Simple, rapid, specific, and sensitive point-of-care detection methods are needed to contain the spread of SARS-CoV-2. CRISPR/Cas9-based lateral flow assays are emerging as a powerful alternative for COVID-19 diagnostics. Here, we developed Bio-SCAN (biotin-coupled specific CRISPR-based assay for nucleic acid detection) as an accurate pathogen detection platform that requires no sophisticated equipment or technical expertise. Bio-SCAN detects the SARS-CoV-2 genome in less than 1 h from sample collection to result. In the first step, the target nucleic acid sequence is isothermally amplified in 15 min via recombinase polymerase amplification before being precisely detected by biotin-labeled nuclease-dead SpCas9 (dCas9) on commercially available lateral flow strips. The resulting readout is visible to the naked eye. Compared to other CRISPR-Cas-based pathogen detection assays, Bio-SCAN requires no additional reporters, probes, enhancers, reagents, or sophisticated devices to interpret the results. Bio-SCAN is highly sensitive and successfully detected a clinically relevant level (4 copies/μL) of synthetic SARS-CoV-2 RNA genome. Similarly, Bio-SCAN showed 100% negative and 96% positive predictive agreement with RT-qPCR results when using clinical samples (86 nasopharyngeal swab samples). Furthermore, incorporating variant-specific sgRNAs in the detection reaction allowed Bio-SCAN to efficiently distinguish between the α, β, and δ SARS-CoV-2 variants. Also, our results confirmed that the Bio-SCAN reagents have a long shelf life and can be assembled locally in nonlaboratory and limited-resource settings. Furthermore, the Bio-SCAN platform is compatible with the nucleic acid quick extraction protocol. Our results highlight the potential of Bio-SCAN as a promising point-of-care diagnostic platform that can facilitate low-cost mass screening for SARS-CoV-2.
Efficient pathogen diagnostics and genotyping methods enable effective disease management and breeding, improve crop productivity and ensure food security. However, current germplas m selection and pathogen detection techniques are laborious, time-consuming, expensive, and not easy to mass-scale application in the field. Here, we optimized a field-deployable lateral flow assay, Bio-SCAN, as a highly sensitive tool to precisely identify elite germplasm and detect mutations, transgenes, and phytopathogens in less than 1 hour, starting from sample isolation to result output using lateral flow strips. As a proof of concept, we genotyped various wheat germplasms for the Lr34 and Lr67 alleles conferring broad-spectrum resistance to stripe rust, confirmed the presence of synthetically produced herbicide-resistant alleles in the rice genome, and screened for the presence of transgenic elements in the genome of transgenic tobacco and rice plants with 100% specificity. We also successfully applied this new assay to the detection of phytopathogens, including viruses and bacterial pathogens in Nicotiana benthamiana, and two destructive fungal pathogens (Puccinia striiformis f. sp. tritici and Magnaporthe oryzae Triticum) in wheat. Our results illustrate the power of Bio-SCAN in crop breeding, genetic engineering, and pathogen diagnostics to enhance food security. The high sensitivity, simplicity, versatility, and infield deployability make the Bio-SCAN as an attractive molecular diagnostic tool for diverse applications in agriculture.
Objectives: Covid-19 is a betacoronavirus that was initially transmitted to humans from an animal host. It enters the cell by binding its protein S with angiotensin-converted enzyme receptors. It is transmitted through direct contact and respiratory drops. The most affected population so far are older adults and people with chronic conditions. The objective of this research is to analyze the possible association between the structure of the population pyramid, the Gross Domestic Product, the type of isolation and screening used to detect Covid-19 in the countries with the highest and lowest mortality from this disease.Design and Methods: Some variables take part in the Covid-19 mortality worldwide, such as the population structure, expressed in the population pyramid by country, the type of isolation adopted in each nation, the Gross Domestic Product (GDP) as well as the type of screening that is implemented in the different countries analyzed.Results: After analyzing the mean difference in the countries with a regressive and progressive population pyramid, an association was identified between the regressive population pyramid structure and the higher mortality rate (p<0.001).Conclusions: The countries with a progressive population pyramid are the most benefited by making their population more screened since the mortality rate decreases significantly compared to the countries with less attribution (p<0.036).
Introducción: el reflejo trigémino cardíaco es una respuesta fisiológica parasimpática repentina, que ocasiona alteraciones cardiovasculares importantes durante la estimulación nerviosa en el trayecto del V par craneal, generalmente ocurre al realizar procedimientos quirúrgicos en cirugía oral y maxilofacial, neurocirugía, oftalmología y dermatología. La artroscopia de la articulación temporomandibular ha sido tradicionalmente considerada un procedimiento quirúrgico seguro, mínimamente invasivo, aun así, esta técnica no está exenta de complicaciones neuro y cardiovasculares. Objetivo: presentar un caso clínico que durante una artroscopia de la articulación temporomandibular en la fase de instrumentación del espacio articular superior, y que, bajo monitoreo continuo del anestesiólogo, reportó una bradicardia súbita. Conclusión: el diagnóstico intraoperatorio de reflejo trigémino cardíaco, fue descrito por el servicio de anestesiología recibiendo un tratamiento farmacológico temprano para esta condición, lo que permitió obtener una adecuada evolución trans y postoperatoria.La artroscopia de la articulación temporomandibular ha sido tradicionalmente considerada un procedimiento quirúrgico seguro, mínimamente invasivo, aun así, esta técnica no está exenta de complicaciones.El objetivo de este artículo es presentar un caso clínico que durante una artroscopia de la articulación temporomandibular en la fase de instrumentación del espacio articular superior sufrió una bradicardia súbita, con un diagnóstico intraoperatorio de reflejo trigémino cardíaco, recibiendo un tratamiento temprano por parte del servicio de anestesiología de esta condición, obteniendo una adecuada evolución trans y postoperatoria.
Antecedentes. En el 2007 se legalizó el aborto en la Ciudad de México, acusando una elevada mortalidad materna por aborto.Objetivo. Analizar los datos generales de la mortalidad materna y por aborto en el país y en la capital.Metodología. Estudio retrospectivo, con datos obtenidos del INEGI. Cálculo de la razón de mortalidad materna general y por aborto. Análisis de correlación de Pearson y regresión lineal de los resultados. Análisis de tendencias de incremento y decremento anual. Desglose de muertes maternas.Resultado. Regresión lineal sobre la RMM nacional (R² = 0.87) con tendencia a la baja; RMM por aborto nacional (R² = 0.49) con débil tendencia hacia la baja; RMM por aborto en la Ciudad de México (R² = 0.001) no muestra una tendencia hacia la baja.Conclusión. La despenalización del aborto en la Ciudad de México no mostró tener un impacto en la reducción de muertes maternas por aborto. El aborto provocado ocupa el 12° lugar de las muertes maternas en México.
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