Complexes of Organic Arsonic Acids: Part VIII - Complexes of VO2+ & Cu2+ with Arylarsonic Acids

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Time resolved evolution of structural, electrical, and thermal properties of copper irradiated by an intense ultrashort laser pulse

The dynamical properties of copper metal are obtained on a picosecond time scale using 100 fs laser pulse at 1015 Wcm-2-an intensity regime relevant to femtosecond micromachining. The dissipation mechanisms and scaling laws spanning a wide temperature range are obtained from femtosecond pump-probe reflectivity. We observe obliteration of the crystalline structure in copper within 400 fs due to lattice disorder caused by the intense laser pulse. The electrical resistivity is obtained by studying the probe reflectivity evolution from 0 to 30 ps. The "resistivity saturation" effect in an unexplored regime intermediate to hot plasma and cold solid is studied in detail. The temperature evolution and thermal conductivity values are also obtained

Ab interno supraciliary microstent surgery for open-angle glaucoma

BACKGROUND: Glaucoma is the leading cause of global irreversible blindness, often associated with raised intraocular pressure (IOP). Where medical or laser treatment has failed or is not tolerated, surgery is often required. Minimally-invasive surgical approaches have been developed in recent years to reduce IOP with lower surgical risks. Supraciliary microstent surgery for the treatment of open-angle glaucoma (OAG) is one such approach. OBJECTIVES: To evaluate the efficacy and safety of supraciliary microstent surgery for the treatment of OAG, and to compare with standard medical, laser or surgical treatments. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2020, Issue 8); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 27 August 2020. SELECTION CRITERIA: We searched for randomised controlled trials (RCTs) of supraciliary microstent surgery, alone or with cataract surgery, compared to other surgical treatments (cataract surgery alone, other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment or medical treatment. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts from the database search to identify studies that met the selection criteria. Data extraction, analysis, and evaluation of risk of bias from selected studies was performed independently and according to standard Cochrane methodology. MAIN RESULTS: One study met the inclusion criteria of this review, evaluating the efficacy and safety of the Cypass supraciliary microstent surgery for the treatment of OAG, comparing phacoemulsification + supraciliary microstent surgery with phacoemulsification alone over 24 months. This study comprised 505 eyes of 505 participants with both OAG and cataract, 374 randomised to the phacoemulsification + microstent group.  In this study, the perceived risk of bias from random sequence generation, allocation concealment and selective reporting was low. However, we considered the study to be at high risk of performance bias as surgeons/investigators were unmasked. Attrition bias was unclear, with 448/505 participants contributing to per protocol analysis. Insertion of a Cypass supraciliary microstent combined with phacoemulsification probably increases the proportion of participants who are medication-free (not using eye-drops) at 24 months compared with phacoemulsification alone (85% versus 59%, risk ratio (RR) 1.27, 95% confidence interval (CI) 1.09 to 1.49, moderate-certainty evidence). There is high-certainty evidence that a greater improvement in mean IOP occurs in the phacoemulsification + microstent group - mean (SD) change in IOP from baseline of -5.4 (3.9) mmHg in the phacoemulsification group, compared to -7.4 (4.4) mmHg in the phacoemulsification + microstent group at 24 months (mean difference -2.0 mmHg, 95% CI -2.85 to -1.15). There is moderate-certainty evidence that insertion of a microstent is probably associated with a greater reduction in use of IOP-lowering drops (mean reduction of 0.7 medications in the phacoemulsification group, compared to a mean reduction of 1.2 medications in the phacoemulsification + microstent group). Insertion of a microstent during phacoemulsification may reduce the requirement for further glaucoma intervention to control IOP at a later stage compared to phacoemulsification alone (RR 0.26, 95% CI 0.07 to 1.04, low-certainty evidence). There is no evidence relating to the rate of visual field progression, or proportion of participants whose visual field loss progressed in this study. There is moderate-certainty evidence showing little or no difference in the proportion of participants experiencing postoperative complications over 24 months between participants in the microstent group compared to those who received phacoemulsification alone (RR 1.1, 95% CI 0.8 to 1.4). Five year post-approval data regarding the safety of the Cypass supraciliary microstent showed increased endothelial cell loss, associated with the position of the microstent in the anterior chamber. There were no reported health-related quality of life (HRQoL) outcomes in the included study. AUTHORS' CONCLUSIONS: Data from this single RCT show superiority of supraciliary microstent surgery when combined with phacoemulsification compared to phacoemulsification alone in achieving medication-free control of OAG. However, there are long-term safety concerns with the device used in this trial, relating to the observed significant loss of corneal endothelial cells at five years following device implantation. At the time of this review, this device has been withdrawn from the market. This review has found that few high-quality studies exist comparing supraciliary microstent surgery to standard medical, laser or surgical glaucoma treatments. This should be addressed by further appropriately designed RCTs with sufficient long-term follow-up to ensure robust safety data are obtained. Consideration of health-related quality of life outcomes should also feature in trial design

Sirolimus use in patients with subglottic stenosis in the context of granulomatosis with polyangiitis (GPA), suspected GPA, and immunoglobulin G4-related disease

OBJECTIVE: Subglottic stenosis (SGS) is a severe, life-threatening disease found in immune-mediated diseases such as granulomatosis with polyangiitis (GPA) and in rare cases of immunoglobulin G4 (IgG4)-related disease. It can result in persistent airway compromise due to the fibrotic response following inflammation. Standard management involves repeated endoscopic interventions to dilate the airway, and tracheostomy is occasionally required. In addition, immunosuppression remains a cornerstone of therapy aimed at controlling the underlying inflammatory disease; however, cumulative dosing leads to significant adverse effects. We present five cases of predominantly anti-neutrophil cytoplasmic antibody-negative GPA and a case of IgG4-related disease with SGS, in whom we evaluated the long-term utility of sirolimus, which has beneficial anti-proliferative and fibrotic effects, in the management of their disease. METHOD: We conducted a retrospective review of a cohort of patients with SGS at a tertiary vasculitis unit. These patients were treated with sirolimus, in addition to conventional medical and endoscopic treatment. Clinical symptoms, frequency and time to endoscopic intervention pre- and post-treatment, additional rescue therapy, and any adverse effects were recorded and analysed. RESULTS: Six patients were treated with sirolimus and followed for up to 9 years; two discontinued the drug owing to adverse effects, early on. In the remaining four patients, glucocorticoids were withdrawn, and the frequency of endoscopic intervention was reduced. One patient on sirolimus required rituximab therapy for disease flare. CONCLUSION: Sirolimus may be a therapeutic option for some patients with severe SGS, allowing steroid withdrawal and resulting in a positive adverse effect profile

Short laser pulse induced generation of hot electrons and their anomalous stopping in overdense plasmas

In the fast ignition (FI) scheme of inertial confinement fusion, the igniter pulse falls on a precompressed overdense target and hence is unable to penetrate it. Thus, for the task of hot spot generation one has to rely on energetic electrons which are produced by the laser pulse at the critical surface. These electrons subsequently move towards the target core and deposit their energy in a sufficiently localized region. It is thus clear that the production of hot electrons by the incident sub-picosecond laser pulse at the critical surface and their subsequent transport in the overdense plasma region are the two main physics issues which are of relevance to the FI scheme. An experimental study and theoretical analysis which may be of relevance to these two issues are presented here. The study shows that the production of energetic electrons occurs through the wave breaking of plasma waves excited at the critical surface by the incident laser beam. Further, the propagation of hot electrons through the overdense region is influenced by electrostatically induced and/or by turbulence induced anomalous resistivity

Laser-pulse-induced second-harmonic and hard x-ray emission: role of plasma-wave breaking

We report time resolved measurements of second-harmonic and hard x rays emitted during the interaction of an intense laser pulse (1016 W cm-2, 100 fs) with a preplasma generated on a solid target. We observe that for a particular length scale the second harmonic goes through a minimum, while hard x-ray emission on the contrary maximizes. Theoretical or numerical modeling of this anticorrelation in terms of wave breaking of strongly driven electron plasma waves clearly brings out hitherto unexplored links between the physical mechanisms of second-harmonic generation and hard x-ray emission