Corneal HOAs on both corneal surfaces in keratoconic eyes were higher than in control eyes. Coma from the posterior surface compensated partly for that from the anterior surface. Residual irregular astigmatism in patients with keratoconus wearing rigid gas permeable contact lenses can be estimated by measuring the HOA from the posterior corneal surface.

No author has a financial or proprietary interest in any material or method mentioned.

With the increasing popularity of selective lamellar keratoplasty procedures, it is important to characterize the optical differences among penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK). The impact of optical differences on the visual acuity (VA) in eyes after keratoplasty is significant. Quantitative evaluation of corneal higher-order aberrations (HOAs) of anterior and posterior surfaces using a rotating Scheimpflug-based corneal topographer, showed that eyes that undergo DSAEK have lower anterior corneal HOAs compared with eyes subjected to PK or DALK. In DSAEK, the anterior corneal surfaces are not replaced, which is in contrast to PK or DALK, where they are replaced. Through evaluation of corneal scatter with a densitometry program associated with the rotating Scheimpflug-based corneal topographer, 3 characteristic patterns of corneal scatter were found in eyes that had undergone keratoplasty. Investigation of the impact of corneal HOAs and corneal scatter on VA after keratoplasty showed that the VA was correlated significantly with corneal scatter.

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Chronologic measurements of corneal tomography in keratoconus demonstrated that the progression of steepening at posterior corneal surface was found not only in patients under 30 years but also in older patients, particularly in advanced keratoconus. The rate of progression can be measured by mapping of corneal curvature and thickness using OCT, and the risk of progression was greater in younger patients with steeper Kmax.

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Oral drug delivery is the most desirable and preferred method of administering therapeutic agent for their systematic effects such as patient acceptance, convenience in administration, and cost-effective manufacturing process. Thus, a wide variety of approaches of drug delivery system (DDS) have been investigated for oral application.1) However, the development process is precluded by several physiological difficulties, such as an inability to restrain and localize the DDS within desired regions of gastrointestinal tract and highly variable nature of gastric emptying process. For example, the relatively brief gastric emptying time (GET) can result in incomplete drug release from the DDS devices leading to diminished efficacy of the administered dose.Intragastric floating drug delivery system (FDDS) is noted as one of the orally applicable DDS for prolongation of the GET.2-4) The bulk density of FDDS is lower than that of gastric fluids and thus it remains buoyant on stomach contents for a long time in the drug releasing process. Hence, it is useful for obtaining the sufficient bioavailability and the effective "plasma" level, especially for drug having limited absorption sites in the upper small intestine, such as furosemide, 5) ketoprofen. 6) In addition, FDDS is one of the optimal systems for stomach mucosa targeting of antitumor agent for the treatment of stomach cancer 7) and antibiotics for the eradication of Helicobacter pylori.8) However, with most of FDDS devices developed previously, it is difficult for all patients to obtain the expected therapeutic effects of drug administered, since the drug is released with a pattern preprogrammed in the manufacturing process despite individual differences in stomach such as pH value and the transit time in gastrointestinal tract. Thus, from a viewpoint of the real optimization of drug therapy, the drug release properties of FDDS should be adjusted to individual stomach conditions.Over the years, in a series on preparation of double-compressed (DC) tablets for use in a DDS with plasma techniques, we have reported that novel sustained-and delayedrelease systems can be prepared by plasma-irradiation on the outer layer of DC tablet, [9][10][11][12][13][14][15][16][17][18][19] as well as matrix-type composite powder for sustained-drug release system can be prepared by mechanically-amplified plasma processing. [20][21][22] During the course of such studies on plasma-assisted DDS preparation, we have found that the carbon dioxide was trapped in the tablet when argon plasma was irradiated onto the DC tablet composed of plasma-crosslinkable polymers possessing carboxyl group as an outer layer. Since such tablets turned to floating system on the water, it was considered that this could be applicable to FDDS. In fact, we have obtained the intragastric FDDS by plasma-irradiation on DC tablet using a mixture of methyl vinyl ether-maleic acid copolymer (VEMAC) and hydroxypropylmethylcellulose phthalate (HPMCP) with plasma-crosslinkable properties as outer layer. The tablet thus ...

We present D(d, n) 3 He reaction rates for a new inertial electrostatic confinement (IEC) device which aims to overcome neutralization (charge exchange) of accelerating ions by operating at D 2 gas pressures of just 5-10 mPa with the aid of an internal ring-shaped magnetron ion source. Initial experiments with a voltage of −60 kV applied to a central spherical cathode grid yield neutron production rates (NPR) proportional to I 1.7 for cathode grid current in the range I = 0.1 − 1 mA. This approaches the ideal ∝ I 2 dependence for a system dominated by energetically preferred, 'beam-beam' reactions between converging nuclei. However, later measurements show NPR ∝ I and also indicate changes in the pressure dependence. In fact the I 1.7 dependence was recovered by increasing the cathode grid voltage to −80 kV, though this too was only temporary. We suggest that time variation of NPR may be partially explained by a significant contribution of beam-grid reactions and temperaturedependent deuteron absorption by the grid cathode.