Search Results (6,418)

Organic violet-blue fluorescent materials have garnered significant interest for a broad spectrum of applications. A series of triazine-based molecules, that is, 2,4,6-tri(9H-carbazol-9-yl)-1,3,5-triazine (TCZT), 2,4,6-tri(1H-indol-1-yl)-1,3,5-triazine (TIDT), and 2,4,6-tris(3,6-di-tert-butyl-9H-carbazol-9-yl)-1,3,5-triazine (TDBCZT), exhibiting violet-blue emission were synthesized via a catalyst-free aromatic nucleophilic substitution reaction. These compounds possess a non-planar and twisted structure with favorable charge-transfer characteristics, demonstrating excellent thermal stability (decomposition temperatures of 370 °C, 384 °C, and 230 °C, respectively). Cyclic voltammetry analysis, combined with time-dependent density functional theory (TD-DFT) calculations at the B3LYP/6-31G(d) level, offered detailed insights into their electronic structures and electrochemical properties. Optical properties were systematically characterized using Ultraviolet–visible (UV–Vis) absorption and photoluminescence (PL) spectroscopy. The compounds exhibited violet-blue luminescence with emission peaks located at 397 nm, 383 nm, and 402 nm in toluene, respectively. In their respective films, the compounds exhibited varying degrees of spectral shifts, with emission peaks at 408 nm, 381 nm, and 369 nm. Moreover, the CIE (Commission Internationale de l’Éclairage) coordinates of TIDT in toluene were (0.155, 0.067), indicative of excellent violet purity. These compounds demonstrated significant two-photon absorption (TPA) properties, with cross-sections of 4.6 GM, 15.3 GM, and 7.4 GM, respectively. Notably, they exhibited large molar absorptivities and substantial photoluminescence quantum yields (PLQYs), suggesting their potential for practical applications as violet-blue fluorescent materials. Full article

Climate conditions in combination with the concentration of pollutants increase the human health stress and exacerbate systemic diseases. The city of Rhodes is a desirable tourist destination that is located in a sensitive climate region of the southeastern Aegean Sea in the Mediterranean region. In this work, hourly recordings from a mobile air quality monitoring system, which is located in an urban area of Rhodes city, are employed in order to measure the concentration of regulated pollutants (${\mathrm{S}\mathrm{O}}_2,{\mathrm{N}\mathrm{O}}_2,{\mathrm{O}}_3,{\mathrm{P}\mathrm{M}}_{10} \mathrm{a}\mathrm{n}\mathrm{d} {\mathrm{P}\mathrm{M}}_{2.5})$ and meteorological factors (pressure, temperature, and relative humidity). The air quality health index (AQHI) and the discomfort index (DI) are calculated to study the impact of air quality and meteorological conditions on human health. The analysis is conducted during a hot summer period, from 29 June to 14 July 2024. During the second half of the studied period, a heatwave episode occurred that affected the bioclimatic conditions over the city. The results show that despite the fact that the concentration of pollutants is lower than the pollutant thresholds (according to Directive 2008/50/EC), the AQHI and DI conditions degrade significantly over the heatwave days. In particular, the AQHI is classified in the “Moderate” class, and the DI indicates that most of the population suffers discomfort. The AQHI and DI simultaneously increase during the days of the heat episode, showing a possible negative synergy for the health risk. Finally, both the day maximum and night minimum temperature are increased (about 0.8 and 0.6 °C, respectively) during the heatwave days as compared to the whole studied period. Full article

In the current era, which is characterized by increasing demand for high-precision location and navigation capabilities, various industries, including those involved in intelligent vehicle systems, logistics, augmented reality, and more, heavily rely on accurate location information to optimize processes and deliver personalized experiences. In this context, the integration of Global Navigation Satellite System (GNSS) and inertial sensor technologies in smartphones has emerged as a critical solution to meet these demands. This research paper presents an algorithm that combines a GNSS with a modified downdate algorithm (MDDA) for satellite selection and integrates inertial navigation systems (INS) in both loosely and tightly coupled configurations. The primary objective was to harness the inherent strengths of these onboard sensors for navigation in challenging environments. These algorithms were meticulously designed to enhance performance and address the limitations encountered in harsh terrain. To evaluate the effectiveness of these proposed systems, vehicular experiments were conducted under diverse GNSS observation conditions. The experimental results clearly illustrate the considerable improvements achieved by the recommended tightly coupled (TC) algorithm when integrated with MDDA, in contrast to the loosely coupled (LC) algorithm. Specifically, the TC algorithm demonstrated a remarkable reduction of over 90% in 2D position root mean square error (RMSE) and a 75% reduction in 3D position RMSE when compared to solutions utilizing the weighting matrix provided by Google with all visible satellites. These findings underscore the substantial advancements in precision resulting from the integration of GNSS and INS technologies, thereby unlocking the full potential of transformative applications in the realm of intelligent vehicle navigation. Full article

In order to gain an insight into the stress state of drillstring in riserless drilling conditions with Casing while Drilling (CwD) technology, a stochastic and nonlinear dynamic model of the drillstring under the excitation of the environmental load is established based on Hamilton principle and finite deformation theory. The distribution of tensile stress, bending stress, and effective stress along the axial direction of drillstring that is exposed to the ambient environment is emphasized, the influence of wall thickness and material of the drillpipe on the stress state of drillstring is also discussed. The numerical results show that significant fluctuations in cross-sectional stress occur during the riserless drilling process, particularly under varying hydrodynamic loads; the tensile stress and effective stress are larger on landing string and the maximum values of these stresses occur at the connection point of the landing string and casing string; the bending stress is larger on casing string and the maximum value occurs near the sea floor; and increasing the wall thickness and selecting the low-density material can help to reduce the stress of the drillstring. It can be concluded from the numerical results that during the CwD riserless drilling process, the effective stress on the cross section of drillstring is mainly determined by the tensile stress and the contribution of bending stress is comparably small, and the dangerous cross section of the drillstring is located at the connection point of landing string and casing string. The proposed dynamic model offers theoretical insights that can inform drillstring design and vibration mitigation strategies in CwD operations. Full article

Unregulated underground group mining in China has led to problems such as unclear locations and complex shapes of mine goafs in mineral engineering, posing serious safety hazards for subsequent mining operations. This paper takes mineral engineering with complex mine goafs as the research object, integrates multi-survey data from surface deformation remote sensing monitoring and 3D laser scanning measurement to survey the area where the surface deformation rate reaches 14cm/ year, accurately identifies the location of risky mine goafs, and constructs detailed representations of the real shapes of the complex mine goafs inside the mineral engineering. The FLAC^3D 6.0 software is used to establish a 3D numerical simulation model of the mine goafs, fully considering the mining process, and conducting characteristic analysis of the stress distribution, failure range and surface deformation response of the mine goafs, revealing the impact of void deformation on the stability of the mine. The numerical simulation results are combined with on-site investigations to verify whether geological disasters have been caused by mine goafs. The research methods and results can provide effective technical means for the detailed survey and stability assessment of mineral engineering with complex mine goafs, which can help to reduce the risk of geological disasters in mines and improve the safety of mineral engineering. Full article

We propose an autofocusing algorithm to obtain, relatively accurately, the 3D position of each particle, particularly its axial location, and particle number of a dense transparent particle solution via its hologram. First, morphological analyses and constrained intensity are used on raw reconstructed images to obtain information on candidate focused particles. Second, axial resolution is used to obtain the real focused particles. Based on the mean intensity and equivalent diameter of each candidate focused particle, all focused particles are eventually secured. Our proposed method can rapidly provide relatively accurate ground-truth axial positions to solve the autofocusing problem that occurs with dense particles. Full article

Purpose: Dirofilariasis is a zoonotic infectious disease caused by a species belonging to the Dirofilaria genus. Human dirofilariasis cases have increased in Europe in the last few decades. Dogs and wild canids represent the definitive hosts and principal reservoirs of Dirofilaria repens, while mosquito species are biological vectors. Humans act as accidental hosts, and clinical manifestations depend on the location of the worm in the organs or tissues. We described the first case of ocular dirofilariasis in the Aosta Valley region (Italy). Case description: a 62-year-old Italian woman complained of recurrent ocular redness, pain and discomfort, accompanied by itching and foreign body sensation in the right eye. The slit lamp biomicroscopic examination revealed conjunctival congestion on the temporal region of bulbar conjunctiva, and a long whitish vermiform mobile mass was detected under the conjunctiva. The anterior chamber showed no flare or cells in either eye, and the dilated fundus examination was normal. The worm was immediately surgically removed to prevent further migration, and was diagnosed morphologically and molecularly as D. repens. Following surgical removal, the symptoms resolved completely and rapidly, with no recurrence of ocular symptoms recorded during 12-month follow-up visits. Conclusions: Ocular dirofilariasis can lead to misdiagnosis due to its rare ocular manifestations, and it is considered an emergent zoonosis in European countries. Accurate diagnosis and control of ocular dirofilariasis by D. repens require a multidisciplinary approach under the One Health framework to effectively address this emergent zoonosis. Full article

This study presents the development and evaluation of a stand-alone solar dryer designed to improve the efficiency of bee bread dehydration. Unlike the electric prototype powered by conventional energy sources, the proposed system operates autonomously, utilizing solar energy as the primary drying agent. The drying chamber is equipped with solar collectors located in its lower section, which ensure convective heating of the product. Active convection is generated by a set of fans powered by photovoltaic panels, maintaining the drying agent’s temperature near 42 °C. The research methodology integrates both numerical simulation and experimental investigation. Simulations focus on the variations in temperature (288–315 K) and relative humidity (1–1.5%) within the honeycomb structure under convective airflow. Experimental trials examine the relationship between moisture content and variables such as bee bread mass, airflow rate, number of frames (5–11 units), and drying time (2–11 h). A statistically grounded analysis based on an experimental design method was conducted, revealing a reduction in moisture content from 16.2–18.26% to 14.1–15.1% under optimized conditions. Linear regression models were derived to describe these dependencies. A comparative assessment using enthalpy–humidity (I–d) diagrams demonstrated the enhanced drying performance of the solar dryer, which is attributed to its cyclic operation mode. The results confirm the potential of the developed system for sustainable and energy-efficient drying of bee bread in decentralized conditions. Full article

Winch-assisted harvesting has expanded considerably in recent years as it enables ground-based machines to work safely on steep slopes. To analyze operator exposure to whole-body and hand–arm vibration (WBV, HAV) and noise exposure (LA_eq, LC_peak) during winch-assisted harvesting (TW) and harvesting without winch assistance (NTW), a field study using a Ponsse Scorpion King harvester and an Ecoforst T-winch traction winch was conducted. Vibrations were measured at three locations inside the cabin (seat, seat base/floor, control lever), while noise exposure was recorded both inside and outside the cabin. WBV exposure during work time operations was highest in the Y-direction, both on the seat (0.49–0.87 m/s²) and on the floor (0.41–0.84 m/s²). The WBV and HAV exposure levels were highest while driving on the forest and skid road. Exposure during the main productive time was significantly influenced by the harvesting system, diameter at breast height (DBH), and tree species. Noise exposure was higher, while WBV and HAV exposures on the seat, floor and control lever were lower during non-work time than during work time. The daily vibration exposure on the seat exceeded the EU action value, while LC_peak noise exposure surpassed the limit value of 140 dB(C) on all measured days. Noise and vibration exposure were constantly higher during TW than NTW harvesting but differences were small. Compared to other studies, the results show that harvesting on steep terrain increases noise and vibration exposure, while non-work time has the opposite effect on vibration and noise exposure. Full article

To address the challenges of obstacle avoidance and low efficiency by robotic arms during apple picking, this paper proposes an improved informed-RRT* motion planning algorithm to improve path planning performance. By integrating the artificial potential field method, the unique location points within the planning space are identified. Segmenting the path planning further accelerates the path searching efficiency. The algorithm includes target bias and cosine offset strategies, along with bidirectional planning to improve planning efficiency, enhancing the purposefulness of informed-RRT* sampling. Spatially expanding sampling by dynamic step size enhances the robustness of path indexing in complex obstacle environments. The algorithm is compared with RRT* and in-formation-RRT* in several scenarios. The experimental results show that compared to RRT* and IRRT*, the average path cost of the optimization algorithm is reduced by 31.565 mm and 14.935 mm and the average search time is reduced by 7.18 s and 4.33 s. In the complex two-dimensional simulation experiment, compared to RRT* and IRRT*, the average path cost of the optimization algorithm is reduced by 362.4 mm and 343.5 mm and the average search time is reduced by 5.49 s and 1.54 s. In the 3D simulation, compared to RRT* and IRRT*, the average path cost is reduced by 1110.17 mm and 469.97 mm and the average search time is reduced by 37.82 s and 11.26 s. The optimization algorithm effectively reduces the total length of the picking path and the path planning time. The research results provide a reference for apple picking robots to perform collision-free picking tasks. Full article

Technological advancements have led to the development of various devices designed to monitor training loads and athletic performance. Power meters, particularly in cycling, allow for the precise quantification of power output, which is crucial for managing training loads and evaluating performance improvements. This study evaluates the validity of the Quarq D-Zero power meter for measuring cycling power output by comparing it with two previously validated devices—the Favero Assioma Duo (FAD) and the Hammer Saris H3 (H3)—noting that, although it shares the same measurement location as the SRM (the gold standard), it has not been directly validated against it. Thirty-one trained male cyclists participated in this study, undergoing tests across various power outputs (100–500 W) and three 10-s sprint efforts. The protocol incorporated different cadences (70, 85, and 100 revolutions per minute), randomized in order, and two cycling positions (seated and standing). Significant differences (p < 0.05) in power readings were observed among the three power meters, except during sprint efforts. However, pairwise comparisons revealed no significant differences (p > 0.05) between the FAD and Quarq power meters, except for the 500 W block. Strong to very strong correlations were observed between the FAD and Quarq power meters (r > 0.883, ICC > 0.879). The coefficient of variation (CV) between the FAD and Quarq devices ranged from 0.62% to 4.89%, and from 0.39% to 6.59% between the H3 and Quarq power meters. In conclusion, the Quarq power meter, integrated into the spider of the bicycle’s bottom bracket, provides valid power output measurements in cycling. Full article

Introduction: Hemangioblastomas (HBs) are benign, highly vascular tumors that can be found intracranially or in the spinal region, representing around 2–15% of primary intramedullary tumors. They can occur sporadically or in association with Von Hipple–Lindau (VHL) disease. Despite recent of advancement of nonsurgical treatments, complete surgical resection remains the gold standard of care for the spinal HBs. Materials and Methods: We conducted an international multicenter retrospective analysis of adult patients surgically treated for spinal HBs in four European referral centers between January 2000 and September 2024, with a minimum post-operative follow-up duration of 6 months. Patients’ sex and age at surgical intervention, clinical presentation, and duration symptoms prior to clinical diagnosis were identified. The pre- and post-operative neurological status at 1 and 6 months and at the last visit was assessed using the modified McCormick score (MCS). The extent of surgical resection was divided into gross total resection (GTR) and subtotal resection (STR). Finally, post-operative complications were inspected as well, namely cerebrospinal fluid leaks, infections, hemorrhages and post-operative spinal stability. Results: A total of 35 patients were included in the cohort, with an age median of 52 years (34.5–60) and a slight male predominance (21/35, i.e., 60%). The median follow-up period was 37.5 months (12–75). More than half were located in the cervical region, making it the most common (54.3%). Syrinxes were observed in 23 cases (72%), and HBs were more commonly intramedullary (80%). GTR was achievable in around 88% of cases. Post-operative complications were observed in nine patients (25.7%). Nearly half of patients were discharged into rehabilitations centers (48.5%). Tumor recurrence was seen in 10.3% only. At the last follow-up, an excellent overall post-operative neurological status (positive ∆ McCormick) was observed in most of patients (88%) and was found to be associated with a relatively younger age group. Tumor location and presence of syrinxes did not show any statistical significance regarding clinical outcome. In patients having benefited from intra-operative monitoring, only D-wave changes showed statistical significance regarding post-operative outcome (p < 0.05). Conclusions: A large majority of patients operated for a spinal HB demonstrated favorable outcome after surgery, with unchanged or improved neurological status. Advanced age could have an impact on the post-operative neurological outcome. Other factors such as tumor size, location, and the presence of syrinx did not seem to significantly impact the neurological outcome. Finally, the surgery of these vascular lesions with no possibility of debulking or piece-meal removal and requiring “en bloc” resection is technically demanding and should be performed by experienced teams in spine and spinal cord surgery only. Full article

Background: Distinguishing between the anatomical variant of an anterior anus and mild forms of imperforate anus with rectoperineal fistula often requires inspection, calibration, and, in uncertain cases, electrical stimulation (ES) under general anesthesia. Anorectal manometry (AM), despite its ability to assess sphincter configuration and function, is rarely reported as a diagnostic tool. This study evaluated the utility of AM in such cases. Methods: A retrospective analysis of AM and clinical data from 38 patients (35 female, 3 male) with suspected anterior anus was conducted from October 2009 to September 2021. Water-perfused catheter probes with eight radial channels were used to perform pull-through maneuvers. Sphincter locations were identified through vector reconstruction, and pressure ratios of the anterior part to the circumference were recorded. Results were compared to clinical data, including ES findings. Statistical significance was assessed using Mann–Whitney U and Chi-Square tests. Results: Following AM, ES was unnecessary in 25 patients. Of the remaining patients, 83% showed abnormal sphincter configurations on ES, and seven underwent anoplasty. Patients with abnormal sphincter complexes demonstrated significantly lower mean anterior pressures (61.2 mmHg vs. 136.4 mmHg, U = 336.5, p = 0.001) and a trend toward lower anterior-to-circumferential pressure ratios (mean 0.42 vs. 0.85, U = 613, p = 0.270). Constipation was also more frequent in this group (X²(1,N = 38) = 4.1, p = 0.044). Average anterior pressures < 75 mmHg and ratios < 0.7 indicated an anus outside the sphincter complex (sensitivity 80%, specificity 90%). Conclusions: AM proves valuable for evaluating ambiguous anterior anus cases, potentially reducing reliance on ES under general anesthesia. 3D high-resolution AM may further increase diagnostic accuracy. Full article

Since 2011, five of Austria’s 29 known prehistoric pile dwellings have been part of the transnational UNESCO World Heritage Site “Prehistoric Pile Dwellings around the Alps”. These remarkable archaeological sites have been preserved for over 7000 years in lakes and moors. Due to their hidden location underwater or in the soil of bogs, the sites are inaccessible to the public, making it difficult to convey the full scope of this heritage. To address this, the national project “Surfaced—the digital pile dwellings” was launched, aiming to create a virtual bridge connecting the sites, collections, and exhibitions across Austria. It involved digitizing 500 objects, scanned in high resolution, and presenting them as 3D models in an open-access web application. The web application PfahlbauKompass allows users to explore these 3D models, view information about the artefacts and the sites, and create digital collections. It provides access to finds from national museums, regional heritage houses, and private collections. The project offers scientific potential as well as opportunities for virtual exhibitions and educational initiatives. It aims to preserve and visualize an essential part of Austria’s cultural heritage and was designed not only to archive finds but also to raise awareness of the hidden sites among the public. Full article

Objectives: The objective of this study was to assess the relationship of VEGF-C and LVD with pathoclinical factors of potential prognostic value and with the survival time of gastric cancer patients. Materials and methods: A total of 103 radically operated patients for gastric cancer who did not undergo neoadjuvant therapy were included in this study. The minimum follow-up period after surgery was 61 months. VEGF-C and lymphatic vessels were immunohistochemically determined using antibodies, including VEGF-C (c-20) sc 1881-Goat Polyclonal IgG (Santa Cruz Biotechnology) and Podoplanin D2-40 Mouse Monoclonal Antibody (ROCHE). The relationship between VEGF-C expression in gastric adenocarcinoma cells and the density of lymphatic vessels at the periphery of the primary tumor was assessed, along with the relationships of VEGF-C and LVD with selected pathoclinical parameters of gastric cancer and prognosis. Results: VEGF-C overexpression was associated with increased LVD (Mann–Whitney U test, p = 0.03) and the Lauren intestinal type of cancer (Pearson’s chi-square test, p < 0.001). Increased LVD was more often associated with cancers located beyond the cardia (Mann–Whitney U test, p = 0.04). We did not demonstrate an association of VEGF-C or LVD with OS or with prognostic features, such as pT, pN, or pTNM staging. However, in the Lauren intestinal type of cancer, VEGF-C overexpression correlated with shorter OS (log-rank, p = 0.01) and, at the level of p = 0.05 in multivariate analysis, it had an independent negative prognostic value. Conclusions: Peritumoral overexpression of VEGF-C in primary gastric cancer tumors is associated with increased LVD. The Lauren intestinal type of cancer is associated with VEGF-C overexpression. The overexpression of VEGF-C in intestinal-type gastric cancer is associated with worse prognosis. Full article