Materials design for industrial forming process in high-strain-rate superplastic Al-Si alloy

The optimum materials design in microstructural control could be developed for the high-strain-rate superplastic materials in the industrial scale. In the present work, it is reported that the high-performance-engine pistons with near-net-shape can be fabricated by the superplastic forging technology in the high-strain-rate superplastic PM Al-Si based alloy, which is produced by using this optimum materials design. Received: 8 February 2000 / Reviewed and accepted: 13 September 2000     

Right ventricular strain and volume analyses through deep learning-based fully automatic segmentation based on radial long-axis reconstruction of short-axis cine magnetic resonance images

Magnetic Resonance Materials in Physics, Biology and Medicine - We propose a deep learning-based fully automatic right ventricle (RV) segmentation technique that targets radially reconstructed...     

Effect of matrix metalloproteinase inhibitor on experimental pseudomonal corneal ulceration

We examined the effect of matrix metalloproteinase (MMP) inhibitor (CS-610) on experimental pseudomonal corneal ulceration by clinical and histological evaluation. Intrastromal injection of 3.5 microliters sterile culture broth of P. aeruginosa, IID-1117 (13.5 unit Type I collagenase equivalent proteinase activities), was done to induce corneal ulcers in guinea pigs. The animals were divided into two groups of 23 each. The CS-610 group received topical CS-610 (400 micrograms/ml) treatment at 2-hour intervals and the control group received only the vehicle of CS-610 at the same intervals. In the control group, corneas developed acute corneal damage following corneal ulcerations at 6-12 hours. In the CS-610 group, these corneal lesions were inhibited in most of the eyes (p < 0.01). In the late period, as inflammatory cells migrated into the cornea, some animals of the CS-610 group developed corneal ulcer. The results indicated that CS-610 had a potent inhibitory activity against pseudomonal proteinases in vivo. The results also suggested that the mechanism of the ulceration model involved not only pseudomonal proteinases but also endogenous responses.     

Induction of Ad4BP/SF-1, steroidogenic acute regulatory protein, and cytochrome P450scc enzyme system expression in newly established human granulosa cell lines

We have established immortalized human granulosa cells by triple transfection of primary cells obtained from in vitro fertilization patients with SV40 DNA, Ha-ras oncogene, and a temperature sensitive (ts) mutant of the tumor suppressor gene p53 (p53val135). Forty-one clones were isolated, and their steroidogenic responses were analyzed. While all the cell lines proliferate rapidly and show only traces of progesterone production, upon stimulation with 50 microM of forskolin (FK), which elevates intracellular cAMP, they become steroidogenic as evidenced by progesterone production. The steroidogenic response of the cell lines was stable even after 20 generations and several cycles of freezing and thawing. A highly responsive cell line (HO-23) was further examined for characteristics of the steroidogenic response. Cells stimulated with FK and 8-Br-cAMP produced high levels of pregnenolone, progesterone, and 20alpha-hydroxy-4-pregnen-3-one (20alpha-OH-progesterone) comparable with amounts produced by highly differentiated primary human granulosa-luteal cells. Hydrocortisone and dexamethasone highly augment the cAMP-stimulated progesterone production, whereas testosterone and PRL enhanced cAMP-induced progesterone synthesis only moderately. Estradiol, insulin-like growth factor I, and insulin showed no significant effect on cAMP-induced steroidogenesis. The phorbol ester TPA, and basic fibroblast growth factor, dramatically suppress cAMP-induced production of progesterone, whereas bovine corneal endothelial cell ECM (BCE/ECM) enhanced cAMP-induced progesterone and antagonized basic fibroblast growth factor suppression of cAMP-induced steroidogenesis. Steroidogenic factor 1 (Ad4BP/SF-1) was expressed in control cells, and its expression was augmented by FK, whereas the steroidogenic acute regulatory protein showed low expression in the nonstimulated cells but was clearly elevated upon cAMP stimulation and was slightly decreased by TPA in cAMP-stimulated cells. Expression of the electron carrier adrenodoxin (ADX), which is a part of the cytochrome P450scc enzyme system, was very low in nonstimulated cells but was dramatically elevated in FK- and 8-Br-cAMP-stimulated cells, whereas no reduction of ADX was evident in cells costimulated with FK and TPA. Immunocytochemical studies revealed a weak staining of ADX in mitochondria of nonstimulated cells and intensive staining in highly clustered mitochondria of FK- or 8-Br-cAMP-stimulated cells. Only moderate reduction in ADX staining was evident in cells costimulated with FK and TPA. These unique cell lines can provide a useful model for the investigation of induced steroidogenesis in human granulosa cells.     

Characteristics of bedridden elderly people living at home and in a hospital

We compared bedridden elderly people living at home to others who were hospital inpatients. Questionnaires regarding medical status and care were returned by 85 of 116 people caring for a bedridden elderly person at home in Obu city, Aichi prefecture and by 62 of 64 nurses and family members caring for bedridden inpatients at Chubu National hospital. All subjects were at least 65 years old. The median age in both groups was 81 years, neither age distribution nor female sex predominance differed between both groups. The percentage of subjects with only one underlying disease was 62.5% among those living at home and 64.4% among inpatients. In both groups the most common disease was cerebrovascular disease (42.5% among those at home and 39.0% among inpatients), followed by dementia (31.3%), infirmity of old age (17.5%) and bone fracture (13.8%) among those at home, and by bone fracture (27.1%), dementia (20.3%) and infirmity of old age (16.9%) among inpatients. The median durations of bedridden status were 2 years and 3 months among those at home and 3 months among inpatients. The proportion of subjects bedridden for less than 6 months was greater among inpatients (p < 0.0001). The percentage who needed medical treatment was 60.0% among those at home and 67.7% among inpatients. The most common conditions for which drugs were taken were hypertension, dementia, chronic cerebrovascular dysfunction, and osteoporosis. Among inpatients, 54.8% were ambulatory before admission, 24.2% were almost completely bedridden, and 17.7% were completely bedridden. The most common cause rending the patients bedridden was infection (usually pneumonia). The degree of disability did not differ between groups. Decubitus ulcers were present in 25.9% of those at home and 17.7% of inpatients.     

Adaptive immunity based reinforcement learning

Recently much attention has been paid to intelligent systems which can adapt themselves to dynamic and/or unknown environments by the use of learning methods. However, traditional learning methods have a disadvantage that learning requires enormously long amounts of time with the degree of complexity of systems and environments to be considered. We thus propose a novel reinforcement learning method based on adaptive immunity. Our proposed method can provide a near-optimal solution with less learning time by self-learning using the concept of adaptive immunity. The validity of our method is demonstrated through some simulations with Sutton’s maze problem. This work was present in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Synthesis and property of 9,9′-spirobifluorene-containing aromatic polyesters as optical polymers with high refractive index and low birefringence

C₂-Symmetric 9,9′-spirobifluorene-containing polyesters (PEs) were synthesized by polycondensation of 2,2′-dihydroxy-9,9′-spirobifluorene (1) with bis(acyl chloride)s (2) at 230 °C in diphenylether. The molecular weights of PEs 3a-3f were sufficiently high (M_w 13,400-41,600). PEs displayed high thermal stability. The glass transition temperatures (T_g) estimated by differential scanning calorimetry analysis appeared in a range 177-352 °C depending on the spacer structure, while the 5% decomposition temperatures (T_d5) measured by thermogravimetric analysis were over 416 °C both under nitrogen atmosphere and in air. PEs showed good solubility in typical organic solvents such as CHCl₃ and THF easily to afford the tough, transparent, and flexible cast films. The transmittance of the polymer films reached over 90% in the wavelength range from ca. 410-900 nm. In addition, PEs exhibited higher refractive index rather than that of commercially available 9,9-diarylfluorene-containing PE, in addition to very low degree of birefringence presumably due to the C₂-symmetric structure.     

Thermodynamic study based on the phase diagram of the Na2O–MnO–Fe2O3 system for H2 production in three-step water splitting with Na2CO3/MnFe2O4/Fe2O3

The phase diagram of the Na₂O–MnO–Fe₂O₃ system forms the basis for thermodynamic consideration of H₂ production in water splitting with the Na₂CO₃/MnFe₂O₄/Fe₂O₃ system. Sodium iron manganese oxides Na_0.71(Mn_1−x, Fe_x)O_2+δwere observed in the phase diagram at T=1273 K under P_O2=1.23×10⁻⁵ atm. Confirmation of this phase, especially for x>0.5, suggests the possibility of H₂ generation under this oxygen partial pressure and results in a value of 1:37 for the ratio of P_H2:P_H2O in the H₂ generation step of water splitting. This oxygen partial pressure is realized by the decomposition of carbon dioxide (CO₂=CO+0.5O₂) and it is concluded that the H₂ generation step can proceed under CO₂ atmosphere.     

Ultrathin channel vertical DG MOSFET fabricated by using ion-bombardment-retarded etching

A vertical ultrathin channel formation process for a vertical type double-gate (DG) MOSFET is proposed. Si wet etching using an alkaline solution has newly been found to be significantly retarded by introducing ion bombardment damage. We have also found that the ion-bombardment-retarded etching (IBRE) is independent of ion species and the implanted impurities can easily be transferred to be the dopants for source and drain regions of MOSFETs. By utilizing the IBRE, vertical type DG MOSFETs with a 12-nm-thick vertical channel were fabricated successfully. The fabricated vertical DG MOSFETs clearly exhibit the unique advantage of DG MOSFETs, i.e., high improvement of short-channel effect immunity by reducing the channel thickness. Thanks to the ultrathin channel, very low subthreshold slopes of 69.8 mV/dec. for a p-channel and 71.6 mV/dec for an n-channel vertical DG MOSFET are successfully achieved with the gate length of 100 nm.