Dissolution mechanism of cellulose in SO2–amine–dimethylsulfoxide

The dissolution mechanism of cellulose in SO₂–amine–dimethylsulfoxide systems was studied by using ¹H- and ¹³C-NMR spectroscopy. SO₂ and amine (diethylamine or triethylamine) were found to form a complex in DMSO, and the SO₂–amine complex, in turn, reacts with an alcoholic hydroxyl group of methanol to produce a new complex. In the case of cellulose, it was proved that all hydroxyl groups in cellulose react with the SO₂–amine complexes and form the same complexes in the solution state as those formed in methanol.     

The role of Alx-4 in the establishment of anteroposterior polarity during vertebrate limb development

We have determined that Strong's Luxoid (lstJ) [corrected] mice have a 16 bp deletion in the homeobox region of the Alx-4 gene. This deletion, which leads to a frame shift and a truncation of the Alx-4 protein, could cause the polydactyly phenotype observed in lstJ [corrected] mice. We have cloned the chick homologue of Alx-4 and investigated its expression during limb outgrowth. Chick Alx-4 displays an expression pattern complementary to that of shh, a mediator of polarizing activity in the limb bud. Local application of Sonic hedgehog (Shh) and Fibroblast Growth Factor (FGF), in addition to ectodermal apical ridge removal experiments suggest the existence of a negative feedback loop between Alx-4 and Shh during limb outgrowth. Analysis of polydactylous mutants indicate that the interaction between Alx-4 and Shh is independent of Gli3, a negative regulator of Shh in the limb. Our data suggest the existence of a negative feedback loop between Alx-4 and Shh during vertebrate limb outgrowth.     

Development of a miniature gamma-ray endoscopic probe for tumorlocalization in nuclear medicine

Two types of miniature gamma-ray endoscopic probes developed for insertion into a body cavity to detect invisibly small or deeply located tumors are described. One is a single detector system using a small BGO (Bi₄Ge₃O₁₂) crystal connected with a fiber optic light guide, and the other is a dual detector system using a pair of single detector probes of the same size combined with a random coincidence technique. The performance of these detectors was tested by using a point source and a hollow cylindrical water phantom that simulated a body cavity. Measured and calculated results indicated that a dual detector system can be used for realistic tumor localization in a body cavity, and a single detector system may be applied only for the detection of tumors in which radiopharmaceuticals that emit gamma rays of energy below about 200 keV are accumulated     

The architecture of a multi-vector processor system, VPP

The VPP system is a multi-vector processor system which mainly aims at effective satellite image processing. It consists of up to 64 element processors (PUs), an S-D loop network, and an image memory. The PUs can execute flexible vector processing by a new vector access method, ‘Index-set’. The S-D loop network achieves high-speed and contention-free data transfer among the PUs. With these components, a new method for parallel processing, ‘Processor Pipeline’, can be realized on the VPP system.     

Development of the new polymer insulating materials for HVDC cable

The properties of modified HDPE, selected from various polymer materials by evaluations of DC characteristics, were examined in both sheet and cable samples. It was found that the modification, which introduced a small amount of polar group into HDPE, considerably enhanced DC breakdown strength to as high as 1.5-2.0 times those of XLPE (cross-linked polyethylene). Under a poling voltage of up to 30 kV/mm, the modified HDPE exhibits particular behavior, with its space charge decreasing as stress is increasing. In addition, the additives in HDPE have a large influence on space-charge characteristics, thereby affecting the DC breakdown strength. The evaluation of cable insulated with optimum modified HDPE was conducted to determine the breakdown strength under various voltage applications. Compared with the XLPE cable, modified HDPE cable exhibited excellent characteristics under all kinds of voltage applications, particularly DC dielectric breakdown strength, which was almost twice that of XLPE     

Beta-decay half-lives calculated on the gross theory

Beta-decay half-lives have been calculated by the use of the gross theory which was formulated by Takahashi, Yamada, and Koyama. Both allowed and first-forbidden transitions have been taken into account, and consideration also has been given to the possibility that all the transitions to the levels near the ground states may be highly forbidden. The Q-values used in the calculation have been taken from the mass formula of Myers and Swiatecki. The calculated half-lives are shown in the PLOTS together with the experimental data and the Q-values. The PLOTS cover all the isotopes between the proton-drip and neutron-drip lines with Z = 3 to Z = 100.     

Absence of an Odd-Error Signal Mechanism in Human Accommodation

Experiments have been designed to demonstrate that the human accommodative system operates with an even-error signal mechanism under restricted monocular viewing conditions. Retinal blur is such an even-error input signal and, thus, these experimental results add to the evidence considering blur as the effective input signal in accommodation. The random 50 percent erroneous initial direction of movement is a null experimental result which should be robust to a variety of experimental artifacts that may have contaminated previously published results.