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Mass Recovery (mass + recovery)

Distribution by Scientific Domains
Life Sciences50%

Selected Abstracts

Runoff transport of faecal coliforms and phosphorus released from manure in grass buffer conditions

LETTERS IN APPLIED MICROBIOLOGY, Issue 3 2005
W.L. Stout
Abstract Aims:, To test the hypothesis that faecal coliform (FC) and phosphorus (P) are transported similarly in surface runoff through the vegetative filter strip after being released from land-applied manure. Methods and Results:, The Hagerstown soil was packed into boxes that were 10 cm deep, 30 cm wide and 100, 200 or 300 cm long. Grass was grown in boxes prior experiments. Same-length boxes were placed under rainfall simulator and tilted to have with either 2% or 4% slopes. Dairy manure was broadcast on the upper 30-cm section. Rainfall was simulated and runoff samples were collected and analysed for Cl, FC and total phosphorus (TP). Mass recovery, the concentration decrease rate k, and the ratio FC : TP showed that there was a consistent relationship between FC and TP in runoff. Conclusion:, The FC and TP transport through simulated vegetated buffer strips were highly correlated. Significance and Impact of the Study:, As a knowledge base on the effect of the environmental parameters on P transport in vegetated buffer strips is substantially larger than for manure-borne bacteria, the observed similarity may enhance ability to assess the efficiency of the vegetated buffer strips in retention of FC currently used as indicator organisms for manure-borne pathogens. [source]

Improved automated extraction and separation procedure for soil lipid analyses

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2004
G. L. B. Wiesenberg
Summary Analysis of soil lipids may contribute to an improved understanding of atmosphere to soil carbon fluxes, soil organic matter source differentiation and pollutant accumulation. Soil lipids, mostly originating from plants and microorganisms, have traditionally been analysed by non-automated extraction and separation methods, which produce several lipid fractions, operationally defined by polarity. Here we present a combination of fast, automated and reproducible techniques, adopted from organic geochemical studies, for preparative separation of individual soil lipid fractions with increasing polarity. These techniques involve commercially available instruments, including accelerated solvent extraction and a two-step automated medium-pressure liquid chromatography procedure. The method yields eight lipid fractions consisting of five fractions fully amenable to gas chromatography/mass spectrometry (GC/MS) (aliphatic hydrocarbons, aromatic hydrocarbons, ketones, alcohols, carboxylic acids), and three fractions of highly polar or high molecular weight compounds (bases, very long-chain wax esters (C40+), high polarity compounds) that were not measurable with GC/MS under standard conditions. We tested the method on five agricultural soils. Results show that (i) mass recoveries for the individual fractions are reproducible, (ii) within individual fractions compound distribution patterns are reproducible, as demonstrated for alkanes and carboxylic acids, and (iii) individual fractions represent distinct and clean compound classes, free of interfering substances detectable by GC/MS. Thus, automated separation can be a fast, effective and reproducible procedure for fractionation of complex mixtures of soil lipids into clean compound classes, directly suitable for a variety of molecular (e.g. GC/MS) and isotopic characterizations (e.g. gas chromatography coupled with isotope ratio monitoring mass spectrometry or accelerator mass spectrometry). [source]

Role of nitric oxide synthesized by nitric oxide synthase 2 in liver regeneration

LIVER INTERNATIONAL, Issue 6 2008
Takafumi Kumamoto
Abstract Background/Aims: Nitric oxide synthase 2 (NOS2) is expressed during liver regeneration after a partial hepatectomy (PHx); NOS2 subsequently synthesizes nitric oxide (NO). However, the role of NOS2-synthesized NO in post-PHx liver regeneration remains unclear. We investigated the role of NOS2-synthesized NO in liver regeneration. Methods: NOS2 knockout (NOS2 -KO) mice and control mice were subjected to PHx. Liver mass recovery and serum alanine aminotransferase (ALT) levels were then evaluated. The expressions of Ki-67 and single-strand DNA were also evaluated in remnant liver specimens. Differences in the gene expression profiles of the two groups of remnant liver specimens were analysed using a microarray and were validated using a reverse transcription-polymerase chain reaction (RT-PCR). Results: In NOS2 -KO mice, liver regeneration was delayed and apoptosis and serum ALT levels were higher than the levels in the control mice. A microarray study and RT-PCR revealed that heat shock protein 70 family (HSP70 family), haeme oxygenase 1 (Hmox1), neuropilin 1 (Nrp1) and epidermal growth factor receptor (EGFR) were downregulated in NOS2 -KO mice. Conclusions: NOS2-synthesized NO may improve hepatocyte viability through the induction of the HSP70 family and Hmox1 and may sensitize the remnant liver to growth factors through the induction of Nrp1 and EGFR post-PHx. [source]

High Recovery Refolding of rhG-CSF from Escherichia coli, Using Urea Gradient Size Exclusion Chromatography

BIOTECHNOLOGY PROGRESS, Issue 1 2008
Chaozhan Wang
Protein folding liquid chromatography (PFLC) is a powerful tool for simultaneous refolding and purification of recombinant proteins in inclusion bodies. Urea gradient size exclusion chromatography (SEC) is a recently developed protein refolding method based on the SEC refolding principle. In the presented work, recombinant human granulocyte colony-stimulating factor (rhG-CSF) expressed in Escheriachia coli ( E. coli) in the form of inclusion bodies was refolded with high yields by this method. Denatured/reduced rhG-CSF in 8.0 mol·L -1 urea was directly injected into a Superdex 75 column, and with the running of the linear urea concentration program, urea concentration in the mobile phase and around the denatured rhG-CSF molecules was decreased linearly, and the denatured rhG-CSF was gradually refolded into its native state. Aggregates were greatly suppressed and rhG-CSF was also partially purified during the refolding process. Effects of the length and the final urea concentration of the urea gradient on the refolding yield of rhG-CSF by using urea gradient SEC were investigated respectively. Compared with dilution refolding and normal SEC with a fixed urea concentration in the mobile phase, urea gradient SEC was more efficient for rhG-CSF refolding&‐;in terms of specific bioactivity and mass recovery, the denatured rhG-CSF could be refolded at a larger loading volume, and the aggregates could be suppressed more efficiently. When 500 ,L of solubilized and denatured rhG-CSF in 8.0 mol·L -1 urea solution with a total protein concentration of 2.3 mg·mL -1 was loaded onto the SEC column, rhG-CSF with a specific bioactivity of 1.0 × 108 IU·mg -1 was obtained, and the mass recovery was 46.1%. [source]