Search Results (10)

Wagner syndrome is a rare autosomal dominant vitreoretinopathy caused by mutations in chondroitin sulphate proteoglycan 2 (CSPG2)/Versican (VCAN). Here, we present a retrospective case series of a family pedigree with genetically confirmed Wagner syndrome (heterozygous VCAN exon 8 deletion), as follows: a 34-year-old mother (P1), 12-year-old daughter (P2), and a 2-year-old son (P3). The phenotype included early-onset cataract (P1), optically empty vitreous with avascular membranes (P1, 2), nasal dragging of optic nerve heads associated with foveal hypoplasia (P1, 2), tractional retinoschisis on optical coherence tomography (P2), and peripheral circumferential vitreo-retinal interface abnormality resembling white-without-pressure (P3) progressing to pigmented chorio-retinal atrophy (P1, 2). P2 developed a macula-off retinal detachment, which was treated initially with encircling band + vitrectomy + gas, followed by vitrectomy + heavy silicone oil tamponade for re-detachment from new inferior breaks. Strong vitreo-retinal adhesion was noted intraoperatively, which prevented the separation of posterior hyaloid beyond the equator. Electroretinograms from P1&2 demonstrated attenuated b-waves, a-waves, and flicker responses in light- and dark-adapted conditions, suggestive of generalised retinal dysfunction. Our patients demonstrated the clinical spectrum of Wagner syndrome, highlighting nasal dragging with foveal disruption as a distinguishing feature from other inherited vitreoretinopathies. Surgical outcomes demonstrate significant challenges in managing vitreo-retinal traction and need for further research into strategies to prevent sight loss. Full article

Silicon plays a crucial role in enhancing plant tolerance to various abiotic and biotic stresses, including drought, salinity, heavy metals, and pathogen/pest attacks. Its application has shown promising results in improving stress tolerance and productivity in medicinal plants. This review synthesizes findings from numerous studies investigating the mechanisms by which silicon confers stress tolerance, including the regulation of antioxidant systems, water relations, nutrient homeostasis, phytohormone signaling, and stress-responsive gene expression. Additionally, it examines the effects of silicon supplementation on the production of valuable secondary metabolites and essential oils in medicinal plants. Silicon application can significantly mitigate stress-induced damage in plants, including medicinally important species such as borage, honeysuckle, licorice, Damask rose, savory, basil, and eucalyptus. The deposition of silicon in cell walls provides physical reinforcement and acts as a barrier against pathogen invasion and insect herbivory. Furthermore, silicon fertilization can enhance the production of valuable secondary metabolites in medicinal crops under stress conditions. The findings underscore the potential of silicon fertilization as a sustainable strategy for improving the productivity and quality of medicinal crops under changing environmental conditions, highlighting the need for further research to elucidate the molecular mechanisms underlying silicon-mediated stress tolerance and practical applications in medicinal plant cultivation. Full article

Anti-VEGF agents, e.g., bevacizumab, are used in retinal surgery, while their interaction with silicone oils and novel hydrogels remains unclear. This study examines the in vitro pharmacokinetics of bevacizumab in silicone oil-filled eyes compared to various hydrogel replacements and the porcine vitreous body as well as its impact on the interface tension of silicone oils. An in vitro model filled with light or heavy silicone oil, porcine vitreous bodies, or hydrogels (alginate and polyethylene glycol (PEG)-based) was equilibrated with a balanced salt solution. Monitoring of bevacizumab in the aqueous phase was conducted for up to 24 h, and its effect on interfacial tension was studied. Significant differences in bevacizumab partitioning were observed across endotamponades after 24 h. In silicone oils, bevacizumab was found exclusively in the aqueous phase, while in the other endotamponades, it accumulated in the gel phase (96.1% in porcine vitreous body, 83.5% in alginate, and 27.6% in PEG-based hydrogel). Bevacizumab significantly reduced interfacial tension (40 to 8 mN/m), possibly enhancing silicone oil emulsification. The type of endotamponade heavily influenced the bevacizumab concentration in the aqueous. The vitreous body and replacement hydrogels likely serve as a drug reservoir, highlighting the need for in vivo studies to explore these interactions prior to clinical application. Full article

Background: Endotamponade of the vitreous body with silicone oil is a common procedure, being the basis of many vitreoretinal surgeries. However, emulsification may happen, which is a clinically relevant adverse event of silicone oil use. Methods: This review provides a thorough analysis of the emulsification process. It focuses on describing factors affecting this event as well as its possible subsequent complications. Results: The viscosity of silicone oil, the duration of emulsification, the status of the lens and many other factors have an influence on the onset and intensity of emulsification. This phenomenon carries several risks for operated eyes such as increased intraocular pressure, keratopathy or structural changes to the retina. Conclusions: The use of modern imaging techniques, especially optical coherence tomography, enables faster detection of the emulsification process. This allows for an adequate clinical response and more accurate follow-up of the patient. Full article

Analysis of the very-low-sulfur fuel oil (VLSFO) and ultra-low-sulfur fuel oil (ULSFO) bunkered in key ports in Asia, the Middle East, North America, Western Europe, and Russia is presented. The characteristics of said fuels, including density, sulfur content, kinematic viscosity, aluminum and silicon content, vanadium and nickel content, as well as pour point are investigated. Furthermore, the main trends and correlations are also discussed. Based on the graphical and mathematical analysis of the properties, the composition of the fuels is predicted. The key fuel components in Asian ports, the most important of which is Singapore, are hydrodesulfurized atmospheric residues (AR) (50–70%) and catalytic cracker heavy cycle oil (HCO) (15–35%) with the addition of other components, which is explained by the presence of a number of large oil refining centers in the area. In the Middle East ports, the most used VLSFO compositions are based on available resources of low-sulfur components, namely hydrodesulfurized AR, the production facilities of which were recently built in the region. In European ports, due to the relatively low sulfur content in processed oils, straight-run AR is widely used as a component of low-sulfur marine fuels. In addition, fuels in Western European ports contain on average significantly more hydrotreated vacuum gas oil (21%) than in the rest of the world (4–5%). Finally, a mixture of hydrotreated (80–90%) and straight-run fuel oil (10–15%) with a sulfur content of no more than 2.0–2.5% is used as the base low-sulfur component of marine fuels in the ports of Singapore and the Middle East. Full article

With the increasing attention to light oil, the catalytic cracking process of heavy oil is being vigorously developed. The silicon hydroxyl groups on the surface of mesoporous silica materials can be used as weak acid centers to preliminarily crack heavy oil macromolecules. Herein, a strategy of introducing titanium into a silica skeleton for modification is proposed to increase active sites, as well as improve the hydrothermal stability. After titanium modification, the mesoporous silica material has more weak acid sites, and shows better ability in deep cracking heavy oil. Notably, when the content of titanium doping is 2%, the CT(2) catalyst exhibited the best high-temperature hydrothermal stability, which can be used as a suitable heavy oil catalytic cracking catalyst. This kind of titanium-modified mesoporous silica material shows great application prospects in heavy oil catalytic cracking, which may provide a novel idea for subsequent development. Full article

A silicon nitride ceramic bearing has good self-lubricating characteristics. It still has a good operational status under the condition of a lack of oil. However, the temperature distribution of a silicon nitride ceramic bearing during its operation is unclear. To clarify the thermal distribution of a full-ceramic ball silicon nitride ceramic bearing under self-lubricating conditions, the changing trend of the rolling friction temperature between the rolling elements and channels with different accuracies is analyzed using the friction testing machine. The bearing heat generation model based on the silicon nitride material coefficient is established, and the life test machine measures the temperature of the bearing to verify the accuracy of the simulation model. The results show that the friction temperature between the ceramic ball and channel decreases with the increase in ceramic ball level. With an increase in the ceramic ball pressure and temperature, the friction temperature rises. Under self-lubrication, when the bearing bears a heavy load, the influence of the rotating speed on temperature rise tends to decrease. Under the condition of high speed, with the increase in load, the change range of temperature rise shows an upward trend. The important relationship between the bearing’s heat and bearing’s load and speed is revealed. It provides some theoretical guidance for the thermal analysis of a silicon nitride ceramic ball bearing under the self-lubricating condition to improve the service life and reliability of full-ceramic ball bearings. Full article

Silicone oil endotamponades provide a reservoir for drugs in the eye. Following vitrectomy surgery to treat retinal detachments, extensive diabetic retinopathy or endophthalmitis, they can be used as long-term lipophilic depots. This study aimed to investigate the physicochemical properties of intravitreally applied drugs of different lipophilicity, namely vancomycin, ceftazidime and voriconazole. For this purpose, an in vitro model of the silicone-oil-filled eye compared to porcine vitreous bodies (PVBs) was used. In a glass container, either light or heavy silicone oil or PVB was set into equilibrium with an aqueous fluid. Vancomycin, voriconazole and ceftazidime were added in concentrations commonly applied in clinical practice. The time course of the concentration of the drugs was determined in the hydrophilic phase for up to 24 h. With silicone oil present, the concentrations of vancomycin, voriconazole and ceftazidime were elevated in the aqueous humor when compared to the vitreous body (p < 0.001 for all drugs). With increasing lipophilicity, higher concentrations of the drug dissolved in silicone oil after 24 h (52.7%, 49.1% and 34.3% for vancomycin, ceftazidime and voriconazole, respectively). While no difference between lighter- and heavier-than-water silicone oil was apparent for vancomycin and ceftazidime (p = 0.17 and p = 0.72), voriconazole dissolved significantly better in the heavier-than-water silicone oil (p = 0.002). A higher-than-expected percentage of the glycopeptide vancomycin dissolved in the porcine vitreous body, possibly due to protein binding. In conclusion, silicone oils influence the drug concentration and distribution of intravitreally applied drugs depending on their lipophilicity. The addition of F6H8 used to create heavy silicone oils attenuates these effects for lipophilic drugs. Knowledge of the distribution of these intravitreally applied drugs is crucial to ensure the desired anti-infectious effect. Full article

Red mud (RM), also called bauxite residue, is a strong alkaline industrial waste generated during the alumina production process. The annual production of RM in China is large, but its average utilization rate is low (only 4%). High generation and low consumption make the disposal of RM mainly by stockpiling, which has caused serious heavy metal pollution and radioactive contamination. In this paper, the various industrial utilization methods of RM in China during the past 60 years have been introduced. Moreover, some recent industrial progresses were referred. The results show that RM can be widely used in building materials, valuable metals extraction, and some novel utilization methods, such as silica-calcium fertilizer, inorganic polymer material and desulfurizer. Most of the industrial utilization methods of RM have been used until now and some successfully applied to other aluminum plants, providing some feasible routes for a large amount utilization of RM. Some industrial utilization methods (such as oil well cement and calcium silicon fertilizer) have not been used due to some problems that cannot be ignored, but it provided a lot of valuable experience and was helpful for the subsequent RM utilization. Moreover, some novel and feasible RM utilization methods were proposed and successfully industrialized, which showed that RM has a broader application prospect. Many actual practices showed that the best way to safely dispose of RM was to develop technology that could consume large amounts of RM or transform it into secondary resources, which may need more time and effort. Full article

Tribological conditions can change drastically during heavy loaded regimes as experienced in metal forming; this is especially critical when lubrication can only be applied at the early stage of the process because the homogeneous lubricant layer can break along the die-workpiece interface. In these cases, adopting a constant friction factor for the lubricant-surface pair may not be a valid assumption. This paper presents a procedure based on the use of dual friction factor maps to determine friction factors employed in heavy loaded regimes. A finite element (FE) simulation is used to obtain the friction factor map for the alloy UNS A96082. Experiments were conducted using four lubricants (aluminum anti-size, MoS₂ grease, silicone oil, and copper paste) to determine the actual friction curves. The experimental procedure is based on the application of lubricant only at the beginning of the first stage of ring compression, and not at intermediate stages as is usual in typical ring compression tests (RCTs). The results show that for small reductions (r_h < 20%), the conventional RCT can be applied because the tribological conditions remain similar. For large reductions (r_h > 20%), it is recommended to obtain an average value of the friction factor for every lubricant-surface pair in the range of deformation considered. Full article