Search Results (70)

This study aimed to examine how downward load applied during instrumentation affects the stress generation and shaping properties in thermally treated and non-treated NiTi rotary instruments. ProTaper Universal (PTU; non-thermally treated) and ProTaper Gold (PTG; thermally treated) were used to prepare J-shaped canals in resin blocks. Load-controlled automated instrumentation and torque/force sensing devices were employed with preset downward loads of 1, 2, or 3 N (n = 10 each). The torque/force, instrumentation time, and canal-centering ratio were measured and analyzed using two-way or one-way analysis of variance with Tukey’s test (α = 0.05). In the PTU-1N group, instrumentation was not completed because a ledge was formed in all canals. The PTU-3N group showed significantly greater upward force (screw-in force) and clockwise torque, along with a significantly smaller canal-centering ratio (less deviation) at the apical 0 mm level, than the PTU-2N group (p < 0.05). The downward load did not influence the instrumentation time (p > 0.05). In the PTG groups, these effects of downward load on the force generation and canal-centering ratio were not significant (p > 0.05). In the non-thermally treated PTU instruments, greater downward loads enhanced screw-in force while decreasing apical canal deviation; however, these effects were abolished in the thermally treated PTG instruments. This study highlights the importance of adapting the instrumentation technique with instrument characteristics: thermally treated flexible instruments facilitate smoother use, while stiffer, non-thermally treated ones may require precise control of downward loads. Full article

This study focuses on Țara Hațegului, a region with significant geological, ecological, and cultural resources, and examines how geosites can inform development strategies that promote geotourism while supporting landscape conservation. The research addresses the need to better integrate geosites into spatial planning by conducting geosite assessment and mapping, overlay analysis with settlement typologies, geosite density analysis, and delineation of priority landscape conservation areas. A methodological framework was developed, combining geospatial analysis, site-specific evaluation, and strategic zoning to support planning and decision-making. In the results, 48 geosites were identified and assessed, out of which 7 were classified as having high Potential Touristic Use (PTU), 13 as moderate, and 28 as low. Spatial analysis revealed that most high-PTU geosites are located in rural or adjacent uninhabited areas, indicating both development opportunities and infrastructural constraints. A geosite density map highlighted clusters suitable for coordinated management, while a prioritization model delineated three landscape conservation zones based on geosite value and distribution. The SWOT analysis further contextualized these findings, outlining strengths such as the region’s rich geoheritage and multi-layered protection, as well as limitations linked to infrastructure and management capacity. By positioning geosites as territorial assets, the research highlights their potential to support sustainable, place-based strategies in regions where geological heritage is a defining element of the local landscape. Full article

Background/Objectives: Thyroid hormone (TH) deficiency during the pregnancy and lactation periods leads to enduring memory impairments in offspring. However, the mechanisms underlying the cognitive and memory deficits induced by developmental hypothyroidism remain largely unexplored. Methods: Mice were exposed to propylthiouracil (PTU) or purified water to detect changes in hippocampal neurogenesis and differentiation of their offspring to explain the pathogenesis of impaired learning and memory. In addition, HT22 cell line were used to investigate the regulation between Maf and Mef2c. Results: Our findings indicate that developmental exposure to PTU results in abnormalities of the preferential differentiation of GABAergic interneurons and a subsequent reduction in PV⁺ inhibitory interneurons in the hippocampus of mouse pups. More significantly, we also indicate that the downregulation of Maf and the consequent alteration of Mef2c are likely responsible for the mechanisms through which developmental hypothyroidism influences the differentiation and development of PV⁺ inhibitory interneurons in offspring. Conclusions: Consequently, the aberrant development of PV⁺ interneuron in the hippocampus of mice subjected to developmental hypothyroidism potentially contributes to memory deficits during adolescence and adulthood. Full article

Traditional marine antifouling coatings function through releasing toxic antifouling agents, causing serious harm to marine ecosystems. To address this challenge, an eco-friendly fluoro-silicon-modified polythiourethane (FSi-PTU) coating has been prepared via a polymerization reaction with dihydroxy propyl silicone oil (HO-PDMS-OH), 1H,1H,2H,2H-perfluorohexanol (FTOH), hexamethylene diisocyanate (HDI), and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP). The FSi-PTU polymer incorporates siloxane segments and fluorinated side chains, which are inhomogeneously distributed on the coating surface and construct a hydrophobic surface. The FSi-PTU coating exhibits good hydrophobicity, strong adhesion (≥2.14 MPa), and improved mechanical properties. The antifouling properties of the FSi-PTU coating have been researched. The results of laboratory tests demonstrate that the FSi-PTU coating exhibits excellent anti-protein adsorption and anti-algal attachment performance. The FSi-PTU-2 coating shows certain antifouling properties in the actual seawater test for three months. The results provide a certain reference value for developing eco-friendly marine antifouling coatings. Full article

German chamomile (Matricaria chamomilla L.) is a suitable medicinal and aromatic crop to cultivate in diverse regions, but its relationship with weather is a major concern in evaluating the development and crop production in the Western Himalayan region. Thus, a field experiment was executed for two years (2018–2019 and 2019–2020) at CSIR-Institute of Himalayan Bioresource Technology, Palampur, India, to evaluate the crop weather relationship studies and different phenological phases of German chamomile under acidic soil conditions of mid hills of Western Himalaya. Agrometeorological indices were worked out for four different sowing times from 20 November to 20 January with foliar application of elicitor, i.e., salicylic acid at three levels (viz., SA0: 0 mg/L, SA1: 25 mg/L, SA2: 50 mg/L). The results revealed that the number of days required for attaining each phenological stage decreased with a delay in sowing time. Higher growing degree days (GDDs), photothermal units (PTUs) and heliothermal units (HTUs) were accumulated for early sowing of 20 November and showed a gradual decrease with delayed sowing. Salicylic acid application produced a significant effect on the accumulation of agrometeorological indices, irrespective of the applied doses, and showed irregularity. Higher accumulation of GDDs, PTUs, and HTUs is associated with higher flower and essential oil yield; thus, the results showed that agrometeorological indices are associated with the production of German chamomile. Full article

The geoheritage present on the “Tindari Cape and Marinello Lakes” site (TCML, Messina Province, NE Sicily, Italy) drew our attention due to the acquired contrasting information. Indeed, the TCML geoheritage was classified in the geosite national catalogue as a geosite (albeit under a non-evaluated status and with regional scientific interest), whereas it was classified in the geosite regional catalogue as a site of attention. The coastal geoheritage included in this site was analyzed by means of a literature review, field work, and a sedimentological and petrographic investigation. Moreover, the reconstruction of the historical to modern evolution of the lagoon and spit’s shapes was carried out across a time span of 85 years. The investigation results were used for the inventorying and quantitative assessment of the TCML geoheritage with the Brilha method. The primary and preeminent scientific interest was geomorphological, the lagoon and spit being an active geomorphosite. This system showed elements of rarity, representativeness, and exemplariness. Secondary-type geomorphological, structural, and palaeontological aspects were also evidenced in geological elements found on the cliffs of the Tindari Cape. For the quantitative assessment of the geodiversity, the scientific value (SV), potential educational use (PEU), potential touristic use (PTU), and degradation risk (DR) were evaluated. The obtained weighted scores were 320 (SV), 250 (PEU), 290 (PTU), and 285 (DR). The high SV suggested that the TCML, due to its geodiversity, could be classified as a geosite. Notwithstanding, the moderate PEU, PTU, and DR (fragility and vulnerability depending on natural climate and anthropogenic factors) values indicated that it was not fully compatible with educational and touristic purposes. The results of the inventorying and quantitative assessment of the TCML site provide scientific data that are useful in establishing the TCML as a global geosite, placing it in the national catalog of geosites. Full article

This paper presents a resonant wireless power transfer method that leverages a 90-degree voltage phase shift between the transmitting and receiving coils to enhance efficiency and maximize power transfer. When the resonant coupling is achieved, the secondary coil with an adjustable capacitor forms a tuned LC circuit. If the primary coil is driven at the resonant frequency of both the primary and secondary sides, the system can transmit 250W of power between the coils over a distance of 50 cm. Using a single power transmitting unit (PTU) board with multiple paralleled gallium nitride high-electron-mobility transistors (GaN HEMTs), the system achieves a maximum power transfer efficiency of 88%, highlighting the effectiveness of the design in high-efficiency, long-distance wireless power transmission. The key to the success of high-power, high-efficiency RWPT is in exhibiting the imaginary turn ratio presented on the air transformer. The imaginary turn ratio can realize the negative impedance conversion that converts the positive resistance on the power-receiving unit into a negative one, and thus, the damping of the resonance oscillation becomes negative and positively encourages more power to be delivered to the power-receiving unit (PRU) load. This paper derives the theory of the imaginary turn ratio and demonstrates the implementation of the RWPT system that exhibits the imaginary turn ratio effect. Full article

Melanin overproduction causes various skin diseases, such as spots, freckles, and wrinkles, resulting in the requirement of melanin synthesis inhibitors like 1-phenyl-2-thiourea (PTU) and kojic acid, which have been commonly used in the pharmaceutical industry. However, these inhibitors can cause side effects such as skin irritation and allergies. Therefore, it is necessary to develop safe and effective melanin inhibitors from natural resources. The purpose of this study was to investigate a whitening agent from natural substances using B16F10 melanoma cells and zebrafish model. We investigated the melanogenesis-inhibiting activities of the fractions from Sargassum pallidum extract. The ethyl acetate fraction from S. pallidum extract (SPEF) significantly decreased tyrosinase activity. SPEF also significantly reduced α-melanocyte stimulating hormone (MSH)-induced intracellular tyrosinase activity and melanin content in B16F10 cells. Moreover, SPEF inhibited the expression levels of key melanogenic proteins such as tyrosinase, TRP-1, TRP-2, and MITF by downregulating the phosphorylation levels of CREB and PKA in α-MSH-stimulated melanoma cells. Furthermore, SPEF significantly suppressed melanin synthesis in the zebrafish model with no developmental toxicity. LC-Q-TOF-MS/MS analysis identified that SPEF was composed of 12 phytochemical compounds, including diterpenes, which were the dominant metabolites. These results altogether show that SPEF effectively suppresses melanogenesis in B16F10 melanoma cells and in a zebrafish model, with potential for usage in pharmaceuticals and cosmeceuticals. Full article

Thyroid dysfunction may affect the intestinal microbiota through short-chain fatty acids (SCFAs) in marine fish. This study investigated the effects of triiodothyronine (T3, 20 ng/g) and thyroxine (T4, 20 ng/g), and propylthiouracil (PTU, 5000 ng/g) on growth performance, intestinal SCFA profiles, and microbiota composition in little yellow croakers Larimichthys polyactis. The results showed that dietary thyroid-active agent supplementation significantly decreased weight gain, and specific growth ratio. Moreover, dietary T3, T4, and PTU induced the states of hyperthyroidism, hyperthyroidism, and hypothyroidism, respectively, leading to differential alterations in intestinal SCFA profiles. Specifically, only dietary T4 supplementation significantly increased the diversity of intestinal microbiota. Our findings suggest that the genera Vibrio and Sediminibacterium play key roles in multiple metabolic pathways within the host intestine. Correlation analyses further indicated that intestinal acetic acid and isobutyric acid were characteristic metabolites involved in the alteration of the genus Vibrio abundance. These results provide a foundation for further investigation into the effects of thyroid-disrupting activities on growth, intestinal SCFA profiles, and microbiota composition in marine fish. Full article

Constant efforts to increase resource efficiency, productivity, and output quantities, as well as growing product requirements, result in high tribological loads on forming tools. The manipulation of the tribological properties of blanking punches by deterministic texturing using machine hammer peening on the lateral surface is a solution to ensure an extended service life. For this purpose, rotationally symmetrical blanking punches were textured using a specially developed texturing center. The machine hammer peening center allows surface texturing with positioning accuracies of less than 2% for individual indentations by controlling a rotary and feed axis in combination with frequency control of the machine hammer peening setup. A modified hammer head with a micro-tip was used as the texturing tool. Different coverage ratios with the same aspect ratio were applied to the surface. These punches were then tested on an industrial high-speed press. To evaluate the effectiveness, the force curves were analyzed and the evolution of the textured topography was continuously evaluated. The experiments showed that the withdrawal force could be reduced by 38% due to microtexturing with a coverage ratio of 18%. Other coverage ratios resulted in an increase. By texturing the lateral surfaces of blanking punches using machine hammer peening, the service life was also significantly improved. Full article

Hypothyroidism causes ovarian dysfunction and infertility in women and animals and impairs the hypothalamic expression of kisspeptin (Kp). However, kisspeptin is also expressed in the genital system, and the lack of the Kp receptor (Kiss1r) in the uterus is linked to reduced implantation rates. This study investigated the impact of hypothyroidism on the uterine expression of Kp and Kiss1r in female rats throughout the estrous cycle and the associated changes in uterine activity modulators. Hypothyroidism was induced through daily administration of propylthiouracil (PTU) over a period of 14 days. Plasma levels of LH, E₂, and P₄, cyclicity, body and uterine weight, uterine histomorphometry, and the gene and/or protein expression of Kiss1, Kiss1r, estrogen receptor α (ERα), progesterone receptor (PR), and thyroid hormone receptor α (TRα) were assessed. Additionally, proliferative activity (CDC-47) and the gene expression of uterine receptivity mediators (SMO, WNT4, BMP2, HAND2, MUC1, and LIF) were evaluated. Hypothyroidism prolonged the diestrus and increased progesterone levels during this phase, while decreasing luteinizing hormone and estradiol on proestrus. In the uterus, hypothyroidism reduced Kp immunostaining on diestrus and KISS1R mRNA levels on proestrus. These changes were accompanied by reduced endometrial glands, reduced uterine proliferative activity, and reduced ERα gene and protein expression. Additionally, hypothyroidism led to reduced uterine gene expression of LIF, BMP2, WNT4, and HAND2. On the other hand, thyroid hypofunction increased uterine PR and TRα immunostaining, while it reduced PGR gene expression on diestrus. These findings demonstrate that hypothyroidism reduces the expression of Kiss1/Kiss1r system in the uterus, which is associated with disrupted uterine estrogen and progesterone signaling and reduced expression of uterine receptivity mediators across the rat estrous cycle. Full article

This study aimed to evaluate the efficacy of various nickel–titanium (Ni-Ti) root canal instrumentation systems in preserving root canal anatomy, focusing on their capacity to limit changes in canal angulation. One hundred canals in fifty extracted human molars were prepared with different techniques: Step-Back, Reciproc, MTwo, ProTaper Universal (PTU), and ProTaper Next (PTN). The curvature of each canal was measured before and after treatment using Schneider’s methodology, a widely accepted method for assessing canal curvature. Descriptive and statistical analyses, including the Kruskal–Wallis test, were employed to compare angular changes across the systems. The results indicated that all techniques effectively reduced canal curvature, with each system exhibiting a reduction in mean canal angle after instrumentation. Although the Reciproc system showed the smallest mean change in angulation, no statistically significant differences were identified between any of the systems (p = 0.182). This finding suggests that while minor differences in performance may exist, they do not translate into clinically meaningful distinctions in preserving root canal anatomy. The Reciproc system’s slight advantage aligns with other studies, highlighting its conservative design and minimal dentinal stress; however, its superiority was not statistically validated in this study. The results suggest that all five systems are clinically comparable in preserving root canal anatomy, highlighting that dentists can choose from these widely available techniques without compromising anatomical preservation. While this study had limitations, including a relatively small sample size and an in vitro design, it aligns with previous findings on the mechanical behavior of Ni-Ti systems in endodontic practice. Full article

This study explores the formation and properties of new complexes involving gallium(III) and thiouracil derivatives—2-thiouracil (TU), 6-methyl-2-thiouracil (MTU), 6-propyl-2-thiouracil (PTU), 5-carboxy-2-thiouracil (CTU), and 6-methoxymethyl-2-thiouracil (MMTU). Conducted in aqueous solutions at relatively low concentrations, this research enabled the formation of soluble complexes, identified and described here for the first time. The influence of metal-to-ligand ratios on species distribution and their fluorescence properties was examined through potentiometric titration, alongside visible and fluorescence spectroscopy. Stability constants were determined, revealing that coordination mode and complex stability are pH-dependent, and nitrogen, sulfur, and oxygen atoms are involved in higher pH coordination. Additionally, the structure of the ligand 6-methoxymethyl-2-thiouracil was characterized. The findings suggest that these complexes hold potential for future biomedical applications, particularly as antibacterial and anticancer agents, warranting further studies under physiological conditions. Full article

In mammals, the maintenance of energy homeostasis relies on complex mechanisms requiring tight synchronization between peripheral organs and the brain. Thyroid hormones (THs), through their pleiotropic actions, play a central role in these regulations. Hypothyroidism, which is characterized by low circulating TH levels, slows down the metabolism, which leads to a reduction in energy expenditure as well as in lipid and glucose metabolism. The objective of this study was to evaluate whether the metabolic deregulations induced by hypothyroidism could be avoided through regulatory mechanisms involved in metabolic flexibility. To this end, the response to induced hypothyroidism was compared in males from two mouse strains, the wild-derived WSB/EiJ mouse strain characterized by a diet-induced obesity (DIO) resistance due to its high metabolic flexibility phenotype and C57BL/6J mice, which are prone to DIO. The results show that propylthiouracil (PTU)-induced hypothyroidism led to metabolic deregulations, particularly a reduction in hepatic lipid synthesis in both strains. Furthermore, in contrast to the C57BL/6J mice, the WSB/EiJ mice were resistant to the metabolic dysregulations induced by hypothyroidism, mainly through enhanced lipid metabolism in their adipose tissue. Indeed, WSB/EiJ mice compensated for the decrease in hepatic lipid synthesis by mobilizing lipid reserves from white adipose tissue. Gene expression analysis revealed that hypothyroidism stimulated the hypothalamic orexigenic circuit in both strains, but there was unchanged melanocortin 4 receptor (Mc4r) and leptin receptor (LepR) expression in the hypothyroid WSB/EiJ mice strain, which reflects their adaptability to maintain their body weight, in contrast to C57BL/6J mice. Thus, this study showed that WSB/EiJ male mice displayed a resistance to the metabolic dysregulations induced by hypothyroidism through compensatory mechanisms. This highlights the importance of metabolic flexibility in the ability to adapt to disturbed circulating TH levels. Full article

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, affecting up to 30% of the population, with approximately 20% of cases occurring in non-obese individuals. The recent shift to the term metabolic dysfunction-associated steatosis liver disease (MASLD) highlights the disease’s heterogeneity. However, there are no well-established animal models replicating non-obese NAFLD (NO-NAFLD). This study aimed to evaluate the relevance of the high-fat diet (HFD) combined with the propylthiouracil (PTU)-induced rat model in mimicking the histopathology and pathophysiology of NO-NAFLD. We first analyzed metabolic and clinical parameters between NO-NAFLD patients (Average BMI = 21.96 kg/m²) and obese NAFLD patients (Average BMI = 29.7 kg/m²). NO-NAFLD patients exhibited significantly higher levels of carnitines, phospholipids, and triglycerides. In the animal model, we examined serum lipid profiles, liver inflammation, histology, and transcriptomics. Hepatic steatosis in the HFD+PTU model at week 4 was comparable to that of the HFD model at week 8. The HFD+PTU model showed higher levels of carnitines, phospholipids, and triglycerides, supporting its relevance for NO-NAFLD. Additionally, the downregulation of lipid synthesis-related genes indicated differences in lipid accumulation between the two models. Overall, the HFD+PTU-induced rat model is a promising tool for studying the molecular mechanisms of NO-NAFLD. Full article