Direct Observation of Microscopic Inhomogeneities with Energy-Dispersive Diffraction of Synchrotron-Produced X-rays     

Skelton EF  Drews AR  Osofsky MS  Qadri SB  Hu JZ  Vanderah TA  Peng JL  Greene RL 《Science (New York, N.Y.)》1994,263(5152):1416-1418

Evidence of structural inhomogeneities in two high-transition-temperature superconductors, YBa(2)Cu(3)O(7-delta) and Nd2-xCexCuO4-y, is presented. When samples were illuminated by highly collimated x-rays produced on a synchrotron wiggler, small changes in the lattice were detected over a spatial scale of 10 micrometers. These changes are interpreted as evidence of variations in the oxygen content in one case and in the cerium content in the other; both affect the superconducting properties. The existence of such structural inhomogeneities brings into question whether exotic experimental results obtained from superconducting materials with high transition temperatures actually reflect intrinsic properties.  相似文献   

Forebrain temperature activates behavioral thermoregulatory response in arctic sculpins     

Hammel HT  Strømme SB  Myhre K 《Science (New York, N.Y.)》1969,165(3888):83-85

Arctic sculpins of the genus Myoxocephalus adapted to water at 5 degrees C escaped from warm water at 20 degrees , 16 degrees , and 12 degrees C when their deep-body temperatures increased from an initial 5 degrees C to about 8 degrees C. Heating parts of the forebrain with water at 25 degrees C circulating through a pair of thermodes astraddle rostral parts of the forebrain shortened the time spent in the warm water and lessened the incease in deep-body temperature before exit from the warm water. Cooling the forebrain to about -1 degrees C caused a large increase in the body temperature and sometimes suppressed the escape from the warm water.  相似文献   

Insulin Secretagogue,Alpha-glucosidase and Antioxidant Activity of Some Selected Spices in Streptozotocin-induced Diabetic Rats     

Patil SB  Ghadyale VA  Taklikar SS  Kulkarni CR  Arvindekar AU 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(1):85-90

Spices are extensively used to enhance the taste and flavor of foods and are known to possess several medicinal properties. Myristica fragrans, Parmelia perlata, Illicium verum, Trachyspermum copticum and Myristica malabarica, the commonly used spices in India were assessed for antidiabetic activity in streptozotocin induced diabetic rats. In the in vitro insulin secretion studies on isolated islets of Langerhans, M. fragrans, T. copticum and M. malabarica showed dose dependent insulin secretion. At 1 mg/ml, P. perlata showed significant in vitro alpha-glucosidase inhibitory activity with IC₅₀ value of 0.14 mg/ml followed by M. malabarica (0.64 mg/ml), I. verum (0.67 mg/ml), M. fragrans (0.85 mg/ml) and T. copticum (0.92 mg/ml). The DPPH free radical scavenging activity of the extracts at a concentration of 1 mg/ml was as M. malabarica (90.45%), M. fragrans (89.89%), I. verum (87.22%), P. perlata (76.70%) and T. copticum (38.14%). P. perlata showed the highest phenolic content (i.e., 118.5 mg gallic acid equivalents/g) followed by M. malabarica (84.13 mg gallic acid equivalents/g). M. malabarica showed the highest flavonoid content (i.e., 38.35 mg quercetin equivalents/g). Regular use of these spices may prevent postprandial rise in glucose levels through inhibition of intestinal alpha-glucosidase and may maintain blood glucose level through insulin secretagogue action.  相似文献   

Comparison of Mycobacterium avium complex (MAC) strains from pigs and humans in Sweden by random amplified polymorphic DNA (RAPD) using standardized reagents     

Ramasoota P  Chansiripornchai N  Källenius G  Hoffner SE  Svenson SB 《Veterinary microbiology》2001,78(3):251-259

Infections with atypical mycobacteria belonging to the Mycobacterium avium/intracellulare complex (MAC) can cause infection in both animals and humans. Using a standardized reagents commercial kit for random amplified polymorphic DNA (RAPD) analysis, 49 MAC strains isolated from 32 slaughter pigs and 17 humans in Sweden were identified and sorted out, yielding 6 RAPD types. By combining the results of RAPD primers 4 and 5 and the primer IS1245A, we found that pigs and humans may be infected with the same types of MAC strains, since 14 strains from humans and 8 strains from pigs were essentially identical and together, comprised RAPD type 2, the largest group of strains (44.8% of strains). With respect to grouping of strains, serotype and RAPD type were uncorrelated, except for serotype 20 and RAPD type 6. Using standardized beads, RAPD analysis is a reproducible technique for typing MAC strains, as the indistinguishable banding patterns obtained with repeated analyses of two isolates from each strain in this study demonstrate. However, primer selection and DNA purity were crucial for differentiating closely related strains.  相似文献   

Survival of Brachyspira hyodysenteriae and B. pilosicoli in terrestrial microcosms   总被引：1，自引：0，他引：1  

Boye M  Baloda SB  Leser TD  Møller K 《Veterinary microbiology》2001,81(1):33-40

The survival of Brachyspira hyodysenteriae and Brachyspira pilosicoli was investigated at 10 degrees C in laboratory microcosms consisting of soil, porcine faeces, and in soil mixed with 10% porcine faeces, respectively. By plate spreading, survival of B. hyodysenteriae was found to be 10, 78 and 112 days in soil, soil mixed with 10% faeces, and in porcine faeces, respectively. The identities of the colonies on the plates were confirmed using PCR targeting 23S rDNA for specific detection of B. hyodysenteriae. A positive PCR signal could be obtained up to 112 days in all microcosms by direct extraction of DNA from microcosms followed by PCR.The survival time for B. pilosicoli was 119 days in pure soil and 210 days in soil mixed with 10% porcine faeces and in pure faeces, respectively, as determined by plate spreading followed by PCR. On the other hand, by direct extraction of DNA followed by specific detection by PCR. B. pilosicoli could be detected up to 330 days in all microcosms.Dot blot hybridisation with digoxigenin-labelled specific oligonucleotide probe targeting rDNA could not be used for direct detection of Brachyspira spp. from microcosms due to low sensitivity. However, it was used for confirmation of the identity of colonies and proved to be a useful technique.These results show that the two Brachyspira species may survive in outdoor environment for the times shown in these investigations using laboratory microcosms.  相似文献   

Prevalence of equine herpesvirus-1 and equine herpesvirus-4 infections in equidae species in Turkey as determined by ELISA and multiplex nested PCR     

Ataseven VS  Dağalp SB  Güzel M  Başaran Z  Tan MT  Geraghty B 《Research in veterinary science》2009,86(2):339-344

In this report we examined the presence of specific antibodies against equine herpesvirus type 1 (EHV-1), and equine herpesvirus type 4 (EHV-4) in several equidae, including mules, donkeys, horses. The presence of EHV-1 and EHV-4 in respiratory diseases of equids, and ability of multiplex nested polymerase chain reaction (PCR) screening in simultaneous diagnosis of horses acutely infected by EHV-1 and EHV-4 were also investigated. Sera from 504 horses, mules and donkeys sampled were tested for the presence of EHV-1 and EHV-4 specific antibodies. Blood samples taken from 21 symptomatic horses and nasal swabs taken from 40 symptomatic horses were tested for the presence of EHV-1 and EHV-4 by a multiplex nested PCR. A total of 14.3% (3/21) of buffy coat samples and 32.5% (13/40) nasal swab samples were found to contain EHV-1 DNA, while 19% (4/21) buffy coat samples and 22.5% (9/40) nasal swab samples were found to be positive for EHV-4 DNA. By species, 14.5% of horses, 37.2% of mules and 24.2% of donkeys tested were EHV-1 seropositive. EHV-4 specific antibodies were detected in 237 (81.7%) of 290 horse sera tested. Results from this investigation demonstrate that EHV-1 and EHV-4 are prevalent throughout the equid population, and that donkeys and mules might also represent an important source of infection for other equids. We also showed that the multiplex nested PCR assay might be useful for diagnosis of mixed respiratory infections in horses due to EHV-1 and EHV-4.  相似文献