Effect of shunt type on rates of tube-cornea touch and corneal decompensation after tube shunt surgery in uveitic glaucoma.

PURPOSE: To evaluate the effect of tube shunt type [Ahmed (AGV) versus Baerveldt (BGI)] on the frequency of tube-cornea touch and corneal decompensation after tube shunt surgery. METHODS: This retrospective comparative study included 145 eyes of 130 patients with uveitic glaucoma who underwent AGV (75 eyes) or BGI (70 eyes) implantations. Electronic medical records were reviewed to document demographic factors, intraocular pressure (IOP) reduction, frequency of tube-cornea touch, corneal decompensation, and need for subsequent corneal transplantation. RESULTS: The mean follow-up was 27.7±3.3 months for AGV and 32.8±3.8 months for BGI (p=0.30). Tube-cornea touch was observed in 5 eyes after BGI and 1 eye in the AGV group (p=0.08). The BGI group reported a significantly higher rate of corneal decompensation (9 versus 0; p=0.001) and transplantation (6 versus 0; p=0.01) compared to the AGV group. Previous trabeculectomy was a significant risk factor for corneal complications in eyes undergoing BGI implantation (odds ratio [OR]= 8.17, 95% confidence interval [CI]=1.78-37.45, p=0.007). CONCLUSION: Similar rates of tube-cornea touch were observed in both shunt types; BGI shunts were associated with a greater incidence of corneal complications and transplantation as compared to AGV in this retrospective series of uveitic glaucoma cases.

Strong Opto-Structural Coupling in Low Dimensional GeSe3 Films.

Chalcogenide glasses as nanoscale thin films have become leading candidates for several optical and photonic technologies, ranging from reflective displays and filters to photonic memories. Current material systems, however, show strong optical absorption which limits their performance efficiencies and complicates device level integration. Herein, we report sputter deposited thin films of GeSe3, which are low loss and in which the flexible nature of the atomic structure results in thermally activated tunability in the refractive index as well as in the film's physical volume. Such changes, which occur beyond a threshold temperature are observed to be accumulative and directed toward a more equilibrium amorphous state of the film, instead of crystallization. Our results provide insight into a new type of configurability that is based on strong coupling in the material's opto-structural properties. The low optical losses in this material system combined with the tunability in the optical properties in the visible and near-infrared have direct application in higher performing optical coatings and in corrective optics.

Defects in the ratio of the dynein isoform, DHC11 in the long-flagella mutants of Chlamydomonas reinhardtii.

The long-flagella mutants (lf1, lf2, lf3 and lf4) of Chlamydomonas reinhardtii are defective in proteins that are required for the assembly of normal flagella, their phenotype being long flagella. In a previous study, we biophysically characterized these mutants for their waveform patterns, swimming speeds, beat frequencies and correlated these parameters with their flagellar lengths. We found an anomaly in this correlation and set out to explore the underlying molecular significance, if any. The diverse inner dynein isoforms are the flagellar motors that convert the chemical energy of ATP into the mechanical energy of motility; we probed the presence of one of these isoforms (DHC11, which might help in bend initiation) in the lf mutants and compared it with the wild-type. Our studies show that the ratio of DHC11 is defective in the long-flagella mutants of Chlamydomonas reinhardtii.

Effect of buprenorphine as an adjunct with plain local anesthetic solution in supraclavicular brachial plexus block on quality and duration of postoperative analgesia.

BACKGROUND AND AIMS: Supraclavicular brachial plexus block is ideal for upper limb surgical procedures. Buprenorphine, an agonist antagonist opioid has been used as an adjunct to prolong analgesia. We aimed to evaluate the quality and duration of postoperative analgesia by addition of buprenorphine to local anesthetic solution. MATERIAL AND METHODS: A prospective, randomized, double-blind control study was conducted on 50 healthy patients of ASA Grade I/II of age group 20-70 years scheduled for orthopedic and reconstructive surgery of upper limb under supraclavicular brachial plexus block. Patients were allocated into two groups, 25 in each group viz.: Group B (buprenorphine group) received 20 ml 0.5% bupivacaine + 15 ml 2% lignocaine with adrenaline (1:200,000) + 4 ml normal saline + 1500 units hyaluronidase + 3 µg/kg buprenorphine diluted to 1 ml normal saline. Group C (control group) received 20 ml 0.5% bupivacaine + 15 ml 2% lignocaine with adrenaline (1:200,000) + 4 ml normal saline + 1500 units hyaluronidase + 1 ml normal saline. The parameters observed were onset and duration of sensory and motor block, quality and duration of analgesia and side-effects. RESULTS: The mean duration of postoperative analgesia was significantly longer in Group B (16.04 ± 3.19 h) than in Group C (6.20 ± 0.74 h). There was no difference between two groups on mean onset of sensory block. The mean duration motor block was significantly longer in Group B (4.93 ± 0.94 h) than in Group C (2.25 ± 0.62 h) [P < 0.05]. The mean duration of sensory block was also significantly longer in Group B (5.71 ± 0.94 h) than in Group C (4.94 ± 0.70 h) with P < 0.05. CONCLUSION: Addition of 3 µg/kg buprenorphine to 0.5% bupivacaine for supraclavicular brachial plexus block prolonged duration of postoperative analgesia and sensory blockade without an increase in side effects.

Closed-loop optogenetic neuromodulation enables high-fidelity fatigue-resistant muscle control.

Closed-loop neuroprostheses show promise in restoring motion in individuals with neurological conditions. However, conventional activation strategies based on functional electrical stimulation (FES) fail to accurately modulate muscle force and exhibit rapid fatigue because of their unphysiological recruitment mechanism. Here, we present a closed-loop control framework that leverages physiological force modulation under functional optogenetic stimulation (FOS) to enable high-fidelity muscle control for extended periods of time (>60 minutes) in vivo. We first uncovered the force modulation characteristic of FOS, showing more physiological recruitment and significantly higher modulation ranges (>320%) compared with FES. Second, we developed a neuromuscular model that accurately describes the highly nonlinear dynamics of optogenetically stimulated muscle. Third, on the basis of the optogenetic model, we demonstrated real-time control of muscle force with improved performance and fatigue resistance compared with FES. This work lays the foundation for fatigue-resistant neuroprostheses and optogenetically controlled biohybrid robots with high-fidelity force modulation.

Intraocular pressure profile following selective laser trabeculoplasty in pigmentary and primary open-angle glaucoma.

PURPOSE: To compare the intraocular pressure (IOP) profile and the incidence of IOP spikes following selective laser trabeculoplasty (SLT) between pigmentary glaucoma (PG) and primary open-angle glaucoma (POAG). MATERIALS AND METHODS: Retrospective comparative study of 65 PG eyes of 51 patients matched with 65 POAG eyes of 65 patients who received SLT. Matching was done based on age, gender, glaucoma severity, pre-laser IOP, and number of medications. Post-SLT IOP spike was defined as IOP elevation ≥5mmHg, 30-45 min after the laser. RESULTS: In PG and POAG groups, the average age was 62.33 ± 9.18 and 62.58 ± 9.19 years (p = 0.95). The glaucoma severity (p = 0.708), baseline IOP (PG = 21.61 ± 1.34mmHg vs. POAG = 21.13 ± 5.09mmHg, p = 0.943), and number of topical glaucoma medications(PG = 2.34 ± 1.34 vs. POAG = 2.1 ± 1.41, p = 0.342) were comparable. More PG patients were on oral acetazolamide (PG = 26.15% vs. POAG = 1.5%, p < 0.001). Average logMAR visual acuity was significantly higher in the POAG group (0.207 ± 0.3 vs. 0.192 ± 0.37, p = 0.012). Eyes with PG received lower laser energy (POAG = 63.65 ± 22.03 mJ vs. PG = 43.71 ± 25.68 mJ, p < 0.001). IOP spikes were recorded in 5 PG eyes (7.6%) and none in the POAG group (p = 0.058). Failure rates were similar (PG = 50.7% and POAG = 43.1%, p = 0.205). In multivariable analysis, only pre-laser IOP (coefficient = 2.154 [CI: 0.765-3.543], p = 0.003) was a significant predictor of IOP change percentage after 12 months. CONCLUSIONS: SLT was comparably effective in both PG and POAG. IOP spikes were observed only in the PG group, though the total laser energy was lower in this group compared with POAG.

Lattice-Mismatch-Driven Small-Angle Moiré Twists in Epitaxially Grown 2D Vertical Layered Heterostructures.

Artificially introduced small twist angles at the interfaces of vertical layered heterostructures (VLHs) have allowed deterministic tuning of electronic and optical properties such as strongly correlated electronic phases and Moiré excitons. But creating a Moiré twist in van der Waals (vdWs) systems by manual stacking is challenging in reproducibility, uniformity, and accuracy of the twist angle, which hinders future studies. Here, it is demonstrated that contrary to the commonly believed 0°-orientation in vdWs epitaxy, these VLHs show small twist angles controlled by the low-order commensurate phase with low energy and local atomic relaxation. A commensurate multilevel map is proposed to predict possible orientations. Remarkably, high-mismatch VLHs show discrete and sometimes non-zero twist angles dependent on their natural mismatch value. Such framework is experimentally confirmed in five epitaxially grown VLHs under high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), and can provide significant insights for large-scale engineering of twist angle in VLHs.

Surgical Management of Glaucoma Secondary to Bilateral Acute Iris Transillumination: A Role for Gonioscopy-assisted Transluminal Trabeculotomy.

PURPOSE: We report a case of bilateral acute iris transillumination (BAIT) in a young woman associated with ocular hypertension which eventually progressed to glaucoma that was treated with gonioscopy-assisted transluminal trabeculectomy (GATT). CASE REPORT: A 37-year-old otherwise healthy female presented with intermittently red and inflamed eyes and blurred vision. She was treated with oral moxifloxacin months prior to presentation. Iris transillumination defects, a pigmented anterior chamber reaction, the absence of keratic precipitates, and a history of upper respiratory infection treated with an oral fluoroquinolone prompted the diagnosis of BAIT. Intraocular pressure (IOP) remained uncontrolled on multiple glaucoma medications. Following the development of new visual field defects, indicating progression to glaucoma, GATT with cataract extraction was performed. CONCLUSION: Although surgical intervention is rare with BAIT, our case demonstrates that GATT may be used effectively in those patients needing better IOP control before considering incisional glaucoma surgery.

Biochemical and biophysical analyses of concerted (U5/U3) integration.

Retrovirus integrase (IN) integrates the viral linear DNA genome ( approximately 10 kb) into a host chromosome, a step which is essential for viral replication. Integration occurs via a nucleoprotein complex, termed the preintegration complex (PIC). This article focuses on the reconstitution of synaptic complexes from purified components whose molecular properties mirror those of the PIC, including the efficient concerted integration of two ends of linear viral DNA into target DNA. The methods described herein permit the biochemical and biophysical analyses of concerted integration. The methods enable (1) the study of interactions between purified recombinant IN and its viral DNA substrates at the molecular level; (2) the identification and characterization of nucleoprotein complexes involved in the human immunodeficiency virus type-1 (HIV-1) concerted integration pathway; (3) the determination of the multimeric state of IN within these complexes; (4) dissection of the interaction between HIV-1 IN and cellular proteins such as lens epithelium-derived growth factor (LEDGF/p75); (5) the examination of HIV-1 Class II and strand transfer inhibitor resistant IN mutants; (6) the mechanisms associated with strand transfer inhibitors directed against HIV-1 IN that have clinical relevance in the treatment of HIV-1/AIDS.

New glaucoma medications: latanoprostene bunod, netarsudil, and fixed combination netarsudil-latanoprost.

Reduction of intraocular pressure is the only proven method to treat glaucoma. Initial treatment of glaucoma commonly involves using anti-glaucoma medications either as monotherapy or combination therapy. Studies on aqueous humour dynamics have contributed to our understanding of aqueous outflow mechanisms that have led to the discovery of new drugs. Three new drugs (latanoprostene bunod 0.24%, netarsudil 0.02%, and fixed combination netarsudil 0.02% -latanoprost 0.005%) have been introduced recently in the market with novel mechanisms of action. Latanoprostene bunod 0.024% is a nitric oxide-donating prostaglandin F2α analogue which increases the aqueous outflow both by uveoscleral and trabecular pathways. Netarsudil 0.02% is a potent Rho kinase/norepinephrine transporter inhibitor acting by increasing the trabecular outflow, decreasing the aqueous production, and possibly decreasing the episcleral venous pressure. This review highlights the role of these drugs in the management of glaucoma, with an overview of the major clinical trials on their efficacy, safety, and tolerability.

Fixed combination netarsudil-latanoprost for the treatment of glaucoma and ocular hypertension.

Introduction: Reduction of intraocular pressure (IOP) is the only known modifiable risk factor for prevention and treatment of glaucoma. Rho-kinase (ROCK) inhibitors are a new class of glaucoma medications introduced recently with novel mechanisms of action and favorable safety profiles. Latanoprost, a common first line drug used for treatment of glaucoma, does not adequately control pressures in all cases. Addition of more than one anti-glaucoma medication affects patient compliance and adherence. Fixed-combination eye drops are combinations of two or more active drugs in a single dosage form, thus simplify dosing. New to this group is the fixed combination netarsudil- latanoprost (FCNL).Area covered: This review focuses on FCNL, its pharmacodynamics and pharmacokinetics. It also details the efficacy and safety of individual drugs compared to FCNL.Expert opinion: The combination of latanoprost and netarsudil is a potent medication and modulates all known targets for IOP reduction in a single drop and has been shown to be more effective than either drug alone. FCNL is an alternative for those with inadequately controlled IOP on a prostaglandin analog alone, as well as those for whom a simplified regimen is desirable, or those who are not good candidates for other classes of glaucoma medications.

Atomic structure and defect dynamics of monolayer lead iodide nanodisks with epitaxial alignment on graphene.

Lead Iodide (PbI2) is a large bandgap 2D layered material that has potential for semiconductor applications. However, atomic level study of PbI2 monolayer has been limited due to challenges in obtaining thin crystals. Here, we use liquid exfoliation to produce monolayer PbI2 nanodisks (30-40 nm in diameter and > 99% monolayer purity) and deposit them onto suspended graphene supports to enable atomic structure study of PbI2. Strong epitaxial alignment of PbI2 monolayers with the underlying graphene lattice occurs, leading to a phase shift from the 1 T to 1 H structure to increase the level of commensuration in the two lattice spacings. The fundamental point vacancy and nanopore structures in PbI2 monolayers are directly imaged, showing rapid vacancy migration and self-healing. These results provide a detailed insight into the atomic structure of monolayer PbI2, and the impact of the strong van der Waals interaction with graphene, which has importance for future applications in optoelectronics.

Ahmed Versus Baerveldt Glaucoma Drainage Device in Uveitic Glaucoma: A Retrospective Comparative Study.

PRECIS: Baerveldt glaucoma drainage device demonstrated a greater reduction in intraocular pressure (IOP) than Ahmed in patients with uveitic glaucoma. The most common cause of failure was uncontrolled IOP in Ahmed and hypotony in the Baerveldt group. PURPOSE: To compare the efficacy and safety of Ahmed and Baerveldt glaucoma drainage devices in uveitic glaucoma. MATERIALS AND METHODS: The retrospective comparative study included patients with uveitic glaucoma who underwent Ahmed or Baerveldt glaucoma drainage device implantation with a minimum follow-up of 3 months. Success was defined as IOP ≥6 and ≤21 mm Hg and >20% reduction on 2 consecutive visits after the third month with (qualified success) or without (complete success) medications and no further glaucoma surgery or loss of vision. IOP, number of medications, visual acuity, complications, and interventions were compared between groups. RESULTS: In total, 137 eyes of 122 patients (67 Ahmed, 70 Baerveldt) were included. The preoperative IOP and number of medications in the Ahmed group (32.7±10.3 mm Hg; 4.1±1.3) were similar to Baerveldt (32.1±10.2 mm Hg; 4.3±1.3; P=0.73, 0.35). These at the last follow-up were (18.1±9.8 mm Hg; 2.1±1) in Ahmed and (12.7±6.9 mm Hg; 1.3±1.3) in Baerveldt groups (P=0.04, 0.01). The Baerveldt had greater IOP reduction (60.3% vs. 44.5%) and complete success rate (30% vs. 9%) with higher complication rate (51.4% vs. 20.9%) (all P≤0.05). The de novo glaucoma reoperation rate was 19% in the Ahmed group and 4% in the Baerveldt group (P=0.006). Hypotony resulted in failure in 7 eyes (10%) in the Baerveldt group and none in the Ahmed group (P=0.013). CONCLUSIONS: Higher complete success rate and significantly greater reduction in mean IOP and number of medications were observed in the Baerveldt group, but with a higher rate of complications including hypotony.

Are Buckminsterfullerenes Molecular Ball Bearings?

Buckminsterfullerenes (C60) are near-spherical molecules, which freely rotate at room temperature in the solid state and when dissolved in solution. An intriguing question arises as to whether C60 molecules can act as "molecular ball bearings," that is, preventing direct contact between two solid surfaces while simultaneously dissipating shear stress through fast rotation. To explore this, we performed measurements of friction across a solution of C60 in the boundary lubrication regime. High-resolution shear and normal force measurements between mica sheets separated by C60 solution were made using a surface force balance to provide single-asperity contact and sub-nanometer resolution in film thickness. We find that, even at a small volume fraction, C60 forms a solidlike amorphous boundary film sustaining a high normal load, suggesting that this system undergoes a glass transition under confinement. The C60 film gives rise to a low friction coefficient up to moderate applied loads, and we discuss the possible relevance of the ball-bearing effect at the molecular scale.

Atomic Structure and Dynamics of Defects and Grain Boundaries in 2D Pd2Se3 Monolayers.

We study the atomic structure and dynamics of defects and grain boundaries in monolayer Pd2Se3 using annular dark field scanning transmission electron microscopy. The Pd2Se3 monolayers are reproducibly created by thermally induced phase transformation of few-layered PdSe2 films in an in situ heating holder in the TEM to promote Se loss. A variety of point vacancies, one-dimensional defects, grain boundaries (GBs), and defect ring complexes are directly observed in monolayer Pd2Se3, which show a series of dynamics triggered by electron beam irradiation. High mobility of vacancies leads to self-healing of point vacancies by migration to the edge and subsequent edge etching under beam irradiation. Specific defects for Pd2Se3 are stabilized by the formation of Se-Se bonds, which can shift in a staggered way to buffer strain, forming a wave-like one-dimensional defect. Bond rotations are also observed and play an important role in defect and grain boundary dynamics in Pd2Se3 during vacancy production. The GBs form in a meandering pathway and migrate by a sequence of Se-Se bond rotations without large-scale vacancy formation. In the GB corners and tilted GBs, other highly symmetric vacancy defects also occur to adapt to the orientation change. These results give atomic level insights into the defects and grain boundaries in Pd2Se3 2D monolayers.

High-Performance WS2 Monolayer Light-Emitting Tunneling Devices Using 2D Materials Grown by Chemical Vapor Deposition.

The solid progress in the study of a single two-dimensional (2D) material underpins the development for creating 2D material assemblies with various electronic and optoelectronic properties. We introduce an asymmetric structure by stacking monolayer semiconducting tungsten disulfide, metallic graphene, and insulating boron nitride to fabricate numerous red channel light-emitting devices (LEDs). All the 2D crystals were grown by chemical vapor deposition (CVD), which has great potential for future industrial scale-up. Our LEDs exhibit visibly observable electroluminescence (EL) at both 5.5 V forward and 7.0 V backward biasing, which correlates well with our asymmetric design. The red emission can last for at least several minutes, and the success rate of the working device that can emit detectable EL is up to 80%. In addition, we show that sample degradation is prone to happen when a continuing bias, much higher than the threshold voltage, is applied. Our success of using high-quality CVD-grown 2D materials for red light emitters is expected to provide the basis for flexible and transparent displays.

Quantification of RAPD by an automated pupillometer in asymmetric glaucoma and its correlation with manual pupillary assessment.

PURPOSE: The relative afferent pupillary defect (RAPD) is an important sign of asymmetrical retinal ganglion cell damage. The purpose of this study was to quantify RAPD by a pupillometer (RAPiDo, Neuroptics) and assess its correlation with asymmetric glaucoma and manual pupillary assessment. METHODS: A total of 173 subjects were enrolled in the study and categorized into glaucoma, n = 130, and control, n = 43. Subjects were all recruited in the Glaucoma Clinic of the Aravind Eye Hospital in Madurai during their follow-up. They were 18 years and older, with best corrected visual acuity of 6/36 or better. Exclusion criteria included all retinal pathologies, optic atrophies, ocular injuries, severe uveitis, cloudy corneas, dense cataracts, or use of mydriatics or miotic drugs. RAPD was assessed in all subjects using an automated pupillometer and the results were compared with the swinging flash light test conducted on the same subjects by an experienced ophthalmologist. We looked at the correlation between RAPD and the intereye difference in cup-to-disc ratio (CDR), mean deviation (MD) of visual field testing, and retinal nerve fiber layer (RNFL) thickness. Sensitivity and specificity were assessed by area under the receiver operator characteristic (AUROC) analysis. RESULTS: Glaucoma patients had significant RAPD (0.55 ± 0.05 log units) when compared with the controls (0.25 ± 0.05 log units), P < 0.001. Significant intereye differences in CDR, MD, and RNFL between glaucoma and control (P < 0.001) were seen. There was a good correlation between the magnitude and sign of RAPD and these intereye differences in CDR (r = 0.52, P < 0.001), MD (r = 0.44, P < 0.001) and RNFL thickness (r = 0.59, P < 0.001). When compared with the experienced ophthalmologist, AUROC was 0.94, with 89% sensitivity and 91.7% specificity. CONCLUSION: The good correlation between the magnitude of RAPD, as measured by the automated pupillometer, and intereye differences in MD, CDR, and RNFL thickness in glaucomatous, and the good sensitivity and specificity when compared with the experienced ophthalmologist, suggest that pupillometry may be useful as a screening tool to assess asymmetric glaucoma.

Direct Imaging of Photoswitching Molecular Conformations Using Individual Metal Atom Markers.

Photoswitching behavior of individual organic molecules was imaged by annular dark-field scanning transmission electron microscopy (ADF-STEM) using a highly electron beam transparent graphene support. Photoswitching azobenzene derivatives with ligands at each end containing single transition-metal atoms (Pt) were designed (Pt-complex), and the distance between the strong ADF-STEM contrast from the two Pt atoms in each Pt-complex is used to track molecular length changes. UV irradiation was used to induce photoswitching of the Pt complex on graphene, and we show that the measured Pt-Pt distances within isolated molecules decrease from ∼2.1 nm to ∼1.4 nm, indicative of a trans-to- cis isomerization. Light illumination of the Pt-complex on the graphene support also caused their diffusion out from initial clusters to the surrounding area of graphene, indicating that the light-activated mobilization overcomes the intermolecular van der Waals interactions. This approach shows how individual isolated heavy metal atoms can be included as markers into complex molecules to track their structural changes using ADF-STEM on graphene supports, providing an effective method to study a diverse range of complex organic materials at the single molecule level.

Striated 2D Lattice with Sub-nm 1D Etch Channels by Controlled Thermally Induced Phase Transformations of PdSe2.

2D crystals are typically uniform and periodic in-plane with stacked sheet-like structure in the out-of-plane direction. Breaking the in-plane 2D symmetry by creating unique lattice structures offers anisotropic electronic and optical responses that have potential in nanoelectronics. However, creating nanoscale-modulated anisotropic 2D lattices is challenging and is mostly done using top-down lithographic methods with ≈10 nm resolution. A phase transformation mechanism for creating 2D striated lattice systems is revealed, where controlled thermal annealing induces Se loss in few-layered PdSe2 and leads to 1D sub-nm etched channels in Pd2 Se3 bilayers. These striated 2D crystals cannot be described by a typical unit cells of 1-2 Å for crystals, but rather long range nanoscale periodicity in each three directions. The 1D channels give rise to localized conduction states, which have no bulk layered counterpart or monolayer form. These results show how the known family of 2D crystals can be extended beyond those that exist as bulk layered van der Waals crystals by exploiting phase transformations by elemental depletion in binary systems.