Single-Charge Tunneling in Codoped Silicon Nanodevices.

Silicon (Si) nano-electronics is advancing towards the end of the Moore's Law, as gate lengths of just a few nanometers have been already reported in state-of-the-art transistors. In the nanostructures that act as channels in transistors or depletion layers in pn diodes, the role of dopants becomes critical, since the transport properties depend on a small number of dopants and/or on their random distribution. Here, we present the possibility of single-charge tunneling in codoped Si nanodevices formed in silicon-on-insulator films, in which both phosphorus (P) donors and boron (B) acceptors are introduced intentionally. For highly doped pn diodes, we report band-to-band tunneling (BTBT) via energy states in the depletion layer. These energy states can be ascribed to quantum dots (QDs) formed by the random distribution of donors and acceptors in such a depletion layer. For nanoscale silicon-on-insulator field-effect transistors (SOI-FETs) doped heavily with P-donors and also counter-doped with B-acceptors, we report current peaks and Coulomb diamonds. These features are ascribed to single-electron tunneling (SET) via QDs in the codoped nanoscale channels. These reports provide new insights for utilizing codoped silicon nanostructures for fundamental applications, in which the interplay between donors and acceptors can enhance the functionalities of the devices.

Clinical and laboratory studies on the effects of capsular tension ring on surgical outcomes of trifocal intraocular lens implantation.

PURPOSE: To assess the influence of capsular tension ring (CTR) on surgical outcomes of trifocal intraocular lens (IOL) implantation in femtosecond laser-assisted cataract surgery. SETTING: Sugita Eye Clinic, Tokyo, and University of Tsukuba, Ibaraki, Japan. DESIGN: Prospective, randomized, paired-eye clinical study and laboratory study. METHODS: In the clinical study involving 44 eyes of 22 patients with no risk of zonular instability, 1 eye received IOL alone and the contralateral eye received IOL with CTR. Preoperative capsular bag diameter and postoperative IOL tilt/decentration were measured using anterior segment optical coherence tomography. In the laboratory study, IOL and CTR were implanted into an artificial capsular bag of 10 mm in diameter, and IOL centration was evaluated. RESULTS: Throughout the 12-month follow-up period, there was no significant difference in refractive and visual outcomes between groups. The amount of IOL decentration was significantly larger in eyes with CTR than in eyes without CTR at 12 months postoperatively (P = .037). There was a significant negative correlation between capsular bag diameter and the amount of IOL decentration in eyes with CTR (P = .038), but not in eyes without CTR (P = .873). The laboratory study indicated that interference between CTR eyelets and IOL haptics significantly increased IOL decentration (P < .001). CONCLUSIONS: The use of CTR did not affect refractive and visual outcomes of trifocal IOL implantation in eyes without the risk of zonular weakness. CTR coimplantation increased IOL decentration possibly due to the interference between CTR eyelets and IOL haptics.

Long-term outcomes of cataract surgery with toric intraocular lens implantation by the type of preoperative astigmatism.

Surgical outcomes of toric intraocular lens (IOL) implantation for 8 years after surgery were analyzed. Data were retrospectively collected in 176 eyes of 176 patients before and 1 month, 1, 3, 5, and 8 years after phacoemulsification and implantation of a toric IOL. Preoperative corneal and postoperative manifest astigmatism was analyzed by converting to power vector notations; horizontal/vertical (J0) and oblique (J45) astigmatism components. Toric IOL implantation significantly reduced pre-existing astigmatism by decreasing J0 in eyes with preoperative with-the-rule (WTR) astigmatism, increasing J0 in eyes with against-the-rule (ATR) astigmatism, and correcting J45 in eyes with oblique astigmatism. After surgery, the eyes with preoperative ATR astigmatism showed a significant ATR astigmatic shift, and J0 at 5 and 8 years was significantly smaller than that at 1 month postoperatively. Uncorrected distance visual acuity was also significantly worse at 5 and 8 years than at 1 month postoperatively. In eyes with WTR and oblique astigmatism, the effects of toric IOLs on astigmatism and visual acuity were sustained for 8 years. The long-term astigmatism-correcting effects did not differ among the models of toric IOL used in this study, SN6AT3-8 (Alcon Laboratories). In eyes with preoperative ATR astigmatism, astigmatism-correcting effects of toric IOLs decreased at 5 years and later postoperatively, indicating that overcorrection may be considered at the time of cataract surgery. In eyes with WTR and oblique astigmatism, the effects of toric IOLs were maintained throughout the 8-year follow-up period.

Effect of small-incision sutureless cataract surgery on the natural course of astigmatism over 10 to 20 years.

PURPOSE: To retrospectively assess astigmatic changes over 10 years and 20 years after small-incision cataract surgery. SETTING: 5 ophthalmic surgical sites in Japan. DESIGN: Retrospective case series. METHODS: Data were collected from patients who had undergone phacoemulsification and implantation of an intraocular lens through a 2.2 to 2.4 mm incision. Preoperative corneal and postoperative manifest astigmatism were converted to power vector notations: horizontal/vertical (J 0 ) and oblique (J 45 ) astigmatism components. RESULTS: 422 eyes of 422 patients were followed for 10 years, and data preoperatively and at 1 month and at 1 year, 3 years, 5 years, 8 years, and 10 years postoperatively were analyzed. The mean J 0 decreased significantly ( P < .001, repeated measures analysis of variance) with an against-the-rule (ATR) shift of 0.363 ± 0.433 diopter (D) over 10 years, but the mean J 45 did not change significantly ( P = .150). Double-angle plot analyses also showed similar ATR shifts in all astigmatism groups. In the subgroup analysis conducted in 34 patients who were followed for 20 years, J 0 declined significantly ( P < .001) by 0.649 ± 0.576 D, whereas J 45 did not ( P = .516). The postoperative changes in J 0 and J 45 were not significantly different between eyes with preoperative with-the-rule, ATR, or oblique astigmatism. CONCLUSIONS: Postoperative astigmatism continued to shift toward ATR during the follow-up period of 20 years after small-incision cataract surgery, which seems to reflect the natural course of corneal astigmatic changes that commonly occur with aging. ATR astigmatic shifts were similar in both pattern and magnitude regardless of the type of preoperative astigmatism.

Inhibitory effects of Bifidobacterium longum on experimental ulcerative colitis induced in mice by synthetic dextran sulfate sodium.

BACKGROUND/AIMS: The relationship between alterations in intestinal microflora and ulcerative colitis is still not clear. Whether improvement in bacterial populations might be a new strategy for prevention or treatment needs to be tested. METHODS: Ulcerative colitis was induced in mice by oral administration of synthetic dextran sulfate sodium (molecular weight 54,000). Inhibitory effects of concomitant treatment with Bifidobacterium longum were assessed in terms of total colon length and severity of histological changes. In addition, changes of microflora and short-chain fatty acids were tested in fecal samples and compared before and after treatment. RESULTS: Administration of B. longum significantly inhibited both shortening of total colon length and the severity of ulcerative colitis compared to controls. It was confirmed that the administered B. longum resided in the gut and blocked the decrease of lactobacilli in fecal samples in mice with dextran sulfate sodium-induced colitis. CONCLUSIONS: Oral administration of B. longum exerts marked inhibitory effects on ulcerative colitis in mice.

Glucose metabolism of lactic acid bacteria changed by quinone-mediated extracellular electron transfer.

It can be expected that extracellular electron transfer to regenerate NAD+ changes the glucose metabolism of the homofermentative lactic acid bacteria. In this work, the glucose metabolism of Lactobacillusplantarum and Lactococcus lactis was examined in resting cells with 2-amino-3-carboxy-1,4-naphthoquinone (ACNQ) as the electron transfer mediator and ferricyanide (Fe(CN)6(3-)) as the extracellular electron acceptor. NADH in the cells was oxidized by ACNQ with the aid of diaphorase, and the reduced ACNQ was reoxidized with Fe(CN)6(3-). The extracellular electron transfer system promoted the generation of pyruvate, acetate, and acetoin from glucose, and restricted lactate production. Diaphorase activity increased when cultivation was aerobic, and this increased the concentrations of pyruvate, acetate, and acetoin relative to the concentration of lactate to increase in the presence of ACNQ and Fe(CN)6(3-)

Oral intake of Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 prevents collagen-induced arthritis in mice.

Oral intake of some lactic acid bacteria can have beneficial effects on the host by activating immune responses and enhancing resistance to infection by pathogens. In this study, effects of Lactobacillus sp. on the development of autoimmune disease were examined in mice with collagen-induced arthritis (CIA). CIA, a model of some types of rheumatoid arthritis (RA), can be induced in DBA/1J mice by immunizing them with bovine type II collagen (bCII). Oral intake of skimmed milk (SM) fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 (SM/OLL1073R-1) was found to markedly inhibit the development of CIA in these mice, compared with a control group fed the control foodstuff. The inhibitory effect of SM fermented with L. delbrueckii subsp. bulgaricus OLLI 102 (SM/OLL1102) or fresh SM was weaker than that of SM/ OLL1073R-1. A deMan Rogosa Sharpe (MRS) broth culture of OLL1073R-1 without any major components of SM had the same inhibitory effect as SM/OLL1073R-1, suggesting that the inhibitory effect of SM/OLL1073R-1 is attributable not only to SM components but also to OLL1073R-1 cells, their metabolites, or both. We found that SM/OLL1073R-1 and SM caused reduced secretion of the cytokine IFN-gamma by lymph node cells (LNCs) in response to bCII. However, SM/OLL1102 did not affect the secretion of IFN-gamma. A polysaccharide fraction secreted by OLL1073R-1 also exhibited the inhibitory effects on both development of CIA and secretion of IFN-gamma.