63 research outputs found
The coupon collector's problem
No full textn this note we will consider the following problem: how many coupons we have to purchase (on average) to complete a collection. This problem, which takes every- body back to his childhood when this was really “a prob- lem”, has been considered by the probabilists since the eighteenth century and nowadays it is still possible to de- rive some new results, probably original or at least never published. We will present some classic results, some new formulas, some alternative approaches to obtain known re- sults and a couple of amazing expressions
Molecole bioattive di protozoi ciliati a vita libera: struttura, meccanismo d'azione e possibilità applicative
No full textIsolamento e caratterizzazione della natura chimica delle tossine prodotte da Dileptus margaritifer, Spirostomum teres e Loxodes striatus. Analisi dello spettro di attività e del meccanismo di tossicità delle tossine note come stentorina e climacostol, per le quali sono già stati predisposti protocolli di sintesi di laboratorio. Analisi di citotossicità su protozoi patogeni come Plasmodium, Trypanosoma e Leishmania, e valutazione di impiego come antibiotici, delle tossine sia naturali che di sintesi che potranno essere ottenute in quantità maggiori e con minor investimento di risorse
Predator-prey interaction between 6 species of ciliates and the turbellarian Stenostomum sphagnetorum
No full textTHE USE OF THE IGG-LATEX TEST IN HUMAN LEUKEMIA.
No full textLymphocytes with receptors for IgG and phagocytes were detected simultaneously by incubating Bøyum separated mononuclear cells with IgG coated latex particles. IgG-latex particles formed rosettes around lymphoid cells with receptors for IgG, whereas phagocytes ingested these particles. This test was performed on cells from normal subjects and from patients with various diseases involving lymphocyte or monocyte proliferations. The results show that most chronic lymphocytic leukemia cells formed IgG-latex rosettes. Hairy cells from the patients studied showed a similar behaviour but poor phagocytic properties. Acute monocytic leukemia cells, in contrast, were largely phagocytes. This test is easy to perform and does not require sophisticated reagents, thus providing a basis for reproducibility, a rare occurrence in cellular immunology studies
Laparoscopic tension-free repair of large paraesophageal hiatal hernias with a composite A-shaped mesh: Two-year follow-up
No full textBackground: Surgical repair of large hiatal hernias is associated with a high recurrence rate when the repair is made by simple cruroplasty. The use of a mesh goes from a reinforcement of a simple cruroplasty to a tension-free repair. We discuss the evolution of this approach and evaluate the outcomes of 27 patients with type II (n = 9), type III (n = 16), and type IV (n = 2) hiatal hernias treated laparoscopically. Methods: Between November 1999 and October 2003, 27 patients (18 women and 9 men) received laparoscopic repair of large hiatal hernias by means of an A-shaped polypropylene-polytetrafluoroethylene mesh. A total or a partial fundoplication was associated in all cases. The mean age was 60.1 years (range, 36-76 years). The patients presented with symptoms of 2 months to 10 years in duration. Preoperative assessment included an upper gastrointestinal endoscopy, esophageal manometry, 24 hour pH monitoring, and barium swallow. Concomitant esophagitis was found in 16 patients and impaired esophageal peristalsis in 2 patients. Four patients had concomitant gall-bladder disease treated at the same time. Results: No conversions occurred in our series. There was no perioperative mortality, and morbidity was low. Follow-up averaged 27 months (range, 6-46 months). There has been 1 recurrence (3.7%), prolonged dysphagia in 4 cases, and no mesh erosion. Conclusion: Early results confirm the feasibility of the tension-free repair of large hiatal hernias and the effectiveness of the composite A-shaped mesh. Long-term follow-up for all patients is necessary to determine the real incidence of recurrence
Chemical defence by means of extrusive cortical granules in the heterotrich ciliate Climacostomum virens
No full textLAPAROSCOPIC REPAIR OF A LARGE HIATAL HERNIA: FIRST REPORT ON THE USE OF CRURASOFT PATCH IN ITALY
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