排序方式: 共有109条查询结果,搜索用时 15 毫秒
1.
Siham A. Lahsasni 《Nucleosides, nucleotides & nucleic acids》2013,32(8):439-452
In this study, 1-(bromoalkanoyl)-1H-pyrimidine-2,4-diones, (2,4-dioxo-pyrimidin-1-yl)-oxo-alkanoic acids, and bis(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-alkanones were successfully prepared via electrophilic substitution of uracil and its derivatives. High yields and pure products were obtained when microwave and ultrasound methodologies were used for undertaking the reactions. Importantly, the use of 4-dimethylaminopyridine in the present investigation gave rise to higher conversions of the starting material and afforded facile access to regioselective N-1 products. 相似文献
2.
Muhammad Yasir Haji Khan Syed Sikander Azam Amar Telke Seon Won Kim Young Ryun Chung 《Journal of microbiology (Seoul, Korea)》2013,51(3):329-335
In the vermicomposting of paper mill sludge, the activity of earthworms is very dependent on dietetic polysaccharides including cellulose as energy sources. Most of these polymers are degraded by the host microbiota and considered potentially important source for cellulolytic enzymes. In the present study, a metagenomic library was constructed from vermicompost (VC) prepared with paper mill sludge and dairy sludge (fresh sludge, FS) and functionally screened for cellulolytic activities. Eighteen cellulase expressing clones were isolated from about 89,000 fosmid clones libraries. A short fragment library was constructed from the most active positive clone (cMGL504) and one open reading frame (ORF) of 1,092 bp encoding an endo-β-1,4-glucanase was indentified which showed 88% similarity with Cellvibrio mixtus cellulase A gene. The endo-β-1,4-glucanase cmgl504 gene was overexpressed in Escherichia coli. The purified recombinant cmgl504 cellulase displayed activities at a broad range of temperature (25–55°C) and pH (5.5–8.5). The enzyme degraded carboxymethyl cellulose (CMC) with 15.4 U, while having low activity against avicel. No detectable activity was found for xylan and laminarin. The enzyme activity was stimulated by potassium chloride. The deduced protein and three-dimensional structure of metagenome-derived cellulase cmgl504 possessed all features, including general architecture, signature motifs, and N-terminal signal peptide, followed by the catalytic domain of cellulase belonging to glycosyl hydrolase family 5 (GHF5). The cellulases cloned in this work may play important roles in the degradation of celluloses in vermicomposting process and could be exploited for industrial application in future. 相似文献
3.
Giuseppe Tortoriello Brandon P. Rhodes Sara M. Takacs Jordyn M. Stuart Arjun Basnet Siham Raboune Theodore S. Widlanski Patrick Doherty Tibor Harkany Heather B. Bradshaw 《PloS one》2013,8(7)
Lipid metabolism is critical to coordinate organ development and physiology in response to tissue-autonomous signals and environmental cues. Changes to the availability and signaling of lipid mediators can limit competitiveness, adaptation to environmental stressors, and augment pathological processes. Two classes of lipids, the N-acyl amides and the 2-acyl glycerols, have emerged as important signaling molecules in a wide range of species with important signaling properties, though most of what is known about their cellular functions is from mammalian models. Therefore, expanding available knowledge on the repertoire of these lipids in invertebrates will provide additional avenues of research aimed at elucidating biosynthetic, metabolic, and signaling properties of these molecules. Drosophila melanogaster is a commonly used organism to study intercellular communication, including the functions of bioactive lipids. However, limited information is available on the molecular identity of lipids with putative biological activities in Drosophila. Here, we used a targeted lipidomics approach to identify putative signaling lipids in third instar Drosophila larvae, possessing particularly large lipid mass in their fat body. We identified 2-linoleoyl glycerol, 2-oleoyl glycerol, and 45 N-acyl amides in larval tissues, and validated our findings by the comparative analysis of Oregon-RS, Canton-S and w1118 strains. Data here suggest that Drosophila represent another model system to use for the study of 2-acyl glycerol and N-acyl amide signaling. 相似文献
4.
Elizabeth L. Turner Siham Sikander Omer Bangash Ahmed Zaidi Lisa Bates John Gallis Nima Ganga Karen O’Donnell Atif Rahman Joanna Maselko 《Trials》2016,17(1)
BackgroundThe negative effects of perinatal depression on the mother and child start early and persist throughout the lifecourse (Lancet 369(9556):145–57, 2007; Am J Psychiatry 159(1):43-7, 2002; Arch Dis Child 77(2):99–101, 1997; J Pak Med Assoc 60(4):329; J Psychosoma Res 49(3):207–16, 2000; Clin Child Fam Psychol Rev 14(1):1–27, 2011). Given that 10–35 % of children worldwide are exposed to perinatal depression in their first year of life (Int Rev Psychiatry 8(1):37–54, 1996), mitigating this intergenerational risk is a global public health priority (Perspect Public Health 129(5):221–7, 2009; Trop Med Int Health 13(4):579–83, 2008; Br Med Bull 101(1):57–79, 2012). However, it is not clear whether intervention with depressed women can have long-term benefits for the mother and/or her child. We describe a study of the effectiveness of a peer-delivered depression intervention delivered through 36 postnatal months, the Thinking Healthy Program Peer-delivered PLUS (THPP+) for women and their children in rural Pakistan.Methods/designThe THPP+ study aims are: (1) to evaluate the effects of an extended 36-month perinatal depression intervention on maternal and index child outcomes using a cluster randomized controlled trial (c-RCT) and (2) to determine whether outcomes among index children of perinatally depressed women in the intervention arm converge with those of index children born to perinatally nondepressed women. The trial is designed to recruit 560 pregnant women who screened positive for perinatal depression (PHQ-9 score ≥10) from 40 village clusters, of which 20 receive the THPP+ intervention. An additional reference group consists of 560 perinatally nondepressed women from the same 40 clusters as the THPP+ trial. The women in the nondepressed group are not targeted to receive the THPP+ intervention; but, by recruiting pregnant women from both intervention and control clusters, we are able to evaluate any carryover effects of the THPP+ intervention on the women and their children. Perinatally depressed women in the THPP+ intervention arm receive bimonthly group-based sessions. Primary outcomes are 3-year maternal depression and 3-year child development indicators. Analyses are intention-to-treat and account for the clustered design.DiscussionThis trial, together with the reference group, has the potential to further our understanding of the early developmental lifecourse of children of both perinatally depressed and perinatally nondepressed women in rural Pakistan and to determine whether intervening with women’s depression in the perinatal period can mitigate the negative effects of maternal depression on 36-month child development.
Trial registration
THPP-P ClinicalTrials.gov Identifier: (registered on 9 April 2014).THPP+ ClinicalTrials.gov Identifier: NCT02111915 (registered on 21 January 2016).Sponsor: Human Development Research Foundation (HDRF). NCT02658994Electronic supplementary material
The online version of this article (doi:10.1186/s13063-016-1530-y) contains supplementary material, which is available to authorized users. 相似文献5.
Streptococcus mitis has emerged as one of the leading causes of bacterial endocarditis and is related to Streptococcus pneumoniae. Antibiotic resistance has also increased among strains of S. mitis and S. pneumoniae. Phages are being reinvestigated as alternatives to antibiotics for managing infections. In this study, the two virulent phages Cp-1 (Podoviridae) and Dp-1 (Siphoviridae), previously isolated from S. pneumoniae, were found to also infect S. mitis. Microbiological assays showed that both pneumophages could not only replicate in S. mitis but also produced more visible plaques on this host. However, the burst size and phage adsorption data were lower in S. mitis as compared to S. pneumoniae. A comparison of the genomes of each phage grown on both hosts produced identical nucleotide sequences, confirming that the same phages infect both bacterial species. We also discovered that the genomic sequence of podophage Cp-1 of the Félix d’Hérelle collection is different than the previously reported sequence and thus renamed SOCP. 相似文献
6.
Tauqeer Ahmad Yasir Sobia Aslam Muhammad Shahid Rizwan Allah Wasaya Muhammad Ateeq Muhammad Naeem Khan Sikander Khan Tanveer Walid Soufan Basharat Ali Allah Ditta Arpna Kumari Ayman EL Sabagh 《Phyton》2022,91(11):2491-2504
In soil biota, higher and enduring concentration of heavy metals like cadmium (Cd) is hazardous and associated
with great loss in growth, yield, and quality parameters of most of the crop plants. Recently, in-situ applications of
eco-friendly stabilizing agents in the form of organic modifications have been utilized to mitigate the adverse
effects of Cd-toxicity. This controlled experiment was laid down to appraise the imprints of various applied
organic amendments namely poultry manure (PM), farmyard manure (FYM), and sugarcane press mud (PS)
to immobilize Cd in polluted soil. Moreover, phytoavailability of Cd in wheat was also accessed under an alkaline
environment. Results revealed that the addition of FYM (5–10 ton ha-1
) in Cd-contaminated soil significantly
increased germination rate, leaf chlorophyll content, plant height, spike length, biological and grain yield amongst
all applied organic amendments. Moreover, the addition of FYM (5–10 ton ha-1
) also reduced the phytoavailability of Cd by 73–85% in the roots, 57–83% in the shoots, and 81–90% in grains of wheat crop. Thus, it is affirmed
that incorporation of FYM (5–10 ton ha-1
) performed better to enhance wheat growth and yield by remediating
Cd. Thus, the application of FYM (5–10 ton ha-1
) reduced the toxicity induced by Cd to plants by declining its
uptake and translocation as compared to all other applied organic amendments to immobilize Cd under sandy
alkaline polluted soil. 相似文献
7.
Benjelloun H Rochex A Lecouturier D Dechemi S Lebeault JM 《Applied microbiology and biotechnology》2005,68(3):316-321
An on-line technique, based on measuring the increase in pressure due to CO2 release in a closed air-tight reactor, was used to evaluate the fermentation of lactate by propionibacteria. The method was applied to batch cultures of Propionibacterium shermanii grown in yeast extract/sodium lactate medium containing lactate as a carbon source under micro-aerophilic conditions. Gas pressure evolution was compared both with substrate consumption and metabolites production and with acidification and growth. Linear relationships were found between gas pressure variation, lactate consumption and propionate and acetate production. The technique also enabled the evaluation of total CO2 produced, by taking account of pressure, oxygen and pH measurements. These results tend to show that this simple and rapid method could be useful to monitor propionic acid bacteria growth. 相似文献
8.
Durand T Guy A Henry O Roland A Bernad S El Fangour S Vidal JP Rossi JC 《Chemistry and physics of lipids》2004,128(1-2):15-33
Isoprostanes (IsoPs) are a complex family of compounds produced, in vivo, from peroxidation of polyunsaturated fatty acids (AA, DHA, EPA, alpha-linolenic) via a free-radical-catalyzed mechanism. Carbocyclic annulations are extremely important reactions and the stereocontrolled intramolecular free-radical cyclization has emerged as a powerful tool for carbon-carbon bond formation in synthetic chemistry. The hex-5-enyl radical cyclization is the most well-known for the synthesis of cyclopentane rings. After a short review of the literature, concerning the total synthesis of isoprostanes and intermediates, we will present our own contributions on the preparation of chiral cyclopentane rings from glucose leading to new isoprostanes. This study allowed us to control the cyclization outcome to yield the all-syn and/or syn-anti-syn precursors which permit us to the total synthesis of a large set of iso-, neuro-, and phytoprostanes. 相似文献
9.
Brassinosteroids (BRs) and polyamines (PAs) are well-established growth regulators playing key roles in stress management among plants. In the present study, we evaluated the effects of epibrassinolide (EBL, an active BR) and spermidine (Spd, an active PA) on the tolerance of radish to oxidative stress induced by Cr (VI) metal. Our investigation aimed to study the impacts of EBL (10(-9) M) and/or Spd (1 mM) on the biochemical and physiological responses of radish (Raphanus sativus L.) under Cr-stress. Applications of EBL and/or Spd were found to improve growth of Cr-stressed seedlings in terms of root length, shoot length and fresh weight. Our data also indicated that applications of EBL and Spd have significant impacts, particularly when applied together, on the endogenous titers of PAs, free and bound forms of IAA and ABA in seedlings treated with Cr-stress. Additionally, co-applications of EBL and Spd modulated more remarkably the titers of antioxidants (glutathione, ascorbic acid, proline, glycine betaine and total phenol) and activities of antioxidant enzymes (guaicol peroxidase, catalase, superoxide dismutase and glutathione reductase) in Cr-stressed plants than their individual applications. Attenuation of Cr-stress by EBL and/or Spd (more efficient with EBL and Spd combination) was also supported by enhanced values of stress indices, such as phytochelatins, photosynthetic pigments and total soluble sugars, and reduction in malondialdehyde and H(2)O(2) levels in Cr-treated seedlings. Diminution of ROS production and enhanced ROS scavenging capacities were also noted for EBL and/or Spd under Cr-stress. However, no significant reduction in Cr uptake was observed for co-application of EBL and Spd when compared to their individual treatments in Cr-stressed seedlings. Taken together, our results demonstrate that co-applications of EBL and Spd are more effective than their independent treatments in lowering the Cr-induced oxidative stress in radish, leading to improved growth of radish seedlings under Cr-stress. 相似文献
10.