200 research outputs found

    Strict Boolean-valued Models

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    Impurity conduction in phosphorus-doped buried-channel silicon-on-insulator field-effect transistors

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    We investigate transport in phosphorus-doped buried-channel metal-oxide-semiconductor field-effect transistors at temperatures between 10 and 295 K. In a range of doping concentration between around 2.1 and 8.7 x 1017 cm-3, we find that a clear peak emerges in the conductance versus gate-voltage curves at low temperature. In addition, temperature dependence measurements reveal that the conductance obeys a variable-range-hopping law up to an unexpectedly high temperature of over 100 K. The symmetric dual-gate configuration of the silicon-on-insulator we use allows us to fully characterize the vertical-bias dependence of the conductance. Comparison to computer simulation of the phosphorus impurity band depth-profile reveals how the spatial variation of the impurity-band energy determines the hopping conduction in transistor structures. We conclude that the emergence of the conductance peak and the high-temperature variable-range hopping originate from the band bending and its change by the gate bias. Moreover, the peak structure is found to be strongly related to the density of states (DOS) of the phosphorus impurity band, suggesting the possibility of performing a novel spectroscopy for the DOS of phosphorus, the dopant of paramount importance in Si technology, through transport experiments.Comment: 9 figure

    Metabolic remodeling of hyperactive rats

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    Spontaneously Running Tokushima Shikoku (SPORTS) rat is a hyperactive rat strain. However, the causative mutation of this phenotype has not yet been identified. To investigate the molecular basis for the unique phenotype of SPORTS rats, we examined gene-expression profiles by microarray analyses. Among adenylate kinase isozymes that maintain the homeostasis of cellular adenine nucleotide composition in the cell, only adenylate kinase 1 is highly up-regulated in both exercised and sedentary SPORTS rats compared with wild-type (WT) rats, 5.5-fold and 3.3-fold, respectively. Further comparative analyses revealed that genes involved in glucose metabolism were up-regulated in skeletal muscle tissue of exercised SPORTS rats compared with sedentary mutants, whereas genes related to extracellular matrix or region were down-regulated compared with WT rats. In brain tissue of sedentary SPORTS rats, genes associated with defense and catecholamine metabolism were highly expressed compared with WT rats. These findings suggest that genetic mutation(s) in SPORTS rat remodels metabolic demands through differentially regulating gene expression regardless of exercise. Therefore, the SPORTS rats are useful animal model not only for further examining the effects of exercise on metabolism but also for deeply studying the molecular basis how mutation affect the psychological motivation with spontaneous voluntary exercise phenotype

    Catalytic Efficiency of [20]Paracyclophane Oxime and Cycloheptaamylose in the Decomposition of Carboxylate and Carbonate Esters

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    The hydrolytic decomposition of dodecyl ρ-nitrophenyl carbonate (LPNC) and ρ-nitrophenyl dodecanoate (PNPL) as mediated by 10-hydroxy-ll-hydroxyimino[20]-paracyclophane (Oxime-I) and cycloheptaamylose (β-CD) has been investigated in aqueous media containing 9.9% (v/v) ethanol and 1.0% (v/v) acetonitrile to gain an insight into the reaction and/or substrate specificity. Both LPNC and PNPL were decomposed effectively by an equimolar amount of Oxime-I. It turned out from the analysis of kinetic data that the binding of LPNC to Oxime-I is 2.5 times tighter than that of PNPL, but the subsequent catalysis is 3.3 times more favorable for PNPL than for LPNC. Hence, the overall efficiency of Oxime-I is 1.3 times greater for PNPL, as changed from a 13-fold difference between both substrates in the simple alkaline hydrolysis. β-CD was found to be effective also in the decomposition of LPNC when added in large excess over substrate. Comparison of kinetic parameters between the two systems, Oxime-I and β-CD, indicated that the former is better in both binding and catalytic effects toward the extremely hydrophobic substrates

    Surgical outcome comparisons of multifocal IOLs of Lentis Comfort LS-313 MF15 and Tecnis Eyhance DIB00V

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    AIM: To compare the surgical outcomes of a multifocal intraocular lens (IOL; Lentis Comfort LS-313 MF15) with those of an enhanced monofocal IOL (Tecnis Eyhance DIB00V). METHODS: This retrospective study included patients who underwent cataract surgery with LS-313 MF15 or Eyhance IOL implantation. Data regarding patient demographics, surgical records, and ophthalmic examination before the cataract surgery and one and three months postoperatively were collected. Visual acuities, refractive values, defocus curves, contrast sensitivities and subjective symptoms were evaluated. RESULTS: Among the 71 eyes (47 patients) included in this study, 32 eyes (20 patients) underwent LS-313 MF15 IOL implantation, and 39 eyes (27 patients) underwent Eyhance IOL implantation. No significant differences were observed in age, axial length, or refractive error between the two groups preoperatively. Furthermore, the distance-corrected and uncorrected distance visual acuities one month postoperatively did not differ between the groups, and both groups had sufficient visual acuities at the distances of 5, 1 m, 70, 50, and 30 cm. Other ophthalmic data, including subjective symptoms based on the 14-item Visual Function Index Questionnaire, monocular defocus curves, contrast sensitivities, and halo and glare, did not differ between the groups three months postoperatively. Moreover, both groups had good outcomes. The spherical equivalent one month postoperatively was significantly myopic in the LS-313 MF15 group compared with that in the Eyhance group (P=0.033); however, this difference was not observed three months postoperatively (P=0.471). CONCLUSION: Comparison of the surgical outcomes of LS-313 MF15 with those of Eyhance with different optical properties reveal that both IOLs show good postoperative outcomes, with no significant differences being noted between the two IOLs

    Identification of nesfatin-1 as a satiety molecule in the hypothalamus

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    The brain hypothalamus contains certain secreted molecules that are important in regulating feeding behaviour. Here we show that nesfatin, corresponding to NEFA/nucleobindin2 (NUCB2), a secreted protein of unknown function, is expressed in the appetite-control hypothalamic nuclei in rats. Intracerebroventricular (i.c.v.) injection of NUCB2 reduces feeding. Rat cerebrospinal fluid contains nesfatin-1, an amino-terminal fragment derived from NUCB2, and its expression is decreased in the hypothalamic paraventricular nucleus under starved conditions. I.c.v. injection of nesfatin-1 decreases food intake in a dose-dependent manner, whereas injection of an antibody neutralizing nesfatin-1 stimulates appetite. In contrast, i.c.v. injection of other possible fragments processed from NUCB2 does not promote satiety, and conversion of NUCB2 to nesfatin-1 is necessary to induce feeding suppression. Chronic i.c.v. injection of nesfatin-1 reduces body weight, whereas rats gain body weight after chronic i.c.v. injection of antisense morpholino oligonucleotide against the gene encoding NUCB2. Nesfatin-1-induced anorexia occurs in Zucker rats with a leptin receptor mutation, and an anti-nesfatin-1 antibody does not block leptin-induced anorexia. In contrast, central injection of alpha-melanocyte-stimulating hormone elevates NUCB2 gene expression in the paraventricular nucleus, and satiety by nesfatin-1 is abolished by an antagonist of the melanocortin-3/4 receptor. We identify nesfatin-1 as a satiety molecule that is associated with melanocortin signalling in the hypothalamus

    Mortality and morbidity in two-year disease-free survivors of small cell lung cancer after treatment with combination chemotherapy with or without irradiation.

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    We evaluated the long-term outcome of 148 patients with small cell lung cancer (SCLC) who had been entered into clinical trials of chemotherapy with or without thoracic and prophylactic cranial irradiation (PCI) between 1981 and 1987. Eighteen patients (12%) survived for 2 or more years. With a minimum follow-up of 4.5 years, 10 of the 18 patients who remained disease-free at 2 years are currently alive and free of SCLC. Seven of these 10 patients currently function as they did before diagnosis. However, three suffer from central nervous system changes of varying degrees in severity which appeared 2-3 years after PCI. Eight of the 18 patients who were disease-free at 2 years have died. Two died of isolated relapse in the brain at 3.6 and 4.2 years after initiation of chemotherapy. Five died of other malignancies while continuing their complete response to SCLC; two of non-small cell lung cancer, two of acute myelogenous leukemia, and one of hepatocellular carcinoma. Another patient died of an unrelated disease without any evidence of SCLC. A small but substantial proportion of patients who underwent intensive treatment will achieve long-term survival; however, these patients remain at higher risk for second cancers and late toxicities. Therefore, attention must be directed to defining the safest way to employ such treatment in the management of SCLC.</p
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