70 research outputs found

    Repetitions in infinite palindrome-rich words

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    Rich words are characterized by containing the maximum possible number of distinct palindromes. Several characteristic properties of rich words have been studied; yet the analysis of repetitions in rich words still involves some interesting open problems. We address lower bounds on the repetition threshold of infinite rich words over 2 and 3-letter alphabets, and construct a candidate infinite rich word over the alphabet Σ2={0,1}\Sigma_2=\{0,1\} with a small critical exponent of 2+2/22+\sqrt{2}/2. This represents the first progress on an open problem of Vesti from 2017.Comment: 12 page

    Simultane Behandlung von obliterativen Karotispathologien und koronarer Herzkrankheit: Aktuelles Konzept und Resultate der letzten 5Jahre

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    Zusammenfassung: Einführung: Die kombinierte Karotisendarteriektomie und aorto-coronare Baypassoperation (C-CABG) weisen ein hohes peri-operatives Risiko auf. Als Alternative wird in letzter Zeit das Stenting der Artera carotis interna propagiert. Das Fehlen von Level I Evidenz hat uns motiviert, die Resultate unserer C-CABG der letzten 5 Jahre zu evaluieren. Methoden und Patienten: Retrospektive Monozenterstudie von 113C-CABG, durchgeführt zwischen Januar 2000 und Dezember 2004. Das mediane Alter der Patienten betrug 65Jahre (22Patienten waren 80Jahre alt oder älter). Die Karotisendarteriektomie wurde vor der aortokoronaren Bypassoperation in derselben Narkose durchgeführt. Resultate: Die 30-Tages-Mortalität war ausschließlich kardial bedingt und betrug 4,4% (5/113). Die neurologischen Komplikationen waren ein Schlaganfall, der innerhalb von 30Tagen vollständig regredient war, und 3TIA (3,5%, 4/113). Schlussfolgerung: C-CABG mit initial durchgeführter Karotisendarteriektomie ist ein sicheres Verfahren mit niedriger neurologischer Komplikationsrate. Der riskante Anteil des kombinierten Eingriffs ist nicht die Karotisendarteriektomie, sondern die aortokoronare Revaskularisation. Demzufolge scheint das Stenting beim kombinierten Eingriff als Alternative nicht gerechtfertigt, solange keine klaren Vorteile hinsichtlich der Früh- und Langzeitresultate gegenüber der alleinigen Karotisendarteriektomie vorliege

    Simultane Behandlung von obliterativen Karotispathologien und koronarer Herzkrankheit

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    Einführung: Die kombinierte Karotisendarteriektomie und aorto-coronare Baypassoperation (C-CABG) weisen ein hohes peri-operatives Risiko auf. Als Alternative wird in letzter Zeit das Stenting der Artera carotis interna propagiert. Das Fehlen von Level I Evidenz hat uns motiviert, die Resultate unserer C-CABG der letzten 5 Jahre zu evaluieren. Methoden und Patienten: Retrospektive Monozenterstudie von 113C-CABG, durchgeführt zwischen Januar 2000 und Dezember 2004. Das mediane Alter der Patienten betrug 65Jahre (22Patienten waren 80Jahre alt oder älter). Die Karotisendarteriektomie wurde vor der aortokoronaren Bypassoperation in derselben Narkose durchgeführt. Resultate: Die 30-Tages-Mortalität war ausschließlich kardial bedingt und betrug 4,4% (5/113). Die neurologischen Komplikationen waren ein Schlaganfall, der innerhalb von 30Tagen vollständig regredient war, und 3TIA (3,5%, 4/113). Schlussfolgerung: C-CABG mit initial durchgeführter Karotisendarteriektomie ist ein sicheres Verfahren mit niedriger neurologischer Komplikationsrate. Der riskante Anteil des kombinierten Eingriffs ist nicht die Karotisendarteriektomie, sondern die aortokoronare Revaskularisation. Demzufolge scheint das Stenting beim kombinierten Eingriff als Alternative nicht gerechtfertigt, solange keine klaren Vorteile hinsichtlich der Früh- und Langzeitresultate gegenüber der alleinigen Karotisendarteriektomie vorliege

    Cellular actors, Toll-like receptors, and local cytokine profile in acute coronary syndromes

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    Aims Inflammation plays a key role in acute coronary syndromes (ACS). Toll-like receptors (TLR) on leucocytes mediate inflammation and immune responses. We characterized leucocytes and TLR expression within coronary thrombi and compared cytokine levels from the site of coronary occlusion with aortic blood (AB) in ACS patients. Methods and results In 18 ACS patients, thrombi were collected by aspiration during primary percutaneous coronary intervention. Thrombi and AB from these patients as well as AB from 10 age-matched controls without coronary artery disease were assessed by FACS analysis for cellular distribution and TLR expression. For further discrimination of ACS specificity, seven non-coronary intravascular thrombi and eight thrombi generated in vitro were analysed. In 17 additional patients, cytokine levels were determined in blood samples from the site of coronary occlusion under distal occlusion and compared with AB. In coronary thrombi from ACS, the percentage of monocytes related to the total leucocyte count was greater than in AB (47 vs. 20%, P = 0.0002). In thrombi, TLR-4 and TLR-2 were overexpressed on CD14-labelled monocytes, and TLR-2 was increased on CD66b-labelled granulocytes, in comparison with leucocytes in AB. In contrast, in vitro and non-coronary thrombi exhibited no overexpression of TLR-4. Local blood samples taken under distal occlusion revealed elevated concentrations of chemokines (IL-8, MCP-1, eotaxin, MIP-1α, and IP-10) and cytokines (IL-1ra, IL-6, IL-7, IL-12, IL-17, IFN-α, and granulocyte-macrophage colony-stimulating factor) regulating both innate and adaptive immunity (all P < 0.05). Conclusion In ACS patients, monocytes accumulate within thrombi and specifically overexpress TLR-4. Together with the local expression patterns of chemokines and cytokines, the increase of TLR-4 reflects a concerted activation of this inflammatory pathway at the site of coronary occlusion in AC

    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

    Prevalence and progression of visual impairment in patients newly diagnosed with clinical type 2 diabetes: a 6-year follow up study

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    <p>Abstract</p> <p>Background</p> <p>Many diabetic patients fear visual loss as the worst consequence of diabetes. In most studies the main eye pathology is assigned as the cause of visual impairment. This study analysed a broad range of possible ocular and non-ocular predictors of visual impairment prospectively in patients newly diagnosed with clinical type 2 diabetes.</p> <p>Methods</p> <p>Data were from a population-based cohort of 1,241 persons newly diagnosed with clinical, often symptomatic type 2 diabetes aged ≥ 40 years. After 6 years, 807 patients were followed up. Standard eye examinations were done by practising ophthalmologists.</p> <p>Results</p> <p>At diabetes diagnosis median age was 65.5 years. Over 6 years, the prevalence of blindness (visual acuity of best seeing eye ≤ 0.1) rose from 0.9% (11/1,241) to 2.4% (19/807) and the prevalence of moderate visual impairment (> 0.1; < 0.5) rose from 5.4% (67/1,241) to 6.7% (54/807). The incidence (95% confidence interval) of blindness was 40.2 (25.3-63.8) per 10,000 patient-years. Baseline predictors of level of visual acuity (age, age-related macular degeneration (AMD), cataract, living alone, low self-rated health, and sedentary life-style) and speed of continued visual loss (age, AMD, diabetic retinopathy (DR), cataract, living alone, and high fasting triglycerides) were identified.</p> <p>Conclusions</p> <p>In a comprehensive assessment of predictors of visual impairment, even in a health care system allowing self-referral to free eye examinations, treatable eye pathologies such as DR and cataract emerge together with age as the most notable predictors of continued visual loss after diabetes diagnosis. Our results underline the importance of eliminating barriers to efficient eye care by increasing patients' and primary care practitioners' awareness of the necessity of regular eye examinations and timely surgical treatment.</p
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