Accommodation response and spherical aberration during orthokeratology.

PURPOSE: To evaluate the changes in the accommodative response and in the corneal and internal spherical aberration during 3 months of wear of orthokeratology lenses from the baseline. METHODS: Fifty children aged 8 to 17 were recruited for a prospective study and were fitted with orthokeratology lenses. Refraction without cycloplegia, high and low uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), accommodation lag, horizontal near phoria without correction, corneal topography, corneal, and total wavefront aberration were performed at baseline, 1 day, 1 week, 1 month, and 3 months. Data were analyzed by Student's t test for related samples, repeated measures ANOVA test, and Pearson correlation test. RESULTS: The spherical equivalent (SE) before and after 3 months was - 3.33 ± 1.60 D and - 0.30 ± 0.46 D, respectively. Accommodation lag was 0.53 ± 0.38 D and 0.20 ± 0.33 D at baseline and at 3 months, respectively. A moderate correlation between lag at the baseline and its change between baseline and the 3-month visit was found (P < 0.05; R = 0.748). The spherical aberration (SA) increased for anterior corneal and total measurement, being statistically significant for all visits (P < 0.05). The internal SA decreased: - 0.105 ± 0.006 at baseline and - 0.196 ± 0.203 at 1 week (P < 0.05). No difference between baseline and the follow-up visits in posterior corneal SA was found (P > 0.05) CONCLUSION: The negative SA of the lens increases during OK treatment compensated for the increase of the anterior corneal surface positive SA, in addition to increasing the accommodative response.

First operation in SPIDER and the path to complete MITICA.

The requirements of ITER neutral beam injectors (1 MeV, 40 A negative deuterium ion current for 1 h) have never been simultaneously attained; therefore, a dedicated Neutral Beam Test Facility (NBTF) was set up at Consorzio RFX (Padova, Italy). The NBTF includes two experiments: SPIDER (Source for the Production of Ions of Deuterium Extracted from Rf plasma), the full-scale prototype of the source of ITER injectors, with a 100 keV accelerator, to investigate and optimize the properties of the ion source; and MITICA, the full-scale prototype of the entire injector, devoted to the issues related to the accelerator, including voltage holding at low gas pressure. The present paper gives an account of the status of the procurements, of the timeline, and of the voltage holding tests and experiments for MITICA. As for SPIDER, the first year of operation is described, regarding the solution of some issues connected with the radiofrequency power, the source operation, and the characterization of the first negative ion beam.

Steady state magnetic sensors for ITER and beyond: Development and final design (invited).

The measurements of the magnetic field in tokamaks such as ITER and DEMO will be challenging due to the long pulse duration, high neutron flux, and elevated temperatures. The long duration of the plasma pulse makes standard techniques, such as inductive coils, prone to errors. At the same time, the hostile environment, with repairs possible only on blanket exchange, if at all, requires a robust magnetic sensor. This contribution presents the final design of novel, steady-state, magnetic sensors for ITER. A poloidal array of 60 sensors mounted on the vacuum vessel outer shell contributes to the measurement of the plasma current, plasma-wall clearance, low-frequency MHD modes and will allow for crosscheck with the outer-vessel inductive coils. Each sensor hosts a pair of bismuth Hall probes, themselves an outcome of extensive R&D, including neutron irradiations (to 1023 n/m2), temperature cycling tests (73-473 K) and tests at high magnetic field (to 12 T). A significant effort has been devoted to optimize the sensor housing by design and prototyping. The production version features an indium-filled cell for in situ recalibration of the onboard thermocouple, vital for the interpretation of the Hall sensor measurement.

Castellated tiles as the beam-facing components for the diagnostic calorimeter of the negative ion source SPIDER.

This paper presents the results of numerical simulations and experimental tests carried out to assess the feasibility and suitability of graphite castellated tiles as beam-facing component in the diagnostic calorimeter of the negative ion source SPIDER (Source for Production of Ions of Deuterium Extracted from Radio frequency plasma). The results indicate that this concept could be a reliable, although less performing, alternative for the present design based on carbon fiber composite tiles, as it provides thermal measurements on the required spatial scale.

Comparison of mesalazine suppositories in proctitis and distal proctosigmoiditis.

BACKGROUND: Mesalazine suppositories at 500 mg b.d. are a safe and effective treatment for patients with ulcerative proctitis or distal proctosigmoiditis. Recently a mesalazine 1 g suppository (Pentasa) has been developed. METHODS: Fifty patients with active ulcerative colitis extending not beyond 20 cm from the anus on sigmoidoscopy, participated in a randomized single-blind study comparing the efficacy, tolerance and acceptance of the new Pentasa mesalazine 1 g suppository, given once daily versus Claversal mesalazine 500 mg suppository b.d. RESULTS: After 2 weeks, clinical remission was observed in 16 of 25 (64%) in the Pentasa group and in 7 of 25 (28%) in the Claversal 500 mg b.d. treated group; sigmoidoscopic remission occurred in 13 of 25 (52%) in the Pentasa group and in six of 25 (24%) in the Claversal group (P < 0.01). After 4 weeks, clinical and sigmoidoscopic remission were observed, respectively, in 84 and 76% of patients treated with Pentasa suppositories, and in 80 and 72% of patients treated with Claversal suppositories 500 mg b.d. (P = N.S.). The patients' evaluation for tolerability and practicality showed that the Pentasa suppository was significantly superior to the Claversal suppository. CONCLUSIONS: Pentasa 1 g suppository once daily induces a quicker clinical and sigmoidoscopic remission, and was better tolerated, than the Claversal 500 mg suppository b.d., and it may represent an advance for the topical treatment of distal proctosigmoiditis.

Long-term efficacy of bismuth carbomer enemas in patients with treatment-resistant chronic pouchitis.

BACKGROUND: Mucosal inflammation of the ileal pouch (pouchitis) is the major long-term complication after ileal pouch-anal anastomosis for ulcerative colitis. Broad-spectrum antibiotics are the mainstay of treatment, however, 15% of patients with pouchitis have a chronic, treatment-resistant disease. AIM: To determine the safety and efficacy of bismuth carbomer enemas in achieving and maintaining remission in treatment-resistant chronic pouchitis. METHODS: Twelve patients with treatment-resistant chronic pouchitis were treated nightly for 45 days with enemas containing elemental bismuth complexed with carbomer. Diagnosis of pouchitis and response to treatment were evaluated with the Pouchitis Disease Activity Index (PDAI), which includes clinical, sigmoidoscopic and histological criteria. Serum bismuth concentrations were determined by atomic absorption. RESULTS: Ten of 12 patients (83%) went into remission, with a significant decrease of mean total PDAI score from 12 (range 9-15) to 6 (4-15) (P < 0.002), and were continued on bismuth carbomer enemas administered every third night for 12 months. Patients were monitored clinically, sigmoidoscopically and histologically every 2 months for evidence of recurrence (increase > or = 2 in the clinical symptom portion of the PDAI). Six of 10 patients (60%) were able to maintain remission throughout the 12-month trial; 4/10 had an exacerbation, two of which occurred soon after discontinuing daily treatment. Serum bismuth levels were negligible in all patients and no side-effects were registered. CONCLUSIONS: Our findings suggest that bismuth carbomer enemas are safe and effective in achieving and maintaining remission in patients with treatment-resistant chronic pouchitis.

Increased expression of IP-10, IL-8, MCP-1, and MCP-3 in ulcerative colitis.

Chemokines are thought to be important for the recruitment of granulocytes and mononuclear cells and thus for the maintenance of inflammation in ulcerative colitis (UC). We have studied the expression of interferon-gamma inducible protein-10 (IP-10), interleukin-8 (IL-8), monocyte chemoattractant protein (MCP)-1, MCP-3, and macrophage inflammatory protein (MIP)-1alpha in UC patients and control individuals to assess the role of these chemokines in disease progression. Colonic biopsies were taken endoscopically from patients and controls, frozen immediately and subsequently stained for IP-10, IL-8, MCP-1, MCP-3, and MIP-1alpha in serial sections. Cells infiltrating the lamina propria but not epithelial cells express the analyzed chemokines. They were differentiated and counted, and chemokine-expressing cells were quantified by image analysis. The percentage of cells expressing IP-10, IL-8, MCP-1, and MCP-3 was significantly enhanced in all UC samples as compared to controls. Expression in the controls was borderline, except for IP-10. No expression of MIP-1alpha was found in controls and UC. IP-10 was also markedly expressed in the mucosa of control biopsies and therefore could have a role in activated T lymphocytes' recruitment into the healthy mucosa.