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Dionex ICS 3000
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Description
high-performance liquid chromatography, nano-HPLC system, liquid chromatography system, nano high performance liquid chromatography system, nanosystem
This model was found at
3448 locations
The model is used in
71 countries
Usage per year (up to 2020)
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192 related research fields
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About the Dionex ICS 3000

The model Dionex ICS 3000 was found in 3448 unique locations in 71 countries where it was mentioned from 2008 until recentlyIt is used by scientists in various research fields such as Molecular Biology, Biochemistry, General Medicine, Analytical Chemistry, and Organic Chemistry. The model is also used in General Chemistry, Molecular Medicine, Drug Discovery, Pharmaceutical Science, General Biochemistry, Genetics and Molecular Biology, Physical and Theoretical Chemistry, Microbiology, Cell Biology, Biotechnology, Food Science, Plant Science, Chemistry, Applied Microbiology and Biotechnology, Pharmacology, General Physics and Astronomy, Genetics, Microbiology (medical), Clinical Biochemistry, Spectroscopy, Bioengineering, Immunology, Catalysis, Computer Science Applications, Renewable Energy, Sustainability and the Environment, and Inorganic Chemistry.
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Research that uses the Dionex ICS 3000

Jinpei Yan, Jinyoung Jung, Miming Zhang, Federico Bianchi, Yee Jun Tham, Suqing Xu, Qi Lin, Shuhui Zhao, Lei Li, Liqi Chen, Atmospheric Chemistry and Physics, 20, 3259-3271 (5), 2020
Abstract. The uptake of methanesulfonic acid (MSA) on existing particles is a major route of the particulate MSA formation, however, MSA uptake on different particles is still lacking in knowledge. Characteristics of MSA uptake on different aerosol particles were investigated in polynya (an area of open sea water surrounded by ice) regions of the Ross Sea, Antarctica. Particulate MSA mass concentrations, as well as aerosol population and size distribution, were observed simultaneously for the first time to access the uptake of MSA on different particles. The results show that MSA mass concentration does not always reflect MSA particle population in the marine atmosphere. MSA uptake on aerosol particle increases the particle size and changes aerosol chemical composition, but it does not increase the particle population. The uptake rate of MSA on particles is significantly influenced by aerosol chemical properties. Sea salt particles are beneficial for MSA uptake, as MSA-Na and MSA-Mg particles are abundant in the Na and Mg particles, accounting for 0.43±0.21 and 0.41±0.20 of the total Na and Mg particles, respectively. However, acidic and hydrophobic particles suppress the uptake of MSA, as MSA-EC (elemental carbon) and MSA-SO42- particles account for only 0.24±0.68 and 0.26±0.47 of the total EC and SO42- particles, respectively. The results extend the knowledge of the formation and environmental behavior of MSA in the marine atmosphere.
Saly Jaber, Audrey Lallement, Martine Sancelme, Martin Leremboure, Gilles Mailhot, Barbara Ervens, Anne-Marie Delort, 2020
Abstract. The sinks of hydrocarbons in the atmosphere are usually described by oxidation reactions in the gas and aqueous (cloud) phases. Previous lab studies suggest that in addition to chemical processes, biodegradation by bacteria might also contribute to the loss of organics in clouds; however, due to the lack of comprehensive data sets on such biodegradation processes, they are not commonly included in atmospheric models. In the current study, we measured the biodegradation rates of phenol and catechol, which are known pollutants, by one of the most active strains selected during our previous screening in clouds (Rhodococcus enclensis). For catechol, biodegradation transformation is about ten times faster than for phenol. The experimentally derived biodegradation rates are included in a multiphase box model to compare the chemical loss rates of phenol and catechol in both the gas and aqueous phases to their biodegradation rate in the aqueous phase under atmospheric conditions. Model results show that the degradation rates in the aqueous phase by chemical and biological processes for both compounds are similar to each other. During daytime, biodegradation of catechol is even predicted to exceed the chemical activity in the aqueous phase and to represent a significant sink (17 %) of total catechol in the atmospheric multiphase system. In general, our results suggest that atmospheric multiphase models may be incomplete for highly soluble organics as biodegradation may represent an unrecognized efficient loss of such organics in cloud water.
Yangang Ren, Bastian Stieger, Gerald Spindler, Benoit Grosselin, Abdelwahid Mellouki, Thomas Tuch, Alfred Wiedensohler, Hartmut Herrmann, 2020
Abstract. To characterize the role of dew water on the ground surface HONO distribution, nitrous acid (HONO) measurements with a MARGA and a LOPAP instrument were performed at the TROPOS research site in Melpitz from 19 to 29 April 2018. The dew water was also collected and analyzed from 8 to 14 May 2019 using a glass sampler. The high-time resolution of HONO measurements showed well-defined diurnal variations that revealed: (i) vehicle emission is a minor source of HONO at the Melpitz station; (ii) heterogeneous conversion of NO2 to HONO on ground surface dominates HONO production at night; (iii) significant nighttime ground surface deposition of HONO with a strength of sink of 0.161 ± 0.122 ppbv h−1; (iv) dew water with mean NO2− of 7.91 ± 2.14 μg m−2 could serve as a temporary HONO source in the morning when the dew droplets evaporate. The nocturnal observations of HONO and NO2 allowed direct evaluation of the ground uptake coefficients for these species at night: γNO2→HONO = 1.4 × 10−6 to 1.5 × 10−5, γHONO,ground = 5.6 to 19.5. A chemical model demonstrated that HONO deposition to the ground surface at night was 90–100 % of the calculated unknown HONO source in the morning. These results suggest that dew water on the ground surface was controlling the temporal HONO distribution rather than straightforward NO2–HONO conversion. This can strongly enhance the OH reactivity throughout morning time or other planted areas that provide large amount of ground surface based on the OH production rate calculation.
Md. Robiul Islam, Thilina Jayarathne, Isobel J. Simpson, Benjamin Werden, John Maben, Ashley Gilbert, Puppala S. Praveen, Sagar Adhikari, Arnico K. Panday, Maheswar Rupakheti, Donald R. Blake, Robert J. Yokelson, Peter F. DeCarlo, William C. Keene, Elizabeth A. Stone, 2019
Abstract. The Kathmandu Valley in Nepal is a bowl-shaped urban basin that experiences severe air pollution that poses health risks to its 3.5 million inhabitants. As part of the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE), ambient air quality in the Kathmandu Valley was investigated from 11 to 24 April 2015, during the pre-monsoon season. Ambient concentrations of fine and coarse particulate matter (PM2.5 and PM10, respectively), online PM1, inorganic trace gases (NH3, HNO3, SO2, and HCl), and carbon-containing gases (CO2, CO, CH4, and 85 non-methane volatile organic compounds; NMVOC) were quantified at a semi-urban location near the center of the valley. Concentrations and ratios of NMVOC indicated that origins primarily from poorly-maintained vehicle emissions, biomass burning, and solvent/gasoline evaporation. During those two weeks, daily average PM2.5 concentrations ranged from 30 to 207 µg m−3, which exceeded the World Health Organization 24 hour guideline by factors of 1.2 to 8.3. On average, the non-water mass of PM2.5 was composed of organic matter (48 %), elemental carbon (13 %), sulfate (16 %), nitrate (4 %), ammonium (9 %), chloride (2 %), calcium (1 %), magnesium (0.05 %), and potassium (1 %). Large diurnal variability in temperature and relative humidity drove corresponding variability in aerosol liquid water content, the gas-aerosol phase partitioning of NH3, HNO3, and HCl, and aerosol solution pH. The observed levels of gas-phase halogens suggest that multiphase halogen-radical chemistry involving both Cl and Br impacted regional air quality. To gain insight into the origins of organic carbon (OC), molecular markers for primary and secondary sources were quantified. Levoglucosan (1230 ± 1153 ng m−3), 1,3,5-triphenylbenzene (0.8 ±0.5 ng m−3), cholesterol (3.0 ± 6.7 ng m−3), stigmastanol (1.4 ± 6.7 ng m−3), and cis-pinonic acid (4.5 ± 0.6 ng m−3) indicate contributions from biomass burning, garbage burning, food cooking, cow-dung burning, and monoterpene secondary organic aerosol, respectively. Drawing on source profiles developed in NAMaSTE, chemical mass balance (CMB) source apportionment modeling was used to estimate contributions to OC from major primary sources including garbage burning (18 ± 5 %), biomass burning (17 ± 10 %) inclusive of open burning and biomass-fueled cooking stoves, and internal-combustion (gasoline and diesel) engines (18 ± 9 %). Model sensitivity tests with newly-developed source profiles indicated contributions from biomass burning within a factor of two of previous estimates, but relatively greater contributions from garbage burning (up to three times), indicating large potential impacts of garbage burning on regional air quality and the need for further evaluation of this source. Contributions of secondary organic carbon (SOC) to PM2.5 OC included those originating from anthropogenic precursors for naphthalene (10 ± 4 %) and methylnaphthalene (0.3 ± 0.1 %) and biogenic precursors for monoterpenes (0.13 ± 0.07 %) and sesquiterpenes (5 ± 2 %). An average of 25 % of the PM2.5 OC was unapportioned, indicating the presence of additional sources (e.g., evaporative and/or industrial emissions such as brick kilns, food cooking, and other types of SOC) or underestimation of the contributions from the identified source types. The source apportionment results indicate that anthropogenic combustion sources (including biomass burning, garbage burning, and fossil-fuel combustion) were the greatest contributors to PM2.5 and, as such, should be considered primary targets for controlling ambient PM pollution.
Jinpei Yan, Jinyoung Joung, Miming Zhang, Federico Bianchi, Yee Jun Tham, Suqing Xu, Qi Lin, Shuhui Zhao, Lei Li, Liqi Chen, 2019
Abstract. The uptake of methanesulfonic acid (MSA) on existing particles is a major route of the particulate MSA formation, however, MSA uptake on different particles is still lack of knowledge. Characteristics of MSA uptake on different aerosol particles were investigated in polynya regions of the Ross Sea, Antarctica. Particulate MSA mass concentrations, as well as aerosol populations and size distributions, were observed simultaneously for the first time to access the uptake of MSA on different particles. The results showed that MSA mass concentration did not always reflect MSA particle population in the marine atmosphere. MSA uptake on aerosol particles increased the particle size and changed aerosol chemical compositions, but did not increase the particle population. The uptake rates of MSA on existing particles were significantly influenced by aerosol chemical properties. The favor uptake of MSA occurred on the sea salt particles, as MSA-Na and MSA-Mg particles were abundant in the Na and Mg particles, accounting for 0.43 ± 0.21 and 0.41 ± 0.20 of the total Na and Mg particles, respectively. However, acidic and hydrophobic particles suppressed the MSA uptake, as MSA-EC and MSA-SO42− accounted only 0.24 ± 0.68 and 0.26 ± 0.47 of the total EC and SO42− particles, respectively. The results extended the knowledge of the formation and environmental behavior of MSA in the marine atmosphere.
Nadja Triesch, Manuela van Pinxteren, Anja Engel, Hartmut Herrmann, 2020
Abstract. This study presents measurements of free amino acids (FAA) in the marine environment to elucidate their transfer from the ocean into the atmosphere to marine aerosol particles and to clouds. FAA were investigated in seawater (underline water (ULW), sea surface microlayer (SML)), in ambient marine size-segregated aerosol particle samples at two heights (ground based at the Cape Verde Atmospheric Observatory (CVAO) and at the Mt. Verde, 744 m height) and in cloud water using concerted measurements. The ∑FAA concentration in the SML varied between 0.13–3.64 µmol L−1, in the ULW between 0.01–1.10 µmol L−1 and a strong enrichment of ∑FAA in the SML (EFSML: 1.1–298.4, average of 57.2) was observed. In the submicron (0.05–1.2 µm) aerosol particles at the CVAO, the composition of FAA was more complex and higher atmospheric concentration of ∑FAA (up to 6.3 ng m−3) compared to the supermicron (1.2–10 µm) aerosol particles (maxima of 0.5 ng m−3) were observed. The total ∑FAA concentration (PM10) was between 1.8–6.8 ng m−3 and tended to increase during the campaign. Averaged ∑FAA concentrations on the aerosol particles at the Mt. Verde were lower (submicron: 1.5 ng m−3, supermicron: 1.2 ng m−3) compared to the CVAO. A similar percentage contribution of ∑FAA to dissolved organic carbon (DOC) in the seawater (up to 7.6&tinsp;%) and to water-soluble organic carbon (WSOC) on the submicron aerosol particles (up to 5.3 %) indicated a related transfer process of FAA and DOC in the marine environment. The FAA were strongly enriched in the submicron aerosol particles (EFaer(∑FAA) 4∙102–3∙104, EFaer(WSOC) 2∙103–1∙104), possibly resulting from film droplet formation. The enrichment in supermicron aerosol particles was several orders of magnitude lower compared to supermicron size range with EFaer(∑FAA) 1∙101–2∙101, EFaer(WSOC) 3∙102–4∙102. A case study showed that several amino acids were transported from the ocean up to cloud level (e.g. aspartic acid, glutamic acid, proline) while other amino acids might not be transferred or quickly degraded (e.g. phenylalanine, tyrosine) or produced (e.g. GABA). The cloud water samples exhibited a similar composition of FAA compared to the SML but a strong variation of the atmospheric concentration of ∑FAA during the campaign (11.2–489.9 ng m−3). FAA in cloud water samples showed a strong enrichment by a factor of 4∙103 compared to the SML. The presence of high concentrations of FAA in general and of biologically produced FAA (aspartic acid) in particular together with the presence of inorganic marine tracers (sodium, methane sulfonic acid) demonstrates the influence of oceanic sources on marine clouds.
Nadja Triesch, Manuela van Pinxteren, Sanja Frka, Christian Stolle, Tobias Spranger, Erik Hans Hoffmann, Xianda Gong, Heike Wex, Detlef Schulz-Bull, Blaženka Gašparović, Hartmut Herrmann, 2020
Abstract. Measurements of lipids as representative species for different lipid classes in the marine environment have been performed to characterize their oceanic sources and their transfer from the ocean into the atmosphere to marine aerosol particles. To this end, a set of lipid classes (hydrocarbons (HC), fatty acid methyl esters (ME), free fatty acids (FFA), alcohols (ALC), 1,3-diacylglycerols (1,3 DG), 1,2-diacylglycerols (1,2 DG), monoacylglycerols (MG), wax esters (WE), triacylglycerols (TG), phospholipids (PP) including phosphatidylglycerols (PG), phosphatidylethanolamine (PE), phosphatidylcholines (PC), glycolipids (GL) including sulfoquinovosyldiacylglycerols (SQDG), monogalactosyl-diacylglycerols (MGDG), digalactosyldiacylglycerols (DGDG) and sterols (ST)) is investigated in both the dissolved and particulate fraction in seawater, differentiated between underlying water (ULW) and the sea surface microlayer (SML), and in ambient submicron aerosol particle samples (PM1) at the Cape Verde Atmospheric Observatory (CVAO) applying concerted measurements. The different lipids are found in all marine compartments but in different compositions. At this point, a certain variability is observed for the concentration of dissolved (∑DLULW: 39.8–128.5 μg L−1, ∑DLSML: 55.7–121.5 μg L−1) and particulate (∑PLULW: 36.4–93.5 μg L−1, ∑PLSML: 61.0–118.1 μg L−1) lipids in seawater of the tropical North Atlantic Ocean along the campaign. Only slight SML enrichments are observed for the lipids with an enrichment factor EFSML of 1.1–1.4 (DL) and 1.0–1.7 (PL). On PM1 aerosol particles, a total lipid concentration between 75.2–219.5 ng m−3 (averaged: 119.9 ng m−3) is measured with high atmospheric concentration of TG (averaged: 21.9 ng m−3) as a potential indicator for freshly emitted sea spray. Besides phytoplankton sources, bacteria influence the lipid concentrations in seawater and on the aerosol particles, so that the phytoplankton tracer (chlorophyll-a) cannot sufficiently explain the lipid abundance. The concentration and enrichment of lipids in the SML is not related to physicochemical properties describing the surface activity. For aerosol, however, the high enrichment of lipids (as a sum) corresponds well with the consideration of their high surface activity, thus the EFaer (enrichment factor on submicron aerosol particles compared to SML) ranges between 9 × 104–7 × 105. Regarding the single lipid groups on the aerosol particles, a weak relation between EFaer and lipophilicity (expressed by the KOW value) was identified, which was absent for the SML. However, overall simple physico-chemical descriptors are not sufficient to fully explain the transfer of lipids. As our findings show that additional processes such as formation and degradation influence the ocean-atmosphere transfer of both OM in general and of lipids in particular, they have to be considered in OM transfer models. Moreover, our data suggest that the extend of enrichment of lipid classes constituents on the aerosol particles might be related to the distribution of the lipid within the bubble-air-water-interface. Lipids, which are preferably arranged within the bubble interface, namely TG and ALC, are transferred to the aerosol particles to the highest extend. Finally, the connection between ice nucleation particles (INP) in seawater, which are active already at higher temperatures (−10 °C to −15 °C), and the lipid classes PE and FFA suggests that lipids formed in the ocean have the potential to contribute to (biogenic) INP activity when transferred to the atmosphere.
Haijie Tong, Fobang Liu, Alexander Filippi, Jake Wilson, Andrea M. Arangio, Yun Zhang, Siyao Yue, Steven Lelieveld, Fangxia Shen, Helmi-Marja K. Keskinen, Jing Li, Haoxuan Chen, Ting Zhang, Thorsten Hoffmann, Pingqing Fu, William H. Brune, Tuukka Petäjä, Markku Kulmala, Maosheng Yao, Thomas Berkemeier, Manabu Shiraiwa, Ulrich Pöschl, 2020
Abstract. Interaction of water with fine particulate matter leads to the formation of reactive species (RS) that may influence the aging, properties, and health effects of atmospheric aerosols. In this study, we explore the RS yields of fine PM from remote forest (Hyytiälä, Finland) and polluted urban air (Mainz, Germany and Beijing, China) and relate these yields to different chemical constituents and reaction mechanisms. Ultrahigh-resolution mass spectrometry was used to characterize organic aerosol composition, electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping technique was used to determine the concentrations •OH, O2•−, and carbon- or oxygen-centered organic radicals, and a fluorometric assay was used to quantify H2O2 concentration. The mass-specific yields of radicals were lower for sampling sites with higher concentration of ambient PM2.5 (particles with a diameter
Claudia Wrozyna, Thomas A. Neubauer, Juliane Meyer, Maria Ines F. Ramos, Werner E. Piller, 2017
Abstract. How environmental change affects a species’ phenotype is crucial not only for taxonomy and biodiversity assessments but also for their application as (paleo-)ecological indicators. Previous investigations addressing the impact of climate and hydrochemical regime on ostracod valve morphology have yielded quite contrasting results. Frequently identified ecological factors influencing carapace shape are salinity, cation and sulphate concentrations and alkalinity. Here, we present a thorough approach integrating data from carapace outline and surface details of the ubiquitous Neotropical cytheroidean ostracod species Cytheridella ilosvayi, as well as several climatic and hydrochemical variables, in order to investigate a potential link between morphology and environmental conditions. A previous study lately demonstrated considerable biogeographical variation in valve morphology among Floridian, Mexican and Brazilian populations of this species. We hypothesize that the climatic differences between the regions it inhabits and associated differences in hydrochemical regimes have influenced valve morphology and eventually led to biogeographically distinctive groups. Generalized least-squares Procrustes Analyses based on outline and structural features were applied to left and right valves of adult females and males. The analyses identified relative carapace length and shape symmetry as most important morphological characteristics representing shape change across all datasets. Two-block partial least-squares analyses and multiple regressions indicate strong relationships between morphological and environmental variables, specifically with temperature seasonality, annual precipitation and chloride and sulphate concentrations. We hypothesize that increased temperature seasonality slowed down growth rates during colder months, potentially triggering the development of shortened valves with well-developed brood pouches. Differences in chloride and sulphate concentrations, related to fluctuations in precipitation, are considered to affect valve development via controlling osmoregulation and carapace calcification. These factors represent hitherto unknown drivers for ostracod ecophenotypy and emphasise that environmental predictors for morphological variability are not consistent across non-marine ostracods.
Noelle A. Held, Eric A. Webb, Matthew M. McIlvin, David A. Hutchins, Natalie R. Cohen, Dawn M. Moran, Korinna Kunde, Maeve C. Lohan, Claire M. Mahaffey, E. Malcolm S. Woodward, Mak A. Saito, 2020
Abstract. Trichodesmium is a globally important marine microbe that provides fixed nitrogen to otherwise N limited ecosystems. In nature, nitrogen fixation is likely regulated by iron or phosphate availability, but the extent and interaction of these controls is unclear. From metaproteomics analyses using established protein biomarkers for iron and phosphate stress, we found that co-stress is the norm rather than the exception for field Trichodesmium colonies. Counter-intuitively, the nitrogenase enzyme was most abundant under co-stress, consistent with the idea that Trichodesmium has a specific physiological state under nutrient co-stress. Organic nitrogen uptake was observed to occur simultaneously with nitrogen fixation. Quantification of the phosphate ABC transporter PstC combined with a cellular model of nutrient uptake suggested that Trichodesmium is confronted by the biophysical limits of membrane space and diffusion rates for iron and phosphate acquisition. Colony formation may benefit nutrient acquisition from particulate and organic nutrient sources, alleviating these pressures. The results indicate that to predict the behavior of Trichodesmium, we must consider multiple nutrients simultaneously across biogeochemical contexts.
France Van Wambeke, Elvira Pulido, Julie Dinasquet, Kahina Djaoudi, Anja Engel, Marc Garel, Sophie Guasco, Sandra Nunige, Vincent Taillandier, Birthe Zäncker, Christian Tamburini, 2020
Abstract. Prokaryotic ectoenzymatic activity, abundance and heterotrophic production were determined in the Mediterranean Sea, within the epipelagic and the upper part of the mesopelagic layers. The Michaelis-Menten kinetics were assessed, using a range of low (0.025 to 1 µM) and high (0.025 to 50 µM) concentrations of fluorogenic substrates. Thus, Km and Vm parameters were determined for both low and high affinity systems for alkaline phosphatase (AP), aminopeptidase (LAP) and β-glucosidase (βGLU). Based on the constant derived from the high AP affinity system, in-situ hydrolysis rates of N-protein contributed of 48 % ± 30 % for the heterotrophic prokaryotic nitrogen demand within epipelagic waters and of 180 % ± 154 % within deeper layers. LAP hydrolysis rate was higher than bacterial N demand only within the deeper layer, and only based on the high affinity system. Although ectoenzymatic hydrolysis contribution to heterotrophic prokaryotic need was high in terms of N, but low in terms of C. Based on a 10 % bacterial growth efficiency, the cumulative hydrolysis rates of C-proteins and C-polysaccharides contributed to a small part of the heterotrophic prokaryotic carbon demand, on average 2.5 % ± 1.3 % in the epipelagic layers. This study notably points out the biases in current and past interpretation of the relative activities differences among the 3 tested enzymes, in regard to the choice of added concentrations of fluorogenic substrates. In particular, enzymatic ratios LAP/βGLU, as well as some trends with depth, were different considering activities resulting from the high or the low affinity system.
Sebastian Zeppenfeld, Manuela van Pinxteren, Anja Engel, Hartmut Herrmann, 2020
Abstract. An optimized method is presented to determine free (DFCHO) and combined monosaccharides (CCHO) in saline matrices, such as oceanic seawater, Arctic ice core samples or brine using a combination between desalination with electro-dialysis and high performance anion exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD). Free neutral sugars, such as glucose and galactose, were found with 95–98 % recovery rates. Free amino sugars and uronic acids were strongly depleted during electro-dialysis at pH = 8, but an adjustment of the pH could result in higher recoveries (58–59 % for amino sugars at pH = 11; 45–49 % for uronic acids at pH = 1.5). The applicability of this method for the analysis of CCHO was evaluated with standard solution and real seawater samples compared with another established desalination method using membrane dialysis. DFCHO in real field samples from different regions on earth ranged between 11–118 nM and CCHO between 260–1410 nM. This novel method potentially contributes to a better understanding of biogeochemical processes in the oceans and sea-air transfer processes of organic matter into the atmosphere during further research studies.
Guitao Shi, Hongmei Ma, Zhengyi Hu, Zhenlou Chen, Chunlei An, Su Jiang, Yuansheng Li, Tianming Ma, Jinhai Yu, Danhe Wang, Siyu Lu, Bo Sun, Meredith G. Hastings, 2020
Abstract. There is a large variability in environmental conditions across the Antarctic ice sheet, and it is of significance to investigate the snow chemistry at as many locations as possible and over time, given that the ice sheet itself, and precipitation and deposition patterns and trends are changing. The China inland Antarctic traverse from coastal Zhongshan Station to the ice sheet summit (Dome A) covers a variety of environments, allowing for a vast collection of snow chemistry conditions across East Antarctica. Surface snow and snow pit samples were collected on this traverse during five campaigns, to comprehensively investigate the spatial and temporal variations in chemical ions (Cl−, NO3−, SO42−, Na+, NH4+, K+, Mg2+, and Ca2+) and the related controlling factors. Results show that spatial patterns of ions in surface snow are consistent among the five campaigns, with Cl−, Na+, K+, and Mg2+ decreasing rapidly with distance from the coast and NO3− showing an opposite pattern. No clear spatial trends in SO42−, NH4+ and Ca2+ were found. In the interior areas, an enrichment of Cl− versus Na+ with respect to seawater composition is ubiquitous as a result of the deposition of HCl, which can account for up to ~40 % of the total Cl− budget, while enriched K+ and Mg2+ are associated with terrestrial particle mass. Ca2+ and SO42− in surface snow are significantly enriched relative to Na+, related to terrestrial dust inputs and marine biogenic emissions, respectively. Snow NH4+ is mainly associated with marine biological activities, with higher concentrations in summer than in winter. On the coast, parts of the winter snow are characterized with a depletion of SO42− versus Na+, and a significant negative correlation between nssSO42− and Na+ was found, suggesting that sea salts originated from the sea ice. In the interior areas, the negative nssSO42− signal in winter snow resulted from inputs of sea salts being completely swamped by the contribution of marine biogenic emissions. Ternary plots of Cl−, Na+, and SO42− suggest that sea salt modification is generally negligible on the coast, while the degree of modification processes to sea salts is high in the interior areas, especially during the summertime. Ion flux assessment suggests an efficient transport of nssSO42− to at least as far inland as the ~2800 m contour line. The interannual variations in ion concentrations in surface snow on the traverse are likely linked to the changes in the Southern Indian Ocean low (SIOL) from year to year, and the deepening of the SIOL in summer tends to promote the transport of marine aerosols to Princess Elizabeth Land.
Barry Shaw, Carla L. Burrell, Darrell Green, Ana Navarro-Martinez, Daniel Scott, Anna Daroszewska, Rob van ’t Hof, Lynn Smith, Frank Hargrave, Sharad Mistry, Andrew Bottrill, Benedikt M. Kessler, Roman Fischer, Archana Singh, Tamas Dalmay, William D. Fraser, Kirstin Henneberger, Turi King, Silvia Gonzalez, Robert Layfield, Proceedings of the National Academy of Sciences, 116, 10463-10472 (21), 2019
Significance We identify an ancient and atypical form of Paget’s disease of bone (PDB) in a collection of medieval skeletons exhibiting unusually extensive pathological changes, high disease prevalence, and low age-at-death estimations. Proteomic analysis of ancient bone-preserved proteins combined with analysis of small RNAs supports a retrospective diagnosis of PDB. Remains affected by other skeletal disorders may therefore hold a chemical memory amenable to similar molecular interrogation. Abnormalities in a contemporary PDB-linked protein detected in ancient tooth samples indicate that dentition may represent an unexplored storehouse for the study of skeletal disorders. Our work provides insights into the natural history of PDB and prompts a similar revaluation of other archaeological collections.
Nico J. Claassens, Giovanni Scarinci, Axel Fischer, Avi I. Flamholz, William Newell, Stefan Frielingsdorf, Oliver Lenz, Arren Bar-Even, Proceedings of the National Academy of Sciences, 117, 22452-22461 (36), 2020
Significance The Calvin cycle is the most important carbon fixation pathway in the biosphere. However, its carboxylating enzyme Rubisco also accepts oxygen, thus producing 2-phosphoglycolate. Phosphoglycolate salvage pathways were extensively studied in photoautotrophs but remain uncharacterized in chemolithoautotrophs using the Calvin cycle. Here, we study phosphoglycolate salvage in the chemolithoautotrophic model bacterium Cupriavidus necator H16. We demonstrate that this bacterium mainly reassimilates 2-phosphoglycolate via the glycerate pathway. Upon disruption of this pathway, a secondary route, which we term the malate cycle, supports photorespiration by completely oxidizing 2-phosphoglycolate to CO 2 . While the malate cycle was not previously known to metabolize 2-phosphoglycolate in nature, a bioinformatic analysis suggests that it may support phosphoglycolate salvage in diverse chemoautotrophic bacteria.
Narin Kirikyali, Jonathan Wood, Ian F Connerton, AMB Express, 4, 2014
Abstract β-xylosidases catalyse the hydrolysis of short chain xylooligosaccharides from their non-reducing ends into xylose. In this study we report the heterologous expression of Aspergillus oryzae β-xylosidase (XylA) in Pichia pastoris under the control of the glyceraldehyde-3-phosphate dehydrogenase promoter. The recombinant enzyme was optimally active at 55°C and pH 4.5 with Km and Vmax values of 1.0 mM and 250 μmol min−1 mg−1 respectively against 4-nitrophenyl β-xylopyranoside. Xylose was a competitive inhibitor with a Ki of 2.72 mM, whereas fructose was an uncompetitive inhibitor reducing substrate binding affinity (Km) and conversion efficiency (Vmax). The enzyme was characterised to be an exo-cutting enzyme releasing xylose from the non-reducing ends of β-1,4 linked xylooligosaccharides (X2, X3 and X4). Catalytic conversion of X2, X3 and X4 decreased (Vmax and kcat) with increasing chain length.
Lixi Cai, Yunmeng Chu, Xin Liu, Yue Qiu, Zhongqi Ge, Guangya Zhang, 2019
Abstract Background: Exploring a simple and versatile technique for direct immobilization of target enzymes from cell lysate without prior purification is urgently needed. Thus, a novel all-in-one strategy for purification and immobilization of β-1, 3-xylanase was proposed, the target enzymes were covalently immobilized on silica nanoparticles via ELP-based biomimetic silicification and SpyTag/SpyCatcher spontaneous reaction. Thus, the functional carriers that did not require the time-consuming surface modification step were quickly and efficiently prepared. These carriers could specifically immobilize the SpyTag-fused target enzymes from the cell lysate without pre-purification. Results: The ELPs-SpyCatcher hardly leaked from the carriers (0.5%), and the immobilization yield of enzyme was up to 96%. Immobilized enzyme retained 85.6% of the initial activity and showed 88.6% of the activity recovery. Compared with free ones, the immobilized β-1, 3-xylanase showed improved thermal stability, elevated storage stability and good pH tolerance. It also retained more than 70.6% of initial activity after12 reaction cycles, demonstrating its excellent reusability. Conclusions: The results clearly highlighted the effectiveness of the novel enzyme immobilization method proposed here due to the improvement of overall performance of immobilized enzyme in respect to free form for the hydrolysis of macromolecular substrates. Thus, it may have great potential in the conversion of algae biomass as well as other related fields.
Tendani E. Sebola, Nkemdinma C. Uche-Okereafor, Lukhanyo Mekuto, Maya Mellisa Makatini, Ezekiel Green, Vuyo Mavumengwana, International Journal of Microbiology, 2020, 1-15, 2020
This study isolated and identified endophytic bacteria from the leaves of Crinum macowanii and investigated the potential of the bacterial endophyte extracts as antibacterial and anticancer agents and their subsequent secondary metabolites. Ethyl acetate extracts from the endophytes and the leaves (methanol: dichloromethane (1 : 1)) were used for antibacterial activity against selected pathogenic bacterial strains by using the broth microdilution method. The anticancer activity against the U87MG glioblastoma and A549 lung carcinoma cells was determined by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Bacterial endophytes that were successfully isolated from C. macowanii leaves include Raoultella ornithinolytica, Acinetobacter guillouiae, Pseudomonas sp., Pseudomonas palleroniana, Pseudomonas putida, Bacillus safensis, Enterobacter asburiae, Pseudomonas cichorii, and Arthrobacter pascens. Pseudomonas cichorii exhibited broad antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria while Arthrobacter pascens displayed the least MIC of 0.0625 mg/mL. Bacillus safensis crude extracts were the only sample that showed notable cell reduction of 50% against A549 lung carcinoma cells at a concentration of 100 μg/mL. Metabolite profiling of Bacillus safensis, Pseudomonas cichorii, and Arthrobacter pascens crude extracts revealed the presence of known antibacterial and/or anticancer agents such as lycorine (1), angustine (2), crinamidine (3), vasicinol (4), and powelline. It can be concluded that the crude bacterial endophyte extracts obtained from C. macowanii leaves can biosynthesize bioactive compounds and can be bioprospected for medical application into antibacterial and anticancer agents.
Fuchao Chen, Baoxia Fang, Peng Li, Sicen Wang, International Journal of Analytical Chemistry, 2021, 1-9, 2021
In this study, a new strategy for the simultaneous quantization of five serotonin 5-hydroxytryptamine receptor antagonists—ondansetron, azasetron, ramosetron, granisetron, and tropisetron—either in infusion samples or in injection dosage form was first established based on high-performance liquid chromatography combined with a quantitative analysis of multiple components by a single marker. The quantitative analysis of multicomponents by a single marker method was conducted with ondansetron as an internal reference substance and performed using relative retention time and ultraviolet spectral similarity as the double indicator. The quantitative analysis of the 5-HT3 receptor antagonists was calculated and investigated based on the relative correction factors. Chromatographic separation was achieved using a C18 column (150 mm × 4.6 mm, 5.0 μm), and the mobile phase was composed of acetonitrile-0.05 mol·L−1 potassium dihydrogen phosphate (pH 4.0) (25 : 75) at a flow rate of 1.0 mL·min−1 and detection wavelengths of 307 nm (ondansetron, azasetron, ramosetron), 302 nm (granisetron), and 285 nm (tropisetron). In addition, the accuracy of the quantitative analysis of multicomponents by a single marker method was compared with an external standard method, and no significant difference was observed between the two methods. The established method is rapid, is easy, and does not require many reference substances, and it can been successfully applied as part of the quality control of the five 5-HT3 receptor antagonists in their injection dosage form and infusion sample drugs in hospitals.
Liuyi Yang, Meng Wang, Yuan Zhou, Jing Yang, Chaoyang Ye, Chen Wang, Evidence-Based Complementary and Alternative Medicine, 2021, 1-13, 2021
Background. Renal interstitial fibrosis is a pathological manifestation of progression of chronic kidney disease induced by various factors. Shen Shuai II Recipe (SSR) has been used in clinical practice for more than 20 years, and clinical studies have confirmed that SSR significantly improves the renal function of patients with chronic kidney disease. However, the specific mechanisms underlying its efficacy require further research. This study aims to explore the influencing factors of renal interstitial fibrosis in the context of hypoxia via the IL-1β/c-Myc pathway and the potential molecular mechanisms of SSR intervention in vivo and in vitro. Methods. A rat model of chronic renal failure was developed by performing 5/6 (ablation/infarction, A/I) surgery on randomly selected, male Sprague Dawley rats. Thirty-six successfully modeled rats were randomly divided into three groups: 5/6 (A/I), 5/6 (A/I) + SSR, and 5/6 (A/I) + losartan. Another 12 rats were used as the sham group. After 8 weeks of the corresponding intervention, renal function, liver function, and protein expression of renal-fibrosis-related factors, HIF-1α, IL-1β, and c-Myc, were detected. In vitro analysis was performed using hypoxia-induced rat renal tubular epithelial cells (NRK-52E) and IL-1β-stimulated rat renal interstitial fibroblasts (NRK-49F). IL-1β concentration in the culture medium and IL-1β protein expression in hypoxic NRK-52E treated with different concentrations of SSR were investigated. Furthermore, we also studied the changes in protein expression of c-Myc and fibrosis-related factors after c-Myc gene silencing in IL-1β-stimulated NRK-49F treated with SSR. Results. Shen Shuai II Recipe significantly reduced RIF and downregulated the expression of HIF-1α, c-Myc, and IL-1β proteins in 5/6 (A/I) rats with chronic renal failure. It also inhibited IL-1β secretion from NRK-52E induced by hypoxia, which in turn inhibited fibroblast activation mediated by the IL-1β/c-Myc pathway, and finally reduced the overproduction of the extracellular matrix. Conclusion. The renoprotective effects of SSR in rats with chronic renal failure may be related to its inhibition of hypoxia via the IL-1β/c-Myc pathway. Thus, SSR is a potentially effective drug for delaying the progression of renal interstitial fibrosis.
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