Acid/extraction treatment of bivalves for organotin speciation

1997 ◽  
Vol 357 (7) ◽  
pp. 1007-1009 ◽  
Author(s):  
J. L. Gomez-Ariza ◽  
E. Morales ◽  
I. Giraldez ◽  
R. Beltran ◽  
J. A. Pozas Escobar
Author(s):  
G. L. Brown

Bismuth (Bi) stains nucleoproteins (NPs) by interacting with available amino and primary phosphate groups. These two staining mechanisms are distinguishable by glutaraldehyde crosslinking (Fig. 1,2).Isolated mouse liver nuclei, extracted with salt and acid solutions, fixed in either formaldehyde (form.) or gl utaraldehyde (glut.) and stained with Bi, were viewed to determine the effect of the extractions on Bi stainina. Solubilized NPs were analyzed by SDS-polyacrylamide gel electrophoresis.Extraction with 0.14 M salt does not change the Bi staining characteristics (Fig. 3). 0.34 M salt reduces nucleolar (Nu) staining but has no effect on interchromatinic (IC) staining (Fig. 4). Proteins responsible for Nu and glut.- insensitive IC staining are removed when nuclei are extracted with 0.6 M salt (Fig. 5, 6). Low salt and acid extraction prevents Bi-Nu staining but has no effect on IC staining (Fig. 7). When nuclei are extracted with 0.6 M salt followed by low salt and acid, all Bi-staining components are removed (Fig. 8).


2018 ◽  
Vol 19 (3) ◽  
pp. 88-89
Author(s):  
Benjamin J Goldstein ◽  
Analia Veitz-Keenan

2008 ◽  
Vol 15 (4) ◽  
pp. 339-343 ◽  
Author(s):  
Hui Li ◽  
Zhaohui Zhang ◽  
Siping Tang ◽  
Yanan Li ◽  
Yongkang Zhang
Keyword(s):  

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 918
Author(s):  
Nóra Emilia Nagybákay ◽  
Michail Syrpas ◽  
Vaiva Vilimaitė ◽  
Laura Tamkutė ◽  
Audrius Pukalskas ◽  
...  

The article presents the optimization of supercritical CO2 extraction (SFE-CO2) parameters using response surface methodology (RSM) with central composite design (CCD) in order to produce single variety hop (cv. Ella) extracts with high yield and strong in vitro antioxidant properties. Optimized SFE-CO2 (37 MPa, 43 °C, 80 min) yielded 26.3 g/100 g pellets of lipophilic fraction. This extract was rich in biologically active α- and β-bitter acids (522.8 and 345.0 mg/g extract, respectively), and exerted 1481 mg TE/g extract in vitro oxygen radical absorbance capacity (ORAC). Up to ~3-fold higher extraction yield, antioxidant recovery (389.8 mg TE/g pellets) and exhaustive bitter acid extraction (228.4 mg/g pellets) were achieved under the significantly shorter time compared to the commercially used one-stage SFE-CO2 at 10–15 MPa and 40 °C. Total carotenoid and chlorophyll content was negligible, amounting to <0.04% of the total extract mass. Fruity, herbal, spicy and woody odor of extracts could be attributed to the major identified volatiles, namely β-pinene, β-myrcene, β-humulene, α-humulene, α-selinene and methyl-4-decenoate. Rich in valuable bioactive constituents and flavor compounds, cv. Ella hop SFE-CO2 extracts could find multipurpose applications in food, pharmaceutical, nutraceutical and cosmetics industries.


Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1091
Author(s):  
Ali A. Rabaan ◽  
Raghavendra Tirupathi ◽  
Anupam A Sule ◽  
Jehad Aldali ◽  
Abbas Al Mutair ◽  
...  

Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several factors and variables can cause a false-negative test. In this context, cycle threshold (Ct) values are being utilized to diagnose or predict SARS-CoV-2 infection. This practice has a significant clinical utility as Ct values can be correlated with the viral load. In addition, Ct values have a strong correlation with multiple haematological and biochemical markers. However, it is essential to consider that Ct values might be affected by pre-analytic, analytic, and post-analytical variables such as collection technique, specimen type, sampling time, viral kinetics, transport and storage conditions, nucleic acid extraction, viral RNA load, primer designing, real-time PCR efficiency, and Ct value determination method. Therefore, understanding the interpretation of Ct values and other influential factors could play a crucial role in interpreting viral load and disease severity. In several clinical studies consisting of small or large sample sizes, several discrepancies exist regarding a significant positive correlation between the Ct value and disease severity in COVID-19. In this context, a revised review of the literature has been conducted to fill the knowledge gaps regarding the correlations between Ct values and severity/fatality rates of patients with COVID-19. Various databases such as PubMed, Science Direct, Medline, Scopus, and Google Scholar were searched up to April 2021 by using keywords including “RT-PCR or viral load”, “SARS-CoV-2 and RT-PCR”, “Ct value and viral load”, “Ct value or COVID-19”. Research articles were extracted and selected independently by the authors and included in the present review based on their relevance to the study. The current narrative review explores the correlation of Ct values with mortality, disease progression, severity, and infectivity. We also discuss the factors that can affect these values, such as collection technique, type of swab, sampling method, etc.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 188
Author(s):  
Tanja Hoffmann ◽  
Andreas Hahn ◽  
Jaco J. Verweij ◽  
Gérard Leboulle ◽  
Olfert Landt ◽  
...  

This study aimed to assess standard and harsher nucleic acid extraction schemes for diagnostic helminth real-time PCR approaches from stool samples. A standard procedure for nucleic acid extraction from stool and a procedure including bead-beating as well as proteinase K digestion were compared with group-, genus-, and species-specific real-time PCR assays targeting helminths and nonhelminth pathogens in human stool samples. From 25 different in-house and commercial helminth real-time PCR assays applied to 77 stool samples comprising 67 historic samples and 10 external quality assessment scheme samples positively tested for helminths, higher numbers of positive test results were observed after bead-beating-based nucleic acid extraction for 5/25 (20%) real-time PCR assays irrespective of specificity issues. Lower cycle threshold values were observed for one real-time PCR assay after the standard extraction scheme, and for four assays after the bead-beating-based scheme. Agreement between real-time PCR results after both nucleic acid extraction strategies according to Cohen’s kappa ranged from poor to almost perfect for the different assays. Varying agreement was observed in eight nonhelminth real-time PCR assays applied to 67 historic stool samples. The study indicates highly variable effects of harsh nucleic acid extraction approaches depending on the real-time PCR assay used.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 390
Author(s):  
Ramiro Recena ◽  
Ana M. García-López ◽  
Antonio Delgado

Zinc (Zn) deficiency constrains crop yield and quality, but soil factors influencing Zn availability to plants and reactions of applied Zn fertilizer are not fully understood. This work is aimed at studying Zn availability in soil and the use efficiency of Zn fertilizers by plants as affected by soil properties and particularly by soil available P. We performed a pot experiment involving four consecutive crops fertilized with Zn sulfate using 36 soils. The cumulative Zn uptake and dry matter yield in the four crops increased with increased initial diethylenetriamine pentaacetic acid extraction of Zn (DTPA-Zn) (R2 = 0.75 and R2 = 0.61; p < 0.001). The initial DTPA-Zn increased with increased Olsen P (R2 = 0.41; p < 0.001) and with increased ratio of Fe in poorly crystalline to Fe in crystalline oxides (R2 = 0.58; p < 0.001). DTPA-Zn decreased with increased cumulative Zn uptake, but not in soils with DTPA-Zn < 0.5 mg kg−1. Overall, the available Zn is more relevant in explaining Zn uptake by plants than applied Zn sulfate. However, in Zn-deficient soils, Zn fertilizer explained most of the Zn uptake by crops. Poorly crystalline Fe oxides and P availability exerted a positive role on Zn availability to plants in soil.


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