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Case Series of Inappropriate Concentration of Intraocular Sulfur Hexafluoride
摘要： Due to high complexity, vitreoretinal surgery presents a higher number of patient safety incidents compared with other ophthalmic procedures. Intraocular gases are one of the most useful adjuncts to vitrectomy and surprisingly, surgeons commonly admit to having occasional problems with incorrect gas concentration. The aim of this study is to present a consecutive case series of patients with improper concentration of sulfur hexafluoride (SF6) applied during vitrectomy. Three patients underwent 27-gauge vitrectomy and at the end of surgery inappropriate dilution of 100% SF6 was administered. It was attributed to a calculation error, change in the gas supplier, or increased partial pressure of SF6 before dilution. Postoperatively, due to IOP increase, two eyes required intravitreal gas-air exchange. Subsequently, cataract surgery was performed in one eye with concomitant vitrectomy and silicone oil tamponade due to retinal detachment. To prevent such complications, we suggest using intraocular gases with great care, training of ophthalmic personnel, and prompting manufacturers to provide SF6 in a prepared concentration of 20%.
关键词： Intraocular pressure,Vitrectomy,Expandable gas,Intraocular tamponade,Sulfur hexafluoride
更新于2025-09-23 15:21:01
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Current review of Excimer laser Trabeculostomy
摘要： Background: Excimer laser trabeculostomy (ELT) is a microinvasive glaucoma surgery (MIGS) that creates multiple laser channels through the trabecular meshwork using a cold laser system, which minimizes tissue fibrosis and aids in bypassing the main area of resistance to aqueous outflow. The purpose of this review is to evaluate the current body of evidence surrounding ELT in terms of efficacy and review the safety profile of the procedure. Main text: Studies screened had to show clear inclusion and exclusion criteria as well as well-defined outcome measures. PubMed, MEDLINE, EMBASE and the Cochrane Controlled Trial Database were searched. Preferred Reporting Items of Systematic Reviews (PRISMA) guidelines were used to assess for study quality and for any bias. Sixty-four articles were initially identified with 18 meeting preliminary screening criteria. Ultimately, 8 studies met inclusion criteria and 2 additional non-referenced publications were also included: 1 randomized control trial, 4 prospective case series and 5 retrospective studies. Overall studies showed moderate intraocular pressure (IOP) lowering of between 20% and 40% from baseline without medication washout and mostly a decrease in glaucoma medications with few complications. Conclusion: Current literature shows a significant IOP-lowering effect of ELT with a favorable safety-profile in standalone cases or combined with cataract surgery. Limitations to these studies are the lack of controls and washout IOP. Overall, ELT is an attractive MIGS option that does not require any residual device remaining in the angle.
关键词： Excimer laser trabeculostomy,ELT,Trabeculotomy,MIGS,Cataract,Intraocular pressure,Glaucoma
更新于2025-09-23 15:21:01
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Lithium Pentazolate Synthesized by Laser Heating Compressed Lithium Azide and Nitrogen
摘要： Searching for polynitrogen compounds has attracted great attention due to their potential applications as high energy density materials. Here, we report a facile approach to the synthesis of solid lithium pentazolate (LiN5) compound by compressing lithium azide and molecular nitrogen under high pressure with laser heating. The formation of LiN5 with crystal structure P21/m-LiN5 was identified according to the appearance of the vibrational modes of N5ˉ rings in Raman spectra and synchrotron X-ray diffraction measurements under high pressure. The LiN5 remains stable down to 18.5 GPa upon decompression. The bond lengths in N5ˉ are between single bond and double bond length. This study indicates that the precursor can effectively tune the high pressure phase of pentazolate providing us an alternative route to synthesize polynitrogen compound with novel structure.
关键词： Lithium azide,Laser heating,High pressure,Nitrogen and Lithium pentazolate
更新于2025-09-23 15:21:01
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Electron dynamics in low pressure capacitively coupled radio frequency discharges
摘要： In low temperature plasmas, the interaction of the electrons with the electric field is an important current research topic that is relevant for many applications. Particularly, in the low pressure regime ((cid:1)10 Pa), electrons can traverse a distance that may be comparable to the reactor dimensions without any collisions. This causes “nonlocal,” dynamics which results in a complicated space- and time-dependence and a strong anisotropy of the distribution function. Capacitively coupled radio frequency (CCRF) discharges, which operate in this regime, exhibit extremely complex electron dynamics. This is because the electrons interact with the space- and time-dependent electric field, which arises in the plasma boundary sheaths and oscillates at the applied radio frequency. In this tutorial paper, the fundamental physics of electron dynamics in a low pressure electropositive argon discharge is investigated by means of particle-in-cell/Monte Carlo collisions simulations. The interplay between the fundamental plasma parameters (densities, fields, currents, and temperatures) is explained by analysis (aided by animations) with respect to the spatial and temporal dynamics. Finally, the rendered picture provides an overview of how electrons gain and lose their energy in CCRF discharges.
关键词： low pressure,particle-in-cell/Monte Carlo collisions simulations,electron dynamics,plasma parameters,capacitively coupled radio frequency discharges
更新于2025-09-23 15:21:01
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Processing and Study of Optical and Electrical Properties of (Mg, Al) Co-Doped ZnO Thin Films Prepared by RF Magnetron Sputtering for Photovoltaic Application
摘要： In this study, high transparent thin films were prepared by radio frequency (RF) magnetron sputtering from a conventional solid state target based on ZnO:MgO:Al2O3 (10:2 wt %) material. The films were deposited on glass and silicon substrates at the different working pressures of 0.21, 0.61, 0.83 and 1 Pa, 300 °C and 250 W of power. X-ray diffraction patterns (XRD), atomic force microscopy (AFM), UV-vis absorption and Hall effect measurements were used to evaluate the structural, optical, morphological and electrical properties of thin films as a function of the working pressure. The optical properties of the films, such as the refractive index, the extinction coefficient and the band gap energy were systematically studied. The optical band gap of thin films was estimated from the calculated absorption coefficient. That parameter, ranged from 3.921 to 3.655 eV, was hardly influenced by the working pressure. On the other hand, the lowest resistivity of 8.8 × 10?2 ? cm was achieved by the sample deposited at the lowest working pressure of 0.21 Pa. This film exhibited the best optoelectronic properties. All these data revealed that the prepared thin layers would offer a good capability to be used in photovoltaic applications.
关键词： working pressure,Al doped ZnO-MgO powder,RF magnetron sputtering,photovoltaic applications,thin films,solid-state method,optoelectronic properties
更新于2025-09-23 15:21:01
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Hanging drop cathode-atmospheric pressure glow discharge as a new method of sample introduction for inductively coupled plasma-optical emission spectrometry
摘要： This work reports the use of hanging drop cathode-atmospheric pressure glow discharge (HDC-APGD) as a new method of sample introduction for inductively coupled plasma-optical emission spectrometry (ICP-OES). The developed arrangement was characterized by a low sample uptake (0.56 mL min?1) and the fact that the entire sample solution volume was consumed by the discharge. This resulted in a very high transport efficiency of analytes from the sample solution into the ICP torch (usually > 80%). Under the optimal operating conditions of HDC-APGD, intensities of emission lines of studied elements were, on average, 2 times higher as compared to those obtained with conventional pneumatic nebulization (PN). Moreover, in the case of I and Y, the observed signal enhancements were even higher, i.e., 6.2 and 6.1 times, respectively. It was also shown that in the case of B and some elements that are known to form different volatile species (Ag, Bi, Cd, Hg, Os, Pb, and Se), the presence of low molecular weight organic compounds in the sample solution, i.e., CH3OH, C2H5OH, HCOOH, CH3COOH, or HCHO, resulted in the additional enhancement of their signals. It was especially evident in the case of Hg for which a 8.6-fold signal enhancement in the presence of HCOOH was noticed. The system presented herein was distinguished from other competitive APGD-type discharges because it could be successfully used for the determination of a vast group of elements, including alkali metals, alkaline earth metals, transition metals, and non-metals.
关键词： Atmospheric pressure glow discharge,Hanging drop cathode,Inductively coupled plasma,Optical emission spectrometry,Sample introduction
更新于2025-09-23 15:21:01
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2D Material Membranes for Operando Atmospheric Pressure Photoelectron Spectroscopy
摘要： Probing the chemistry that occurs at catalyst interfaces under realistic process conditions is key to the rational design of better materials for industrial catalytic reactions. Ambient pressure X-ray photoelectron spectroscopy, has until recently been limited to pressures two orders of magnitude below atmosphere. However, the development of photoelectron transparent membranes based on two-dimensional materials that can maintain large pressure differences and yet have thicknesses approaching or even falling below the inelastic mean free path of photoelectrons, now allows the atmospheric pressure regime and above to be accessed. We introduce here the fundamental principles underlying this membrane-based approach to atmospheric pressure photoelectron spectroscopy, and in this context highlight some of the key design concepts and challenges in performing experiments with this technique. We discuss a number of recent proof-of-concept studies, and highlight the potential of the membrane-based approach for operando characterisation of catalyst interfaces under reaction conditions, as well as some current challenges and limitations in this area.
关键词： Atmospheric pressure,XPS,Operando spectroscopy,Graphene,Reaction cell
更新于2025-09-23 15:21:01
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Formamidinium-based Perovskite Solar Cells with Enhanced Moisture Stability and Performance via Confined Pressure Annealing
摘要： Formamidinium (FA) based perovskite solar cells (PSC) shows enhanced stability comparing to their methylammonium (MA) based counterpart. However, its stability needs to be further enhanced for the potential commercial applications. We demonstrate here that the high-quality thin film can be obtained for FA-based perovskite with remarkably enhanced moisture stability using a confined-pressure annealing (CPA) processing and controlling the amount of Cs introduced into the FAPbI3 perovskite precursor solution. Without additional 2D cation additives, surface passivation or encapsulation, no phase degradation was observed for the Cs0.1FA0.9PbI3 perovskite under a humidity of 70 RH% over 500 hours. The unencapsulated device maintained over 70% performances for 500 hours comparing to <80 h of the conventional processed devices, which is the comparable to the outstanding moisture stability of the 2D/3D perovskites. The FA-based perovskite grain size was promoted to over 1 micrometer with a high static water contact angle up to 112°. The surface cations composition was varied with the concentrated FA cation species at surface while homogenized Cs/FA distribution inside the film. The trapped state density and carrier recombination rate were also reduced with a high fill factor of 82% and the efficiency over 20.23%. This work suggests the intrinsic stability of the 3D perovskite could be further enhanced with adjusting of the surface compositions during the crystallization process.
关键词： Confined pressure annealing,Perovskite solar cells,Cation distribution,Moisture stability,Formamidinium
更新于2025-09-23 15:21:01
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Laser machined ultralow water adhesion surface by low pressure processing
摘要： Ultralow water adhesion aluminum surface has been fabricated by eco friendly low pressure processing technique. The laser patterned surface shows interconnected spongy porous nanostructures with micro packets at regular intervals. The micro volume of air present inside the interconnected porous surface structure together with the adsorbed hydrocarbons by low pressure processing leads to ultralow water adhesion surface. Application of bigger droplet volumes to the patterned surface showed a decrease in static contact angle measurement due to larger radius of curvature and axisymmetrical compared to the smaller droplets.
关键词： Sliding angle,Ultrafast laser,Low pressure,Wetting,Adhesion
更新于2025-09-23 15:21:01
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A new type of structure of optical fiber pressure sensor based on polarization modulation
摘要： In this study, a new type of structure of optical fiber pressure sensor (OFPS) based on polarization modulation is proposed, which selects a high-birefringence fiber (HBF) as the sensing unit to measure the pressure in the fluid medium. The PM-1550-01 fiber produced by NTK Photonics Inc. is evaluated as the sample in our subject. Firstly, the regularities of birefringence variation on the PM-1550-01 followed by the external pressure load and the ambient temperature are analyzed by the finite element method (FEM). The results show that the pressure sensitivity is 2.05 × 10 ? 6 RIU/MPa in the pressure range of 0–100 MPa, and the temperature sensitivity is 7.27 × 10 ? 10 RIU/°C in the temperature range of 0–100 °C. Thus, the pressure-temperature cross-sensitivity is only 0.355 kPa/°C in theory. Secondly, the expression of the output light intensity of the introduced OFPS is deduced based on the principles of polarization interference and phase modulation. Combined with simulation results, the measurement ranges of the sensor can be set and adjusted by the length of the sensing unit. Finally, the proposed OFPS is fabricated and external pressure tests within the range of 0–50 MPa are completed. The results show that the pressure sensitivity is approximately 0.145 dB/MPa in the pressure range of 0–44 MPa. There is a fine consistency between the experimental data and simulation results. In addition, the proposed OFPS has many other advantages, such as small size, simple fabrication process and large measurement range, which make it appropriate to be applied in high-pressure measurement in hostile conditions, e.g., downhole and ocean-bottom.
关键词： Low temperature cross-sensitivity,Polarization modulation,High-birefringence fiber,Optical fiber pressure sensor
更新于2025-09-23 15:21:01