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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Boletín diario de información científica N° 32

01 June 2020 (has links)
Boletín que incluye información científica sobre el COVID-19, incluye artículos científicos y artículos preprint actualizados al 01 de Junio de 2020.
142

Boletín diario de información científica N° 33

Asociación Peruana de Bibliotecas Académicas ALTAMIRA 02 June 2020 (has links)
Boletín que incluye información científica sobre el COVID-19, incluye artículos científicos y artículos preprint actualizados al 02 de Junio de 2020.
143

Capital flows during times of crises : A study of 21st century economic crises and their impact on FDI-flows

Andreas, Repeta, Carl, Palm January 2021 (has links)
Foreign direct investment has been sharply affected by the global SARS-CoV-19 pandemic, as quarantine measures have decimated global trade, aviation and domestic economies through lockdowns which have wreaked havoc on markets. Macroeconomic indicators including GDP growth rates, unemployment, business confidence, consumer confidence, retail sales and inflation have all been negatively affected due to the simultaneous supply & demand shock caused by the pandemic. Economic crises are a regularly occurring feature, with a degree of cyclicality determining their emergence. The uniqueness of crises, in their appearance and dissipation, stems from a large variance in relevant macroeconomic, fundamental and societal factors giving rise to the crisis in the first place, with the uniqueness being bound and pertinent to a selected period of time in history under which they occurred. In this thesis we explored the impact of the two most significant economic crises of the 21st century, the Great Recession and the ongoing SARS-CoV-19 pandemic and their impact on capital flows, specifically on FDI-flows in two developed markets and two emerging markets. Our findings suggest that FDI-flows display a high synchronicity with stages of economic cycles, and tend to decrease during economic recessions and increase during economic expansions.
144

Comprehensive virtual screening of 4.8 k flavonoids reveals novel insights into allosteric inhibition of SARS-CoV-2 M<sup>PRO</sup>

Jiménez-Avalos, Gabriel, Vargas-Ruiz, A. Paula, Delgado-Pease, Nicolás E., Olivos-Ramirez, Gustavo E., Sheen, Patricia, Fernández-Díaz, Manolo, Quiliano, Miguel, Zimic, Mirko, Agurto-Arteaga, Andres, Antiparra, Ricardo, Ardiles-Reyes, Manuel, Calderon, Katherine, Cauna-Orocollo, Yudith, de Grecia Cauti-Mendoza, Maria, Chipana-Flores, Naer, Choque-Guevara, Ricardo, Chunga-Girón, Xiomara, Criollo-Orozco, Manuel, De La Cruz, Lewis, Delgado-Ccancce, Elmer, Elugo-Guevara, Christian, Fernández-Sanchez, Manolo, Guevara-Sarmiento, Luis, Gutiérrez, Kristel, Heredia-Almeyda, Oscar, Huaccachi-Gonzalez, Edison, Huerta-Roque, Pedro, Icochea, Eliana, Isasi-Rivas, Gisela, Juscamaita-Bartra, Romina A., Licla-Inca, Abraham, Montalvan, Angela, Montesinos-Millan, Ricardo, Núñez-Fernández, Dennis, Ochoa-Ortiz, Adiana, Páucar-Montoro, Erika, Pauyac, Kathy, Perez-Martinez, Jose L., Perez-M, Norma, Poma-Acevedo, Astrid, Quiñones-Garcia, Stefany, Ramirez-Ortiz, Ingrid, Ramos-Sono, Daniel, Rios-Angulo, Angela A., Rios-Matos, Dora, Rojas-Neyra, Aldo, Romero, Yomara K., Salguedo-Bohorquez, Mario I., Sernaque-Aguilar, Yacory, Soto, Luis F., Tataje-Lavanda, Luis, Ticona, Julio, Vallejos-Sánchez, Katherine, Villanueva-Pérez, Doris, Ygnacio-Aguirre, Freddy 01 December 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / SARS-CoV-2 main protease is a common target for inhibition assays due to its high conservation among coronaviruses. Since flavonoids show antiviral activity, several in silico works have proposed them as potential SARS-CoV-2 main protease inhibitors. Nonetheless, there is reason to doubt certain results given the lack of consideration for flavonoid promiscuity or main protease plasticity, usage of short library sizes, absence of control molecules and/or the limitation of the methodology to a single target site. Here, we report a virtual screening study where dorsilurin E, euchrenone a11, sanggenol O and CHEMBL2171598 are proposed to inhibit main protease through different pathways. Remarkably, novel structural mechanisms were observed after sanggenol O and CHEMBL2171598 bound to experimentally proven allosteric sites. The former drastically affected the active site, while the latter triggered a hinge movement which has been previously reported for an inactive SARS-CoV main protease mutant. The use of a curated database of 4.8 k flavonoids, combining two well-known docking software (AutoDock Vina and AutoDock4.2), molecular dynamics and MMPBSA, guaranteed an adequate analysis and robust interpretation. These criteria can be considered for future screening campaigns against SARS-CoV-2 main protease. / Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica / Revisión por pares
145

Microscopic morphomolecular characterization of humanized mouse models of SARS-CoV-2 implanted with human fetal lung xenografts

Montanaro, Paige 24 November 2021 (has links)
INTRODUCTION: SARS-CoV-2 is a novel virus from the coronavirus family that emerged in the Hubei province of China in December 2019 and rapidly spread throughout the world. On March 11, 2020, the World Health Organization declared a global pandemic. Infection with SARS-CoV-2 causes coronavirus disease 19 (COVID19) which can be fatal. There is an obvious and pressing need for research surrounding SARS-CoV-2 that will aid in eradication of this pandemic. OBJECTIVE: The goal of this study was to absolve the dire need for small animal models of human disease that demonstrate hallmark pathological features of infection. Due to ethical and financial obstacles, the use of animals that closely resemble human immunity, such as non-human primates, is often not a viable option. For this reason, there is a push to develop small animal models that can mimic human disease responses, particularly those in viral infections that have a narrow species tropism. To achieve this in the context of the novel coronavirus, SARS-CoV-2, we studied various mouse models and their capacity to become infected with and mount an immune response to SARS-CoV-2. Our goal was to identify a model that sufficiently mimics severe COVID19 seen in humans as well as provide molecular insight into pathways that prevent the development of severe disease. METHODS: NRG-L and HIS-NRGF-L mice were subcutaneously implanted with human fetal lung xenografts and infected with SARS-CoV-2. Tissues were stained with H&E for histopathological scoring. NRG-L and HIS-NRGF-L tissues were fluorescently labeled using 2 different multiplex immunohistochemistry panels. Slides were digitized by a Vectra Polaris™ fluorescent whole slide scanner and digital analysis was completed using HALO™. Statistical analysis was conducted using GraphPad Prism™ 9.0.1. RESULTS: Infected NRG-L mice present extensive histopathological manifestations when compared to uninfected controls. Cumulative histology scores at both 2 and 7DPI were increased when compared to uninoculated fLX. Neutrophil influx, intra-airspace necrosis, capillary fibrin thrombi, and presence of syncytial cells were the most significant independent observations that contributed to the increased cumulative score. Together these findings indicate that fLX inoculated with SARS-CoV-2 faithfully recapitulate several features of diffuse alveolar damage (DAD) described in severe COVID-19. HIS-NRGF-L mice displayed decreased influx of neutrophils, intra-airway necrosis, and syncytial cells when compared to NRG-L fLX. Hemorrhage was decreased at both 2 and 7 DPI for HIS-NRGF-L fLX compared to NRG-L fLX. Cumulative histology scores were decreased in HIS-NRGF-L fLX at 7 DPI when compared to NRG-L fLX. Taken together these findings support the hypothesis that human myeloid and lymphoid infiltrates suppress or prevent the disparate host response observed in NRGL-L fLX that manifested in pronounced diffuse alveolar damage. CONCLUSION: Using digital image analysis of multiplex immunohistochemistry paired with semi-quantitative histopathological scoring, this study characterized important hallmark lesions observed in severe COVID19 as seen in small animal models. NRG-L and HIS-NRGF-L mice that are subcutaneously implanted with human fetal lung xenografts are susceptible to infection with SARS-CoV-2 and can produce severe and moderate disease phenotypes respectively. Co-engraftment with human fetal lung tissue and human immune system components in HIS-NRGF-L mice suppresses the divergent host response that is observed in NRG-L mice. For this reason, NRG-L mice engrafted with fLX are an ideal small animal model of severe COVID19, whereas HIS-NRGF-L mice severe as a valuable and informative model for deciphering molecular mechanisms driving severe COVID-19 that will serve as targets for therapeutic development.
146

KINETIC AND STRUCTURAL EVALUATION OF POTENT, SMALL-MOLECULE PROTEASE INHIBITORS FOR THE TREATMENTS OF ALZHEIMER’S DISEASE, TYPE II DIABETES, AND COVID-19

Emma K Lendy (11797643) 19 December 2021 (has links)
This work details the inhibition of BACE1, BACE2, and SARS-CoV-2 3CLpro through several novel and potent protease inhibitors. Nanomolar potency of BACE1 and BACE2 is achieved with all tested inhibitors, and the S2 subsite has been identified as a BACE2 selectivity determinant. This is supported by the observation that the novel BACE2 mutant, BACE2 L246N, displays increased potency and selectivity over BACE1 against this peptidomimetic scaffold. Nanomolar to micromolar potency of SARS-CoV-2 3CLpro is achieved with the compounds tested in this study. Kinetic data illustrates the allowed substitutions at the P1’, P1, P2, and P4 positions on two scaffolds: ML188 and GC376. Finally, this work presents the high-resolution crystal structures of four inhibitors bound to BACE1 and 12 inhibitors bound to SARS-CoV-2 3CLpro. These structural data help to explain the selectivity determinants of BACE1 and BACE2 and further enable structure-based drug design against these two enzymes for the treatments of Alzheimer's Disease and Type II Diabetes, respectively. Additionally, these structural data illustrate the flexibility of the GC376 scaffold at the P3/P4 position, providing a structural rationale for the observed differences in potency across the different analogs. These structural data further enable structure-based drug design against SARS-CoV-2 3CLpro for the treatment of COVID-19.
147

Synthesis of SARS-CoV-2 Main Protease Inhibitors

Elfström, Mia January 2021 (has links)
Coronaviruses have been responsible for several global disease outbreaks over the last 20 years, including the “Severe Acute Respiratory Syndrome” in 2002/2003, the “Middle East Respiratory Syndrome” in 2012, and the “Coronavirus Disease of 2019 (COVID19)”. These viruses are highly contagious and can cause multiple medical disorders upon contraction, such as common cold or lower respiratory infections. SARS-CoV-2, the newly emerged coronavirus variant of 2019, has been confirmed as the cause of the ongoing COVID19 pandemic, which infected over 167 million people worldwide and, by the end of May 2021, has a death toll of over 3 million people. Even though several SARS-CoV-2 vaccines have made it to the market, no proven options have yet been discovered for treating COVID19 infections. The aim of this project is, therefore, to improve the potency of two active SARS-CoV-2 main protease (Mpro) inhibitors (ML188 and X77) by performing a structure-activity-relationship study where two specific sites of the inhibitors are altered. The inhibition activity of these compounds is then tested on isolated SARS-CoV-2 Mpro. The four-component Ugi reaction was utilized to synthesize the ML188 and X77 analogs, which were purified by column chromatography before testing. During this project, six pure analogs were successfully synthesized and will be sent shortly for testing. Inhibitors with good activity against SARS-CoV-2 Mpro will be further tested for their antiviral activity in cell-based infection assays. The results obtained from this study will later be used to perform a second structure-activity-relationship study to further improve the potency of the two inhibitors by developing a 2nd generation library.
148

Användning av e-hälsa under SARS-CoV-2 : En enkätstudie om distriktssköterskans upplevelse

Svanberg, Linus, Westberg, Alexander January 2020 (has links)
Användandet av e-hälsa har ökat både nationellt och internationellt de senaste åren. Under SARS-CoV-2-pandemin har nyttjandet i Sverige varit explosionsartat, då icke-fysiska möten minimerar risken för smittspridning. Tidigare forskning visar att e-hälsa har positiva effekter, men ses också som ett hot av distriktssköterskor. Studien belyser därför distriktssköterskans upplevelse av arbetet med e-hälsa under den pågående pandemin och är en kvantitativ enkätstudie med induktiv ansats. Deltagarna rekryterades med hjälp av bekvämlighetsurval och begränsades till legitimerade sjuksköterskor och specialistsjuksköterskor inom primärvården. Den totala svarsfrekvensen var 48 %. Analysen av enkäterna genomfördes med hjälp av IBM SPSS Statistics. De analyser som utfördes var Spearmans rangkorrelation och Kruskal-Wallis icke-parametriska test. Resultatet visade att det fanns en brist i utbildning kring e-hälsa hos informanterna. E-hälsotjänsterna var inte användarvänliga och de var tidskrävande för informanterna. Tid avsattes inte heller för arbetet med e-hälsa på arbetsplatserna. Det fanns potential för minskad smittspridning av SARS-CoV-2 genom arbetet med e-hälsa förutsatt att den vård som gavs genom e-hälsa var av god kvalitet. Ytterligare studier bör genomföras för att få en djupare förståelse för vad som kan och bör förbättras med e-hälsotjänsterna.
149

Variantes del SARS-CoV-2: epidemiología, fisiopatología y la importancia de las vacunas / SARS-COV-2 variants: epidemiology, pathophysiology and the importance of vaccines

Bedoya-Sommerkamp, Marcelo, Medina-Ranilla, Jesús, Chau-Rodríguez, Víctor, Li-Soldevilla, Renato, Vera-Albújar, Álvaro, García, Patricia J. 13 October 2021 (has links)
El SARS-CoV-2 es un virus ARN monocatenario de la familia de los coronavirus, causante de la COVID-19 (Coronavirus Disease 2019). Este virus es responsable de la pandemia actual que, desde su aparición a finales de 2019, ha provocado la muerte de millones de personas y ha tenido un impacto global no solo a nivel sanitario sino también económico y social. Por ello, el presente artículo tiene como objetivo revisar la información más actualizada sobre el SARS-CoV-2, empezando por describir los mecanismos de transmisión del virus, su fisiopatología y filogenética. Asimismo, presentará a las variantes emergentes del SARS-CoV-2, su relevancia para la salud pública local y global, su epidemiología en Perú, y finalmente, el rol y la importancia de las vacunas en este contexto. / SARS-CoV-2 is a single-stranded RNA virus of the coronavirus family, which causes COVID-19 (Coronavirus Disease 2019). This virus is responsible for the current pandemic, which, since its emergence in late 2019, has caused millions of deaths and has had a global impact not only on public health but also on social and economic areas. Therefore, this article aims to review the most up-to-date information on SARS-CoV-2, beginning with the description of the pathophysiology and phylogenetics of the virus. Also, we will present the emerging SARS-CoV-2 variants, their relevance for local and global public health, their epidemiology in Peru, and finally, the role and importance of vaccines in this context.
150

Tratamiento con Tocilizumab en COVID-19 crítico: Reporte de un centro hospitalario [Breve] / Tocilizumab treatment in critical COVID-19: Report from a hospital center

Hueda Zavaleta, Miguel, Bardales Silva, Fabrizzio, Copaja Corzo, Cesar, Flores Palacios, Rodrigo, Barreto Rocchetti, Luis, Córdova Tejada, Eyner 19 August 2021 (has links)
Se realizó un estudio descriptivo en el que se evaluaron las características clínicas y laboratoriales en la evolución de pacientes con diagnóstico de síndrome de distrés respiratorio agudo (SDRA) secundario a infección por SARS-CoV-2 y que recibieron Tocilizumab. Veinticuatro pacientes recibieron Tocilizumab, la mayoría eran varones (95,8 %), la comorbilidad más frecuente fue obesidad (33,3 %), al momento de recibir Tocilizumab la mediana de PaO2/FiO2 fue 159,5 (RIC 114,5-255,3). Veintiún (87,5 %) pacientes presentaron mejoría clínica y 3 (12,5 %) fallecieron. Quince pacientes (62,5 %) desarrollaron hepatotoxicidad, la mayoría de grado 3 (33,3 %) y tres (12,5 %) pacientes presentaron injuria hepática grado 4. Once pacientes (45,8 %) presentaron sobreinfección bacteriana, siendo el germen más frecuente Acinetobacter baumannii. Luego de la administración de Tocilizumab más de la mitad de los pacientes presentó una reacción adversa, a pesar de ello la mortalidad fue baja y la mayoría tuvo una mejora clínica. / A descriptive study was carried out, in which clinical and laboratory characteristics were evaluated in patients with a diagnosis of acute respiratory distress syndrome (ARDS) secondary to SARS-CoV-2 infection and who received Tocilizumab. Twentyfour patients received Tocilizumab, the majority were male (95.8%), the most frequent comorbidity was obesity (33.3%). At the time of receiving Tocilizumab the median PAO2 / FiO2 was 159.5 (IQR 114.5-255, 3). Twenty-one (87.5%) patients presented clinical improvement and 3 (12.5%) died. Fifteen patients (62.5%) developed hepatotoxicity, the majority grade 3 (33.3%) and three (12.5%) patients presented grade 4 liver injury. Eleven patients (45.8%) presented bacterial superinfection, the more common organism being Acinetobacter baumannii. After the administration of Tocilizumab, more than half of the patients presented an adverse reaction; despite this, mortality was low, and the majority had a clinical improvement.

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