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排序方式: 共有301条查询结果,搜索用时 343 毫秒
91.
92.
Levan AJ Tanvir NR Cenko SB Perley DA Wiersema K Bloom JS Fruchter AS Postigo Ade U O'Brien PT Butler N van der Horst AJ Leloudas G Morgan AN Misra K Bower GC Farihi J Tunnicliffe RL Modjaz M Silverman JM Hjorth J Thöne C Cucchiara A Cerón JM Castro-Tirado AJ Arnold JA Bremer M Brodie JP Carroll T Cooper MC Curran PA Cutri RM Ehle J Forbes D Fynbo J Gorosabel J Graham J Hoffman DI Guziy S Jakobsson P Kamble A Kerr T Kasliwal MM Kouveliotou C Kocevski D Law NM Nugent PE Ofek EO Poznanski D 《Science (New York, N.Y.)》2011,333(6039):199-202
Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ~100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy. 相似文献
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94.
Forbes AW 《Science (New York, N.Y.)》1923,58(1511):493-494
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96.
The effect of treatment with eprinomectin on milk yield, milk composition and somatic cell counts (SCCs) was studied in 105 dairy cows located on seven farms in South Tyrol, Italy. On each farm, half of the animals were treated with eprinomectin and the other half were used as an untreated control group. Three test day records per animal were obtained before treatment (days -117, -75 and -33) and another three test day records were obtained after treatment (days 22, 62 and 131). Test day records comprised milk yield, milk composition, SCC and days in milk. On the day of treatment, blood samples and faecal samples were taken for parasitological analysis. Cows with positive faecal egg counts yielded less milk. A significant effect of eprinomectin on milk yield was observed after treatment and was most pronounced on the second and the third test days after treatment (+1.90 kg [P=0.002] and +2.63 kg [P<0.001], respectively). Furthermore, a significant decrease in SCC was observed on the second test day after treatment. 相似文献
97.
S Forbes R W Nelson L Guptill 《Journal of the American Veterinary Medical Association》1990,196(8):1285-1287
Primary hypoparathyroidism caused by lymphocytic parathyroiditis was diagnosed in a cat. Other causes of hypocalcemia (ethylene glycol toxicosis, phosphate enema administration, pancreatitis, renal insufficiency, and malabsorption) were ruled out on the basis of history, clinicopathologic data, and lack of supportive clinical signs, which in this cat included inappetence and tetanic muscle spasms. The diagnosis was confirmed by histologic examination of a surgically excised thyroparathyroid lobe that comprised lack of recognizable parathyroid tissue and a lymphocytic plasmacytic infiltrate adjacent to the cranial pole. A treatment regimen similar to that for iatrogenic postthyroidectomy hypoparathyroidism was successful in controlling clinical signs of the disease. 相似文献
98.
Brucella abortus infection in 14 farm dogs 总被引:1,自引:0,他引:1
L B Forbes 《Journal of the American Veterinary Medical Association》1990,196(6):911-916
Fourteen dogs were obtained from 10 farms with Brucella-infected cattle and were studied for periods ranging from 2 to 81 days. At necropsy, Brucella abortus biovar 4 was isolated from all 14 dogs. Mandibular, medial retropharyngeal, tracheobronchial, and mesenteric lymph nodes yielded the highest rate of recovery. Urogenital infection with active shedding was seen in a single aged bitch. Fecal samples (291 from 13 dogs) were B abortus culture negative. Ten dogs monitored serologically over time had standard tube agglutination test titers that fluctuated between 1:50 with incomplete reaction and greater than or equal to 1:200 with positive reaction. At necropsy, the magnitude of seroconversion was not directly related to the number of culture-positive tissues. The maximal duration of infection, based on the time interval between the last possible exposure to infected cattle and recovery of the organism at necropsy, was 464 days. If it were assumed that infection occurred at about the same time as seroconversion in the cattle herd of origin, maximal observed duration of infection was 539 days. The actual maximal duration of infection could not be determined from this study, but would have exceeded the values reported here. The data indicate that dogs have the potential to infect cattle and could pose a threat for longer duration of disease transmission than had previously been assumed. Although the risk of transmission appears small, infection of human beings or cattle associated with Brucella-infected dogs would cause unfavorable political and economic consequences, particularly in low-incidence areas. Removal of contact dogs from infected herds should prevent such transmission. 相似文献
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100.
SUMMARY Thirteen Tammar wallabies (Macropus eugenii) were dosed orally with 500, 1000 or 10 000 oocysts of Toxoplasma gondii, as part of a vaccination trial. Eleven animals died of acute toxoplasmosis 9 to 15 days after challenge. The lesions were similar in all animals, consisting of foci of necrosis and inflammation in the intestines, lymphoid tissue, adrenal cortex, heart, skeletal muscle and brain, and severe generalised pulmonary congestion and oedema. Free and intracellular tachyzoites of Toxoplasma were associated with the lesions. The remaining 2 animals had shown no signs of disease when euthanased four months after challenge. Small, focal, non-suppurative inflammatory lesions were seen in brain, heart and skeletal muscle of these animals and chronic Toxoplasma infection was confirmed by mouse inoculation. 相似文献