Fv-4 is a mouse gene that dominantly confers resistance to infection with Friend murine leukemia virus (F-MuLV) (S. Suzuki, Jpn. J. Exp. Med. 45:473-478, 1975). Despite complete resistance to ecotropic MuLV infection in mice carrying the Fv-4 gene, it is known that cells carrying the resistance gene in tissue culture do not always show resistance as extensive as that in vivo (H. Yoshikura and T. Odaka, JNCI 61:461-463, 1978). To investigate the immunological effect on resistance in vivo, we introduced the Fv-4 gene into BALB/c nude mice (Fv-4-/- nude[nu/nu]) by mating them with Fv-4 congenic BALB/c mice (Fv-4r/r nude+/+) and examined the susceptibility of the F2 progeny to F-MuLV. All BALB/c nude mice without the Fv-4 gene (Fv-4-/- nude[nu/nu]) were permissive to F-MuLV and developed erythroleukemia within 2 weeks after virus inoculation. The BALB/c nude mice with the Fv-4 gene (Fv-4r/r nude[nu/nu]) did not develop leukemia, and no or little virus was detected in the spleen 7 weeks after virus inoculation. The resistance to F-MuLV was dominant in (Fv-4 congenic BALB/c x BALB/c nude) F1 mice with the Fv-4r/- nude(nu/+) genotype as strictly as in (Fv-4 congenic BALB/c x BALB/c) F1 mice with the Fv-4r/- nude+/+ genotype. However, almost all BALB/c nude mice with the Fv-4r/- nude(nu/nu) genotype developed the disease within 7 weeks, and the virus was detected in all of their spleens even in the mice without leukemia. These results show that the resistance caused by the Fv-4 gene is recessive in nude mice and dominant in BALB/c mice. Some immunological effects, perhaps cell-mediated immunity, may play important roles in the resistance to F-MuLV infection in vivo in addition to the dosage effect of the Fv-4 product. 相似文献
Glass molding press is an efficient manufacturing technology for ultraprecision optical elements with complex shapes. In glass molding, viscoelastic property of glass is an essential aspect that determines the glass deformation behavior around the molding temperature. In this paper, viscoelasticity of glass has been measured experimentally by uniaxially compressing cylindrical glass preforms above the glass transition temperature using an ultraprecision glass molding machine. The elastic modulus and viscosity of glass were obtained by curve fitting techniques using the Burgers model and the Maxwell model for creep and stress relaxation, respectively. Based on the thermo mechanical and viscoelastic parameters obtained from experiments, finite element model simulations of the glass molding process were performed, which can be used to visualize the stress/strain distribution and to predict the residual stress in glass. 相似文献
We have been conducting a project to digitize the Bayon temple, located at the center of Angkor-Thom in the kingdom of Cambodia.
This is a huge structure, more than 150 meters long on all sides and up to 45 meters high. Digitizing such a large-scale object
in fine detail requires developing new types of sensors for obtaining data of various kinds related to irregular positions
such as the very high parts of the structure occluded from the ground. In this article, we present a sensing system with a
moving platform, referred to as the Flying Laser Range Sensor (FLRS), for obtaining data related to these high structures
from above them. The FLRS, suspended beneath a balloon, can be maneuvered freely in the sky and can measure structures invisible
from the ground. The obtained data, however, has some distortion due to the movement of the sensor during the scanning process.
In order to remedy this issue, we have developed several new rectification algorithms for the FLRS. One method is an extension
of the 3D alignment algorithm to estimate not only rotation and translation but also motion parameters. This algorithm compares
range data of overlapping regions from ground-based sensors and our FLRS. Another method accurately estimates the FLRS’s position
by combining range data and image sequences from a video camera mounted on the FLRS. We evaluate these algorithms using a
IS-based method and verify that both methods achieve much higher accuracy than previous methods. 相似文献
Characterization of the differences and algal-available fractions of P in soils, suspended solids, and bottom sediments have been the main topics of research during the past decade. However, the size distribution and properties of particulate matter in runoff have not been much studied in Japan. Here we study particle size distribution during runoff and the chemical characteristics of P in each soil size fraction and relate them to land use. The temporal variation of particulate sizes during rain events is different in each watershed. Most particles have the size in the range of 10-100 microm. Also, the percentage of BAP in TP as well as percentage of PCOD in SS also varies temporally and spatially during runoff. To investigate how soil particles characteristics depend on land use, soil samples from two watersheds are examined. For particle size distribution and specific gravity, no significant difference among watersheds is found. However, C, N, and P content are indirectly proportional to the particle size, which means smaller particle size results in larger. H2O-extracted P, NH4Cl-extracted P, NAI-P, Apatite-P, Organic-P, and TP contents in each soil particle sample vary depending on particle size, land use, and watershed. 相似文献
In offspring exposed in utero to a maternal diet high in fat (HF), we have previously demonstrated that despite similar birth weights, HF adult offspring at 6 months of age had significantly higher body weights, greater adiposity, and increased triacylglycerol (TAG) levels as compared to controls. We hypothesized that a maternal HF diet predisposes to offspring adiposity via a programmed increase in the synthesis of monounsaturated fatty acids in the liver and hence increased substrate availability for liver TAG synthesis. We further hypothesized that programmed changes in offspring liver fatty acid metabolism are associated with increased liver expression of the lipogenic enzyme stearoyl‐CoA desaturase‐1 (SCD‐1). Female rats were maintained on a HF diet rich in monounsaturated fatty acids (MUFA) prior to and throughout pregnancy and lactation. After birth, newborns were nursed by the same dam, and all offspring were weaned to control diet. Plasma and liver fatty acid compositions were determined using gas chromatography/mass spectrometry. Fatty acid C16 desaturation indices of palmitoleic/palmitic and (vaccenic + palmitoleic)/palmitic and the C18 desaturation index of oleic/stearic were calculated. Liver protein abundance of SCD‐1 was analyzed in newborns and adult offspring. Plasma and liver C16 desaturation indices were decreased in HF newborns, but increased in the adult offspring. Liver SCD‐1 expression was increased in the HF adult offspring. These data show that the maternal HF diet during pregnancy and lactation increases offspring liver SCD‐1 protein abundance and alters the liver C16 desaturase pathway. 相似文献
The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts arylation of the resulting products gave the corresponding 2,4,6‐triarylphenol derivatives. The present method provides useful highly substituted polyarylated compounds.
Vibrio parahaemolyticus densities in spiked and naturally contaminated seafood samples were enumerated by the MPN method combined with a PCR procedure (MPN-PCR method) targeting the species-specific thermolabile hemolysin gene (tlh), and by the MPN method using subcultivation of alkaline-peptone-water (APW) enrichment culture on thiosulfate-citrate-bile-sucrose (TCBS) agar (MPN-TCBS method). In the samples spiked with both V. parahaemolyticus and V. alginolyticus, the numbers of V. parahaemolyticus enumerated by the MPN-PCR method were similar to, or higher than the numbers of spiked cells, whereas those enumerated by the MPN-TCBS method were below the numbers of spiked cells. In naturally contaminated seafood samples, the numbers of V. parahaemolyticus enumerated by the MPN-PCR method were higher than those by the MPN-TCBS method. In the case of the MPN-TCBS method, isolation of V. parahaemolyticus from some APW cultures was difficult because of the overgrowth of many colonies other than V. parahaemolyticus (e.g., V. alginolyticus) on TCBS agar. In contrast, the PCR technique could detect tlh from APW culture without isolation of V. parahaemolyticus, so the possibility of failing to obtain a positive result in APW culture by the MPN-PCR method was considered to be lower than that by the MPN-TCBS method. Furthermore, utilization of the PCR technique reduces the time and labor required for the biochemical identification tests used in the MPN-TCBS method. For the detection and enumeration of V. parahaemolyticus in seafood, especially for samples that show many colonies other than V. parahaemolyticus on TCBS agar, the MPN-PCR method may be more convenient and reliable than the MPN-TCBS method. 相似文献
The cover image, by Yuko Shimamura et al, is based on the Research Article Inhibitory effects of Japanese horseradish (Wasabia japonica) on the formation and genotoxicity of a potent carcinogen, acrylamide, DOI: 10.1002/jsfa.8055 .