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排序方式: 共有226条查询结果,搜索用时 13 毫秒
221.
Russian Journal of Bioorganic Chemistry - VEGFR-2 inhibition represents an attractive strategy for anticancer drug design. A new series of quinoline derivatives were synthesized and structurally...  相似文献   
222.
Molecular and Cellular Biochemistry - In individuals with sepsis-related neurodegenerative illness, sleep and circadian rhythm disturbance are common. The alteration in genomic expression linked...  相似文献   
223.
Plastic formulations containing up to 40% starch were prepared and blown into thin films using extrusion methods. Extruded films were evaluated for their biodegradability by exposing them to a consortium of starch degrading bacteria in the laboratory for 45 days and in the ‘La Silla’ river located in Monterrey, N.L. Mexico for up to 60 days. Biodegradability was assessed by measuring changes in weight loss and chemical composition of the films using Fourier transform infrared (FTIR) spectroscopy. While little or no degradation was apparent in control films made up of 100% low density polyethylene (LDPE) or 100% poly-(ethylene-co-acrylic acid) (EAA), most of the starch was depleted in starch-containing films exposed in the river. Starch degradation in films exposed to amylolytic bacteria in the laboratory was relatively slower. Also, increasing the amount of EAA from 25% to 50% substantially reduced starch depletion in these films.  相似文献   
224.
Levansucrase (EC 2.4.1.10) was purified approximately 40-fold from the extracellular culture fluid of Erwinia herbicola NRRL B-1678. The purified enzyme in its native form occurred as an aggregate. Poly(acrylamide) gel electrophoresis in the presence of sodium dodecyl sulfate showed an active monomer having a molecular weight of 48,000. The enzyme had a Km for sucrose of 28m and a pH optimum of 6.0, and was stable from −18 to +52°. It was free from - -glucosidase, amylase, and glucansucrase activities, but exhibited considerable β- -fructofuranosidase activity.  相似文献   
225.
O-diphenoloxidase activity was studied in 15 patients with lepromatous leprosy, 15 with tuberculois leprosy, and 15 controls. O-diphenoloxidase isolated from skin and serum samples of patients with lepromatous leprosy had the specificity of a bacterially derived enzyme and not that of a mammalian-derived enzyme. Only the patients who had lepromatous leprosy for over two years showed enzyme activity in serum, though all showed it in skin tissue. O-diphenoloxidase activity in serum may be a useful diagnostic marker of lepromatous leprosy.  相似文献   
226.
A single physiologic dose (0.1 mg) of estradiol-17β in sesame-oil vehicle or vehicle alone (n = 8) was given to heifers on day 14 after ovulation to study the effect on circulating 13-14-dihydro-15-keto-PGF2α (PGFM), PGFM pulses, and changes in progesterone concentrations within a PGFM pulse. Blood samples were collected hourly for 16 h after treatment. The estradiol group had a greater mean concentration of PGFM, greater number of heifers with PGFM pulses and number of pulses/heifer, and greater prominence of the PGFM pulses. Changes in progesterone concentrations were not detected during the 16 h sampling session in the vehicle group, indicating that the heifers were in preluteolysis. Progesterone decreased after 12 h in the estradiol group, indicating a luteolytic effect of the estradiol-induced PGF secretion as represented by PGFM concentrations. Intrapulse changes in progesterone were detected during a PGFM pulse in the estradiol group (P < 0.006), but not in the vehicle group. Progesterone increased (P < 0.01) between Hours −2 and −1 of an estradiol-induced PGFM pulse (Hour 0 = peak of pulse), decreased (P < 0.004) between Hours −1 and 0, and increased (P < 0.01) or rebounded between Hours 0 and 1. Results were compatible with previous reports of a role for estradiol in the induction of PGFM pulses in cattle and demonstrated intrapulse changes in progesterone concentrations during an induced PGFM pulse.  相似文献   
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