Vitrectomy with complete posterior hyaloid removal for ischemic central retinal vein occlusion: Series of cases

BACKGROUND: Central retinal vein occlusion (CRVO) is a common retinal vascular disorder with potentially complications: (1) persistent macular edema and (2) neovascular glaucoma. No safe treatment exists that promotes the return of lost vision. Eyes with CRVO may be predisposed to vitreous degeneration. It has been suggested that if the vitreous remains attached to the macula owing to a firm vitreomacular adhesion, the resultant vitreous traction can cause inflammation with retinal capillary dilation, leakage and subsequent edema6. The roll of vitrectomy in ischemic CRVO surgical procedures has not been evaluated. CASE PRESENTATION: This is a non comparative, prospective, longitudinal, experimental and descriptive series of cases. Ten eyes with ischemic CRVO. Vitrectomy with complete posterior hyaloid removal was performed. VA, rubeosis, intraocular pressure (IOP), and macular edema were evaluated clinically. Multifocal ERG (m-ERG), fluorescein angiography (FAG) and optic coherence tomography (OCT) were performed. Follow-up was at least 6 months. Moderate improvement of visual acuity was observed in 60% eyes and stabilized in 40%. IOP changed from 15.7 ± 3.05 mmHg to 14.9 ± 2.69 mmHg post-operative and macular edema from 976 ± 196 μm to 640 ± 191 μm to six month. The P1 wave amplitude changed from 25.46 ± 12.4 mV to 20.54 ± 11.2 mV. CONCLUSION: A solo PPV with posterior hyaloid removal may help to improve anatomic and functional retina conditions in some cases. These results should be considered when analyzing other surgical maneuvers

Guanidinium octahydrotriborate: an ionic liquid with high hydrogen storage capacity

For chemical hydrogen storage, capacity is one key criterion that has spurred intense efforts to investigate compounds with high hydrogen content. The guanidinium cation and the octahydrotriborate anion possess 6 H+ and 8 H-, respectively. The combination of these two ions yields guanidinium octahydrotriborate with 13.8 wt% hydrogen. This paper presents its facile synthesis, as confirmed by 11B and 1H nuclear magnetic resonance spectroscopy. The results show that guanidinium octahydrotriborate is an ionic liquid with a melting point below -10°C, which makes it a possible injectable/pumpable hydrogen carrier. It decomposes selectively to hydrogen, in stark contrast to the formation of various boranes from related solid octahydrotriborates. The much improved H2 purity can be ascribed to the more effective combination of H+ and H-, and the higher H+/H- ratio in liquid guanidinium octahydrotriborate

Sodium-difluoro(oxalato)borate (NaDFOB): A new electrolyte salt for Na-ion batteries

A new electrolyte salt, sodium-difluoro(oxalato)borate (NaDFOB), was synthesized and studied, which enables excellent reversible capacity and high rate capability when used in Na/Na0.44MnO2 half cells. NaDFOB has excellent compatibility with various common solvents used in Na-ion batteries, in strong contrast to the solvent dependent performances of NaClO4 and NaPF6. In addition, NaDFOB possesses good stability and generates no toxic or dangerous products when exposed to air and water. All these properties demonstrate that NaDFOB could be used to prepare high performance electrolytes for emerging Na-ion batteries

Design localized high concentration electrolytes via donor number and solubility

The salt-concentrated electrolytes offer superior properties beyond conventional dilute electrolytes yet suffer from high cost and viscosity that hinder their practical applications. A key strategy to address this challenge is to introduce a secondary solvent as a diluent that reduces the salt content while maintaining the local structure of salt-concentrated electrolytes, giving rise to localized high concentration electrolytes (LHCEs). Through a thorough investigation involving ~700 samples, we find that, the dielectric constant of solvent, a widely used parameter for electrolyte design, does not serve as a useful screening criterion for diluents; instead, donor number (DN) is an effective design parameter to achieve LHCE structure, i.e., the primary solvent must have DN > 10 and the diluent must have DN < 10. Correlating DN with solvent solubility leads to a simpler screening rule: Li-salt-insoluble solvents are diluents while Li-salt-soluble solvents become co-solvents. Both DN- and solubility-based design principles can be understood in an atomistic model of LHCE and are applicable to other electrolyte systems

Progress in electrolytes for rechargeable Li-based batteries and beyond

Owing to almost unmatched volumetric energy density, Li-based batteries have dominated the portable electronic industry for the past 20 years. Not only will that continue, but they are also now powering plug-in hybrid electric vehicles and zero-emission vehicles. There is impressive progress in the exploration of electrode materials for lithium-based batteries because the electrodes (mainly the cathode) are the limiting factors in terms of overall capacity inside a battery. However, more and more interests have been focused on the electrolytes, which determines the current (power) density, the time stability, the reliability of a battery and the formation of solid electrolyte interface. This review will introduce five types of electrolytes for room temperature Li-based batteries including 1) non-aqueous electrolytes, 2) aqueous solutions, 3) ionic liquids, 4) polymer electrolytes, and 5) hybrid electrolytes. Besides, electrolytes beyond lithium-based systems such as sodium-, magnesium-, calcium-, zinc- and aluminum-based batteries will also be briefly discussed. Keywords: Electrolyte, Ionic liquid, Polymer, Hybrid, Batter

Controlled Cationic Disordering Eliminates Irreversible Anionic Redox for High-Energy-Density Lithium Battery

Lithium-rich layered oxides (LLOs) that can support both cationic and anionic redox chemistry are promising cathode materials, but they often suffer from significant oxygen evolution when first charged to a high voltage, resulting in a large capacity loss and deteriorated durability in subsequent charge-discharge cycles. We reported a simple method to eliminate the irreversible anionic redox in Li1.2Mn0.54Co0.13Ni0.13O2 via low-potential charge-discharge activation (LOWPA), achieving an ultra-high reversible capacity of 322 mAh g-1 (corresponding to 1141 Wh kg-1) as well as improved cycling durability and rate capability. Combined experimental and theoretical investigations reveal that LOWPA enables a delicate control of the order-to-disorder transformation of the transition metal layers of LLOs, leading to a cation-disordered structure that can support reversible oxygen redox up to 4.8 V by forming a stable ozonic ion (O3-). This LOWPA approach is simple and effective, boosting the development of high-energy-density batteries based on the oxygen-redox chemistry

Lithium Borohydride Ethylenediaminates: A Case Study of Solid-State LiBH₄–Organic Amine Complexes

Nitrogen (N) containing ligands, such as ammonia (NH₃), hydrazine (N₂H₄), and ethylenediamine (en), can form a series of complexes with common features in crystal structures and thermal behaviors by coordinating with LiBH₄. Two newly synthesized lithium borohydride ethylenediaminates were investigated in this work. Through comparing the crystal structures of LiBH₄–en, LiBH₄–NH₃, and LiBH₄–N₂H₄ complexes, similar coordination environments of Li were observed in which they have the same Li/N molar ratios. Meanwhile, the establishment of dihydrogen bonding networks, together with the Li⁺/N containing ligand interactions, may be important reasons for the structural stabilization and are expected to have profound impacts on their thermal behaviors. When heated under Ar flow, LiBH₄–N containing complexes decompose via desorption of N containing ligands followed by dehydrogenation. The coordination strength is affected by the number of ligands, i.e., with the increase of N/Li ratio the ligands can be released more easily. For dehydrogenation, the complex with the shortest NH···HB distance gave rise to the lowest initial temperature. When heated in a closed system, direct dehydrogenation can be achieved at relatively low temperatures with Co-based catalyst. About 8.5 and 7.7 wt % of hydrogen can be released from Co-catalyzed LiBH₄·en and (LiBH₄)₂·en at 180 °C, respectively

Synthesis, Thermal Behavior, and Dehydrogenation Kinetics Study of Lithiated Ethylenediamine

The lithiation of ethylenediamine by LiH is a stepwise process to form the partially lithiated intermediates LiN(H)CH2CH2NH2 and [LiN(H)CH2CH2NH2][LiN(H)CH2CH2N(H)Li](2) prior to the formation of dilithiated ethylenediamine LiN(H)CH2CH2N(H)Li. A reversible phase transformation between the partial and dilithiated species was observed. One dimensional {LinNn} ladders and three-dimensional network structures were found in the crystal structures of LiN(H)CH2CH2NH2 and LiN(H)CH2CH2N(H)Li, respectively. LiN(H)CH2CH2N(H)Li undergoes dehydrogenation with an activation energy of 181 +/- 8kJmol(-1), whereas the partially lithiated ethylenediamine compounds were polymerized and released ammonia at elevated temperatures. The dynamical dehydrogenation mechanism of the dilithiated ethylenediamine compounds was investigated by using the Johnson-Mehl-Avrami equation