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101.
Anup Adhikari Sajan Shakya Shreesti Shrestha Dipa Aryal Kavi Prasad Timalsina Dipesh Dhakal Yogan Khatri Niranjan Parajuli 《Biotechnology and bioengineering》2023,120(12):3465-3492
Cytochrome P450s belong to a family of heme-binding monooxygenases, which catalyze regio- and stereospecific functionalisation of C–H, C–C, and C–N bonds, including heteroatom oxidation, oxidative C–C bond cleavages, and nitrene transfer. P450s are considered useful biocatalysts for the production of pharmaceutical products, fine chemicals, and bioremediating agents. Despite having tremendous biotechnological potential, being heme-monooxygenases, P450s require either autologous or heterologous redox partner(s) to perform chemical transformations. Randomly distributed P450s throughout a bacterial genome and devoid of particular redox partners in natural products biosynthetic gene clusters (BGCs) showed an extra challenge to reveal their pharmaceutical potential. However, continuous efforts have been made to understand their involvement in antibiotic biosynthesis and their modification, and this review focused on such BGCs. Here, particularly, we have discussed the role of P450s involved in the production of macrolides and aminocoumarin antibiotics, nonribosomal peptide (NRPSs) antibiotics, ribosomally synthesized and post-translationally modified peptide (RiPPs) antibiotics, and others. Several reactions catalyzed by P450s, as well as the role of their redox partners involved in the BGCs of various antibiotics and their derivatives, have been primarily addressed in this review, which would be useful in further exploration of P450s for the biosynthesis of new therapeutics. 相似文献
102.
Ming-Kuo Lee James A. Saunders Theodore Wilson Eric Levitt Shahrzad Saffari Ghandehari Prakash Dhakal 《Bioremediation Journal》2019,23(1):1-21
This research demonstrates that biogenic pyrite formed by stimulation of indigenous sulfate-reducing bacteria (SRB) in a natural aquifer can remove dissolved arsenic from contaminated groundwater under strongly reducing conditions. SRB metabolism led to the precipitation of biogenic pyrite nanoparticles capable of sorbing and co-precipitating arsenic. The field site is an industrial site where shallow groundwater in an unconfined sandy aquifer is contaminated by arsenic. Therefore, biodegradable organic carbon, ferrous iron, sulfate, and fertilizer were injected into groundwater and SRB metabolism began about 1 week later. Microscopic, X-ray diffraction, X-ray fluorescence, and electron microprobe analyses confirm the bio-mineralization of pyrite and over time, pyrite nanoparticles grew to form well-formed crystals (1–10?µm in diameter) or spherical aggregates that contain 0.05–0.4?wt. % arsenic, indicative of their capacity to sequester arsenic. Consequently, dissolved arsenic decreased from its initial concentration of 0.3–0.5?mg/L to below the regulatory clean-up standard for the site of 0.05?mg/L in three downgradient wells in a matter of weeks after injection. The main sequestration stage, with total arsenic removal rates greater than 90%, lasted for at least 6 months until the arrival and mixing of untreated groundwater from upgradient. Treated groundwater with most active bacterial sulfate reduction became enriched in heavy 34S (range from 2.02 to 4.00 ‰) compared to unaffected well water (0.40–0.61 ‰). One to three orders of magnitude increases in SRB cells were observed in treated wells for at least 2?months after injection. For a full-scale remediation, the injection of solution should start at positions hydrologically upgradient from the major plume and proceed downgradient. If needed, aquifers may be repeatedly amended with biodegradable organic carbon to reestablish the reducing conditions that favor arsenic sequestration. 相似文献
103.
Kumar B Joshi J Kumar A Pandey BN Hazra B Mishra KP 《Molecular and cellular biochemistry》2007,304(1-2):287-296
The development of radio-resistant tumor cells might be overcome by the use of tumor selective cytotoxic agents in combination
with radiation treatment of cancer. Thus, we are exploring the radiomodifying potential of D7, a tumor-inhibitory compound
derived from a plant product, diospyrin, in breast carcinoma cells, MCF-7. The present study indicated that D7 could enhance
the radiation-induced cytotoxicity and apoptosis through down-regulation of the anti-apoptotic Bcl-2 and COX-2 gene expression,
and up-regulation of pro-apoptotic genes, like p53 and p21. The higher expression of PUMA, a pro-apoptotic protein was also
observed in the combination treatment. Effect of D7 on up-regulation of p21 expression in irradiated MCF-7 cells was concomitant
with the cell cycle arrest in the G1 phase. Thus, it was concluded that D7 could sensitize the effect of radiation in breast
carcinoma by regulating the gene expression involved in cell cycle and apoptosis. 相似文献
104.
Hemanta Dhakal Hari Prasad Sharma Christopher J. W. McClure Munir Virani Brian W. Rolek Narendra Man Babu Pradhan Krishna Prasad Bhusal 《Ecology and evolution》2022,12(1)
Due to an abundance and diversity of vultures, Nepal is one of the most important countries for vulture conservation. Within Nepal, the Pokhara Valley is especially significant. We examine the distribution of vultures within the Pokhara Valley by conducting counts at 11 potential feeding or roosting sites using point count method. We further surveyed people of the valley regarding their perception of vulture ecology and conservation, knowledge of diclofenac use within the valley, and burial of livestock carcasses. We detected eight species of vultures, four of which are currently threatened with extinction. White‐rumped vulture Gyps bengalensis, Egyptian vulture Nephron percnopterus, and Himalayan vulture G. himalayensis were the most abundant. Almost all respondents (98%) had sighted the vultures in the wild. Formally educated respondents reported seeing vultures’ slightly more than nonformally educated respondents. Fifty‐eight percent respondents suspected habitat loss was the major threat for the vulture population decline in Pokhara Valley, and 97% respondents were not aware of any diclofenac use. The knowledge of vultures in people with different age groups suggests a more awareness programs are needed for local people, especially those who carry out animal husbandry and provide livestock to the vulture restaurant. 相似文献
105.
Molecular Ecology Resources Primer Development Consortium Aurelle D Baker AJ Bottin L Brouat C Caccone A Chaix A Dhakal P Ding Y Duplantier JM Fiedler W Fietz J Fong Y Forcioli D Freitas TR Gunnarsson GH Haddrath O Hadziabdic D Hauksdottir S Havill NP Heinrich M Heinz T Hjorleifsdottir S Hong Y Hreggvidsson GO Huchette S Hurst J Kane M Kane NC Kawakami T Ke W Keith RA Klauke N Klein JL Kun JF Li C Li GQ Li JJ Loiseau A Lu LZ Lucas M Martins-Ferreira C Mokhtar-Jamaï K Olafsson K Pampoulie C 《Molecular ecology resources》2010,10(4):751-754
This article documents the addition of 228 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anser cygnoides, Apodemus flavicollis, Athene noctua, Cercis canadensis, Glis glis, Gubernatrix cristata, Haliotis tuberculata, Helianthus maximiliani, Laricobius nigrinus, Laricobius rubidus, Neoheligmonella granjoni, Nephrops norvegicus, Oenanthe javanica, Paramuricea clavata, Pyrrhura orcesi and Samanea saman. These loci were cross-tested on the following species: Apodemus sylvaticus, Laricobius laticollis and Laricobius osakensis (a proposed new species currently being described). 相似文献
106.
Uttam B. Shrestha Pramod Lamsal Suresh K. Ghimire Bharat B. Shrestha Sajita Dhakal Sujata Shrestha Kishor Atreya 《Ecology and evolution》2022,12(8)
Medicinal and aromatic plants (MAPs) contribute to human well‐being via health and economic benefits. Nepal has recorded 2331 species of MAPs, of which around 300 species are currently under trade. Wild harvested MAPs in Nepal are under increasing pressure from overexploitation for trade and the effects of climate change and development. Despite some localized studies to examine the impact of climate change on MAPs, a consolidated understanding is lacking on how the distribution of major traded species of MAPs will change with future climate change. This study identifies the potential distribution of 29 species of MAPs in Nepal under current and future climate using an ensemble modeling and hotspot approach. Future climate change will reduce climatically suitable areas of two‐third of the studied species and decrease climatically suitable hotspots across elevation, physiography, ecoregions, federal states, and protected areas in Nepal. Reduction in climatically suitable areas for MAPs might have serious consequences for the livelihood of people that depend on the collection and trade of MAPs as well as Nepal''s national economy. Therefore, it is imperative to consider the threats that future climate change may have on distribution of MAPs while designing protected areas and devising environmental conservation and climate adaptation policies. 相似文献
107.
108.
Sanjaya Dhakal Mohammad Jahirul Karim Abdullah Al Kawsar Jasmine Irish Mujibur Rahman Cara Tupps Ashraful Kabir Rubina Imtiaz 《PLoS neglected tropical diseases》2020,14(12)
In 2008, Bangladesh initiated Preventive Chemotherapy (PCT) for school-age children (SAC) through bi-annual school-based mass drug administration (MDA) to control Soil-Transmitted Helminth (STH) infections. In 2016, the Ministry of Health and Family Welfare’s Program on Lymphatic Filariasis Elimination and STH (ELFSTH) initiated district-level community impact assessments with Children Without Worms (CWW) using standardized, population-based sampling to measure the post-intervention STH burden across all ages (≥ 1 yr) for the three STH species. The Integrated Community-based Survey for Program Monitoring (ICSPM) was developed by CWW and was used to survey 12 districts in Bangladesh from 2017–2020. We excluded the first two district data as piloting caused some sampling errors and combined the individual demographic and parasite-specific characteristics from the subsequent 10 districts, linking them with the laboratory data for collective analysis. Our analysis identified district-specific epidemiologic findings, important for program decisions. Of the 17,874 enrolled individuals, our results are based on 10,824 (61.0%) stool samples. Overall, the prevalence of any STH species was substantially reduced to 14% from 79.8% in 2005. The impact was similar across all ages. STH prevalence was 14% in 10 districts collectively, but remained high in four districts, despite their high reported PCT coverage in previous years. Among all, Bhola district was unique because it was the only district with high T.trichuris prevalence. Bangladesh successfully lowered STH prevalence across all ages despite targeting SAC only. Data from the survey indicate a significant number of adults and pre-school age children (PSAC) were self-deworming with purchased pills. This may account for the flat impact curve across all ages. Overall prevalence varied across surveyed districts, with persistent high transmission in the northeastern districts and a district in the central flood zone, indicating possible service and ecological factors. Discrepancies in the impact between districts highlight the need for district-level data to evaluate program implementation after consistent high PCT coverage. 相似文献
109.
Zhitai Hao Vitaly Epshtein Kelly H. Kim Sergey Proshkin Vladimir Svetlov Venu Kamarthapu Binod Bharati Alexander Mironov Thomas Walz Evgeny Nudler 《Molecular cell》2021,81(2):281-292.e8
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110.
Objective: This study projects midlife obesity status in future older Australians. Design and Methods: Cross‐sectional prevalence of being obese or overweight by broad age groups was interpolated to obtain single‐year‐age data. These estimates were then used to derive prevalence of normal weight and underweight. Data by birth year and year of observation of persons aged 30–70 years were used to construct prediction equations. Results: Results show that older people with a history of midlife obesity is projected to rise substantially in the future. For people aged 65 years, midlife obesity was estimated at 22% in 2010 and is projected to increase to 43% for males and 37% for females in 2050. Conclusion: While the proportion of individuals with midlife normal weight is projected to decline substantially, prevalence of midlife overweight remains almost stable. The number of persons aged 65 years and over having a history of midlife obesity is projected to increase nearly six‐fold from less than 500,000 persons in 2010 to 2.8 million in 2050. In comparison, between 2010 and 2050, Australia's older population aged 65 years and over is projected to increase by only 2.5‐fold. Growing obesity prevalence in the Australian population translates into a large increase in older people with a history of midlife obesity, with major implications for the future burden of disease in older persons. 相似文献