Search Results (177)

Novel laparoscopic optical forceps (OFs), developed and patented by the University of Bari Aldo Moro (EP4119030, Bari, Italy), were designed to enhance safety and efficiency during laparoscopic ovariectomy in dogs by enabling atraumatic ovarian suspension and surgical maneuvers. This study aimed to describe the design, prototyping, sterilization validation, and preliminary clinical evaluation of this instrument. Prototypes were fabricated using ABS-like Pro resin via LSPc 3D printing. EtOx (ethylene oxide) sterilization proved to be the only effective method ensuring both microbiological safety and material integrity after 25 cycles. A randomized clinical trial involving 36 female dogs compared the OFs with conventional extracorporeal suture (ES) suspension using two-port laparoscopic ovariectomy. Surgical performance was assessed via operative times and complication rates. The OF group demonstrated significantly reduced ovariectomy (7.5 ± 1.6 min vs. 23.7 ± 7.6 min, p < 0.01) and overall surgical (14.2 ± 1.7 min vs. 30.4 ± 7.4 min, p < 0.01) times. No intraoperative complications occurred in the OF group, while the ES group exhibited instances of needle breakage, multiple suture attempts, and increased bleeding. The OFs enabled surgical maneuvers and ovarian suspension without requiring additional incisions or complex techniques, offering ergonomic advantages and compatibility with standard optics. These findings support the OFs as a promising tool to simplify and improve minimally invasive ovariectomy in veterinary surgery. Full article

Background/Objectives: This study aims to evaluate the long-term efficacy and safety of ab interno techniques using minimally invasive glaucoma surgery (MIGS), specifically XEN gel stent implantation, by evaluating its 2-year outcomes in patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG). Methods: This retrospective single-center study consecutively included 31 eyes of 31 patients with POAG or PXG who underwent XEN gel stent implantation. Patients were followed for 24 months, with assessments at multiple time points. Success was defined as achieving an IOP of less than 14 mmHg and a reduction of more than 20% from preoperative IOP without additional glaucoma surgery. Bleb morphology was evaluated using anterior segment optical coherence tomography (AS-OCT) and slit-lamp photographs. Postoperative interventions and complications were also recorded. Results: At 24 months, complete success and qualified success rates were 35.5% (11/31) and 51.6% (16/31), respectively. There was no difference in surgical success rates at 2 years based on the tip location (intraconjunctiva, intratenon, and uviform) on the 1st postoperative day. Patients with high sparse wall on AS-OCT imaging or avascular bleb morphology via slit-lamp photography at 6 months postoperatively had higher complete success rates at 2 years than those without (p = 0.007, p = 0.009, respectively). Patients with avascular bleb types at 6 months postoperatively had higher qualified success rates at 2 years compared with the vascular types (p = 0.038). Needling was performed in 32.3% of eyes, with secondary surgical procedures required in 16.1% of eyes. The most common adverse event was hypotony, occurring in 67.7% of eyes on the 1st postoperative day but resolving within 6 months. Conclusions: The ab interno XEN gel stent is an effective and minimally invasive option for managing POAG and PXG, with long-term success predicted by the AS-OCT assessment of bleb morphology at 6 months. Proactive postoperative management, emphasizing early intervention and monitoring, is crucial for maintaining optimal outcomes. Full article

This paper reports the first evidence of the presence of the mineral tremolite asbestos in Roman building materials from the Micia archaeological site (Romania), thus contributing to the understanding of the implications of ancient building materials. The Micia archaeological site includes both a fort and a civilian Roman military settlement that was inhabited by both civilians and soldiers from various Roman troops. Over time, since the late 2nd century AD, the settlement has undergone significant reconstruction, especially after some fires. Tremolite asbestos is a non-flammable mineral that, due to its fibrous properties, was used in the past in building materials, although it poses health risks when inhaled. To highlight it, several advanced and highly sensitive scientific techniques are used in this work to discover the presence of tremolite asbestos and to examine its structure, composition, and morphology inside the investigated samples. Tremolite asbestos is typically white to gray or greenish in color, characterized by thin, needle-like fibers that can easily become airborne and inhaled. It is a crystalline mineral that usually forms long, straight, sharp fibers. Under high magnification in optical microscopy or in scanning electron microscope images, correlated with other performant analytical techniques (XRD, WDXRF, FTIR, Raman, BET, TGA), tremolite asbestos appears as elongated, slender fibers—often bundled or intertwined—with smooth or slightly striated surfaces. Full article

Optimal needle trajectory selection is critical in biopsy procedures to minimize tissue damage and ensure diagnostic accuracy. Timely trajectory planning is essential, as it relies on preoperative CT imaging. Prolonged processing times increase the risk of patient movement, rendering the planned path invalid. Traditional methods relying on clinician expertise or slow algorithms struggle with complex anatomical modeling for structures such as blood vessels. We introduce a novel method that reframes trajectory planning as an optimal puncture site identification problem by leveraging optical principles and computer rendering. A 3D model of key anatomical structures is reconstructed from CT images and segmented using SegResNet (average Dice similarity coefficient of 0.9122). A virtual light source positioned at the target illuminates the space, assigning distinct absorption coefficients to tissues based on needle permissibility and risk. Diffuse reflection simulates needle angle, and accumulated absorption represents depth, capturing puncture constraints. This simulation generates a grayscale map on the skin surface, highlighting candidate puncture sites. Furthermore, we employ a random forest-based method to model clinician preferences. This model analyzes an RGB image derived from the grayscale distribution to automatically select the optimal path and determine the needle entry point. The experimental evaluation demonstrates an average computation time of just 1.905 s per sample, which is significantly faster than traditional methods that require seconds to minutes. Moreover, clinical assessment by a thoracic surgeon found that 78% of the recommended paths met clinical standards, with 0% deemed unsatisfactory. These findings suggest that our method provides a rapid, intuitive, and reliable decision-support tool, improving biopsy safety and efficiency. Full article

Accurately detecting defect-induced photon emissions enables early defect detection and characterization. To address this, a defect evolution state recognition model based on phase-resolved photon counting and dimensionality reduction calculations is proposed under alternating current (AC) excitation. Initially, photon information from protruding metal defects simulated using needle–plane electrodes during partial discharge (PD) evolution is analyzed in SF₆. Subsequently, phase-resolved photon counting (PRPC) techniques and statistical analysis are employed to extract feature parameters for quantitative characterization of defect-induced photon responses. Finally, a t-distributed stochastic neighbor embedding (t-SNE) dimensionality reduction analysis is utilized to establish criteria for categorizing defect evolution states. The findings reveal that metal-particle-triggered optical PRPC maintains the obvious polarity effect, and the entire evolution of the discharge can be divided into three processes. These research findings are expected to advance the accurate assessment of operational risks in gas-insulated systems. Full article

Over 250,000 gastrostomy tubes (G-tubes) are placed annually in the United States. Percutaneous endoscopic gastrostomy (PEG) is the most widely used clinical method for placing G-tubes within the stomach. However, endoscope detectability is limited due to the scattering of light by tissues. Poor organ visibility and low sensitivity of the palpation techniques cause blind needle insertions, which cause colon/liver perforations, abdominal bleeding, and gastric resections. Additionally, imaging artifacts and the poor distinguishability between water-filled tissues make ultrasound (US) imaging-based techniques incompatible with G-tube placement. The risk of ionizing radiation exposure and the confinement of fluoroscopy to radiology suites limits its bedside utility in patients. Considering these limitations, we propose to design a safe, point-of-care integrated US and photoacoustic (PA) imaging system for accurate G-tube placement procedures, for a broad spectrum of patients, and to characterize the system’s effectiveness. Our proposed technology utilizes a clinically safe contrast agent and a dual-wavelength approach for precise procedures. Our ex vivo tissue studies indicated that PA imaging accurately differentiates the different organs at specific wavelengths. Our characterization studies revealed that PA imaging could detect lower concentrations of Indocyanine Green (ICG) dye coating the colon wall, minimizing the risk of ICG dye-related toxicity and providing safer G-tube placements. Full article

Background/Objectives: Primary brain tumors are difficult to identify intraoperatively due to their infiltrative character in the marginal zone. Several optical methods have been suggested. Of these, 5-ALA-induced fluorescence visualized through a microscope is the most common. The aim is to present an investigational probe-based optical system and its translation for clinical use, summarize previous studies, and give examples of clinical implementations during resection and burr hole biopsies. Methods: The FluoRa system combines 5-ALA fluorescence spectroscopy with laser Doppler flowmetry (LDF). Probe designs are available for brain tumor resection (hand-held probe) or burr hole needle biopsies (frame-based or navigated). The outer cannulas of biopsy needles are modified with an opening at the tip for simultaneous use with optical probes during insertion along the trajectory. An updated version of FluoRa is introduced and experimentally investigated. Results: Probe-based fluorescence spectroscopy has been successfully translated for clinical use and applied during brain tumor resection (n = 75) and burr hole needle biopsies (n = 47). Forward-looking optical measurements through the biopsy needle reduce the number of trajectories (28/27) compared to prior to insertion (28/20), at the same time that the target for tissue sampling can be identified in situ. Additionally, increased microcirculation is identified along the trajectory with LDF. This is accomplished with FluoRa. Conclusions: Intraoperative probe-based spectroscopic measurements quantify 5-ALA fluorescence and thus identify glioblastoma and lymphoma tissue in situ during resection and burr hole needle biopsies. Full article

Additive manufacturing (AM) has become a key element of Industry 4.0, particularly the extrusion AM (EAM) of thermoplastic materials, which is recognized as the most widely used technology. Fused Filament Fabrication (FFF), however, depends on expensive commercially available filaments, making pellet extruder-based EAM techniques more desirable. Large-format EAM systems could benefit from printing lightweight objects with reduced material use and lower power consumption by utilizing hollow rather than solid extrudates. In this study, a custom extruder head was designed and an EAM system capable of extruding inflatable hollow extrudates from a variety of materials was developed. By integrating a co-axial nozzle-needle system, a thermoplastic shell was extruded while creating a hollow core using pressurized nitrogen gas. This method allows for the production of objects with gradient part density and varied mechanical properties by controlling the inflation of the hollow extrudates. The effects of process parameters— such as extrusion temperature, extrusion speed, and gas pressure were investigated—using poly-lactic acid (PLA) and styrene-ethylene-butylene-styrene (SEBS) pellets. The preliminary tests identified the optimal range of these parameters for consistent hollow extrudates. We then varied the parameters to determine their impact on the dimensions of the extrudates, supported by analyses of microscopic images taken with an optical microscope. Our findings reveal that pressure is the most influential factor affecting extrudate dimensions. In contrast, variations in temperature and extrusion speed had a relatively minor impact, whereas changes in pressure led to significant alterations in the extrudate’s size and shape. Full article

The aim of this research is to investigate the phase composition and structural peculiarities of complex metamorphic manganese ores from Central Kazakhstan before and after sintering in the temperature range of 600–1200 °C in an air atmosphere. X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and optical microscopy were used to analyze changes in elemental and phase composition. In their initial state, according to XRF analysis, the Bogach ore was manganese-rich, with a manganese content of 60.77 wt.%, while the Zhaksy ore contained manganese (44.88 wt.%), silicon (20.85 wt.%), and iron (6.14 wt.%) as its main components. In the Bogach ore samples, manganese content increased from 60.77% to 65.7% as the sintering temperature rose to 1100 °C, while the hausmannite phase (Mn₃O₄) emerged as the dominant phase, comprising 95.77% of the crystalline component at 1200 °C. Conversely, the Zhaksy ore samples displayed a sharp increase in braunite-phase (Mn₇O₁₂Si) content, reaching 83.81% at 1100 °C, alongside significant quartz amorphization. The degree of crystallinity in Bogach ore peaked at 56.2% at 900 °C but declined at higher temperatures due to amorphous phase formation. A surface morphology analysis revealed the transformation of dense, non-uniform particles into porous, granular structures with pronounced recrystallization as the temperature increased. In the Bogach samples, sintering at 900 °C resulted in elongated, needle-like crystalline formations, while at 1200 °C, tetragonal crystals of hausmannite dominated, indicating significant grain growth and recrystallization. For Zhaksy samples, sintering at 1100 °C led to a porous morphology with interconnected grains and microvoids, reflecting enhanced braunite crystallization and quartz amorphization. These findings provide quantitative insights into optimizing manganese oxide phases for industrial applications, such as catalysts and pigments, and emphasize the impact of thermal treatment on phase stability and structural properties. This research contributes to the development of efficient processing technologies for medium-grade manganese ores, aligning with Kazakhstan’s strategic goals in sustainable resource utilization. Full article

Background: This review evaluates needle navigation technologies in minimally invasive cardiovascular surgery (MICS), identifying their strengths and limitations and the requirements for an ideal needle navigation system that features optimal guidance and easy adoption in clinical practice. Methods: A systematic search of PubMed, Web of Science, and IEEE databases up until June 2024 identified original studies on needle navigation in MICS. Eligible studies were those published within the past decade and that performed MICS requiring needle navigation technologies in adult patients. Animal studies, case reports, clinical trials, or laboratory experiments were excluded to focus on actively deployed techniques in clinical practice. Extracted data included the study year, modalities used, procedures performed, and the reported strengths and limitations, from which the requirements for an optimal needle navigation system were derived. Results: Of 36 eligible articles, 21 used ultrasound (US) for real-time imaging despite depth and needle visibility challenges. Computer tomography (CT)-guided fluoroscopy, cited in 19 articles, enhanced deep structure visualization but involved radiation risks. Magnetic resonance imaging (MRI), though excellent for soft-tissue contrast, was not used due to metallic tool incompatibility. Multimodal techniques, like US–fluoroscopy fusion, improved accuracy but added cost and workflow complexity. No single technology meets all the criteria for an ideal needle navigation system, which should combine real-time imaging, 3D spatial awareness, and tissue integrity feedback while being cost-effective and easily integrated into existing workflows. Conclusions: This review derived the criteria and obstacles an ideal needle navigation system must address before its clinical adoption, along with novel technological approaches that show potential to overcome those challenges. For instance, fusion technologies overlay information from multiple visual approaches within a single interface to overcome individual limitations. Additionally, emerging diagnostic methods like vibroacoustic sensing or optical fiber needles offer information from complementary sensory channels, augmenting visual approaches with insights into tissue integrity and structure, thereby paving the way for enhanced needle navigation systems in MICS. Full article

Studies on emeralds from Habachtal (Austria) are scarce and non-exhaustive. However, they represent a significant interest to the community, as they have been assumed to be present in historical pieces of jewelry. Along with Egypt, Habachtal is suggested to be one of the main sources of gem-quality emeralds of archaeological significance. In this regard and due to their similar macroscopic look and geological context, it has always been challenging to distinguish Austrian and Egyptian emeralds set in historic jewelry. In this paper, a first comprehensive study of several Habchtal emeralds is presented based on a combination of classic gemology, chemistry and spectroscopy, using non-destructive to micro-destructive methods. Spectroscopic analyses, such as via Raman, FTIR and UV-Vis–NIR spectroscopies, showed that emeralds from Habachtal (Austria) contain Type II H₂O molecules with alkalis and they are colored by chromium and iron, similarly to emeralds from Egypt. Under an optical microscope (and identified by Raman spectroscopy), actinolite needle-like inclusions are frequently observed in Austrian emeralds. Other inclusions, such as quartz, plagioclase, albite, phlogopite and pyrite, can also be observed in Austrian samples. Chemical analysis of Austrian emeralds’ trace elements by LA–ICP–MS show similar results to those from Egypt, with the exception of V, K and Rb, which show a lesser content in Austrian emeralds. Thanks to the determination of inclusions combined with a careful examination of specific chemistry, this study shows that Austrian emeralds can be distinguished from their Egyptian counterpart. Full article

The current study focused on the synthesis of doped silver nanoparticles (doped AgNPs) with yttrium (Y), gadolinium (Gd), and chromium (Cr) from pine needle leaf extract (PNLE). X-ray diffraction (XRD) was performed to assess the phase formation, detecting 61.83% from Ag and 38.17% for secondary phases of AgCl, AgO, Y, Cr-, and Gd phases. The size and shape of the NPs were determined by transmission electron microscopy (TEM), showing a spherical shape with an average particle size of 26.43 nm. X-ray photoelectron spectroscopy (XPS) detected the oxidation state of the presented elements. The scanning electron microscope (SEM) and the energy-dispersive X-ray analysis (EDX) determined the morphology and elemental composition of the NPs, respectively. Fourier transform infrared spectroscopy (FTIR) determined the different functional groups indicating the presence of Ag, Y, Gd, Cr, and other groups. Photoluminescence (PL) spectroscopy showed the optical properties of the NPs. A vibrating sample magnetometer (VSM) revealed the ferromagnetic behavior of the doped AgNPs. The antibacterial activity of the doped AgNPs was tested against six uro-pathogenic bacteria (Staphylococcus aureus, Staphylococcus haemolyticus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa) using the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) microdilution assays, agar well diffusion assay, time–kill test, and antibiofilm screening assays, revealing significant activity, with MICs ranging between 0.0625 and 0.5 mg/mL and antibiofilm activity between 40 and 85%. The antioxidant activity was determined by the 1,1, diphenyl 1-2 picrylhydrazyl (DPPH) radical scavenging assay with a potential of 61.3%. The docking studies showed that the doped AgNPs had the potential to predict the inhibition of crucial enzymes such as penicillin-binding proteins, LasR-binding proteins, carbapenemase, DNA gyrase, and dihydropteroate synthase. The results suggest that the doped AgNPs can be applied in different medical domains. Full article

In recent years, the issue of increasing the wear resistance of the working bodies of agricultural machinery designed for cutting and breaking the soil has received special attention. The surface layers of working bodies of agricultural machinery during operation are subjected to intensive abrasive wear, which leads to rapid wear of equipment and a reduction in its service life. The induction cladding method using materials such as Sormait-1 is widely used to increase the wear resistance of tool working surfaces. However, after coating, additional heat treatment is required to improve the physical and mechanical properties of the material and increase its durability. In electrofriction technology (EFT) hardening, the surfaces of the parts are subjected to melting under the influence of electric arcs. In this work, three types of surface treatment of L53 steel have been investigated: induction cladding using Sormait-1, electrofriction treatment, and a combination of induction cladding followed by electrofriction treatment. The microstructure was analyzed using optical microscopy and scanning electron microscopy. Erosion and abrasion tests were carried out in accordance with ASTM G65 and ASTM G76-04 international standards to evaluate the wear resistance of the materials under mechanical stress. A dendritic structure was formed after the induction cladding of the Sormait-1 material, but subsequent electrofriction treatment resulted in a reduction of this dendritic structure, which contributed to an increase in the hardness of the material. However, the highest hardness, reaching 965 HV, was recorded after electrofriction treatment of L53 steel. This is explained by needle martensite in the structure, which is formed as a result of quenching. Further, the influence of structural characteristics and hardness on erosion and abrasion wear resistance was examined. The analysis showed that the material microstructure and hardness have a decisive influence on the improvement of wear resistance, especially under conditions of intensive erosion and abrasive friction. Full article

Additive manufacturing (AM) has emerged as one of the core components of the fourth industrial revolution, Industry 4.0. Among others, the extrusion AM (EAM) of thermoplastic materials has been named as the most widely adopted technology. Fused filament fabrication (FFF) relies on the commercial availability of expensive filaments; hence, pellet extruder-based EAM techniques are desired. Large-format EAM systems would benefit from the ability to print lightweight objects with less materials and lower power consumption, which is possible with the use of hollow extrudates rather than solid extrudates to print objects. In this work, we designed a custom extruder head and developed an EAM system that allows the extrusion of inflatable hollow extrudates of a relatively wide material choice. By incorporating a co-axial nozzle–needle system, a thermoplastic shell was extruded while the hollow core was generated by using pressurized nitrogen gas. The ability to print using hollow extrudates with controllable inflation allows us to print objects with gradient part density with different degrees of mechanical properties. In this article, the effect of different process parameters, namely, extrusion temperature, extrusion speed, and gas pressure, were studied using poly-lactic acid (PLA) pellets. Initially, a set of preliminary tests was conducted to identify the maximum and minimum ranges of these parameters that result in consistent hollow extrudates. Finally, the parameters were varied to understand how they affect the core diameter and shell thickness of the hollow extrudates. These findings were supported by analyses of microscopic images taken under an optical microscope. Full article

Background: In the one-stop breast clinic setting, breast cytology traditionally provides immediate diagnosis of carcinoma. Fluorescence confocal microscopy (FCM) is an emerging optical technique enabling ex vivo analysis of breast biopsies in real-time. This study represents the first proof of concept for integrating FCM imaging into the routine workflow of breast core needle biopsies (CNB) at Gustave Roussy’s one-stop breast clinic. Methods: Fifty women with breast masses underwent consecutive enrollment. Biopsies were stained with acridine orange and fast green, followed by imaging using the Vivascope 2500M-G4 (FCM). Interpretation was conducted by two pathologists in real time (PT1) or postoperatively (PT2). Concordance with definitive histology, the duration of the FCM protocol, and its impact on conventional histopathology, immunohistochemistry, and FISH analyses were evaluated. Results: In our study of 50 biopsies, a concordant diagnosis of malignancy was performed using FCM on the malignant cases at definitive histology in 93.5% (29/31 cases) and in 90.3% (28/31 cases) according to PT1 and PT2, respectively. When the FCM suspicious cases were added, FCM identified 100% (31/31 cases) and 96.7% (30/31 cases) of the malignant cases according to PT1 and PT2, respectively. A notable false positive case was identified as a complex sclerosing lesion. The median time for sample preparation (including tissue reception) was 5 min, while the median time for imaging acquisition with interpretation was 3 min for PT1, but 1 min required for interpretation alone by PT2. Histopathological alterations were not more prevalent in FCM-imaged biopsies compared to conventionally treated biopsies. The immunophenotyping and molecular assessment of tissue were preserved after FCM protocol. Conclusions: FCM shows promise as a new histological method for the immediate diagnosis of breast carcinoma on core needle biopsies in a one-stop clinic setting, while also preserving tissue specimens for final histology. Full article