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排序方式: 共有91条查询结果,搜索用时 31 毫秒
81.
Townson DH Tsang PC Butler WR Frajblat M Griel LC Johnson CJ Milvae RA Niksic GM Pate JL 《Journal of animal science》2002,80(4):1053-1058
Cows with two waves of follicular growth during the estrous cycle yield follicles that are older and larger at ovulation compared with cows having three waves. The objectives of the current research were 1) to compare fertility in cows with two or three follicular waves and 2) to examine associations between luteal function, follicular development, and fertility after breeding. Follicular waves were monitored by ultrasonography during the estrous cycle before insemination in 106 dairy cows. Fewer cows had three follicular waves before next estrus and ovulation than two waves (P < 0.01; 30% vs 68%, respectively), but pregnancy rate was higher (P = 0.058; 81 vs 63%, respectively). Cows with two waves had shorter estrous cycles (P < 0.01), with the ovulatory follicle being both larger (P < 0.05) and older (P < 0.01). In cows with three waves, luteal function was extended (P < 0.05) and the peak in plasma progesterone occurred later (P < 0.05) in the estrous cycle compared to two wave cows. Considering cows that became pregnant, luteal phase length was shorter (P < 0.05) during the estrous cycle preceding insemination than for nonpregnant cows. In conclusion, fertility was greater in lactating cows inseminated after ovulation of the third-wave follicle that had developed for fewer days of the estrous cycle as compared with two-wave cows. 相似文献
82.
C G Schelling C E Greene A K Prestwood V C Tsang 《American journal of veterinary research》1986,47(12):2669-2673
Ten dogs were experimentally infected with 150 3rd-stage larvae of the lungworm Angiostrongylus vasorum (Baillet, 1866). Blood samples obtained once a week for 5 weeks after infection was induced were examined for coagulation alterations. Thrombocytopenia developed in infected dogs before and after parasitic patency, which occurred 6 weeks after infection was induced. Prolongation of activated partial thromboplastin time and thrombocytopenia initially were associated with periods of larval migration and, later, at patency, with pulmonary egg embolism and hatching of 1st-stage larvae in the lung. Decreased factor-V activity, significantly shortened values for the prothrombin time, and increased factor-VIII activity were evident during postpatent periods of parasitic infection. Significant changes were not found in factors-XII and -IX activities throughout the course of infection. Coagulation abnormalities were attributed to excessive intravascular coagulation. Immature adults and first stages of the parasite seemed to have initiated the coagulopathy in the prepatent phase of infection, with subsequent coagulation abnormalities occurring at the time of patency. 相似文献
83.
Ikki Mitsui L Paige Jackson Laurent L Cou?til Tsang L Lin José A Ramos-Vara 《Journal of veterinary diagnostic investigation》2007,19(1):128-132
A 13-year-old Quarterhorse mare had a 6-month history of diarrhea, progressive weight loss, and lethargy. At presentation the mare was hirsute, had hyperhidrosis, and abnormal fat distribution in addition to severe diarrhea. A presumptive clinical diagnosis of protein-losing enteropathy and pituitary pars intermedia dysfunction was made. T-cell lymphoma was diagnosed in a rectal biopsy specimen. The owner elected to euthanize the mare because of poor prognosis and the severity of the disease. At necropsy, the mare had hypertrichosis and the pituitary gland was diffusely enlarged. Histologically, neoplastic lymphocytes infiltrated the gastrointestinal mucosa, mesenteric lymph nodes, and the pituitary gland. In addition, there was hyperplasia of the pituitary gland pars intermedia. Pituitary adenoma was not present. Hypertrichosis in this case could have been triggered by a combination of adenomatous hyperplasia of pars intermedia and lymphoma resulting in disruption of the hypothalamic dopaminergic tone or disruption of the hypothalamic thermoregulatory center. 相似文献
84.
José A Ramos-Vara Ching Ching Wu Tsang Long Lin Margaret A Miller 《Journal of veterinary diagnostic investigation》2007,19(5):577-580
An adult Domestic Longhair cat developed a subcutaneous mass in its tail. Histologically, this mass consisted of ill-defined pyogranulomas centered around aggregates of gram-positive, acid-fast filamentous bacteria, consistent with Nocardia. Due to the lack of fresh samples, DNA was extracted from formalin-fixed paraffin-embedded tissue sections and subjected to polymerase chain reaction amplification and DNA sequencing of 16S ribosomal RNA gene encompassing Nocardia sp.-specific sequences. Sequences analyzed using the GenBank database revealed 99.5% homology with Nocardia spp. and had the highest sequence homology of 98.2% with Nocardia tenerifensis among Nocardia spp. To the authors' knowledge, this is the first report of detection of N. tenerifensis genome associated with cutaneous nocardiosis in an animal. 相似文献
85.
The human body loading with arsenic (As) through rice consumption is a global health concern. There is a crucial need to limit As build-up in rice, either by remediating As accumulation in soils or reducing As levels in irrigation water. Several conventional approaches have been utilized to alleviate the As accumulation in rice. However, except for some irrigation practices, those approaches success and the adoption rate are not remarkable. This review presents human health risks posed due to consumption of As contaminated rice, evaluates different biomarkers for tracing As loading in the human body, and discusses the latest advancement in As reducing technologies emphasizing the application of seed priming, nanotechnology, and biochar application for limiting As loading in rice grains. We also evaluate different irrigation techniques to reduce As accumulation in rice. Altering water management regimes significantly reduces grain As accumulation. Bio- and nano-priming of rice seeds improve germination and minimize As translocation in rice tissues by protecting cell membrane, building pool around seed coat, methylation and volatilization, or quenching harmful effects of reactive oxygen species. Nanoparticle application in the form of nano-adsorbents or nano-fertilizers facilitates nano-remediation of As through the formation of Fe plaque or sorption or oxidation process. Incorporating biochar in the rice fields significantly reduces As through immobilization, physical adsorption, or surface complexation. In conclusion, As content in cooked rice depends on irrigation source and raw rice As level. 相似文献
86.
Purpose
This study aimed to compare the effectiveness of chemical-enhanced soil washing (with chelating agents, humic substances and inorganic acids) and soil stabilisation by inorganic industrial by-products (coal fly ash, acid mine drainage sludge and zero-valent iron) and organic resource (lignite) for timber treatment site remediation.Materials and methods
Both remediation options were assessed in terms of extraction/leaching kinetics and residual leachability (toxicity characteristic leaching procedure, TCLP) of the major risk drivers, i.e. Cu and As.Results and discussion
In chemical-enhanced soil washing, chelating agents only minimised the Cu leachability. Humic substances were ineffective while inorganic acids reduced the As leachability to the detriment of the soil quality. For the waste-stabilised soil, the short-term leaching potential (72 h) and long-term TCLP leachability (9 months) revealed that Fe-/Al-/Ca-rich AMD sludge and coal fly ash sequestered As through adsorption and (co-)precipitation, while carbonaceous lignite stabilised Cu with oxygen-containing functional groups. The short-term and long-term leaching of Cu and As into the soil solution was negligible in the presence of the waste materials. However, the waste-stabilised soil did not maintain sufficient Cu stability in the TCLP tests, in which acetate buffer induced significant mineral dissolution of the waste materials.Conclusions
These results suggest that chelant-enhanced washing (significant reduction of Cu leachability) may be augmented with subsequent stabilisation with inorganic waste materials (effective control of As leachability), thus minimising the environmental risks of both Cu (heavy metal) and As (metalloid) while preserving the reuse value of the soil. Additional tests under field-relevant conditions are required to provide a holistic performance evaluation. 相似文献87.
88.
89.
Transmission dynamics of the etiological agent of SARS in Hong Kong: impact of public health interventions 总被引:2,自引:0,他引:2
Riley S Fraser C Donnelly CA Ghani AC Abu-Raddad LJ Hedley AJ Leung GM Ho LM Lam TH Thach TQ Chau P Chan KP Lo SV Leung PY Tsang T Ho W Lee KH Lau EM Ferguson NM Anderson RM 《Science (New York, N.Y.)》2003,300(5627):1961-1966
We present an analysis of the first 10 weeks of the severe acute respiratory syndrome (SARS) epidemic in Hong Kong. The epidemic to date has been characterized by two large clusters-initiated by two separate "super-spread" events (SSEs)-and by ongoing community transmission. By fitting a stochastic model to data on 1512 cases, including these clusters, we show that the etiological agent of SARS is moderately transmissible. Excluding SSEs, we estimate that 2.7 secondary infections were generated per case on average at the start of the epidemic, with a substantial contribution from hospital transmission. Transmission rates fell during the epidemic, primarily as a result of reductions in population contact rates and improved hospital infection control, but also because of more rapid hospital attendance by symptomatic individuals. As a result, the epidemic is now in decline, although continued vigilance is necessary for this to be maintained. Restrictions on longer range population movement are shown to be a potentially useful additional control measure in some contexts. We estimate that most currently infected persons are now hospitalized, which highlights the importance of control of nosocomial transmission. 相似文献
90.
A E Gonzalez M Verastegui J C Noh C Gavidia N Falcon T Bernal H H Garcia V C Tsang R H Gilman P P Wilkins 《Veterinary parasitology》1999,86(2):113-118
We evaluated the presence and persistence of anticysticercal antibodies in piglets born to Taenia solium infected sows. Infected sows from a disease-endemic area of Peru were transported to a nondisease-endemic area and impregnated. Serum samples were collected from sows and piglets on Day 2 through Week 35 after birth. Using an immunoblot specific for cysticercosis, Ig isotypes to 7 cyst antigens were measured and quantified. Serum samples from the piglets contained detectable antibodies from Week 1 through Week 35 (27 weeks after weaning). The primary Ig isotype present in both sows and piglets was IgG. Antibodies did not appear in piglet serum samples until after suckling, demonstrating that anti-cysticercal antibodies are transferred solely via colostrum. Our data have shown that maternally transferred antibodies to cyst antigens may persist through much of a pig's life. Therefore, the presence of passively transferred antibodies must be considered in studies that examine the prevalence of cysticercosis in pigs. Furthermore, when designing control strategies for cysticercosis, careful evaluation and selection of sentinel pigs becomes a crucial component of sentinel selection. 相似文献