全文获取类型
收费全文 | 126篇 |
免费 | 4篇 |
国内免费 | 3篇 |
出版年
2023年 | 2篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有133条查询结果,搜索用时 23 毫秒
101.
Tariq Al-Najjar Mohammad I. Badran Claudio Richter Michael Meyerhoefer Ulrich Sommer 《Hydrobiologia》2007,579(1):69-83
Seawater samples were collected biweekly from the northern Gulf of Aqaba, Red Sea, for Phytoplankton analysis during the period
May 1998 to October 1999. Microscopic counts and HPLC methods were employed. Procaryotic and eucaryotic ultraplankton dominated
throughout most of the year, with larger nano- and microplankton making up only 5% of the photosynthetic biomass. Moderate
seasonal variations in the 0–125 m integrated Chl a contrasted with a pronounced seasonal succession of the major taxonomic groups, reflecting the changes in the density stratification
of the water column: Prochlorococcus dominated during the stratified summer period and were almost absent in winter. Chlorophyceae and Cryptophyceae were dominant
during winter mixing but scarce or absent during summer. Diatoms and Synechococcus showed sharp and moderate biomass peaks in late winter and spring respectively, but remained at only low Chl a levels for the rest of the year. Chrysophyceae, Prymnesiophyceae and the scarce Dinophyceae showed no clear seasonal distribution
pattern. The implications of alternating procaryotic and eucaryote dominated algal communities for the Red Sea pelagic food
web are discussed.
Electronic Supplementary Material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
102.
Clement Gaignard Nesrine Gargouch Pascal Dubessay Cedric Delattre Guillaume Pierre Celine Laroche Imen Fendri Slim Abdelkafi Philippe Michaud 《Biotechnology advances》2019,37(1):193-222
Research on marine microalgae has been abundantly published and patented these last years leading to the production and/or the characterization of some biomolecules such as pigments, proteins, enzymes, biofuels, polyunsaturated fatty acids, enzymes and hydrocolloids. This literature focusing on metabolic pathways, structural characterization of biomolecules, taxonomy, optimization of culture conditions, biorefinery and downstream process is often optimistic considering the valorization of these biocompounds. However, the accumulation of knowledge associated with the development of processes and technologies for biomass production and its treatment has sometimes led to success in the commercial arena. In the history of the microalgae market, red marine microalgae are well positioned particularly for applications in the field of high value pigment and hydrocolloid productions. This review aims to establish the state of the art of the diversity of red marine microalgae, the advances in characterization of their metabolites and the developments of bioprocesses to produce this biomass. 相似文献
103.
Sorbus aucuparia and Sorbus aria as a Source of Antioxidant Phenolics,Tocopherols, and Pigments 下载免费PDF全文
Katarina P. Šavikin Gordana M. Zdunić Dijana B. Krstić‐Milošević Helena J. Šircelj Danijela D. Stešević Dejan S. Pljevljakušić 《化学与生物多样性》2017,14(12)
Due to its nutritive and medicinal properties, berries of some Sorbus species are used for the preparation of jams and jelly as well as in traditional medicine. On the other hand, their chemical composition is not much studied especially of those grown in Balkan Peninsula. We have analyzed individual phenolics, tocopherols, carotenoids and chlorophylls using HPLC in berries from Sorbus aucuparia and Sorbus aria collected in different localities in Serbia and Montenegro together with the amounts of total phenolics and proanthocyanidins as well as their radical scavenging activity against DPPH radical. Berries of S. aucuparia were richer source of polyphenolics in comparision with S. aria and, regardless the species and locality, caffeoylquinic acids such as neochlorogenic and chlorogenic acid were the most abundant compounds. Among analyzed tocopherols the most abundant in all samples was α‐tocopherol (0.48 – 19.85 μg/g dw) as it was β‐carotene among carotenoids (mean concentration of 0.98 μg/g dw in S. aucuparia and 0.40 μg/g dw in S. aria, respectively). Correlation between total phenolics and DPPH radical scavenging activity was noticed. Our study represents comprehensive report on chemical composition of S. aucuparia and S. aria which could contribute to a better understanding of their quality. 相似文献
104.
Coastal reef degradation and widespread bleaching of corals, i.e. loss of pigments and/or symbiotic zooxanthellae, is increasing
globally. Remote sensing from boats, aircraft or satellites has great potential for assessing the extent of reef change, but
will require ground-verified spectral algorithims characteristic of healthy and degraded reef populations. We collected seven
species of Caribbean reef corals and also representative macroalgae from reefs near Lee Stocking Island, Bahamas and quantified
their pigments using high performance liquid chromatography. We also measured the fluorescence and reflectance spectra of
corals and macroalgae using an in situ benthic spectrofluorometer. In visibly pigmented (unbleached) coral from 4 to 5 m depth,
the mean (±SD) surface density of pigments (3.0±1.3 μg chlorophyll-a cm-2 and 2.1±0.7 μg peridinin cm-2) was similar between colonies of the same species, but differed among species. The mean quantity of pigment per zooxanthella
(1.8±0.9 pg chl-a cell-1 and 1.4±0.7 pg peridinin cell-1) also differed among species and sometimes between colonies of the same species. Chl-a and peridinin densities per surface
area of coral were positively correlated. When excited with blue light (480 nm), macroalgae and corals had typical chlorophyll
fluorescence with a peak at 680 nm and a smaller shoulder peak at 730 to 740 nm. Most corals, unlike macroalgae, also had
distinct fluorescence peaks between 500 and 530 nm. In visibly bleached corals 680 nm fluorescence was greatly reduced in
amplitude. Pigmented coral, under natural lighting conditions, had a reflected light peak at about 570 nm. Reflectance increased
over all wavelengths in bleached corals, with the greatest increase at the wavelengths where chlorophyll and accessory pigments
absorb light, i.e. 670 and 450 to 550 nm. Both fluorescence and reflectance spectra appear promising to remotely differentiate
between pigmented and bleached coral and between coral and macroalgae.
Accepted: 15 March 1999 相似文献
105.
Angelina Metaxatos Lydia Ignatiades 《Journal of experimental marine biology and ecology》2003,294(2):203-217
A series of multi-taxa cultures containing five blue-green algae, three diatoms, one prymnesiophyte and one dinoflagellate was set up by using as inoculum sea water collected during a mucus-forming phytoplankton bloom in Euboikos Gulf, Aegean Sea. The cultured algae produced mucilage material that undergone quantitative and qualitative pigment, monosaccharide and aminoacid analyses with the use of HPLC methodology. Eight pigments (chlorophyll α, chlorophyll c, fucoxanthin, zeaxanthin, 19′-butanoylofucoxanthin, 19′-hexanoylofucoxanthin, peridinin and phaeophytin α) were identified and confirmed the species viability and their state of senescence. The qualitative composition of the recorded 8 monosaccharides (glucose, galactose, xylose, fucose, mannose, rhamnose, arabinose and glucosamine) and 15 aminoacids (arginine, glutamine, aspartate, serine, lysine, glysine, threonine, alanine, tyrosine, methionine, valine, phenylalanine, isoleucine, leucine and histidine) was similar in all cultures, but their quantitative composition differed among them and this might be due to their differences in species composition. The results also showed that the relative abundance of aminoacids and monosaccharides depended on the physiological state of the cells, the former being more abundant during the exponential phase and the latter mainly during the stationary phase of the cultures. 相似文献
106.
Physiological evidence was obtained for a light shielding role for gas vacuoles inMicrocystis aeruginosa Kuetz. emend. Elenkin, by comparing photosynthetic oxygen evolution, growth behaviour and pigment composition of cells with intact or collapsed gas vacuoles. The oxygen evolution rates were strongly dependent on cell concentration, a maximum rate for cells with intact gas vacuoles occurring at about 1.4×109 cells/ml and for cells with collapsed gas vacuoles at about 2.5×109 cells/ml. By using light saturation curves for oxygen evolution, it was estimated that at low light intensities up to 30% of the photosynthetically useable light was shielded at a cell concentration of 6×108 cells/ml. Collapsing the gas vacuoles twice daily did not alter the initial growth rate of the cultures, but enabled them to reach a higher final cell density. Collapsing of gas vacuoles during growth for about four generations resulted in a lower level of all acetone soluble pigments with a greater relative reduction in carotenoids than in chlorophyll a. Collapse of the gas vacuoles does not alter the cell volume. Various optical interactions which could account for light shielding are discussed. 相似文献
107.
Jessica Wiethaus Andrea W. U. Busch Klaus Kock Lars I. Leichert Christian Herrmann Nicole Frankenberg-Dinkel 《The Journal of biological chemistry》2010,285(48):37561-37569
In contrast to the majority of cyanobacteria, the unicellular marine cyanobacterium Prochlorococcus marinus MED4 uses an intrinsic divinyl-chlorophyll-dependent light-harvesting system for photosynthesis. Despite the absence of phycobilisomes, this high-light adapted strain possesses β-phycoerythrin (CpeB), an S-type lyase (CpeS), and enzymes for the biosynthesis of phycoerythrobilin (PEB) and phycocyanobilin. Of all linear tetrapyrroles synthesized by Prochlorococcus including their 3Z- and 3E-isomers, CpeS binds both isomers of PEB and its biosynthetic precursor 15,16-dihydrobiliverdin (DHBV). However, dimerization of CpeS is independent of bilins, which are tightly bound in a complex at a ratio of 1:1. Although bilin binding by CpeS is fast, transfer to CpeB is rather slow. CpeS is able to attach 3E-PEB and 3Z-PEB to dimeric CpeB but not DHBV. CpeS transfer of 3Z-PEB exclusively yields correctly bound βCys82-PEB, whereas βCys82-DHBV is a side product of 3E-PEB transfer. Spontaneous 3E- and 3Z-PEB addition to CpeB is faulty, and products are in both cases βCys82-DHBV and likely a PEB bound at βCys82 in a non-native configuration. Our data indicate that CpeS is specific for 3Z-PEB transfer to βCys82 of phycoerythrin and essential for the correct configuration of the attachment product. 相似文献
108.
A psychrophilic bacterium (named GL8) producing red pigments was isolated from the high altitude Pangong Tso Lake located in Leh Ladakh, India. Based on 16S rDNA sequencing amplicon of 1370 bp, the psychrophilic bacterium was identified as Rhodonellum psychrophilum (R. psychrophilum GL8) and deposited in Gen Bank under accession no. MH031708.1.The red colored pigments from R. psychrophilum GL8 showed antimicrobial activity against E. coli, S. aureus, C. albicans, (MTCC 277, ATCC 90028) and S. cerevisiae (H1086) with minimum inhibitory concentrations from 31.25 μg/mL to 500 μg/mL. Red colored pigments also showed synergistic antifungal activity when combined with fluconazole and amphotericin B against C. albicans (MTCC 277 and ATCC 90028) and S. cerevisiae; vancomycin and erythromycin against E. coli and S. aureus. The red pigments showed antioxidant activity with an IC50 of 13.159 μg/mL, LC–MS/MS analysis demonstrated that red pigment extracts contained a mixture of 2-methyl-3-butyl-prodigine, Prodigiosin, 2-methyl-3hexyl-prodigine, 3, 4-Didehydrorhodopsin, anhydrorhodovibrin, alloxanthin and Tetradecanoyl-hexadecanoyl compounds. Red pigment extracts were used to develop antimicrobial fabrics and did not show any cytotoxicity to U87MG human glioblastoma cell line, but showed a marginal growth inhibition to A172 human glioblastoma cell lines. In contrast, the red pigment extracts showed significant growth stimulation on L929 mouse fibroblast cell lines. 相似文献
109.
Jaschke PR Hardjasa A Digby EL Hunter CN Beatty JT 《The Journal of biological chemistry》2011,286(23):20313-20322
Heme and bacteriochlorophyll a (BChl) biosyntheses share the same pathway to protoporphyrin IX, which then branches as follows. Fe(2+) chelation into the macrocycle by ferrochelatase results in heme formation, and Mg(2+) addition by Mg-chelatase commits the porphyrin to BChl synthesis. It was recently discovered that a bchD (Mg-chelatase) mutant of Rhodobacter sphaeroides produces an alternative BChl in which Mg(2+) is substituted by Zn(2+). Zn-BChl has been found in only one other organism before, the acidophilic Acidiphilium rubrum. Our objectives in this work on the bchD mutant were to 1) elucidate the Zn-BChl biosynthetic pathway in this organism and 2) understand causes for the low amounts of Zn-BChl produced. The bchD mutant was found to contain a Zn-protoporphyrin IX pool, analogous to the Mg-protoporphyrin IX pool found in the wild type strain. Inhibition of ferrochelatase with N-methylprotoporphyrin IX caused Zn-protoporphyrin IX and Zn-BChl levels to decline by 80-90% in the bchD mutant, whereas in the wild type strain, Mg-protoporphyrin IX and Mg-BChl levels increased by 170-240%. Two early metabolites of the Zn-BChl pathway were isolated from the bchD mutant and identified as Zn-protoporphyrin IX monomethyl ester and divinyl-Zn-protochlorophyllide. Our data support a model in which ferrochelatase synthesizes Zn-protoporphyrin IX, and this metabolite is acted on by enzymes of the BChl pathway to produce Zn-BChl. Finally, the low amounts of Zn-BChl in the bchD mutant may be due, at least in part, to a bottleneck upstream of the step where divinyl-Zn-protochlorophyllide is converted to monovinyl-Zn-protochlorophyllide. 相似文献
110.
Zengling Ma Kunshan Gao Zhaoli Xu Yangqiao Zheng 《Journal of experimental marine biology and ecology》2011,397(2):214-219
The main impacts of cooling water from thermal (nuclear) power plants on aquatic organisms were caused by chlorination and temperature increase. In this study, we investigated the impacts of residual chlorine and short-term heat shocks on growth, pigment contents and photosynthesis of Phaeodactylum tricornutum. Growth of P. tricornutum was completely inhibited; Chlorophyll a and carotenoids contents deceased about 63.3% and 61.4% in 24 h treated with 0.2 mg L− 1 chlorine. The negative effects of chlorination increased with enhanced concentration and prolonged exposure time. Relative electrode transfer rate (rETR) of P. tricornutum was significantly suppressed when treated with 0.2 mg L− 1 residual chlorine for 24 h. Furthermore, the effective quantum yield (Fv'/Fm') decreased first but then recovered with prolonged exposure when residual chlorine ranged between 0.1 and 0.2 mg L− 1. The cells were less sensitive to heat shocks compared with chlorination: the rETR and Fv'/Fm' was suppressed only when the temperature exceeded 35 °C for 1 h. When P. tricornutum was exposed to chlorination combined with heat shocks, the rETR was further inhibited at 35 °C. It indicated that both chlorination and heat shocks had negative impacts on the primary producers living in discharging coastal waters; furthermore, there were synergistic effects of heat shocks on chlorination toxicity. 相似文献