Spontaneous nephrotic mice (ICGN mice), a new mutant strain of mouse from outbred ICR, were clinically, macroscopically, histologically and immunohistochemically studied to establish their value as a model for human nephrotic syndrome. Most of the affected mice developed proteinuria, hypoproteinaemia and hypercholesterolaemia, and some of them developed systemic oedema. A high concentration of blood urea nitrogen (BUN) and a low haematocrit value were also observed. The kidneys of severe cases showed a decrease in size and had a yellowish granular surface. These findings indicated that the mice were terminally affected by chronic renal in-sufficiency. Histopathology demonstrated glomerular lesions consisting of thickened basement membranes of the capillary loops with irregular spike-like protrusions and enlargement of the mesangium unaccompanied by cellular proliferation. The immunofluorescence technique revealed positive granular staining for IgA, IgG and IgM and to a lesser extent for C3 along the capillary loops in affected mice. The similarity between this spontaneous disease and human nephrotic syndrome caused by idiopathic glomerular lesions is discussed. ICGN mice may be a useful animal model for this human disease.
The requirements for a distance sensor to realise adaptive cruise control (ACC) were studied, and 76GHz radar for the ACC was developed. This is Frequency Shift Keying (FSK) radar, which transmits two frequencies in time-duplex, and a monopulse feature detects the azimuth angle of targets without a scanning mechanism. A fully MMIC (Monolithic Microwave Integrated Circuits) 76GHz module and signal processing electronics are combined into a single compact unit. Basic radar performance gave good results. The mechanism of multi-pass interference was studied, and a new feature of the algorithm to discriminate multiple stationary targets functioned satisfactorily. For the covering abstract see ITRD E114174.
A 77GHz MMIC transceiver module has been developed for automotive radar applications by using a low-cost thick-film multi-layer ceramic substrate. The module accommodating all MMIC-based transceiver functions in a single-cavity housing for improved manufacturability can be either assembled with built-in Tx/Rx antennas or mounted on external antenna sheet, depending on required antenna beam width. The module, measuring 25/spl times/25/spl times/3.4mm/sup 3/ with 3.3g in weight, has demonstrated >150m target detection capability when evaluated in a radar system, compatible with our current production-type radar.
Strontium-90 is one of the most important fission products due to the potential health risks of its uptake and retention in the human body. Conventional analysis techniques involve β counting, which requires ingrowth of 90Y over a period of two weeks. Accelerator mass spectrometry (AMS) has the potential to shorten the analysis time while offering a lower limit of detection than β counting. Here, Sr in samples was recovered as SrF2 to provide sufficient negative ions in the caesium-sputtering ion source. In the sample preparation step, 95–98% of Sr was recovered and 99–100% of Zr removed by ion-exchange separation. Sr recovery was ~30% in the precipitation process, and this can be improved. A maximum 500 nA beam current of SrF3 – ions was obtained from SrF2 samples mixed with PbF2. A five-anode gas ionization detector was used to avoid isobaric interference from 90Zr. The 90Sr/Sr atomic ratio background of ~6 × 10–13 (~3 mBq 90Sr) was comparable with that achieved at other AMS facilities. Good linearity in 90Sr/Sr atomic ratios was obtained from 1.75 × 10–10 to 3.38 × 10–9. Suitable techniques for sample preparation and measurement were thus achieved for 90Sr analysis by AMS.
Abstract Cosmogenic nuclides in tree rings and polar ice cores record the information of past cosmic ray intensities and solar activities. A large 14 C increase over 10 years has been discovered around 5480 BCE. The 14 C variations in this event differ from those of other short‐term cosmic ray events and typical grand solar minima. To elucidate the cause of the 14 C increase around 5480 BCE, we measured the 10 Be and 36 Cl concentrations in the Antarctic Dome Fuji ice core at quasi‐annual and 4–5 years resolutions, respectively. Based on the combined 14 C, 10 Be, and 36 Cl data, the 5480 BCE event was probably not caused by a solar proton event (SPE) or a gamma‐ray event, because the 36 Cl concentration did not significantly increase as expected in these events. The incremented 10 Be data were enhanced similarly to those of recent grand solar minima, but more rapidly increased (over ∼10 years). These results suggest that an unusual grand solar minimum occurred around 5480 BCE, characterized by a rapidly decreasing solar activity.
Mouse pronuclear embryos were obtained by in vitro fertilization with oocytes of 55 strains of immature females by gonadotrophin-induced ovulation and epididymal sperm of Slc:ICR strain. The number of oocytes ovulated with hormones (5.3-49.4 oocytes per head; average, 22.6), rates of in vitro fertilization (12.2-95.3%; average, 70.7%) and subsequent preimplantation development in Whitten's medium (WM) varied greatly among strains. F1 hybrids developed significantly better than other strains of mice and outbred animals did not develop as well as inbred animals. Within inbred mice, coat colour had no significant effect. In addition, the observation of preimplantation development in WM supplemented with ethylenediamine tetraacetic acid (EDTA) showed that the beneficial effect of the chelator was not universal to mouse embryos; EDTA had a good effect on ICR and PW/aSlc embryos but not on AKR or ddY embryos. The results indicate that strain differences should be considered when interpreting reproductive experiments using mouse embryos.
