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991.
The fumigant toxicity of various volatile constituents of essential oils extracted from sixteen Korean spices and medicinal plants towards the rice weevil, Sitophilus oryzae L (Coleoptera: Curculionidae), was determined. The most potent toxicity was found in the essential oil from Mentha arvensis L var piperascens (LC50 = 45.5 µl litre?1 air). GC–MS analysis of essential oil from M arvensis showed it to be rich in menthol (63.2%), menthone (13.1%) and limonene (1.5%), followed in abundance by β‐pinene (0.7%), α‐pinene (0.6%) and linalool (0.2%). Treatment of S oryzae with each of these terpenes showed menthone to be most active (LC50 = 12.7 µl litre?1 air) followed by linalool (LC50 = 39.2 µl litre?1 air) and α‐pinene (LC50 = 54.9 µl litre?1 air). Studies on inhibition of acetylcholinesterase activity of S oryzae showed menthone to have a nine‐fold lower inhibitory effect than menthol, despite menthone being 8.1‐fold more toxic than menthol to the rice weevil. Different modes of toxicity of these monoterpenes towards S oryzae are discussed. © 2001 Society of Chemical Industry  相似文献   
992.
993.
Cilostazol (CLZ) is a cyclic adenosine monophosphate (cAMP) modulator that influences the steady state of the meiotic stage. This study was conducted to determine the effects of CLZ treatment during in vitro maturation (IVM) on developmental competence of pig oocytes. Immature oocytes were exposed to 0 (control), 0.5, 2 and 4 μm CLZ during the first 22 h of IVM. Nuclear maturation, intraoocyte glutathione content and embryo cleavage after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) were not influenced by CLZ at any concentrations. However, 4 μm CLZ significantly (p < 0.05) improved blastocyst formation after PA (52.1% vs 38.7–46.0%) and SCNT relative to other concentrations (40.8% vs 25.0–30.7%). The mean cell numbers of SCNT blastocysts were significantly increased by 4 μm CLZ compared to the control (42.6 cells vs 35.3 cells/blastocyst). CLZ treatment significantly increased the intraoocyte cAMP level and effectively arrested oocytes at the germinal vesicle (GV) and GV break down stages compared to the control (74.5% vs 45.4%). Our results demonstrated that improved developmental competence of PA and SCNT pig embryos occurred via better synchronization of nuclear and cytoplasmic maturation induced by increased cAMP and delayed meiotic resumption after CLZ treatment.  相似文献   
994.
The objective of this study was to examine the effects of canthaxanthin (Cx) treatment during in vitro maturation (IVM) of porcine oocytes on embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), on intracellular glutathione (GSH) and reactive oxygen species (ROS) levels in mature oocytes, and on gene expression in both PA‐ and SCNT‐derived blastocysts. To determine the optimal effective concentration of Cx, porcine oocytes were cultured in IVM medium supplemented with various concentrations (0, 20, 40 and 80 μM) of Cx for 22 hr. Compared to other groups, supplementation with 40 μM Cx significantly improved blastocyst formation rates after PA (< .05), but no significant differences were observed among groups in total blastocyst cell numbers. Subsequently, oocytes were cultured in IVM medium supplemented with or without 40 μM Cx. Oocytes treated with 40 μM Cx showed significantly increased cleavage and blastocyst formation rates after SCNT compared to the control group (< .05). Moreover, significantly increased intracellular GSH and reduced ROS levels were observed in the Cx‐treated group (< .05). In addition, both PA‐ and SCNT‐derived blastocysts from the 40 μM Cx‐treated group showed significantly increased mRNA expression of Bcl2 and Oct4 and decreased Caspase3 expression level (< .05), when compared with the control group. PA‐derived blastocysts from the 40 μM Cx‐treated group also exhibited significantly decreased expression of Bax (< .05). Our results demonstrated that treatment with 40 μM Cx during IVM improves the developmental competence of PA and SCNT embryos. Improvement of embryo development by Cx is most likely due to increased intracellular GSH synthesis, which reduces ROS levels in oocytes, and it may also positively regulate apoptosis‐ and development‐related genes.  相似文献   
995.
This study was conducted to evaluate the effect of dietary fenugreek seed extract (FSE) on growth performance, apparent total tract digestibility (ATTD), diarrhoea scores, blood profiles, faecal microflora and faecal gas emission in weanling pigs. A total of 135 weanling pigs [(Yorkshire × Landrace)  × Duroc] with an average BW of (7.96 ± 1.03 kg; 28 days of age) were used in a 42‐day study. Piglets were randomly allotted to three experimental diets with nine replicate pens and five pigs per pen. Dietary treatments were as follows: CON, basal diet; FSE1, basal diet + 0.1% FSE; FSE2, basal diet + 0.2% FSE. Pigs were fed with phase 1 (0–14 days) and phase 2 (14–42 days) diets in the form of mash. Average daily gain (ADG) was linearly increased (p = 0.031) by FSE supplementation compared with CON diet during days 0–14. From days 14–42, FSE2 diet had increased ADG and growth efficiency (G/F) compared with the CON diet (p = 0.014 and 0.026 respectively). Moreover, ADG and G/F were increased by FSE supplementation during days 0–42 (linear, p = 0.037 and 0.014 respectively). Energy digestibility was higher (linear, p = 0.030) by FSE supplementation at 6 weeks. On day 42, dietary supplementation of FSE linearly increased red blood cells (RBC) and immunoglobulin G (IgG) concentration (p = 0.042 and 0.038 respectively). Piglets fed FSE2 diet had higher (linear, p = 0.025) serum high‐density lipoprotein cholesterol (HDL‐C) concentration compared with those fed CON diet. However, piglets fed FSE2 diet had linearly reduced faecal ammonia (NH3) and hydrogen sulphide (H2S) gas emission compared with those fed the CON diet (p = 0.018 and 0.010 respectively). In conclusion, FSE supplementation increased the performance and reduced faecal gas emission in weanling pigs.  相似文献   
996.
A 9‐year‐old intact female mixed breed dog was presented for mammary gland tumor surgery, and preoperative radiographs showed a tubular soft tissue opacity mass with multifocal mineralization in the caudoventral abdominal cavity. Subsequent ultrasonography demonstrated uterine dilation with echogenic fluid and endometrial acoustic shadowing consistent with mineralization. Resection of mammary gland tumors and ovariohysterectomy were performed. Pyometra was diagnosed on cytologic examination of uterine fluid. Histopathology of the uterine tissue confirmed a diagnosis of cystic endometrial hyperplasia with uterine mineralization.  相似文献   
997.
This study was conducted to assess time-sensitive magnetic resonance (MR) changes in canine blood using low-field MR. Arterial and venous blood samples were collected from eight healthy beagle dogs. Samples were placed in 5-mL tubes and imaged within 3 hours of collection at 1 day intervals from day 1 to day 30. The following sequences were used: T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2-star gradient-echo (T2*-GRE). Visual comparison of the images revealed that four relatively homogenous blood clots and twelve heterogeneous blood clots developed. The margination of the clot and plasma changed significantly on day 2 and day 13. On day 2, heterogeneous blood clots were differentiated into 2 to 3 signal layers in the T2W, T1W, and especially the STIR images. Hypointense signal layers were also detected in the blood clots in STIR images, which have T2 hypo, FLAIR hypo, and T1 hyper intense signals. In all images, these signal layers remained relatively unchanged until day 13. Overall, the results suggest that hematomas are complex on low-field MRI. Accordingly, it may not be feasible to accurately characterize hemorrhages and predict clot age based on low-field MRI.  相似文献   
998.
The objectives of this study were to investigate the effects of dietary n‐6/n‐3 fatty acid (FA) ratio on digestibility, blood metabolites and FA profile of Hanwoo heifers. Fifteen Hanwoo heifers (22 ± 3 months old; 357 ± 69.7 kg) were randomly assigned to three dietary treatments with n‐6/n‐3 FA ratios of 2.07, 5.18 and 7.37. The animals were housed individually in digestion crates and fed total mixed rations at 2.2% of body weight for 2 weeks of adaptation and 1 week of collection. Treatment effects on in vivo digestibility, plasma metabolite and fatty acid profiles, and in vitro ruminal fermentation and fatty acid profiles were examined. In vivo digestibility was not affected (P > 0.05) by dietary n‐6/n‐3 FA ratio. However, in vitro dry matter digestibility and concentrations of total volatile fatty acids and propionate decreased (P < 0.05) linearly with increasing n‐6/n‐3 FA ratio. Plasma insulin and progesterone increased linearly (P < 0.05), but linolenic acid and total n‐3 FA decreased linearly (P < 0.05) with increasing n‐6/n‐3 ratio. Increasing the dietary n‐6/n‐3 FA ratio can increase the n‐6/n‐3 FA ratio in plasma and ruminal fluid as well as plasma progesterone secretion.  相似文献   
999.
Six growing lambs were used to evaluate the feeding value of two forage‐based diets in a long‐term feeding period by measuring body weight (BW) gain, digestibility, nitrogen (N) retention and microbial N (MBN) yield. The animals were fed imported low‐quality timothy hay (TH) with concentrate diet (THD) or imported low‐quality Italian ryegrass straw (IR) with concentrate diet (IRD) for 9 months. The forages were offered at 2% BW, and concentrate was fed at 40% of forage intake. The BW gain averaged 82.6 and 66.2 g/day for THD and IRD, respectively, without showing significant difference. Average forage intake (% BW) was significantly greater for IR than for TH, although it was not affected by feeding periods. The digestibility did not differ between diets or periods. The numerically greater (P = 0.06) ratio of retained N to absorbed N for IRD than that for THD was prominent. Neither diet nor period had significant effect on MBN supply and efficiency of MBN synthesis. The results suggest that the IR‐based diet can be also used for long‐term periods of feeding to growing ruminant animals as a grass hay‐based diet without any detrimental effects on nutrient utilization and growth performance.  相似文献   
1000.
Oil cake, widely used as an organic source of nutrients in horticultural production in South Korea, is a by-product when oil is extracted from various oilseeds. Split applications of oil cake were supplied to evaluate their effects on tree growth and fruit production in organic, non-astringent persimmon (Diospyros × kaki Thunb.) trees in 2009 and in 2010. Treatments included a single annual application of oil cake at 150 kg N ha?1 in April (single application), two applications in April and July (105 and 45 kg N ha?1, respectively; two-split application), or three applications in April, June, and August (60, 45, and 45 kg N ha?1, respectively; three-split application), as well as zero application of oil cake (control). All applications of oil cake significantly increased the amount of ground-cover vegetation compared to the control. The single and two-split applications increased soil organic matter (OM), K2O, CaO, and MgO concentrations, and cation exchange capacity to a soil depth of 0–30 cm in 2010. Oil cake applications increased soil porosity in 2010, as well as overall chlorophyll (SPAD values) and macronutrient concentrations in leaves in 2009 and 2010. Single and two-split applications stimulated water-sprout development, reduced the light intensity inside the tree canopy, and increased fruit drop. Fruit yield was higher in the two-split [24.7 metric tonnes (MT) ha?1] and three-split application trees (25.0 MT ha?1) compared to zero application control trees (19.8 MT ha?1) and single application trees (21.0 MT ha?1) in 2010. A single application resulted in soft fruit and slow skin colouration during maturation. Total soluble solids contents were higher in the control and three-split application trees in both years. The three-split application in 2010 increased the estimated production income by approx. 21% compared to the zero application, and by approx. 33% compared to a single application of oil cake.  相似文献   
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