Acid Extraction Procedure Research Articles

Spleen Swabs for Sensitive and High-Throughput Detection of African Swine Fever Virus by Real-Time PCR.

African swine fever (ASF) continues to spread in Africa, Europe, Asia and the island of Hispaniola, increasing the need to develop more streamlined and highly efficient surveillance and diagnostic capabilities. One way to achieve this is by further optimization of already established standard operating procedures to remove bottlenecks for high-throughput screening. Real-time polymerase chain reaction (real-time PCR) is the most sensitive and specific assay available for the early detection of the ASF virus (ASFV) genome, but it requires high-quality nucleic acid extracted from the samples. Whole blood from live pigs and spleen tissue from dead pigs are the preferred samples for real-time PCR. Whole blood can be used as is in nucleic acid extractions, but spleen tissues require an additional homogenization step. In this study, we compared the homogenates and swabs prepared from 52 spleen samples collected from pigs experimentally inoculated with highly and moderately virulent ASF virus strains. The results show that not only are the spleen swabs more sensitive when executed with a low-cell-count nucleic acid extraction procedure followed by real-time PCR assays but they also increase the ability to isolate ASFV from positive spleen samples. Swabbing is a convenient, simpler and less time-consuming alternative to tissue homogenization. Hence, we recommend spleen swabs over tissue homogenates for high-throughput detection of ASFV by real-time PCR.

Geochemical base for As, Co, Cu, Ni, P, Pb, S, V and Zn in road dust collected in areas of oil industry activity in the Metropolitan Region of Salvador, Bahia, Brazil

Road dust collection was carried out in Salvador and some municipalities in the Metropolitan Region of Salvador (MRS), such as Simões Filho, Candeias, Madre de Deus and São Francisco do Conde, situated within an area of oil activity. In the chemical-physical characterisation of the road dust collected, the average fractions of coarse sand (17.44 %), medium (27.15 %), fine (32.63 %) and very fine (15.54 %) were found in the 17 samples collected. The samples underwent an acid extraction procedure in a closed digester block, with the mixture HCl + HNO3 + H2O2. The extract was analysed and concentrations of Al, As, Co, Cu, Fe, Ni, Pb, P, Sb, V and Zn were determined. Linear regression analysis was applied to the concentrations of As, Co, Cu, Ni, Pb, P, V and Zn, generating the equations of the straight lines, which served as a geochemical baseline for the region of road dust samples. For the enrichment factor (EF), most chemical elements showed values lower than < 1 at the collection points, except for Cu, Mn, and P (10 < EF < 25) and for Co, Cu, P and Ni (5 < EF < 10), in the regions of Candeias and Simões Filho. On the other hand, the geoaccumulation index (Igeo) of most points were evaluated as uncontaminated (class 0) and moderate or uncontaminated (class 1) for Igeo, except for P (class 4) and Mn (class 5). Principal component analysis (PCA) showed accumulated total variance corresponding to 76.45 %. For the hierarchical cluster analysis (HCA), the results agree with those found in the PCA. Points P3 (Candeias) and P16 (Simões Filho) were the points that showed less dissimilarity with the other points analysed, indicating possible enrichment of the chemical elements found at these points, confirmed by the EF values.

CHARACTERIZATION AND PHARMACEUTICAL EVALUATION OF DAUCUS CAROTA PECTIN AS A SUSPENDING AGENT IN ORAL DOSAGE FORMS

Background: Suspensions are equilibrated two-phased thermodynamically unstable systems increasingly used in the stability and bioavailability enhancement of a myriad of drug substances. Biodegradable, biocompatible and cost-effective biopolymers such as pectin are becoming popular alternative suspending agents to decrease sedimentation and ensure uniformity and accuracy in drug dosing. Nevertheless, limited commercial pectin sources with ideal gelling properties necessitate the search for novel sources such as carrots, a versatile vegetable. Objectives: The study therefore centred on the characterization and pharmaceutical evaluation of the suspending qualities of Daucus carota (carrot) pectin acquired from the conventional acid extraction procedure. Methodology: Fresh carrots were acquired, authenticated and processed before pectin extraction. The pectin extracted was characterized and evaluated for phytochemical properties such as proximate composition and degree of esterification. Different concentrations (1% and 2%) of carrot pectin and acacia gum (as a standard) were utilized in formulating paracetamol suspensions as suspending agents. Results: The pectin yield was 11.6% and contained glycosides, tannins, saponins, and phenols. FTIR analysis identified all the essential pectin functional groups while other characterization parameters showed quality high methoxyl pectin. Carrot pectin suspensions demonstrated significantly (P &lt; 0.01) lower re-dispersibility and sedimentation rate when compared to acacia. The flow rate and sedimentation volumes were however non-significantly different. Conclusion: The characterization and suspending properties of carrot pectin have been successfully evaluated. Ultimately, acacia gum can be substituted with carrot pectin as a suspending agent.

A fast, low-cost, robust and high-throughput method for viral nucleic acid isolation based on NAxtra magnetic nanoparticles

The year of 2020 was profoundly marked by a global pandemic caused by a strain of coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19). To control disease spread, a key strategy adopted by many countries was the regular testing of individuals for infection. This led to the rapid development of diagnostic testing technologies. In Norway, within a week, our group developed a test kit to quickly isolate viral RNA and safely detect SARS-CoV-2 infection with sensitivity comparable to available kits. Herein, the procedure employed for the detection of SARS-CoV-2 in swab samples from patients using the NTNU-COVID-19 test kit is described in detail. This procedure, based on NAxtra magnetic nanoparticles and an optimized nucleic acid extraction procedure, is robust, reliable, and straightforward, providing high-quality nucleic acids within 14 min. The NAxtra protocol is adaptable and was further validated for extraction of DNA and RNA from other types of viruses. A comparison of the protocol on different liquid handling systems is also presented. Due to the simplicity and low cost of this method, implementation of this technology to diagnose virus infections on a clinical setting would benefit health care systems, promoting sustainability.

Evaluation of amino acid profile by targeted metabolomics in the eukaryotic model under exposure of benzo[a]pyrene as the exclusive stressor

Amino acids (AAs) are a class of important metabolites in metabolomics methodology that investigates metabolite changes in a cell, tissue, or organism for early diagnosis of diseases. Benzo[a]pyrene (BaP) is considered a priority contaminant by different environmental control agencies because it is a proven carcinogenic compound for humans. Therefore, it is important to evaluate the BaP interference in the metabolism of amino acids. In this work, a new amino acid extraction procedure (derivatized with propyl chloroformate/propanol) using functionalized magnetic carbon nanotubes was developed and optimized. A hybrid nanotube was used followed by desorption without heating, and excellent extraction of analytes was obtained. After exposure of Saccharomyces cerevisiae, the BaP concentration of 25.0 μmol L−1 caused changes in cell viability, indicating metabolic changes. A fast and efficient GC/MS method using a Phenomenex ZB-AAA column was optimized, enabling the determination of 16 AAs in yeasts exposed or not to BaP. A comparison of AA concentrations obtained in the two experimental groups showed that glycine (Gly), serine (Ser), phenylalanine (Phe), proline (Pro), asparagine (Asn), aspartic acid (Asp), glutamic acid (Glu), tyrosine (Tyr), and leucine (Leu) statistically differentiated, after subsequent application of ANOVA with Bonferroni post-hoc test, with a confidence level of 95%. This amino acid pathway analysis confirmed previous studies that revealed the potential of these AAs as toxicity biomarker candidates.

Ultra-sensitive, rapid detection of dried bloodstains by surface enhanced Raman scattering on Ag substrates

A simple water extraction and transfer procedure is found to result in reproducible and highly sensitive 785 nm excited SERS spectra of 24 h dried bloodstains on Ag nanoparticle substrates. This protocol allows confirmatory detection and identification of dried stains of blood that have been diluted by up to 105 in water on Ag substrates. While previous SERS results demonstrated similar performance on Au substrates when a 50% acetic acid extraction and transfer procedure was used, the water/Ag methodology avoids any potential DNA damage when the sample size is extremely small (≤∼1 μL) due to low pH exposure. The water only procedure is not effective on Au SERS substrates. This metal substrate difference results from the efficient red blood cell lysis and hemoglobin denaturation effects of the Ag nanoparticle surfaces as compare to that of Au nanoparticles. Consequently, the 50% acetic acid exposure is required for the acquisition of 785 nm SERS spectra of dried bloodstains on Au substrates.

Impact of nucleic acid extraction procedures on human papillomavirus (HPV) detection and genotyping.

Human papillomavirus (HPV) infections are often asymptomatic, but some of the >200 HPV genotypes confer a high risk for precancerous cervical lesions and cervical cancer. Current clinical management of HPV infections relies on reliable nucleic acid testing detection and genotyping. We prospectively compared nucleic acid extraction without and with prior centrifugation enrichment for detecting and genotyping HPV in cervical swabs with atypical squamous or glandular cells. Consecutive swabs were analyzed from 45 patients with atypical squamous or glandular cells. Nucleic acids were extracted in parallel using three procedures, Abbott-M2000, Roche-MagNA-Pure-96 Large-Volume Kit without (Roche-MP-large) and with prior centrifugation (Roche-MP-large/spin) and tested using Seegene-Anyplex-II HPV28. In total, 54 HPV-genotypes were detected in 45 samples, 51 by Roche-MP-large/spin, 48 by Abbott-M2000 and 42 by Roche-MP-large. The overall concordance was 80% for detecting any HPV and 74% for specific HPV-genotypes. Roche-MP-large/spin and Abbott-M2000 showed the highest concordance for HPV detection (88.9%; kappa 0.78), and genotyping (88.5%). Two and more HPV-genotypes were detected in 15 samples, often with one HPV being more abundant. Dilution series confirmed the specific detection of multiple HPV-genotypes and their relative abundance. In 285 consecutive follow-up samples extracted by Roche-MP-large/spin, the top three detected genotypes were the high-risk HPV16, HPV53, HPV56 and the low-risk HPV42, HPV54 and HPV61. Rate and breadth of HPV detection in cervical swabs depends on extraction protocols being highest after centrifugation/enrichment. As multivalent HPV-vaccine coverage increases, detecting the evolving HPV virome depends on improved extraction and broader genotype coverage.

Development of loop-mediated isothermal amplification (LAMP) assay for rapid and direct screening of yellowfin tuna (Thunnus albacares) in commercial fish products.

Tuna is one of the most widely consumed fish on the European market, being available in various consumable options. Among them, Thunnus albacares, also called yellowfin tuna, is a delicacy and is consumed by millions of people around the world. Due to its comparatively high cost and demand, it is more vulnerable to fraud, where low-cost tuna or other fish varieties might be replaced for economic gain. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for targeting the mitochondrial cytochrome b gene for fast and direct detection of Thunnus albacares, which is a valuable tuna species. The analytical specificity was confirmed using 18 target samples (Thunnus albacares) and 18 samples of non-target fish species. The analytical sensitivity of the LAMP assay was 540 fg DNA per reaction. In addition, a simple and direct swab method without time-consuming nucleic acid extraction procedures and the necessity for cost-intensive laboratory equipment was performed that allowed LAMP detection of Thunnus albacares samples within 13 minutes. Due to its high specificity and sensitivity, the LAMP assay can be used as a rapid and on-site screening method for identifying Thunnus albacares, potentially providing a valuable monitoring tool for food authenticity control by the authorities.

Solar driven photocatalytic dye degradation through the novel Ti2C– ZnCo2O4MXenes nanocomposite

Two-dimensional (2D) zinc cobalt oxide (ZnCo2O4) has considerable promise material for efficient dye photocatalytic degradation. A novel family of two-dimensional anisotropic carbides and nitrides from early transition metals (MXenes) is particularly fascinating among 2D materials, such as graphene, due to their potential uses in electronics, medicine, and photo-catalysis. The extended Ti2C phases were created by synthesizing them from their parent Ti2AlC MAX phases under the same circumstances as the traditional acidic aluminum extraction procedure. However, due to its limited specific surface area and high carrier recombination rate, photo-catalytic performance is usually inadequate. Preparation, morpho-structural characterization, band gap measurement, and congo red photo-degradation potential of Ti2C MXene and three nano-composites made up of MXene enhanced by ZnCo2O4 are presented in this study. SEM images revealed hill like agglomerated rough microstructure with round shape many particles morphology. The experimentally obtained band gaps using Tauc's approach are in the 2.60–2.84 eV range. In recent years, the approach of photo-catalytic breakdown of contaminants employing semiconductor photo-catalysts with UV–visible light has grown in importance. The addition of ZnCo2O4 boosted the establishment of strong interfacial coupling between Ti2C and ZnCo2O4, shortening the route of carrier transfer and promoting the direct transfer of photo-generated electrons from Ti2C's valence band to ZnCo2O4.The specific surface area of composites increased significantly at the same time, which was beneficial for improving the UV-absorption capability of Ti2C composites. This research proposes a practical design method for increasing the degrading performance of 2D photo-catalysts, which may serve as a technical suggestion for the modification design of additional photo-catalysts. The MXene based nano-composites revealed high activity in the congo-red photo-degradation reaction (56%–78% of degraded congo-red after 270 min). Ti2C(97%)/ZnCo2O4(3%) composite showed an enhanced efficiency for degradation of congo-red.

Innovative isolation of colorant from Butea monosperma for surface-modified silk dyeing

Recently, there has been a surge of interest in adopting natural dyes to avoid the environmental difficulties connected with synthetic coloring compounds. This research focuses on extracting natural dyes from Butea monosperma plants and on developing sustainable dyeing methods for silk fabric. Natural colorants were extracted using an aqueous and an acidic extraction procedure, and silk fabrics were dyed with the extracts using mordanting with a variety of metal mordants and bio-mordants. The treatment of fabric and extracts was carried out using microwave (MW) irradiation. It was found that the bio-mordants have shown higher color strength than metallic mordant. It was also observed that the acacia and pine nut hull at 80°C and before dyeing pomegranate extract at 80°C and after dyeing of silk fabric at 40°C using bio-mordants gave higher color strength than metallic mordants. For comparative analysis, aluminum (Al) salt at 40°C, iron (Fe) salt at 60°C and tannic acid at 80°C gave acceptable results. The colorfastness characteristics were also found good to excellent. The bio-mordants not only provide the higher color strength and fastness properties, but these extracts have also shown an environmental friendly approaches. Scanning electron microscopy image and Fourier transform infrared spectroscopy analyses revealed the difference between irradiated and unirradiated silk fabrics. Therefore, it is recommended that MW rays and bio-mordants should be used in the natural dyeing of silk fabric to produce colorfast shades of acceptable strength.

Comparison of Rapid Nucleic Acid Extraction Methods for SARS-CoV-2 Detection by RT-qPCR.

Since 2020, humanity has been facing the COVID-19 pandemic, a respiratory disease caused by the SARS-CoV-2. The world’s response to pandemic went through the development of diagnostics, vaccines and medicines. Regarding diagnostics, an enormous challenge was faced due to shortage of materials to collect and process the samples, and to perform reliable mass diagnosis by RT-qPCR. In particular, time-consuming and high cost of nucleic acid extraction procedures have hampered the diagnosis; moreover, several steps in the routine for the preparation of the material makes the extracted sample susceptible to contamination. Here two rapid nucleic acid extraction reagents were compared as extraction procedures for SARS-CoV-2 detection in clinical samples by singleplex and multiplex RT-qPCR analysis, using different transport media, samples with high and low viral load, and different PCR machines. As observed, rapid nucleic acid extraction procedures can be applied for reliable diagnosis using a TaqMan-based assay, over multiple platforms. Ultimately, prompt RNA extraction may reduce costs with reagents and plastics, the chances of contamination, and the overall time to diagnosis by RT-qPCR.

Effects of alkali treatment on properties of willow bark fiber as potential fillers for polymer composites

In this work, willow fiber was extracted from willow inner bark and modified with alkali solution of various concentrations, temperature and time. The morphology, surface functional group, crystal and thermal stability were investigated by using a scanning electron microscopy, a Fourier transform infrared spectroscopy, an X-ray powder diffractometer, and a simultaneous thermal analyzer, respectively. The acid (H2SO4, 2 ml/l) extraction procedure removed the hemicellulose and part of lignin from willow bark, cleared the aggregation of WB, kept the crystal structure of willow fiber, dramatically increased the crystal length of fiber (from 18.46 to 30.15 nm), and enhanced the onset degradation temperature (from 262.23℃ to 297.62℃) and chemical reactivity (DTG: from 0.57%/s to 0.84%/s). The alkali treatment further removed lignin from willow fiber, smoothed the fiber surface, increased the intensity of cellulose [Formula: see text] from 646 counts to 1292 counts, and lengthened the crystal length from 30.15 to 41.84 nm. Varying the alkali treating condition, the crystal index and thermal stability reached to the climax at 60℃ of treating temperature and 7 h treating time. The treated willow fiber may have potential applications to composite with polymer, and to be used in pharmaceutical field as additives.

An elution independent collection device (EICD) for rapid collection of Anaplasma marginale DNA from blood samples

Currently utilized molecular detection methods are based mainly on nucleic acid extraction, amplification, and detection procedures that may require costly equipment, numerous reagents, and highly trained personnel. These requirements make diagnostic tests expensive, time-consuming, and not suitable for point-of-care applications. There is an increasing demand for simple, low-cost portable technologies. To overcome these challenges, a paper-based elution independent collection device (EICD) was designed to collect microorganisms and recover nucleic acids for molecular biology applications with minimal steps. In this study, we demonstrate a simpler Anaplasma marginale detection that uses an EICD for nucleic acid collection combined with recombinase polymerase amplification (RPA), and a lateral flow dipstick for detection of the specified target. A pre-lysis blood treatment was optimized that uses Triton X-100 lysis buffer and bovine serum album in wash buffer. Blood samples were incubated for 5 min at room temperature and run through the EICD. Four 1-mm diameter discs excised from EICD were used as template in basic RPA and lateral flow (nfo) (endonuclease IV) RPA assays. Each disc of soluble central membrane (SCM) carried circa 0.249 pg/µl of Anaplasma DNA. The percentage of nucleic acid recoverable from the SCM ranged between 60% - 70%. Blood samples infected with A. marginale were treated with Triton X-100 pre-lysis protocol. All samples tested positive by PCR and RPA methods. EICD-driven collection of blood samples is a practical method successfully adapted to detect Anaplasma spp. or blood-borne pathogen DNA and has potential for point-of-care detection in resource-limited settings.

Direct SARS-CoV-2 Nucleic Acid Detection by Y-Shaped DNA Dual-Probe Transistor Assay.

Rapid screening of infected individuals from a large population is an effective means in epidemiology, especially to contain outbreaks such as COVID-19. The gold standard assays for COVID-19 diagnostics are mainly based on the reverse transcription polymerase chain reaction, which mismatches the requirements for wide-population screening due to time-consuming nucleic acid extraction and amplification procedures. Here, we report a direct nucleic acid assay by using a graphene field-effect transistor (g-FET) with Y-shaped DNA dual probes (Y-dual probes). The assay relies on Y-dual probes modified on g-FET simultaneously targeting ORF1ab and N genes of SARS-CoV-2 nucleic acid, enabling high a recognition ratio and a limit of detection (0.03 copy μL–1) 1–2 orders of magnitude lower than existing nucleic acid assays. The assay realizes the fastest nucleic acid testing (∼1 min) and achieves direct 5-in-1 pooled testing for the first time. Owing to its rapid, ultrasensitive, easily operated features as well as capability in pooled testing, it holds great promise as a comprehensive tool for population-wide screening of COVID-19 and other epidemics.

The Effects of Waste Cement on the Bioavailability, Mobility, and Leaching of Cadmium in Soil.

Waste cement is a construction and demolition waste produced from old buildings’ demolition and transformation. In recent years, the recycling of recycled concrete is limited to the use of recycled aggregate, and the research on the utilization of waste cement in waste concrete is scarce. This study explored the effective application of waste cement for the adsorption of cadmium (Cd2+) from an aqueous solution and the bioavailability and immobility of Cd2+ in soil. Results showed that the maximum adsorption capacities of ordinary Portland cement(OPC) paste, fly ash cement (FAC) paste, and zeolite cement (ZEC) paste for Cd2+ were calculated to be 10.97, 9.47, 4.63 mg·g−1, respectively. The possible mechanisms for Cd2+ adsorption in the solution by waste cement mainly involve precipitation by forming insoluble Cd2+ compounds in alkaline conditions, and ion exchange for Cd2+ with the exchangeable calcium ions in waste cement, which were confirmed by XRD and SEM. Results from diethylene triaminepentaacetic acid (DTPA) extraction and toxicity characteristic leaching procedure (TCLP) implied reduction of the Cd2+ mobility. DTPA-extractable Cd2+ decreased by 52, 48 and 46%, respectively, by adding 1% OPC, FAC and ZEC. TCLP-extractable Cd2+ decreased by 89.0, 80.3, and 56.0% after 1% OPC, FAC, and ZEC treatment, respectively. BCR analyses indicate that OPC, FAC, and ZEC applications increased the percentage of Cd2+ in residual fraction and induced a high reduction in the acid-soluble Cd2+ proportion. The leaching column test further confirmed a reduction in Cd2+ mobility by waste cement treated under continuous leaching of simulated acid rain (SAR). Therefore, waste cement exhibited a significant enhancement in the immobilization of Cd2+ under simulated acid rain (SAR) leaching. In summary, the application of alkaline waste cement could substantially remove Cd2+ from wastewater and reduce Cd2+ mobility and bioavailability in contaminated soil.

Rapid identification of clinical mycobacterial isolates by protein profiling using matrix assisted laser desorption ionization-time of flight mass spectrometry

Purpose: The purpose of this study was to evaluate the identification of Mycobacterium tuberculosis which is often plagued with ambiguity. It is a time consuming process requiring 4-8 weeks after culture positivity, thereby delaying therapeutic intervention. For a successful treatment and disease management, timely diagnosis is imperative. We evaluated a rapid, proteomic based technique for identification of clinical mycobacterial isolates by protein profiling using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Materials and Methods: Freshly grown mycobacterial isolates were used. Acetonitrile/trifluoroacetic acid extraction procedure was carried out, following which cinnamic acid charged plates were subjected to identification by MALDI-TOF MS. Results: A comparative analysis of 42 clinical mycobacterial isolates using the MALDI-TOF MS and conventional techniques was carried out. Among these, 97.61% were found to corroborate with the standard methods at genus level and 85.36% were accurate till the species level. One out of 42 was not in accord with the conventional assays because MALDI-TOF MS established it as Mycobacterium tuberculosis (log (score)>2.0) and conventional methods established it to be non-tuberculous Mycobacterium. Conclusions: MALDI-TOF MS was found to be an accurate, rapid, cost effective and robust system for identification of mycobacterial species. This innovative approach holds promise for early therapeutic intervention leading to better patient care.

Differing Effects of Standard and Harsh Nucleic Acid Extraction Procedures on Diagnostic Helminth Real-Time PCRs Applied to Human Stool Samples.

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.

Performance Parameters of Inductively Coupled Plasma Optical Emission Spectrometry and Graphite Furnace Atomic Absorption Spectrometry Techniques for Pd and Pt Determination in Automotive Catalysts.

Palladium (Pd) and platinum (Pt) are extensively used as catalysts in the petrochemical and automotive industries, and due to high demand for them on the market, their recycling from spent supported catalysts is clearly needed. To assess the content of Pd and Pt in catalysts in order to establish their commercial value or to evaluate the recovery efficiency of technologies used for recycling, reliable analytical methods for determination of these elements are required. Spectrometric methods, such as inductively coupled plasma optical emission spectrometry (ICP-OES) and graphite furnace atomic absorption spectrometry (GFAAS) are powerful tools that can be employed for the determination of Pd and Pt in various sample matrices. However, these methods allow only the injection of liquid samples. In this regard, the digestion of solid sample by microwave-assisted acid extraction procedures at high pressures and temperatures is often used. In this study, a microwave acid digestion method was optimized for the extraction of Pd and Pt from spent catalysts, using a four-step program, at a maximum 200 °C. The resulting solutions were analyzed using ICP-OES, at two different wavelengths for each metal (Pd at 340.458 and 363.470 nm, and Pt at 265.945 and 214.423 nm, respectively) and using GFAAS (Pd at 247.64 nm, Pt at 265.94 nm). Five types of spent catalyst were analyzed and the standard deviations of repeatability for five parallel samples were less than predicted relative standard deviations (PRSD%) calculated using Horvitz’s equation for all the analyzed samples.

An innovative environmental process for the treatment of scrap Nd-Fe-B magnets

Strict environmental regulations as well as requirement of conservation of natural resources compelled the researchers to recycle the metal values from secondary resources. The scrap magnets found to be a potential alternative resource to extract rare earth metal, Nd. Present paper reports a novel process flow-sheet for the recycling of scrap Nd-Fe-B magnets to recover Nd as marketable salt and other valuable by-products. The Nd-Fe-B magnets were demagnetized, crushed and charged to atmospheric leaching resulting in ~99.99% recovery of REMs (Nd, Pr, Dy) and Fe using 1 M H2SO4 solution at room temperature for 90 min and pulp density 50 g/L. The obtained leach liquor was subjected to acid extraction procedure by mixing the liquor with 70% TEHA diluted in kerosene for 10 min, which requires five stages for complete extraction of acid from the liquor having O/A ratio 2:1. Ammonia solution was used to increase the pH of acid free leach liquor to 1.65 for the precipitation of Nd (with minor amount of Pr and Dy) and above that to precipitate Fe. Further, processing of these valuables make them industrially applicable. The leached residue was checked using Toxicity Characteristics Leachability Procedure (TCLP) test and found the remained metals within the permissible limit. This process offers a simple and efficient means to reduce the toxicological effect by recovering Nd from magnets of computer hard disks.

First Report of High Plains Wheat Mosaic Emaravirus Infecting Foxtail Barley and Wheat in Canada

HomePlant DiseaseVol. 104, No. 12First Report of High Plains Wheat Mosaic Emaravirus Infecting Foxtail Barley and Wheat in Canada PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of High Plains Wheat Mosaic Emaravirus Infecting Foxtail Barley and Wheat in CanadaI. Abdullahi, H. Bennypaul, J. Phelan, R. Aboukhaddour, and M. W. HardingI. AbdullahiCentre for Plant Health, Canadian Food Inspection Agency, North Saanich, BC, V8L 1H3, CanadaSearch for more papers by this author, H. Bennypaul†Corresponding author: H. Bennypaul; E-mail Address: Harvinder.bennypaul@canada.cahttp://orcid.org/0000-0002-3569-7376Centre for Plant Health, Canadian Food Inspection Agency, North Saanich, BC, V8L 1H3, CanadaSearch for more papers by this author, J. PhelanCentre for Plant Health, Canadian Food Inspection Agency, North Saanich, BC, V8L 1H3, CanadaSearch for more papers by this author, R. AboukhaddourAgriculture and Agri-Food Canada, Lethbridge, AB, T1J 4B1, CanadaSearch for more papers by this author, and M. W. Hardinghttp://orcid.org/0000-0002-9322-1894Alberta Agriculture and Forestry, Crop Diversification Centre South, Brooks, AB, T1R 1E6, CanadaSearch for more papers by this author AffiliationsAuthors and Affiliations I. Abdullahi1 H. Bennypaul1 † J. Phelan1 R. Aboukhaddour2 M. W. Harding3 1Centre for Plant Health, Canadian Food Inspection Agency, North Saanich, BC, V8L 1H3, Canada 2Agriculture and Agri-Food Canada, Lethbridge, AB, T1J 4B1, Canada 3Alberta Agriculture and Forestry, Crop Diversification Centre South, Brooks, AB, T1R 1E6, Canada Published Online:20 Oct 2020https://doi.org/10.1094/PDIS-04-20-0872-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleHigh Plains wheat mosaic virus (HPWMoV) is a monocistronic octapartite single-stranded negative-sense RNA virus in the genus Emaravirus, family Fimoviridae (ICTV 2018). It infects a number of cereal crops including wheat (Triticum aestivum L.), maize (Zea mays L.), barley (Hordeum vulgare L.), and some weeds (Seifers et al. 1998). HPWMoV is transmitted by the wheat curl mite Aceria tosichella Keifer (Seifers et al. 2009). It can coinfect wheat with some cereal viruses including wheat streak mosaic virus (WSMV) (Burrows et al. 2009). A field survey in southern Alberta, Canada, in late June 2017, evaluated 34 and 37 plants of wheat and grassy weed species, respectively, for the presence of cereal viruses. The sampled wheat plants showed yellow flecks and streaks, with some heavily chlorotic leaves showing necrotic patches along margins. Leaves with extreme symptoms were completely scorched and/or desiccated. Grassy weed species were collected nearby symptomatic wheat but did not show any typical symptoms. The incidence of symptoms varied among the sampled wheat fields, ranging from trace levels to 75% infected. RT-PCR was performed using primers WMoV-F (Byamukama et al. 2016) and WMoV-RR targeting the RNA 3B region of HPWMoV, after total nucleic acid extraction using an in-house procedure (SOP L036-02(a): KingFisher ml total nucleic acid extraction procedure, Sidney Laboratory, Canadian Food Inspection Agency, North Saanich, BC). All primer sequences, their location in the genome, and amplicon sizes are given in the supplementary table. Four wheat plants (one plant of cultivar AAC Elevate and three plants of unknown cultivar) and one foxtail barley plant (Hordeum jubatum L.) from Lethbridge County tested positive for HPWMoV. One wheat plant (cv. Glenn) from the Medicine Hat area also tested positive for HPWMoV. Results were confirmed by two independent RT-PCRs with primers targeting the RNA-6 segment (WmoV-F1 and WmoV-R1) and RNA-2 segment (WmoV-F2 and WmoV-R2), respectively. BLASTn analysis of a representative of each of the two fragments, which have been submitted to NCBI under accession numbers MT124696 and MT124697, showed that they share more than 99% sequence identity with respective RNA sequences of some HPWMoV isolates from the United States (KT988861, KJ939624, KJ939629, and KT988866). All but one of the HPWMoV-infected wheat plants were also positive for WSMV. WSMV infection was confirmed using DAS-ELISA (Agdia, U.S.A.) and RT-PCR with primers targeting the WSMV coat protein (WSMV-CP2 and WSMV-CP4, Dwyer et al. 2007). Next-generation sequencing analysis of one RT-PCR positive sample yielded 10,012,849 clean reads. The dsRNA extraction method, library preparation, sequencing, and bioinformatics analyses were done according to the method of Rott et al. (2017). The obtained clean reads were searched for viral sequences using Virtool software (https://www.virtool.ca), revealing 31 HPWMoV-specific contigs. Sixteen contigs, ranging in length from 252 to 1,728 bp, covered 72.92% of the HPWMoV KS7 isolate genome (KT988860 to KT988868) and shared 95 to 100% identity with it. This virus could be present in, or spread to, other parts of the Canadian prairies where coinfections with other wheat curl mite-transmissible viruses could occur. Coinfections of WSMV and HPWMoV have been reported to correlate with increased symptom severity (Burrows et al. 2009). WSMV infections have led to wheat yield losses of 7 to 18% in the Texas panhandle and in the North American prairies, including Alberta, Canada (Hadi et al. 2011). The appearance of HPWMoV in Canada is concerning because coinfections with WSMV could increase severity and yield loss.The author(s) declare no conflict of interest.