64 research outputs found

    Double jumps and transition rates for two dipole-interacting atoms

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    Cooperative effects in the fluorescence of two dipole-interacting atoms, with macroscopic quantum jumps (light and dark periods), are investigated. The transition rates between different intensity periods are calculated in closed form and are used to determine the rates of double jumps between periods of double intensity and dark periods, the mean duration of the three intensity periods and the mean rate of their occurrence. We predict, to our knowledge for the first time, cooperative effects for double jumps, for atomic distances from one and to ten wave lengths of the strong transition. The double jump rate, as a function of the atomic distance, can show oscillations of up to 30% at distances of about a wave length, and oscillations are still noticeable at a distance of ten wave lengths. The cooperative effects of the quantities and their characteristic behavior turn out to be strongly dependent on the laser detuning.Comment: Substantially revised versio

    Genome-wide RNA-Sequencing analysis reveals a distinct fibrosis gene signature in the conjunctiva after glaucoma surgery

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    Fibrosis-related events play a part in most blinding diseases worldwide. However, little is known about the mechanisms driving this complex multifactorial disease. Here we have carried out the first genome-wide RNA-Sequencing study in human conjunctival fibrosis. We isolated 10 primary fibrotic and 7 non-fibrotic conjunctival fibroblast cell lines from patients with and without previous glaucoma surgery, respectively. The patients were matched for ethnicity and age. We identified 246 genes that were differentially expressed by over two-fold and p < 0.05, of which 46 genes were upregulated and 200 genes were downregulated in the fibrotic cell lines compared to the non-fibrotic cell lines. We also carried out detailed gene ontology, KEGG, disease association, pathway commons, WikiPathways and protein network analyses, and identified distinct pathways linked to smooth muscle contraction, inflammatory cytokines, immune mediators, extracellular matrix proteins and oncogene expression. We further validated 11 genes that were highly upregulated or downregulated using real-time quantitative PCR and found a strong correlation between the RNA-Seq and qPCR results. Our study demonstrates that there is a distinct fibrosis gene signature in the conjunctiva after glaucoma surgery and provides new insights into the mechanistic pathways driving the complex fibrotic process in the eye and other tissues

    Is post-trabeculectomy hypotony a risk factor for subsequent failure? A case control study

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    BACKGROUND: Ocular hypotony results in an increased break down of the blood-aqueous barrier and an increase in inflammatory mediator release. We postulate that this release may lead to an increased risk of trabeculectomy failure through increased bleb scarring. This study was designed to try to address the question if hypotony within one month of trabeculectomy for Primary Open Angle Glaucoma (POAG), is a risk factor for future failure of the filter. METHODS: We performed a retrospective, case notes review, of patients who underwent trabeculectomy for POAG between Jan 1995 and Jan 1996 at our hospital. We identified those with postoperative hypotony within 1 month of surgery. Hypotony was defined as an intraocular pressure (IOP) < 8 mmHg or an IOP of less than 10 mmHg with choroidal detachment or a shallow anterior chamber. We compared the survival times of the surgery in this group with a control group (who did not suffer hypotony as described above), over a 5 year period. Failure of trabeculectomy was defined as IOP > 21 mmHg, or commencement of topical antihypertensives or repeat surgery. RESULTS: 97 cases matched our inclusion criteria, of these 38 (39%) experienced hypotony within 1 month of surgery. We compared the survival times in those patients who developed hypotony with those who did not using the log-rank test. This data provided evidence of a difference (P = 0.0492) with patients in the hypotony group failing more rapidly than the control group. CONCLUSION: Early post-trabeculectomy hypotony (within 1 month) is associated with reduced survival time of blebs

    Interaction between intracardiac sympathetic neurons and adrenal medulla

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