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排序方式: 共有49条查询结果,搜索用时 31 毫秒
1.
Iturin A: A potential new fungicide for stored grains   总被引:6,自引:0,他引:6  
The removal of many synthetic fungicides from the market has created a demand for new, environmentally safe fungicides. Iturin A, a cyclic lipopeptide produced byBacillus subtilis, has strong antifungal properties and low mammalian toxicity. To determine the efficacy of this compound as a potential fungicide on stored feed grains, lots of corn, peanuts and cottonseed were treated with varying concentrations of iturin A. The mycoflora of treated seed was assayed along with that of untreated seed and seed treated with fungicides used commercially for planting seed. Fungal species varied considerably in their sensitivity to iturin A. Significant reductions in total mycoflora occurred in most seed lots tested at iturin A concentrations of 50 to 100 ppm.  相似文献   
2.
A new series of coumarin inhibitors of DNA gyrase B bearing a N-propargyloxycarbamate at C-3' of various 5',5'-dialkylnoviose, including RU79115, were synthesised and their antibacterial activities have been delineated. Introduction of dialkyl substituents at 5'5'-position of noviose leads to coumarin analogues with improved in vitro and in vivo antibacterial activity.  相似文献   
3.
Background aimsLimited cell dose has hampered the use of cord blood transplantation (CBT) in adults. One method of minimizing nucleated cell loss in cord blood (CB) processing is to deplete or reduce plasma but not red blood cells - plasma depletion/reduction (PDR).MethodsThe nucleated cell loss of PDR was studied, and determined to be less than 0.1% in the discarded supernatant plasma fraction in validation experiments. After testing and archival sampling, the median nucleated cell recovery for PDR processing was 90%, and median CD34+ cell recovery 88%. In a CB bank inventory of 12 339 products with both pre- and post-processing total nucleated cells (TNC), PDR processing resulted in median post-processing TNC recoveries of 90.0% after testing and archival samples removal. Using the same 10 CB units divided into two halves, we compared directly the recovery of PDR against hydroxyethyl starch red cell reduction (RCR) for TNC, CD34+ cells and colony-forming units (CFU-GM, CFU-E, CFU-GEMM and total CFU) after parallel processing. We also compared the loss of very small embryonic-like stem cells (VSEL).ResultsWe demonstrated significantly higher recoveries using PDR for TNC (124%), CD34+ cells (121%), CFU-GM (225%), CFU-GEMM (201%), total CFU (186%) and VSEL (187%). The proportion of high TNC products was compared between 10 912 PDR and 38 819 RCR CB products and found to be 200% higher for products that had TNC ≥150 × 107 (P = 0.0001) for the PDR inventory.ConclusionsOur data indicate that PDR processing of CB provides a significantly more efficient usage of this valuable and scarce resource.  相似文献   
4.
An unusual, sterigmatocystin-producing taxon with characteristics of both Emericella nidulans (anamorph Aspergillus nidulans) and Emericella rugulosa (anamorph Aspergillus rugulovalvus, formerly A. rugulosus) was isolated repeatedly during a mycofloral survey of desert cotton field soils where aflatoxin is a chronic problem. Members of this taxon had ascospores with smooth convex walls like E. nidulans but grew slowly like E. rugulosa; moreover, they were similar to an industrial echinocandin B-producing strain which had been classified as "Aspergillus nidulans var. roseus." These new desert isolates were compared with "A. nidulans var. roseus" and representative wild-type isolates of E. nidulans and E. rugulosa using traditional morphological characters, secondary metabolite profiles of mycelial extracts, and Southern blot analysis of genomic DNA. The desert isolates and "A. nidulans var. roseus shared morphological, physiological and molecular characters with E. rugulosa. These isolates constitute a new non-rugulose variant of E. rugulosa.  相似文献   
5.
To determine the relationship between the polymorphism of vitamin D receptor gene and the bone mineral density in children. The study group consisted of 395 children aged 6–18 years. All patients underwent genotyping using the PCR-RFLP method within polymorphic loci BsmI (rs1544410), FokI (rs2228570), ApaI (rs7975232) and Taq I (rs731236) of the VDR gene. The BMD (g/cm2, Z score) and BMC (g, Z score) by DXA method, as well as Z scores of the BUA, SOS and Stiffness ultrasound parameters were evaluated. Based on densitometry results, children were divided into 3 groups: I—Z score ± 1.0; II—Z score from −1.1 to −2.0; and III—Z score ≤ −2.1. A control group numbering 294 children was used for the purpose of allele frequency comparisons. The occurrence of studied polymorphism alleles in the control group did not significantly differ from the values expected according to the Hardy–Weinberg equilibrium (p values: 0.1224 for BsmI; 0.5958 for TaqI; 0.0817 for ApaI; and 0.8901 for FokI). Allele a ApaI carrier status in group III children was associated with an increased BMD (x = 0.8 vs 0.69, p = 0.0296) and BMC value (x = 28.76 vs 22.14, p = 0.0565) in spine projection results, Stiffness (x = −1.12 vs −1.91, p = 0.0347) and SOS (x = −1.43 vs −2.27, p = 0.0319) ultrasound parameters. In group II, significantly increased SOS values (−1.13 vs −1.73, p = 0.0378) were noted in f (FokI) carriers. The presence of aa ApaI and ff FokI polymorphisms favours a higher bone mass and better bone structure (decreased bone mass loss) in the analysed group.  相似文献   
6.
7.
Klich  Maren A. 《Mycopathologia》1998,142(2):97-100
Soil is presumed to be a major source of inoculum for Aspergillus flavus which contaminates cottonseed and produces the potent carcinogen, aflatoxin. Little is known about the mycoflora of the low desert soils of cotton fields where aflatoxin is a chronic problem. In this study, soils from cotton fields in southwestern Arizona and southeastern California were assayed for filamentous fungi. Forty-two taxa, predominantly in the genera Aspergillus, Penicillium and Fusarium, were isolated. To determine whether or not compounds produced by these fungi could be potential inhibitors of A. flavus, extracts of strains of each taxon were tested for their ability to inhibit growth of A. flavus. Twelve taxa produced compounds inhibitory to A. flavus, including several strains of Fusarium solani, Penicillium vinaceum and Aspergillus auricomus. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
8.
The main aim of the study was to assess the attitudes of communities in northeastern Poland to the European bison Bison bonasus. Four forest complexes were analyzed: two sites to which animals will be reintroduced in the near future (Augustowska and Romincka forests) and two sites where European bison subpopulations already exist (Knyszyńska and Borecka forests). We also analyzed the factors affecting these attitudes. The survey was based on direct interviews with respondents, and answers were transformed onto a 7-point Likert scale. The results showed that respondents living in areas where reintroduction is planned had more negative attitudes than those living in the vicinity of forest complexes where European bison already lives. The difference was probably a result of myths about the E. bison and crop damage by wildlife. We conclude that proper management of the European bison may lead to higher societal acceptance levels, especially among farmers. Moreover, management and acceptance of the wisent could also influence attitudes to state forests. Negative attitudes to the E. bison can be minimized by workshops that can clarify underlying issues and increase trust towards conservation authorities. The workshops should be aimed at farmers with larger farms and more towards women than men.  相似文献   
9.
Pluripotent very small embryonic/epiblast derived stem cells (VSELs) as we hypothesize are deposited at begin of gastrulation in developing tissues and play an important role as backup population of pluripotent stem cells (PSCs) for tissue committed stem cells (TCSCs). We envision that during steady state conditions these cells may be involved in tissue rejuvenation and in processes of regeneration/repair after organ injuries. Molecular analysis of adult bone marrow (BM)-derived purified VSELs revealed that they i) express pluripotent stem cells markers e.g., Oct4, Nanog, Klf-4, SSEA-1 ii) share several markers characteristic for epiblast as well as migratory primordial germ cells (PGCs), and iii) possess a unique pattern of genomic imprinting (e.g., erasure of differently methylated regions at Igf2-H19 and Rasgrf1 loci and hypermethylation at KCNQ1 and Igf2R loci). This supports that VSELs are related to epiblast-derived migrating PGC-like cells and, despite their pluripotent stem cell character, changes in the epigenetic signature of imprinted genes keep these cells quiescent in adult tissues and prevent them from teratoma formation. In contrast epigenetic changes/mutations that lead to activation of imprinted genes could potentially lead to tumor formation by these cells. Mounting evidence accumulates that perturbation of expression of imprinted genes is a common phenomenon observed in developing tumors.  相似文献   
10.
Klich MA  Cary JW  Beltz SB  Bennett CA 《Mycologia》2003,95(6):1252-1260
Aspergillus ochraceoroseus produces the yellow-gold conidia and other characteristics of Aspergillus subgenus Circumdati section Circumdati. However, this species produces aflatoxin, a secondary metabolite characteristic of some members of subgenus Circumdati section Flavi and sterigmatocystin, a related secondary metabolite usually associated with subgenus Nidulantes sections Nidulantes and Versicolores, as well as members of several other genera. Our morphological data support the placement of A. ochraceoroseus in subgenus Circumdati. Sequence data from A. ochraceoroseus aflatoxin and sterigmatocystin genes aflR and nor-1/stcE, as well as 5.8S ITS and beta tubulin genes, were compared to those of aspergilli in sections Circumdati, Flavi, Nidulantes and Versicolores. In the sequence comparisons, A. ochraceoroseus was related more closely to the species in subgenus Nidulantes than to species from subgenus Circumdati.  相似文献   
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