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排序方式: 共有188条查询结果,搜索用时 15 毫秒
21.
22.
DNA Extraction from Activated Sludges 总被引:16,自引:0,他引:16
To optimize the cell lysis step for DNA extraction from activated sludge samples, two floc dispersion methods (sonication
versus stirring with a cation exchange resin), and three cell lysis treatments (lysozyme + SDS, sonication in a water bath,
and thermal shock) were tested. For dispersion, stirring with cation exchange resin was more efficient than sonication. The
cell lysis procedures were applied in two sequences, and DNA was quantified after each cell lysis treatment. Lysozyme + SDS
was the most effective step in the cell lysis procedures. The cell lysis treatment sequences giving the highest DNA yields
were not the same for all the sludges. The differences in sludge microbial compositions and floc structures required specifically
adapted cell lysis protocols. The proposed protocols were highly efficient for DNA extraction, yielding about 50 mg DNA g−1 volatile suspended solids, and allowed PCR amplification of 16S rDNA.
Received: 26 September 1998 / Accepted: 13 February 1999 相似文献
23.
Maria Teresa Borrello Benjamin Schinor Katharina Bartels Hanae Benelkebir Sara Pereira Wafa T. Al-Jamal Leon Douglas Patrick J. Duriez Graham Packham Günter Haufe A. Ganesan 《Bioorganic & medicinal chemistry letters》2017,27(10):2099-2101
We report a series of tranylcypromine analogues containing a fluorine in the cyclopropyl ring. A number of compounds with additional m- or p-substitution of the aryl ring were micromolar inhibitors of the LSD1 enzyme. In cellular assays, the compounds inhibited the proliferation of acute myeloid leukemia cell lines. Increased levels of the biomarkers H3K4me2 and CD86 were consistent with LSD1 target engagement. 相似文献
24.
Bouzid W Stefka J Hypsa V Lek S Scholz T Legal L Ben Hassine OK Loot G 《International journal for parasitology》2008,38(12):1465-1479
Parasite species with global distributions and complex life cycles offer a rare opportunity to study alternative mechanisms of speciation and evolution in a single model. Here, genealogy and genetic structure, with respect to geography and fish host preference, have been analyzed for Ligula intestinalis, a tapeworm affecting freshwater fish. The data analyzed consisted of 109 tapeworms sampled from 13 fish host species in 18 different localities on a macrogeographic scale. Two mitochondrial genes, cytochrome oxidase subunit I and cytochrome B, and the nuclear sequence of intergenic transcribed spacer 2 (ITS2) were used for the genetic reconstruction. Different evolutionary patterns were found at the local and at the global geographic scales. On a local scale, the flat genetic structure was mainly attributed to contiguous range expansion. Migrating birds are the most likely cause of the homogenisation of the whole population, preventing the creation of significant genetic barriers. By contrast, on a global scale, genetically distant and well-separated clusters are present in different geographic areas. Reproductive isolation was found even between clades living in sympatry and infecting the same definitive host, suggesting the existence of efficient biologically determined genetic barriers, and thus possibly separate species. Although the ITS2 sequences were found to display considerable intragenomic variability, their relationships were generally in good agreement with the topology derived from mitochondrial genes. 相似文献
25.
Azoulay M Tuffin G Sallem W Florent JC 《Bioorganic & medicinal chemistry letters》2006,16(12):3147-3149
Many drugs induce severe side-effects caused by their lack of selectivity. One way to overcome this problem is to design a specific system which releases a free drug in a controlled manner. Herein we describe a new way to liberate a drug from a prodrug using the Staudinger ligation as the trigger. 相似文献
26.
Katharigatta N. Venugopala Sandeep Chandrashekharappa Pran Kishore Deb Christophe Tratrat Melendhran Pillay Deepak Chopra Nizar A. Al-Shari Wafa Hourani Lina A. Dahabiyeh Pobitra Borah Rahul D. Nagdeve Susanta K. Nayak Basavaraj Padmashali Mohamed A. Morsy Bandar E. Aldhubiab Mahesh Attimarad Anroop B. Nair Nagaraja Sreeharsha Michelyne Haroun Sheena Shashikanth Viresh Mohanlall Raghuprasad Mailavaram 《Journal of enzyme inhibition and medicinal chemistry》2021,36(1):1472
A series of 1,2,3-trisubstituted indolizines (2a–2f, 3a–3d, and 4a–4c) were screened for in vitro whole-cell anti-tubercular activity against the susceptible H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 2b–2d, 3a–3d, and 4a–4c were active against the H37Rv-MTB strain with minimum inhibitory concentration (MIC) ranging from 4 to 32 µg/mL, whereas the indolizines 4a–4c, with ethyl ester group at the 4-position of the benzoyl ring also exhibited anti-MDR-MTB activity (MIC = 16–64 µg/mL). In silico docking study revealed the enoyl-acyl carrier protein reductase (InhA) and anthranilate phosphoribosyltransferase as potential molecular targets for the indolizines. The X-ray diffraction analysis of the compound 4b was also carried out. Further, a safety study (in silico and in vitro) demonstrated no toxicity for these compounds. Thus, the indolizines warrant further development and may represent a novel promising class of InhA inhibitors and multi-targeting agents to combat drug-sensitive and drug-resistant MTB strains. 相似文献
27.
Rym Chamakh-Ayari Rachel Bras-Gon?alves Narges Bahi-Jaber Elodie Petitdidier Wafa Markikou-Ouni Karim Aoun Javier Moreno Eugenia Carrillo Poonam Salotra Himanshu Kaushal Narender Singh Negi Jorge Arevalo Francesca Falconi-Agapito Angela Privat Maria Cruz Julie Pagniez Gérard-Marie Papierok Faten Bel Haj Rhouma Pilar Torres Jean-Loup Lemesre Mehdi Chenik Amel Meddeb-Garnaoui 《PloS one》2014,9(5)
PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection. 相似文献
28.
29.
Munef A. Mohammed Dietmar Keyser Mohammed A. Al-Wosabi Bassim Al-Khirbash Wafa M. Al-Qadassi 《Revue de Micropaléontologie》2014
Eleven species belonging to ten genera of fresh water Ostracoda, have been identified from thirteen sediment samples collected from the bottom of permanent streams running along the N-NE part of Socotra Island. The fauna shows close affinity with the S-E African and S-E Asian assemblages, with interesting findings regarding the Palearctic Limnocythere stationis Vávra, 1891. The taxonomy and geographic distribution of the fauna are here discussed in detail. 相似文献
30.
Enzyme-Linked Immunofiltration Assay To Estimate Attachment of Thiobacilli to Pyrite 总被引:3,自引:0,他引:3
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Marie-Antoinette Dziurla Wafa Achouak Bach-Tuyet Lam Thierry Heulin Jacques Berthelin 《Applied microbiology》1998,64(8):2937-2942
An enzyme-linked immunofiltration assay (ELIFA) has been developed in order to estimate directly and specifically Thiobacillus ferrooxidans attachment on sulfide minerals. This method derives from the enzyme-linked immunosorbent assay but is performed on filtration membranes which allow the retention of mineral particles for a subsequent immunoenzymatic reaction in microtiter plates. The polyclonal antiserum used in this study was raised against T. ferrooxidans DSM 583 and recognized cell surface antigens present on bacteria belonging to the genus Thiobacillus. This antiserum and the ELIFA allowed the direct quantification of attached bacteria with high sensitivity (104 bacteria were detected per well of the microtiter plate). The mean value of bacterial attachment has been estimated to be about 105 bacteria mg−1 of pyrite at a particle size of 56 to 65 μm. The geometric coverage ratio of pyrite by T. ferrooxidans ranged from 0.25 to 2.25%. This suggests an attachment of T. ferrooxidans on the pyrite surface to well-defined limited sites with specific electrochemical or surface properties. ELIFA was shown to be compatible with the measurement of variable levels of adhesion. Therefore, this method may be used to establish adhesion isotherms of T. ferrooxidans on various sulfide minerals exhibiting different physicochemical properties in order to understand the mechanisms of bacterial interaction with mineral surfaces. 相似文献