma }_{net}={{(\sigma }_{max}-{\sigma }_{min})}_{net}$ and the measurement of crack length using the direct current electric potential drop (DCPD) method were adopted. This method was effective in specifying the failure life and crack initiation life by verifying the crack growth length. However, to show the universality of these results, it is important to compare the experimental results obtained under strain-controlled creep and fatigue conditions with those obtained under stress-controlled creep and fatigue conditions and with those for smooth specimens estimated based on the linear and nonlinear damage summation rule. Furthermore, it may also be important to compare these results with those of smooth specimens estimated based on the Manson–Coffin law when the failure life is fatigue-dominant. Considering these aspects, detailed experiments and analyses were systematically conducted for P92 steel in this study, and the above comparisons were conducted. The results aid in achieving a unified understanding of the law of fracture life, including those under stress- and strain-controlled creep and fatigue conditions. Full article

Background: Effective mask ventilation is a very important aspect of ensuring adequate oxygenation and ventilation. However, predicting difficult mask ventilation (DMV) using bedside clinical tests remains challenging due to poor sensitivity. Our objective was to determine the correlation between the preoperative ultrasonography of anterior neck anatomy and difficult mask ventilation in different obesity classes. Methods: A prospective, observational study enrolled 90 adult obese patients undergoing general anesthesia from December 2020 to November 2021 (30 patients for each class of obesity). Ultrasonography measurements were recorded for the distance of skin (DS) to hyoid bone (DSHB), epiglottis (DSEM), the anterior commissure of the vocal cords (DSAC), thyroid isthmus (DSTI), and trachea at jugular notch (DSTJ). The difficulty of bag mask ventilation was graded using the Han scale. The Kendall Tau correlation coefficient was used to correlate the different ultrasonography parameters to DMV. Receiver-operating characteristic (ROC) curves were used to determine the sensitivity and specificity of the measured ultrasonography distances, and the Youden index was used to calculate the optimal cut-off values. Results: Results revealed twenty patients (22.2%) were categorized as having difficult mask ventilation. There was a statistically significant increase (p = 0.011) in the number of patients with Mallampati II in class III obesity compared to class I obesity. DSHB showed a statistically significant and strong correlation with difficult mask ventilation in patients with class II (p = 0.002, r = 0.464) and class III obesity (p = 0.002, r = 0.475). A DSHB cut-off value of 1.35 cm has a sensitivity of 83.3% and specificity of 78.8% for class III obesity. Similarly, a DSTJ cut-off value of 1.13 cm has a sensitivity of 83.3% and specificity of 66.7% for class III obesity. Conclusions: Notably, DSHB was the most specific parameter and equally as sensitive as DSTJ in predicting difficult mask ventilation in morbidly obese patients. Full article

It is well established that different fasting strategies offer a range of benefits and may even serve as potential therapeutic approaches for metabolic diseases. The biological effects of intermittent fasting (IF) are multidimensional, involving the induction of metabolic switching from glucose to fatty acid and ketone utilization, thereby enhancing fat metabolism and improving glucose tolerance and insulin sensitivity. In addition, IF modulates the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis by lowering IGF-1 levels, a change associated with enhanced cellular protection, reduced tumorigenesis, and delayed aging. Moreover, IF modulates key signaling pathways, including mitogen-activated protein kinases, Notch, and nuclear factor kappa B, which collectively contribute to reduced oxidative stress, attenuated inflammation, and hepatoprotection. Although fasting may present certain challenges, it is essential to be adequately informed about its potential benefits and appropriate preparatory strategies before undertaking various fasting protocols. This review summarizes the current knowledge on various IF protocols and periodic short-term fasting (PSTF) lasting more than 24 h and up to 72 h, highlighting the signaling pathways through which these interventions affect metabolic processes. Additionally, it aims to provide a practical guide for the safe preparation for PSTF lasting more than 24 h and up to 72 h. Full article

Cardiac fibrosis is a key physiopathological process underlying the progression of virtually all heart diseases and related conditions, including myocardial infarction, pressure overload, and heart failure. Once regarded as a homogeneous and passive population, cardiac fibroblasts are now recognized as highly heterogeneous and dynamic, comprising distinct subpopulations with specialized molecular and functional identities. These subpopulations include resident fibroblasts, activated myofibroblasts, matrifibrocytes, inflammatory fibroblasts, and senescent fibroblasts, each contributing uniquely to extracellular matrix (ECM) remodeling, cytokine secretion, and intercellular crosstalk. Recent advances in single-cell transcriptomics, lineage tracing, and epigenetic profiling have revealed the plasticity and phenotypic transitions of cardiac fibroblasts in both physiological and pathological contexts. This review synthesizes current knowledge on fibroblast diversity in the adult heart, including their embryological origins and anatomical distribution, and explores how these insights could guide the development of precision anti-fibrotic therapies. We discuss a selection of emerging therapeutic strategies, including subtype-specific targeting (e.g., anti-POSTN, anti-IL1β), modulation of key signaling pathways (e.g., TGF-β, Wnt, Notch), with a brief mention also of novel approaches based on non-coding RNAs and epigenetic regulators. A better understanding of cardiac fibroblast heterogeneity holds significant potential for the design of more specific cell-type and context-tailored interventions, moving toward more effective and personalized treatments for cardiac fibrosis and its sequelae. Full article

The Charpy impact toughness of single-phase austenitic Fe-32Mn-0.6C steel was systematically investigated across a wide temperature spectrum from 25 °C to −196 °C using Charpy V-notch impact tests. The material exhibited a remarkable temperature dependence of impact energy, decreasing dramatically from 120 J at ambient temperature (25 °C) to 13 J under cryogenic conditions (−196 °C). Notably, a steep transition in impact energy occurred within the critical temperature window of −100 °C to −150 °C. Microstructural analysis revealed that synergistic effects of high strain rates and low temperatures significantly restrict dislocation slip and multiplication mechanisms, while also suppressing deformation twinning activation. This restricted plasticity accommodation mechanism fundamentally differs from the deformation characteristics reported in conventional low-carbon high-manganese steels and other face-centered cubic (FCC) alloy systems. Full article

To investigate the mechanical behavior and damage mechanism of notch–stud connectors in timber–concrete composites under fatigue loading, fifteen push-out specimens in five groups were designed with load cycles as the key variable. Fatigue failure modes and mechanisms were analyzed to examine fatigue life, stiffness degradation, and cumulative damage laws of connectors. Numerical simulations with up to 100 load cycles explored timber/concrete damage effects on stud fatigue performance. Based on the results, an S-N curve was established, a fatigue damage model developed, and a fatigue design method proposed for such connectors. Primary failure modes were stud fracture and local concrete crushing in notches. Stiffness degradation followed an inverted “S”-shaped “fast–slow–fast” pattern. Using residual slip as the damage variable, a two-stage fatigue damage evolution model was constructed from the damage–cycle ratio relationship, offering a new method for shear connector fatigue damage calculation in timber–concrete composites and enabling remaining life prediction for similar composite beam connectors. Finite element simulations of push-out specimens showed high consistency between calculated and experimental fatigue life/damage results, validating the conclusions. Full article