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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.
201

Analyse dynamique en champ proche de la contribution des sources de composés organiques volatils, en région urbaine sous influence industrielle / New-field dynamic analysis of the contribution of Volatile Organic Compounds sources, in urban region under industrial influence

Xiang, Yang 14 December 2011 (has links)
À ce jour, l'identification des sources de Composés Organiques Volatils (COV) a fait l'objet de nombreuses études, afin de déterminer leur contribution à la pollution atmosphérique. Néanmoins, le comportement dynamique de l'atmosphère, dans sa dimension micro-météorologique, n'a jamais été pris en compte dans une approche sources-récepteur. Celui-ci est pourtant essentiel dans l'interprétation des mesures physico-chimiques de la pollution de l'air en champ proche, dans une région urbaine sous influence industrielle. La complexité de ces zones d'études provient non seulement des différents modes d'émissions et de la variété des activités industrielles, mais aussi des phénomènes météorologiques à multi-échelles, qui influent la dispersion et le transport à petite échelle spatiale (typiquement quelques kilomètres). En nous appuyant sur la mesure de 85 COV (dont 23 COV oxygénés) sur une durée de plusieurs mois, nous avons développé une méthodologie novatrice, associant lors de l'analyse des résultats d'un modèle sources-récepteur PMF (Positive Matrix Factorization) des grandeurs météorologiques, pour identifier des sources et comprendre leur comportement dynamique. En introduisant la turbulence verticale, pour la première fois dans ce type d'analyse, la température et le rayonnement solaire, comme paramètre d'analyse des facteurs de comportements ont pu être différenciés, permettant de distinguer les modes d'émissions diffuses et canalisées. Ainsi, nous avons pu classer les sources des COV par nature et par mode d'émissions, et également mettre en évidence des masses d'air âgées contenant des espèces secondaires. / Recently, sources apportionment of Volatile Organic Compounds (VOC) has been the subject of a great numbers of studies, in order to determine their contributions to atmospheric pollution. However, the dynamical behavior of atmosphere, within its micro-meteorological scale, has never been taken into account in the sources-receptor approach, yet it is the main factor to interpret near-field physic-chemical measurements of air pollution, in an urban area under industrial influences. The complexity of such a study area results from not only the emission modes and the various industrial activities, but also the meteorological phenomenon in multi-scale, which influences the dispersion and transport in a small scale (tipically several kilometers). With measurements of 85 VOC (including 23 oxygenated VOC) during several months, we have developed an innovative methodology, associating the results of the PMF (Positive Matrix Factorization) modeling and the meteorological parameters, in order to identify the sources and to understand their dynamical behaviors. By introducing the vertical turbulence for the first time in this kind of analysis, the temperature and the solar radiation, as parameters of factor analyses, two behaviors have been distinguished, leading to identify the emissions near ground and in the upper part of surface layer. In this way, we have labeled the sources according to their nature as well as their emission mode, and we have highlighted the aged air mass containing secondary pollutants.
202

Vergleich der Sensitivität und Spezifität von SARS-CoV¬-2 Nukleoprotein- und Spike-Protein-Elisa mit einem Elisa, der beide Proteine kombiniert

Reiners, Nina Ellen 07 February 2022 (has links)
SARS-CoV-2-Antikörpertests sind deswegen von Bedeutung, weil damit insbesondere die Ausbreitung des Virus exakt nachverfolgt und politische Maßnahmen und Einschränkungen angepasst werden können. Zum Antikörpernachweis werden hauptsächlich das Spike und das Nukleo-Protein als Fängerprotein verwendet. Ausgangspunkt für die vorliegenden Studie war die Beobachtung, dass Covid-positive Seren, die in S-Protein basierten Antikörpertests stark reagiert hatten, teilweise im N-Protein-Tests gar nicht reagierten und umgekehrt. Daraufhin stellte sich die Frage, wie sich die Kombination der Nukleo- und Spike-Proteine in einem Kombinations-Test, im Vergleich zu einem Test mit dem Nukleo-Protein und dem Spike-Protein allein, auf die Sensitivität und Spezifität auswirkt. So entstand die Idee, die beiden Proteine in einem gemeinsamen Test zu kombinieren, um einerseits die Sensitivität zu verbessern, ohne aber gleichzeitig eine Verschlechterung der Spezifität in Kauf nehmen zu müssen. Um diese Arbeitshypothese optimal untersuchen zu können, wurde ein eigener S-Protein-ELISA und ein Kombinatios-ELISA, der das Spike und das Nukleo-Protein als Fängerprotein benutzt, etabliert und mit dem bereits von Frau Schnurra etablierten N-Protein-ELISA verglichen. Untersucht wurde die Hypothese mithilfe der drei ELISA-Antikörpertests, in denen 123 Covidseren von 2020 und 180 Blutbankseren und Plasmen von vor 2019 miteinander verglichen wurden. Der N-Protein-ELISA, der S-Protein-ELISA und der Kombinations-ELISA folgten dabei einem fast identischen Protokoll. Somit wurde garantiert, dass ausschließlich die Auswirkung der Proteine und Proteinkombinationen verglichen wurden und Sensitivitäten und Spezifitäten nicht wegen verschiedener Testqualitäten oder verwendeter Substanzen schwankten. Um den optimalen Vergleich der ELISA ermöglichen zu können, wurde die Spezifität der drei Tests mithilfe der ROC-Analyse auf 98,33 % angeglichen. Im Vergleich der Sensitivitäten der drei Tests ist zu sehen, dass die Sensitivität tatsächlich gesteigert werden kann, wenn das S- und das N-Protein miteinander kombiniert werden. Der N-Protein-ELISA hat mit 82,9 % (CI: 75,1% - 89,1%) die geringste Sensitivität, gefolgt von dem S-Protein-ELISA mit 93,5 % (CI: 87,6% - 97,2%). Die höchste Sensitivität hat der ELISA, der die beiden Proteine kombiniert mit 95,9 % (CI 90,8% - 98,7%). Werden die AUC‘s der drei Tests berechnet, die die Genauigkeit eines Tests angeben, wie zum Beispiel die Unterscheidung der diagnostischen Gruppe in krank und gesund, schneidet auch hier der Kombinationstest mit 0,986 (CI: 0,965 – 0,996) am besten ab. Auf dem zweiten Platz landet der S-Protein-ELISA mit 0,985 (CI: 0,964- 0,995) und auf dem dritten Platz der N-Protein-ELISA mit 0,96 (CI: 0,931 – 0,979). Wird die Spezifität der drei Tests bei einem Cut-off von 1 miteinander verglichen, ist deutlich, dass sich die Spezifität durch die Kombination der beiden Proteine verschlechtert. Von 180 Seren und Plasmen, die vor 2019 abgenommen wurden, wird im N-Protein-ELISA ein Serum als falsch positiv erkannt, im S-Protein-ELISA ein Serum und ein Plasma. Im Kombinations-ELISA werden jeweils die beiden zuvor genannten Seren und das Plasma als falsch positiv erkannt. Eine zusätzliche Überprüfung ist hierbei erforderlich, indem noch mehr Covid-negative Seren untersucht werden. Zur praktischen Nutzung der Ergebnisse kommen folgende Möglichkeiten in Frage: Wird ein besonders sensitiver Test benötigt, wie es zum Beispiel der Fall ist, wenn eine große Bevölkerung auf ihre Durchseuchung untersuchen werden soll, könnte ein ELISA benutzt werden, der beide Proteine kombiniert. Anschließend müssten die positiven Seren in einem hoch spezifischen Test, wie zum Beispiel dem Siemens-Test, nachgetestet werden. Das hätte den Vorteil, dass mit einem relativ günstigen ELISA die größte Anzahl an Seren aussortiert werden könnte. Daraufhin müsste dann nur noch eine kleine Gruppe an Seren mit dem teureren Antikörpertest, in diesem Falle dem Siemens-Test, nachgetestet werden. Wird primär ein besonders spezifischer ELISA benötigt, könnte das N-Protein wieder allein verwendet werden.  :Inhaltsverzeichnis ABKÜRZUNGSVERZEICHNIS III 1 EINFÜHRUNG 1 1.1 Besonderheiten des SARS-Coronavirus-2 1 1.1.1 Aufbau des SARS-CoV-2 3 1.1.2 Antikörperantwort auf SARS-CoV-2 5 1.2 SARS-CoV-2 Diagnostik 7 1.2.1 SARS-CoV-2 Akutdiagnostik/ Direkter Erregernachweis 8 1.2.2 SARS-CoV-2-Antikörpertests/ Indirekter Erregernachweis 9 1.2.2.1 Die Bedeutung von SARS-CoV-2 Antikörpertests 10 1.3 Aufgabenstellung 11 2 MATERIAL UND METHODEN 12 2.1 Materialien 12 2.1.1 Blutproben 12 2.1.2 Herstellung des RBD-Bestandteils des S1-Proteins 12 2.2 Methoden 13 2.2.1 Allgemeines ELISA-Protokoll 13 2.2.2 Datenanalyse 14 3 ERGEBNISSE 15 3.1 Entwicklung des ELISA-Protokolls 15 3.1.1 Antigenbeschichtungslösung 15 3.1.2 Antigenbeschichtungskonzentration 16 3.1.3 Vergleich verschiedener Entwicklungszeiten 19 3.1.4 Versuch der Reduktion falsch positiver Ergebnisse 24 3.1.5 Herstellung des Calibrators 29 3.1.6 Herstellung des Standardserums 32 3.1.7 Finales Elisa Protokoll 36 3.2 Stabilisierung des ELISAs 36 3.2.1 Stabilisierung der Beschichtung 36 3.2.2 Stabilisierung von Positiv-/ Negativkontrolle und Calibrator 39 3.3 Vergleich der Sensitivitäten und Spezifitäten der verschiedenen ELISA 39 3.3.1 Sensitivitäten der Antikörpertests bei einem Cut-off von 1 40 3.3.1.1 Aufschlüsselung der Testergebnisse der Sensitivität 42 3.3.2 Spezifitäten der Antikörpertests 43 3.3.2.1 Aufschlüsselung der Testergebnisse der Spezifität 44 3.3.3 Angleichung der Spezifität zum Vergleich der drei ELISA 45 3.3.3.1 Angleichung der Spezifität auf 99,4% 45 3.3.3.2 Angleichung der Spezifität auf 98,3 % 47 3.4 Vergleich der Flächen unter den ROC-Kurven 50 4 DISKUSSION 51 5 ZUSAMMENFASSUNG DER ARBEIT 58 6 LITERATURVERZEICHNIS 61 7 ANHANG 68 8 ERKLÄRUNG ÜBER DIE EIGENSTÄNDIGE ABFASSUNG DER ARBEIT 69 9 LEBENSLAUF 70 10 PUBLIKATIONEN 71 11 DANKSAGUNG 72
203

Sociodemographic Predictors Associated with the Willingness to Get Vaccinated against COVID-19 in Peru: A Cross-Sectional Survey

Vizcardo, David, Salvador, Linder Figueroa, Nole-Vara, Arian, Dávila, Karen Pizarro, Alvarez-Risco, Aldo, Yáñez, Jaime A., Mejia, Christian R. 01 January 2022 (has links)
During the race for the development of a vaccine against COVID-19, even before its commercialization, part of the population has already shown a growing fear of its application. We designed an analytical cross-sectional study using an anonymous survey in the 25 departments of Peru. We surveyed whether the participants were planning on getting vaccinated, as well as other characteristics that were cross-checked in a uni-, bi-and multivariate manner. Of the 1776 respondents, 70% (1251) stated that they were planning to be vaccinated, 20% (346) did not know yet or doubted it, and 10% (179) did not want to be vaccinated. We observed that those who did not get infected with COVID-19 exhibited a higher frequency to not wanting or were uncertain about getting vaccinated (aPR: 1.40; 95% CI: 1.09–1.81; p-value = 0.008). In contrast, there was a lower frequency of vaccine refusal among university students (aPR: 0.75; 95% CI: 0.61–0.92; p-value = 0.005) and healthcare workers (aPR: 0.59; 95% CI: 0.44–0.80; p-value = 0.001); adjusted by place of residence. There is still an important percentage of respondents who do not want to be vaccinated or are hesitant to do it, which was associated with educational level, being a healthcare worker and if they were previously infected with COVID-19. Our results could offer useful information about COVID-19 vaccination campaigns. / Revisión por pares
204

Unlocking SARS-CoV-2 detection in low- and middle-income countries

Alcántara, Roberto, Peñaranda, Katherin, Mendoza-Rojas, Gabriel, Nakamoto, Jose A., Martins-Luna, Johanna, del Valle-Mendoza, Juana, Adaui, Vanessa, Milón, Pohl 22 November 2021 (has links)
Low- and middle-income countries (LMICs) are significantly affected by SARS-CoV-2, partially due to their limited capacity for local production and implementation of molecular testing. Here, we provide detailed methods and validation of a molecular toolkit that can be readily produced and deployed using laboratory equipment available in LMICs. Our results show that lab-scale production of enzymes and nucleic acids can supply over 50,000 tests per production batch. The optimized one-step RT-PCR coupled to CRISPR-Cas12a-mediated detection showed a limit of detection of 102 ge/μL in a turnaround time of 2 h. The clinical validation indicated an overall sensitivity of 80%–88%, while for middle and high viral load samples (Cq ≤ 31) the sensitivity was 92%–100%. The specificity was 96%–100% regardless of viral load. Furthermore, we show that the toolkit can be used with the mobile laboratory Bento Lab, potentially enabling LMICs to implement detection services in unattended remote regions. / Fondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica / Revisión por pares
205

Ambulanssjuksköterskans upplevelser av hur vårdandet av patienten påverkas under COVID-19 pandemin : En kvalitativ intervjustudie

Gerle, Anna, Jahic, Belma January 2021 (has links)
Bakgrund och problemformulering: Första fallet av SARS-Co-2 rapporterades i Kina i slutet på år 2019 och tidigt år 2020 förklarades smittspridningen av viruset vara en pandemi. I frontlinjen av pandemin finns ambulanssjuksköterskan som dagligen möts av utmaningarna som pandemin innebär. Det går inte att med säkerhet fastställa vilka patienter som bär på viruset vilket innebär att samtliga patienter måste betraktas som potentiella smittbärare. Ambulanssjuksköterskan arbetar nära patienten och ofta i trånga utrymmen vilket innebär en ökad risk för smittspridning. Syfte: Syftet med studien var att beskriva ambulanssjuksköterskans upplevelser av hur vårdandet av patienten påverkas under COVID-19 pandemin. Metod: För att besvara syftet genomfördes en intervjustudie med induktiv innehållsanalys. Urvalet innefattade sex ambulanssjuksköterskor. Resultat: Ambulanssjuksköterskorna beskrev att skyddsutrustningen har påverkat vårdandet genom att vården fördröjs, kommunikationen försvåras samt att vårdarbetet försvåras. Hygienrutinerna har ändrats och vården av patienterna påverkas i dels bedömning och behandling, dels i handläggningen av patienterna. Okunskap gällande det nya viruset skapade en osäkerhet. Resultatet påvisar även en rädsla för att bli smittade hos ambulanssjuksköterskorna. Diskussion och slutsats: COVID-19 pandemin har påverkat det prehospitala vårdandet av patienten på flera sätt. Ambulanssjuksköterskorna upplevde att informationen och rutinerna gällande vården under pandemin var bristfällig vilket stämde överens med annan befintlig forskning. Upplevelsen av fysiska hinder och kommunikationssvårigheter som förekom under användning av skyddsutrustning var fynd som framkom även i tidigare forskning och slutsatsen gjordes att COVID-19 pandemin komplicerat vårdande av patienterna prehospitalt. Ökad beredskap inför framtida kriser och utveckling av skyddsutrustningen för att minska negativ påverkan på vårdarbetet är förslag på förbättringsarbete.
206

Clinical and epidemiological characteristics of children with sars-cov-2 infection admitted to a peruvian hospital

Rodríguez-Portilla, Ricardo, Llaque-Quiroz, Patricia, Guerra-Ríos, Claudia, Cieza-Yamunaqué, Liliana Paola, Coila-Paricahua, Edgar Juan, Baique-Sánchez, Pedro Michael, Pinedo-Torres, Isabel 01 April 2021 (has links)
We carried out an observational, retrospective and descriptive study in order to identify the clinical and epidemiological characteristics of children with SARS-CoV-2 infection admitted to a Peruvian national referral hospital. We included patients from one month old to fourteen years old hospitalized between March and August 2020. A total of 125 patients with SARS-CoV-2 infection were admitted, 18.4% (n = 23) had critical illness and 16.8% (n = 21) had multisystem inflammatory syndrome (MIS-C). The absence of comorbidities and previous history of epidemiological contact were more frequent in patients with MIS-C. Patients in critical condition and patients with MIS-C had lower lymphocyte and platelet counts, and higher C-reactive protein, ferritin and D-dimer values than patients who did not have said conditions. Six (4.8%) out of 125 children died, as well as 3 (13%) children from the group of patients in critical condition. None of the children with MIS-C died. / Revisión por pares
207

Nutritional Implications in SARS-CoV-2

Daff, Kaitlyn M. 06 August 2020 (has links)
No description available.
208

Blood Type Effect on COVID-19 Infection And Tooth Movement

Lerman, Avigael, 0000-0003-1721-4294 January 2022 (has links)
Introduction: The objective of this study was to explore the influence of ABO blood type on COVID-19 infection rate. Discovered relationships may uncover whether genetic makeup may affect treatments and such information could be related to orthodontic tooth movements. Methods: The PubMed database was searched using the terms: ABO Blood Group System; Blood-Group System, ABO; System, ABO Blood-Group; H Blood Group System; H Blood Group; Blood Group, H; ABH Blood Group; Blood Group, ABH; Blood Group H Type 1 Antigen; ABO Factors; Factors, ABO. Also included, were studies of ABO blood type and COVID infection or outcomes. Opinion pieces, animal studies, in-vitro studies, studies using blood other than ABO, and pre-2000 papers were excluded, as were studies that were not published in or translated to English. Of the included studies, the references were manually screened to identify additional qualified studies. Two independent reviewers reviewed the initial batch of reports to select the appropriate publications. To resolve conflicts, they met to discuss for a consensus. Studies were appraised by the Joanna Briggs Institute appraisal index. For the meta-analysis, studies which used odds ratio in their statistical analysis and COVID-19 infection as an outcome were included. Outcomes were analyzed using Forest Plots. Results: Overall, this systematic review included 39 studies. 19 studies were cohort (2 prospective and 17 retrospective), 16 retrospective case control, and 4 were systematic reviews or meta-analysis. 31 studies reported a relationship between ABO blood type and COVID infection rates and 5 studies found no relationship. For the meta-analysis, 13 studies were included and analyzed. The estimated frequency of COVID-19 infection in terms of ABO blood groups and the overall effect size between blood groups was calculated with 95% confidence interval. The effect size of COVID-19 infection for blood group O versus the other blood groups was estimated as 0.174 (95% CI, o.o86-0.261) p<0.001. The effect size of COVID-19 infection for blood group A versus non-A was estimated as -0.174 (95% CI, -o.248- -0.100) p<0.001. The effect size of COVID-19 infection for blood group B versus non-B was estimated as -0.010 (95% CI, -0.107-0.086) p=0.831. The effect size of COVID-19 infection for blood group AB versus non-AB was estimated as -0.140 (95% CI, -o.344-0.064) p=0.179. Conclusion: This meta-analysis indicates individuals with type O blood may be less susceptible to COVID-19 infection while those with type A blood may be more susceptible. Numerous studies, however, were not methodologically strong, as they had small sample size or suffered selection bias. Furthermore, no randomized controlled trials to determine causal relationships were found. Clearly this is understandable, given the speed with which the studies needed to be published. Despite such limitation, these findings have important implications for orthodontics because it may indicate that those with variants of Type A blood are more prone to inflammation, as orthodontic tooth movement is facilitated by the inflammatory responses of periodontal tissues. / Oral Biology
209

Construction of the Social Distance Scale and the Relationship Between Trait Empathy and Social Distancing

Prachthauser, Michaela 01 January 2021 (has links)
This paper describes the development of a brief self-report screening measure of adherence to social distancing and self-protective behaviors in pandemic situations. It provides initial statistical evaluations of correlations between social distancing behaviors and two trait measures (social desirability and trait empathy). Items measures were designed to quantify behaviors recommended by the CDC as primary strategies to prevent and reduce the spread of the COVID-19 infection. An item pool of 29 questions was generated with the aim of estimating the frequency of specific behaviors and were written to avoid confounding the description of behavioral actions with evaluative judgements. Responses were collected from 401 young adults using an anonymous online survey. An Exploratory Factor Analysis was conducted with the purpose of item reduction and subscale development. A 14-item Social Distance Scale (SDS) emerged, consisting of 4-subscales: Isolation from Community (IC), Work from Home (WH), Family Contact (FC), and Protective Behaviors (PB). The initial psychometric evaluation of the scales indicated adequate internal consistency and test-retest reliability. The Social Distance Scale is a promising new instrument which may be applied at the population or individual level. It may be used in conjunction with COVID-19 testing to measure interactions between social distancing factors and transmission. In addition, a reliable screening measure has utility for health service providers to assess patient risk and to provide education/counseling. A secondary purpose of this research was to examine the relationship between trait empathy and social distancing. A MANCOVA was performed using the four subscales of the SDS v.1 with Empathy Group and Gender Group as fixed factors and the Socially Desirable Response Set (SDRS-5) as a covariate. The SDRS-5 was found to be a significant covariate for both the IC and PB subscales of the SDS v.1 , where higher levels of socially desirable responding lead to higher scores on IC and PB. It was hypothesized that participants high in self-reported trait empathy would demonstrate higher levels of social distancing. Indeed it was found that a significant main effect for Empathy Group emerged, where Empathy Group was significantly related to IC, WH, and PB. In line with expectations, participants in the High Empathy Group scored higher on these three dimensions of social distancing than those in the Low Empathy Group. A significant main effect for Gender Group was obtained for PB. Women were found to be significantly more likely to engage in protective behaviors such as hand washing, mask wearing, and maintaining 6 feet of distance than men.
210

Ramipril Reduces Acylcarnitines and Distinctly Increases Angiotensin-Converting Enzyme 2 Expression in Lungs of Rats

Kosacka, Joanna, Berger, Claudia, Ceglarek, Uta, Hoffmann, Anne, Blüher, Matthias, Klöting, Nora 12 June 2023 (has links)
The angiotensin-converting enzyme 2 (ACE2) receptor has been identified as the entry receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is abundantly expressed in many organs. With respect to the role of circulating ACE2 and its receptor expression in the pathogenesis of the SARS-CoV-2 infection, it is still debated whether diseases such as hypertension or pharmacotherapies, including ACE inhibitors and angiotensin receptor blockers that affect ACE2 receptor expression, may modulate the severity and outcome of the coronavirus disease 2019 (COVID-19). We therefore tested the hypothesis that treatment with the ACE inhibitor Ramipril affects organ-specific ACE2 receptor mRNA and protein expression as well as the serum metabolome in BioBreeding (BB) rats. Twelve male BioBreeding rats were randomly divided into a Ramipril (10 mg/kg body weight) treatment group or a control group (N = 12; n = 6 per group) over a period of seven days. Ramipril treatment resulted in the reduction of acylcarnitines (C3–C6) out of 64 metabolites. Among the different organs studied, only in the lungs did Ramipril treatment significantly increase both Ace2 mRNA and ACE2 receptor membrane protein levels. Increased ACE2 receptor lung expression after Ramipril treatment was not associated with differences in ACE2 serum concentrations between experimental groups. Our data provide experimental in vivo evidence that the ACE inhibitor Ramipril selectively increases pulmonary ACE2 receptor mRNA and protein levels and reduces acylcarnitines.

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