Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 51
Filter
1.
International Journal of Applied Pharmaceutics ; 15(3):1-11, 2023.
Article in English | EMBASE | ID: covidwho-20242785

ABSTRACT

Recent advancements in nanotechnology have resulted in improved medicine delivery to the target site. Nanosponges are three-dimensional drug delivery systems that are nanoscale in size and created by cross-linking polymers. The introduction of Nanosponges has been a significant step toward overcoming issues such as drug toxicity, low bioavailability, and predictable medication release. Using a new way of nanotechnology, nanosponges, which are porous with small sponges (below one microm) flowing throughout the body, have demonstrated excellent results in delivering drugs. As a result, they reach the target place, attach to the skin's surface, and slowly release the medicine. Nanosponges can be used to encapsulate a wide range of medicines, including both hydrophilic and lipophilic pharmaceuticals. The medication delivery method using nanosponges is one of the most promising fields in pharmacy. It can be used as a biocatalyst carrier for vaccines, antibodies, enzymes, and proteins to be released. The existing study enlightens on the preparation method, evaluation, and prospective application in a medication delivery system and also focuses on patents filed in the field of nanosponges.Copyright © 2023 The Authors.

2.
J Virol Methods ; 319: 114759, 2023 May 29.
Article in English | MEDLINE | ID: covidwho-2327796

ABSTRACT

The circulation of certain SARS-CoV-2 variants may have a great impact on the epidemiological status of a geographical area; therefore, it is important that their presence is monitored. Currently, the gold standard method used to identify newly emerged variants is sequencing of either genes or whole genomes. However, since this method is relatively expensive and has a long turnaround time, other rapid strategies should also be employed. The current study aimed to evaluate the performance of the Simplexa® SARS-CoV-2 Variants Direct assay, which is a RT-PCR that determines the variant present in a nasopharyngeal swab sample in approximately two hours. Totally, 527 positive samples for SARS-CoV-2 were analyzed from January until December 2022 and next-generation sequencing (NGS) was used as the reference method. The assay showed high sensitivity, ranging from 94.12 % to 100 %, depending on the variant. The assay also showed high specificity, reaching 100 % for Delta and BA.1 variants, and 99.74 % and 98.67 % for BA.2 and BA.4/BA.5 variants, respectively. Moreover, the assay was able to identify the correct variant category in the presence of any subvariant in the sample. We conclude that the assay can be used to facilitate faster monitoring of circulating SARS-CoV-2 variants, however sequencing cannot be completely replaced, since new variants always emerge, and constant updates are needed, so that the user is able to interpret the melting curve patterns.

3.
Microbiol Spectr ; 11(3): e0005523, 2023 Jun 15.
Article in English | MEDLINE | ID: covidwho-2319646

ABSTRACT

Coronavirus disease 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a considerable threat to global public health. This study developed and evaluated a rapid, low-cost, expandable, and sequencing-free high-resolution melting (HRM) assay for the direct detection of SARS-CoV-2 variants. A panel of 64 common bacterial and viral pathogens that can cause respiratory tract infections was employed to evaluate our method's specificity. Serial dilutions of viral isolates determined the sensitivity of the method. Finally, the assay's clinical performance was assessed using 324 clinical samples with potential SARS-CoV-2 infection. Multiplex HRM analysis accurately identified SARS-CoV-2 (as confirmed with parallel reverse transcription-quantitative PCR [qRT-PCR] tests), differentiating between mutations at each marker site within approximately 2 h. For each target, the limit of detection (LOD) was lower than 10 copies/reaction (the LOD of N, G142D, R158G, Y505H, V213G, G446S, S413R, F486V, and S704L was 7.38, 9.72, 9.96, 9.96, 9.50, 7.80, 9.33, 8.25, and 8.25 copies/reaction, respectively). No cross-reactivity occurred with organisms of the specificity testing panel. In terms of variant detection, our results had a 97.9% (47/48) rate of agreement with standard Sanger sequencing. The multiplex HRM assay therefore offers a rapid and simple procedure for detecting SARS-CoV-2 variants. IMPORTANCE In the face of the current severe situation of increasing SARS-CoV-2 variants, we developed an upgraded multiplex HRM method for the predominant SARS-CoV-2 variants based on our original research. This method not only could identify the variants but also could be utilized in subsequent detection of novel variants since the assay has great performance in terms of flexibility. In summary, the upgraded multiplex HRM assay is a rapid, reliable, and economical detection method, which could better screen prevalent virus strains, monitor the epidemic situation, and help to develop measures for the prevention and control of SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Sensitivity and Specificity , Polymerase Chain Reaction
4.
Forests ; 14(3), 2023.
Article in English | Scopus | ID: covidwho-2292820

ABSTRACT

The COVID-19 pandemic brought a period of high consumption of protective masks and an increase in their waste. Therefore, it was necessary to look at possibilities for their disposal. This article is focused on the disposal of FFP2 masks in the form of pellets blended with sawdust. Further, their ash melting behavior was observed. The method of ash preparation can impact the resulting values of melting temperatures. Therefore, this article investigates the resulting values of ash melting temperatures determined during different ash preparations, such as temperatures (550 °C and 815 °C) and ash size (non-sifted, smaller than 50 µm and 100 µm). All measured deformation temperatures were higher than 1100 °C and even higher than 1200 °C for some samples. Moreover, the presence of FFP2 masks in pellets only insignificantly affected the values of melting temperatures compared to pure wood pellets. The measured values also showed that increasing the temperature of ash preparation from 550 to 815 °C can increase the resulting values of melting temperature. The most significant proportion of the fraction size on the resulting melting temperatures was observed for beech with 5% and 10% of masks at an ash temperature of 550 °C and for spruce with 10% of masks at an ash temperature of 815 °C. © 2023 by the authors.

5.
Applied Sciences ; 13(3):2003, 2023.
Article in English | ProQuest Central | ID: covidwho-2265434

ABSTRACT

This article presents the history of zinc, its production and demand. The quantity of zinc production, both primary zinc from ores and concentrates, and secondary zinc from scrap and zinc-rich waste, was discussed. A comprehensive economic analysis covers zinc prices in the years 1960–2021. The basic methods of obtaining zinc from ores, including pyrometallurgical (Imperial Smelting Process ISP, Kivcet, Ausmelt) and hydrometallurgical (roasting–leaching–electrowinning RLE, atmospheric direct leaching ADL, Engitec Zinc Extraction EZINEX, zinc pressure leach) and their short characteristics, are presented. The global zinc market and the main areas of its application were analyzed. Technologies used for the recovery of zinc from scrap are discussed along with their characteristics. Galvanized steel is the main source of secondary zinc, both in the galvanizing process and in the remelting of galvanized steel. It can be easily recycled with other scrap steel in the electric arc furnace (EAF) for steel production. Currently, with high volatility in the price of zinc, as well as its natural resources in the earth's crust, recycling is an important activity, despite the fact that zinc concentrates have a relatively constant chemical composition, while the resulting zinc waste contains zinc in varying amounts.

6.
J Virol Methods ; 314: 114678, 2023 04.
Article in English | MEDLINE | ID: covidwho-2181191

ABSTRACT

High-resolution melting (HRM) analysis is a PCR-based method that can be used as a screening assay to identify SARS-CoV-2 variants. However, conventional HRM assays hardly detect slight melting temperature differences at the A-T to T-A transversion. As the N501Y substitution results from A-T to T-A transversion in A23063, few or no studies have shown that a conventional HRM assay can identify N501Y variants. This study successfully developed an HRM assay for identifying the N501Y mutation. Two HRM assays were used in the N501 site because the discrimination results were affected by the virus copy numbers. One is a conventional HRM assay (detectable at 103-106 copies/mL) and the other is a modified HRM assay by adding the wild-type fragment (detectable at 105-1010 copies/mL). Using viral RNAs from cultured variants (Alpha, Beta, and Gamma), a modified HRM assay correctly identified three N501Y variants because of high-copy-number RNAs in those viral samples. The sensitivity and specificity of the N501Y assay were 93.3% and 100%, respectively, based on 209 clinical samples (105 for N501; 104 for N501Y). These results suggest that our HRM-based assay is a powerful tool for rapidly identifying various SARS-CoV-2 variants.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Polymerase Chain Reaction/methods , Temperature , Mutation
7.
Biochimica Clinica ; 46(3):S118, 2022.
Article in English | EMBASE | ID: covidwho-2168105

ABSTRACT

Since September 2020 the current global pandemic of COVID-19 caused by the SARS-CoV-2 coronavirus is characterized by a succession of waves of infection due to the emergence of new variants of the original virus, presenting various genomic mutations. Many mutations are present in the gene encoding the Spike protein, the main target of the nucleic acidbased vaccines. The Variants of Concern that have been reported since autumn 2020 include Alpha/ B.1.1.7 and sublineages, Beta/B.1.351, Gamma/P.1 and sublineages, Delta/B.1.617.2 and sublineages, Omicron/ B.1.1.529 and sublineages. The rapid and cheap variant monitoring in the population is pivotal for epidemiological studies and for the prompt detection of SARS-CoV-2 variants characterized by high transmissibility or reduced susceptibility to neutralizing antibodies induced by vaccination. Surveillance of genomic variants is currently based on viral whole genome sequencing (WGS) performed on a random fraction of samples positive to molecular tests. WGS involves high costs and extended analysis time compared to a PCR-based diagnostic test, as well as specialized staff and expensive instruments. To rapidly identify the variant in samples positive to SARS-CoV-2, different rapid tests based on real-time PCR and high-resolution melting (HRM) were designed and applied on 88 oropharyngeal swab samples collected from October 2020 to February 2022 (84 positive samples and 4 negative samples). The HRM results were confirmed by PCR product sequencing. Overall, the assays showed 100% specificity and sensitivity compared with commercial PCR assay for COVID-19 testing. Moreover, 83 samples out of 84 (98.8%) were correctly identified as follows: 8 Wuhan (wild type), 12 Alpha, 23 Delta, 37 Omicron BA.1, 1 Omicron BA.1.1, 2 Omicron BA.2. With our lab equipment, about 10 samples can be processed every 3 hours at the cost of 8.5 per sample, including RNA extraction. The identified variants overlapped with mutation and case prevalence over time in Italy (as reported in outbreak.info, which collects genomic data from the GISAID Initiative), accounting for the feasibility of this approach.

8.
Vaccines (Basel) ; 10(11)2022 Nov 18.
Article in English | MEDLINE | ID: covidwho-2116051

ABSTRACT

The clinical presentation of COVID-19 and the specific antibody responses associated with SARS-CoV-2 variants have not been investigated during the emergence of Omicron variants in Bangladesh. The Delta and Omicron variants were identified by post-PCR melting curve analysis of the spike (S) protein receptor binding domain amplicons. Anti-S-protein immunoglobulin-G anti-nucleocapsid (N)-protein immunoglobulin-G and immunoglobulin-A levels were measured by ELISA. The Delta variant was found in 40 out of 40 (100%) SARS-CoV-2 RT-PCR positive COVID-19 patients between 13 September and 23 October 2021 and Omicron variants in 90 out of 90 (100%) RT-PCR positive COVID-19 patients between 9 January and 10 February 2022. The Delta variant associated with hospitalization (74%, 80%, and 40%) and oxygen support (60%, 57%, and 40%) in the no vaccine, dose-1, and dose-2 vaccinated cases, respectively, whereas the Omicron COVID-19 required neither hospitalization nor oxygen support (0%, p < 0.0001). Fever, cough, and breathlessness were found at a significantly higher frequency among the Delta than Omicron variants (p < 0.001). The viral RNA levels of the Delta variant were higher than that of the Omicron variants (Ct median 19.9 versus 23.85; p < 0.02). Anti-spike protein immunoglobulin-G and anti-N-protein immunoglobulin-G within 1 week post onset of Delta variant COVID-19 symptoms indicate prior SARS-CoV-2 infection. The Delta variant and Omicron BA.1 and BA.2 breakthrough infections in the Dhaka region, at 240 days post onset of COVID-19 symptoms, negatively correlated with the time interval between the second vaccine dose and serum sampling. The findings of lower anti-spike protein immunoglobulin-G reactivity after booster vaccination than after the second vaccine dose suggest that the booster vaccine is not necessarily beneficial in young Bangladeshi adults having a history of repeated SARS-CoV-2 infections.

9.
Viruses ; 14(11)2022 Oct 29.
Article in English | MEDLINE | ID: covidwho-2090369

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariant BA.5 emerged as of February 2022 and replaced the earlier Omicron subvariants BA.1 and BA.2. COVID-19 genomic surveillance should be continued as new variants seem to subsequently appear, including post-BA.5 subvariants. A rapid assay is needed to differentiate between the currently dominant BA.5 variant and other variants. This study successfully developed a high-resolution melting (HRM)-based assay for BA.4/5-characteristic spike mutation F486V detection and demonstrated that our assay could discriminate between BA.1, BA.2, and BA.5 subvariants in clinical specimens. The mutational spectra at two regions (G446/L452 and F486) for the variant-selective HRM analysis was the focus of our assay. The mutational spectra used as the basis to identify each Omicron subvariant were as follows: BA.1 (G446S/L452/F486), BA.2 (G446/L452/F486), and BA.4/5 (G446/L452R/F486V). Upon mutation-coding RNA fragment analysis, the wild-type fragments melting curves were distinct from those of the mutant fragments. Based on the analysis of 120 clinical samples (40 each of subvariants BA.1, BA.2, and BA.5), this method's sensitivity and specificity were determined to be more than 95% and 100%, respectively. These results clearly demonstrate that this HRM-based assay is a simple screening method for monitoring Omicron subvariant evolution.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Sensitivity and Specificity , Biological Assay , Mutation , Spike Glycoprotein, Coronavirus/genetics
10.
Meteorological Applications ; 29(5), 2022.
Article in English | Web of Science | ID: covidwho-2082821

ABSTRACT

The Met Office held a testbed over winter 2020/2021 where a new numerical weather prediction (NWP) sub-km ensemble was set up on-demand in response to interesting weather phenomena in the United Kingdom. The domain for the model was chosen in real time by a community of Met Office Research Scientists and Operational Meteorologists and over a 4-month period the ensemble was triggered for nine events. The purpose of the testbed was to investigate whether a real-time weather regime-based enhancement in NWP capability was feasible, to understand what benefits a testbed environment might give, and to explore the practicalities of running such an event. Case studies from the testbed demonstrated that forecast ensembles at 2.2 km and 300 m grid spacing were able to capture observed winter weather, with greater spatial detail apparent, especially over complex orography, in the 300-m model. Ensemble spread appeared less influenced by resolution, potentially due to the size of the domains tested or the weather regimes of the case studies. The testbed also showcased underutilized observations and additional radiosonde ascents were conducted. All the testbed meetings were conducted virtually due to COVID-19 restrictions, and decisions were made about when to trigger the event using an online message board. The winter 2020/2021 testbed provides ideas for how on-demand weather-dependent testbeds might be conducted in the future. However, several recommendations are made that would enhance testbed benefits further, including more dedicated resource, stronger technology and data visualization and greater participation from both academia and weather information users.

11.
ASHRAE Transactions ; 127:100-107, 2021.
Article in English | ProQuest Central | ID: covidwho-1980720

ABSTRACT

As the coronavirus pandemic has brought about global economic recession and reduction in greenhouse gas emissions, energy efficient building retrofitting has become a comprehensive solution to increase the employment rate and reduce the energy consumption of buildings. This situation requires more energy-efficient integrated generation systems. In this study, an integrated generation system is proposedfor building integrated photovoltaic, thermoelectric generator, and phase change material as an enhanced generation system for buildings. In the proposed system, the phase change material absorbs solar radiation as latent heat within the melting temperature, increasing the photovoltaic conversion efficiency. Additionally, the thermoelectric generator harvests additional electricity as the temperature difference is maintained during the phase change. The total generated energy of the proposed system highly depends on the melting temperature and thickness of the phase change material. Therefore, the appropriate melting temperature and thickness design conditions of the phase change material were derived with the following simulations based on transient energy balance equations in 12 daily profiles. As a result, the optimal melting temperature increased by 5.4°F (3.6°C) and 1.9°F (1.04°C) with an insolation increase of 317 Btu/ft2 (1000 Wh/m2) and a 1.8°F (1°C) increase in ambient temperature, respectively. In addition, the optimal thickness increased by 0.04 in (2.5 mm) with an insolation increase of 317 Btu/ft2 (1000 Wh/m2).

12.
International Journal on Interactive Design and Manufacturing (IJIDeM) ; 2022.
Article in English | Web of Science | ID: covidwho-1966179

ABSTRACT

The use of digital manufacturing for the construction of orthosis and prostheses has become common since the popularization of 3D printers and the advent of Industry 4.0. Furthermore, due to the fact that the manufacture of orthosis is interactive and for personal use, generic production is difficult. In this sense, the large-scale production of these products lacks of improvements, standardization of processes and production optimization. An aggravation of this is the recent social distance due to the COVID-19 pandemic, which makes the use of temporary orthosis made in 3D printers to have a recent growth. Parallel to this, the use of multi-lattice inner structures for internal structuring of prints has also been increasing and taking on a more consolidated form. This article aims to present the multi-lattice optimization as a solution to this problem, in order to reduce material waste while maintaining the mechanical behavior of printed parts.

13.
Our Dermatology Online / Nasza Dermatologia Online ; 13(3):286-288, 2022.
Article in English | Academic Search Complete | ID: covidwho-1954730

ABSTRACT

The launch of COVID-19 vaccines in India has raised the expectations of the dreadful COVID-19 pandemic ending in the future. Various mild and benign cutaneous manifestations of the different forms of the COVID-19 vaccine have been documented. Herein, we are reporting a unique case of Blaschkoid pityriasis rosea (PR) developing after COVID-19 vaccination. A forty-two-year-old female presented with PR along a linear arbitrary zone on the back at the level of L1-L2 extending to involve the abdomen and an oblique zone on the thigh. She was vaccinated with the first dose of the COVISHIELD ChAdOx1/nCoV-19 (recombinant) coronavirus vaccine six days before the onset of the lesions. There are only several case reports of typical pityriasis rosea occurring after COVID-19 vaccination. Our unique case depicts the occurrence of atypical PR after COVID-19 vaccination. [ FROM AUTHOR] Copyright of Our Dermatology Online / Nasza Dermatologia Online is the property of Our Dermatology Online and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

14.
Microbiol Spectr ; 10(4): e0136722, 2022 08 31.
Article in English | MEDLINE | ID: covidwho-1950020

ABSTRACT

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. As of March 2022, Omicron variant BA.2 is rapidly replacing variant BA.1. As variant BA.2 may cause more severe disease than variant BA.1, variant BA.2 requires continuous monitoring. The current study aimed to develop a novel high-resolution melting (HRM) assay for variants BA.1 and BA.2 and to determine the sensitivity and specificity of our method using clinical samples. Here, we focused on the mutational spectra at three regions in the spike receptor-binding domain (RBD; R408, G446/L452, and S477/T478) for the variant-selective HRM analysis. Each variant was identified based on the mutational spectra as follows: no mutations (Alpha variant); L452R and T478K (Delta variant); G446S and S477N/T478K (Omicron variant BA.1); and R408S and S477N/T478K (Omicron variant BA.2). Upon analysis of mutation-coding RNA fragments, the melting curves of the wild-type fragments were distinct from those of the mutant fragments. The sensitivity and specificity of this method were determined as 100% and more than 97.5%, respectively, based on 128 clinical samples (40 Alpha, 40 Delta, 40 Omicron variant BA.1/BA.1.1, and 8 Omicron variant BA.2). These results suggest that this HRM-based assay is a promising screening method for monitoring the transmission of Omicron variants BA.1 and BA.2. IMPORTANCE This study seeks to apply a novel high-resolution melting (HRM) assay to identify and discriminate BA.1 and BA.2 sublineages of the SARS-CoV-2 Omicron variant. Variant BA.2 may cause more severe disease than variant BA.1, meaning that identifying this variant is an important step toward improving the care of patients suffering from COVID-19. However, screening for these variants remains difficult, as current methods mostly rely on next-generation sequencing, which is significantly costlier and more time-consuming than other methods. We believe that our study makes a significant contribution to the literature because we show that this method was 100% sensitive and over 97.5% specific in our confirmation of 128 clinical samples.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , Freezing , Humans , Pilot Projects , SARS-CoV-2/genetics
15.
Arctic ; 75(2):285-289, 2022.
Article in English | ProQuest Central | ID: covidwho-1918811

ABSTRACT

Lhù'ààn Mân' is located in the southwest corner of Yukon Territory, tucked into the foot of Kluane Ranges of the St. Elias Mountains. The lake is situated on the traditional territory of the Kluane First Nation, Champagne and Aishihik First Nations, and the White River First Nation. The lake and its watershed are culturally significant and provide sources of fresh water, fish, land animals for hunting and trapping, berries, and lumber. Miller is a a PhD candidate in the Department of Geography at the University of Calgary working on an exploratory hydrology research project in the Lhù'ààn Mân' watershed. In May of 2016, Kaskawulsh Glacier retreat redirected the meltwater away from it. The event caused the volume of water to decrease significantly, leaving the areas of the river valley that were previously under water dry. Kaskawulsh Glacier runoff was the largest source of glacial water to the lake until then. By August, its level dropped nearly 2 m and has not refilled. This drastic change over a short time period drew a lot of attention and has raised questions in the academic and local communities about glacially-connected water resources in a changing climate.

16.
Biochem Biophys Rep ; 31: 101306, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1914178

ABSTRACT

High-resolution melting (HRM) analysis was conducted to discriminate between SARS-CoV-2 Omicron variant BA.1 (B.1.1.529.1) and subvariant BA.2 (B.1.1.529.2). We performed two-step PCR consisting of the first PCR and the second nested PCR to prepare the amplicon for HRM analysis, which detected G339D, N440K, G446S and D796Y variations in the SARS-CoV-2 spike protein. The melting temperatures (Tms) of the amplicons from the cDNA of the Omicron variant BA.1 and subvariant BA.2 receptor binding domain (RBD) in spike protein were the same: 75.2 °C (G339D variation) and 73.4 °C (D796Y variation). These Tms were distinct from those of SARS-CoV-2 isolate Wuhan-Hu-1, and were specific to the Omicron variant. In HRM analyses that detected the N440K and G446S variations, the Tms of amplicons from the cDNA of the Omicron variant BA.1 and subvariant BA.2 RBDs were 73.0 °C (N440K and G446S variations) and 73.5 °C (G446S variation). This difference indicates that the SARS-CoV-2 Omicron variants BA.1 and BA.2 can be clearly discriminated. Our study demonstrates the usefulness of HRM analysis after two-step PCR for the discrimination of SARS-CoV-2 variants.

17.
J Med Virol ; 94(11): 5543-5546, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-1913851

ABSTRACT

Patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 has increased worldwide since the beginning of 2022 and the variant has spread more rapidly than the Delta variant, which spread in the summer of 2021. It is important to clarify the cause of the strong transmissibility of the Omicron variant to control its spread. In 694 patients with coronavirus disease 2019, the copy numbers of virus in nasopharyngeal swab-soaked samples and the viral genotypes were examined using quantitative polymerase chain reaction (PCR) and PCR-based melting curve analysis, respectively. Whole-genome sequencing was also performed to verify the viral genotyping data. There was no significant difference (p = 0.052) in the copy numbers between the Delta variant cases (median 1.5 × 105 copies/µl, n = 174) and Omicron variant cases (median 1.2 × 105 copies/µl, n = 328). During this study, Omicron BA.1 cases (median 1.1 ×105 copies/µl, n = 275) began to be replaced by BA.2 cases (median 2.3 × 105 copies/µl, n = 53), and there was no significant difference between the two groups (p = 0.33). Our results suggest that increased infectivity of the Omicron variant and its derivative BA.2 is not caused by higher viral loads but by other factors, such as increased affinity to cell receptors or immune escape.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Viral Load
18.
Int J Infect Dis ; 122: 401-404, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1907181

ABSTRACT

OBJECTIVES: Considering the spread of new genetic variants and their impact on public health, it is important to have assays that are able to rapidly detect SARS-CoV-2 variants. METHODS: We retrospectively examined 118 positive nasopharyngeal swabs, first characterized by the Sanger sequencing, using the Simplexa® SARS-CoV-2 Variants Direct assay, with the aim of evaluating the performance of the assay to detect N501Y, G496S, Q498R, Y505H, E484K, E484Q, E484A, and L452R mutations. RESULTS: A total of 111/118 nasopharyngeal swabs were in complete agreement with the Sanger sequencing, whereas the remaining seven samples were not amplified due to the low viral load. The evaluation of the ability of the assay to detect the E484Q mutation was performed using a viral isolate of the SARS-CoV-2 Kappa variant, showing concordance in 15/15 samples. Simplexa® SARS-CoV-2 Variant Direct assay was able to detect mutation pattern of Alpha, Beta, Gamma, Delta, and Omicron variants with 100% specificity and 94% sensitivity, whereas 100% sensitivity and specificity for the Kappa variant was observed. CONCLUSION: The assay can be useful to obtain faster results, contributing to a prompt surveillance of SARS-CoV-2 variants; however, it requires to be confirmed by the Sanger method, especially in the case of pattern of mutations that are different from those expected and also requires updates as new variants emerge.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , COVID-19 Testing , Humans , Mutation , RNA, Viral/genetics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics
19.
Molecules ; 27(11)2022 May 25.
Article in English | MEDLINE | ID: covidwho-1892923

ABSTRACT

Food authenticity has become increasingly important as a result of food adulteration. To identify the authenticity of sweet potato starch noodles, the ladder-shape melting temperature isothermal amplification (LMTIA) method of determining cassava (Manihot esculenta Crantz) DNA in sweet potato starch noodles was used. A set of primers targeted at the internal transcription spacer (ITS) of cassava was designed, genomic DNA was extracted, the LMTIA reaction temperature was optimized, and the specificity of the primer was verified with the genomic DNAs of cassava, sweet potato (Ipomoea batatas L.), Solanum tuberosum L., Zea mays L., Vigna radiate L., Triticum aestivum L., and Glycine max (L.) Merr. The sensitivity with the serially diluted genomic DNA of cassava and the suitability for the DNA extracted from sweet potato starch adulterated with cassava starch were tested. The LMTIA assay for identifying the cassava component in sweet potato starch noodles was established. At the optimal temperature of 52 °C, the primers could specifically distinguish a 0.01% (w/w) cassava component added to sweet potato starch. Additionally, the LMTIA method was applied to the cassava DNA detection of 31 sweet potato starch noodle samples purchased from retail markets in China. Of these, 14 samples were positive. The LMTIA assay could be a reliable method for the rapid detection of cassava components in sweet potato starch noodles, to protect the rights of consumers and to regulate the sale market order of starch noodles.


Subject(s)
Ipomoea batatas , Manihot , Ipomoea batatas/genetics , Manihot/genetics , Starch , Temperature , Vegetables
20.
Indian Journal of Pharmaceutical Education and Research ; 56(2):S216-S224, 2022.
Article in English | EMBASE | ID: covidwho-1884617

ABSTRACT

Background: Nasal route of drug administration has gained popularity nowadays specially for drugs acting on nasopulmonary area. Atazanavir is an antiviral drug which has proved efficacy in different viral infection including COVID-19. Therefore the hypothesis is, if given through intra nasal route this formulation will be able to prevent the viral infection like COVID-19 by directly acting on the virus at its entry point. Objectives: This study aims to prepare a stable mucoadhesive microcrystal formulation of this antiviral drug with good permeation for intra nasal delivery. Materials and Methods: The formulation was prepared by high-speed homogenization process. Prepared microcrystals were estimated for in vitro drug release and permeation, drug excipient interaction study by DSC, FTIR and in vitro mucoadhesiveness study on agar gel plate. A short-term stability study was conducted on all formulations for 6 months. Results: The melting point and absorbance maxima of atazanavir were found as 200.9°C and 248 nm. The DSC and FTIR study results confirmed no drug excipient interaction was there in the formulation. The particle size of the formulations was found as 5-11 µm in range. Drug release was better and faster from the microcrystals as compare to pure powder drug. The flux for microcrystal formulation was found to be 100 whereas flux for the pure drug powder was 24. Formulations had sufficient mucoadhesive strength due to incorporation of HPMC 400 polymer and they were found stable after six months stability study. Conclusion: Lastly, it can be concluded that this formulation would be a promising system for the delivery through intra nasal route as it showed good drug release and permeation during a short time span in in vitro nasal condition with a particle size range suitable for intranasal delivery. However, further in vivo studies are required to confirm the hypothesis.

SELECTION OF CITATIONS
SEARCH DETAIL