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991.
This review is devoted to the study of the biological activity of polyether ionophores produced by bacteria, unicellular marine algae, red seaweeds, marine sponges, and coelenterates. Biological activities have been studied experimentally in various laboratories, as well as data obtained using QSAR (Quantitative Structure–Activity Relationships) algorithms. According to the data obtained, it was shown that polyether toxins exhibit strong antibacterial, antimicrobial, antifungal, antitumor, and other activities. Along with this, it was found that natural polyether ionophores exhibit such properties as antiparasitic, antiprotozoal, cytostatic, anti-mycoplasmal, and antieczema activities. In addition, polyethers have been found to be potential regulators of lipid metabolism or inhibitors of DNA synthesis. Further study of the mechanisms of action and the search for new polyether ionophores and their derivatives may provide more effective therapeutic natural polyether ionophores for the treatment of cancer and other diseases. For some polyether ionophores, 3D graphs are presented, which demonstrate the predicted and calculated activities. The data presented in this review will be of interest to pharmacologists, chemists, practical medicine, and the pharmaceutical industry.  相似文献   
992.
Marine sponge-derived endozoic fungi have been gaining increasing importance as promising sources of numerous and unique bioactive compounds. This study investigates the phytochemical profile and biological activities of the ethyl acetate extract of Penicillium chrysogenum derived from Cliona sp. sponge. Thirty-six compounds were tentatively identified from P. chrysogenum ethyl acetate extract along with the kojic acid (KA) isolation. The UPLC-ESI-MS/MS positive ionization mode was used to analyze and identify the extract constituents while 1D and 2D NMR spectroscopy were used for kojic acid (KA) structure confirmation. The antimicrobial, antioxidant, and cytotoxic activities were assessed in vitro. Both the extract and kojic acid showed potent antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa with MIC 250 ± 0.82 µg/mL. Interestingly, the extract showed strong antifungal activity against Candida albicans and Cryptococcus neoformans with MIC 93.75 ± 0.55 and 19.53 ± 0.48 µg/mL, respectively. Furthermore, KA showed the same potency against Fusarium oxysporum and Cryptococcus neoformans with MIC 39.06 ± 0.85 and 39.06 ± 0.98 µg/mL, respectively. Ultimately, KA showed strong antioxidant activity with IC50 33.7 ± 0.8 µg/mL. Moreover, the extract and KA showed strong cytotoxic activity against colon carcinoma (with IC50 22.6 ± 0.8 and 23.4 ± 1.4 µg/mL, respectively) and human larynx carcinoma (with equal IC50 30.8 ± 1.3 and ± 2.1 µg/mL, respectively), respectively. The current study represents the first insights into the phytochemical profile and biological properties of P. chrysoenum ethyl acetate extract, which could be a promising source of valuable secondary metabolites with potent biological potentials.  相似文献   
993.
A 12-year-old neutered male American Staffordshire terrier dog was referred to the Atlantic Veterinary College, Prince Edward Island, Canada, for suspected immune-mediated hemolytic anemia. Babesiosis (Babesia vulpes) was confirmed using polymerase chain reaction testing. The dog was successfully treated with a 10-day protocol of atovaquone/proguanil (TEVA Pharmaceutical Industries, Toronto, Ontario), 13.5 mg/kg BW, PO, q8h and azithromycin (Pharmascience, Montreal, Quebec), 10 mg/kg BW, PO, q24h. To the authors’ knowledge, this report is the first documented case of babesiosis caused by Babesia vulpes in a dog from Canada.  相似文献   
994.
Nine mature Quarter Horse mares were trained for ten weeks by continuous (n=4) or intermittent (n=5) treadmill work. Both groups of horses trotted at 3.3m/sec. The continuous work was performed at a 3% incline while the intermittent work was done at a 9% incline. Heart rate, cardiac output and blood lactate concentration were measured during a standard exercise test that included work on both treadmill grades before and after five and ten weeks of training. The two conditioning programs did not produce differences in the measured parameters of the two groups of horses. However, there was an overall conditioning effect observed in both groups of horses throughout the ten weeks of treadmill conditioning. Heart rate decreased (P<.05) during exercise on both treadmill grades after ten weeks of training. Lactate concentration decreased (P<.05) during the 9 percent grade trot after five weeks of training. Only slight further decreases occurred between week five and week ten of conditioning. Cardiac output increased (P<.05) between rest and exercise on both grades but there was no conditioning effect.  相似文献   
995.
996.
In recent years, natural deep eutectic solvents (NADES) have been widely investigated for the extraction of food and medicinal plants as well as seaweeds. However, the ability of NADES for trace elements co-extraction from natural sources is not well investigated. The aim of this study was to investigate the ability of common NADES for trace elements co-extraction from Fucus vesiculosus. All of the tested NADES did not recover As and Co (concentration <LOQ). Moreover, all of the tested NADES provided a low recovery (<9%) of Ba, Ca, Fe, Mg, Mn, Sr, and Zn. The method of extraction had not shown a statistically significant effect on the co-extraction of all elements (excluding Ba and Ca). In contrast, the water content in NADES was significantly affected on the recovery of Ba, Ca, Mg, Mn, Sr, and Zn. The recovery of Al and Cr was relatively high and considerably varied (from 1.5 to 59.9%). NADES comprising lactic acid:glucose:H2O (5:3:1) provided the lowest contents of all elements, and the highest extracted amounts were obtained employing water contents of 60–80%. The calculated daily intake of all the elements contained in NADES extracts were less than the daily dose risk estimators. The hazard quotients, hazard indexes, and carcinogenic risk calculated for all trace elements and their combination were considerably less than 1. This evidences no health risk, and carcinogenic risk after topical application of all studied NADES. For the first time, the results of the current study demonstrated that NADES extracts of F. vesiculosus contain a lower amount of trace metals and are safer than the extracts obtained with water and 70% acetone. This indicates a significant advantage for NADES compared with the other solvents.  相似文献   
997.
以色列野生二棱大麦农艺性状差异及相关性分析   总被引:7,自引:0,他引:7  
严俊  程剑平 《麦类作物学报》2007,27(6):969-973999
为给野生大麦的遗传和基因资源的研究提供依据,对起源于以色列不同地区6个群体的16个生态型野生二棱大麦的物候性状进行了研究.结果表明,不同生态型间的物候性状差异明显.从个体水平上分析,其最大值均出现在湿生生态型中,除旗叶面积外,其最小值则出现在旱生生态型中;从群体水平上分析,除每穗粒数外,湿生型平均值皆高于旱生型平均值.曼-怀氏等级和检验显示,湿生型和旱生型之间的这些物候性状差异达到显著水平.斯皮尔曼秩相关性检验则表明,9个物候与性状间,除三叶期与粒重、穗粒重无相关性外,其余物候性状间均呈显著的相关性,其中生长期与旗叶面积、株高、穗长、芒长等呈显著正相关,与每穗粒数则呈显著负相关;芒长与旗叶面积、株高,稳长与株高存在显著正相关,而每穗粒数则与芒长和旗叶面积分别呈显著负相关,芒长与穗长亦呈显著正相关.分析表明,以色列不同地区野生大麦物候性状差异是其生境主导下生存选择的结果,其丰富的表现型多样性,可用于遗传与育种研究.  相似文献   
998.
999.
通过观察思茅松在12月至翌年1月感染松材线虫病的外部特征,得出思茅松感病后的主要外部特征和区别于其他松树的感病特点,并提出择伐感病思茅松时在外观特征上的判定标准和处理建议。  相似文献   
1000.
促使云杉矮槲寄生果实提前脱落药剂筛选   总被引:1,自引:0,他引:1  
云杉矮槲寄生正在威胁三江源地区的部分云杉林,为阻断其传播途径,在云杉矮槲寄生刚结果初期喷施植物激素,促使其果实在种子未成熟就提前脱落。采用40%乙烯利水剂、20%国光萘乙酸粉剂、50%国光丁酰肼可溶性粉剂这3种植物激素进行促使云杉矮槲寄生的果实提前脱落的药剂筛选,结果表明在果实上喷施浓度为1:200的40%乙烯利水剂,施药后3d果实开始脱落,7d果实脱落率达到100%,其它2种药剂虽然也能促使提前落果,但效果次之。  相似文献   
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