70 research outputs found
Electrochemical Fabrication of Hybrid Plasmonic-dielectric Nanomaterial Based on Gold-diamond Clusters
Hybrid plasmonic-dielectric material were fabricated by micro-discharge through water sols of sub-micrometer-sized diamonds mixed with HAuCl4 acid. Primary characterization of their deposits on a silicon wafer surface by means of electron microscopy and energy-dispersive x-ray spectroscopy indicate close proximity of gold nanoparticles and diamond particles, which is supported by photoluminescence studies demonstrating strong â almost two-fold â damping of diamond luminescence owing to the attachment of gold nanoparticles. UV-near IR spectroscopy of their sols consistently exhibits small red spectral shifts for the fabricated nanomaterial, comparing to bare gold nanoparticles. Keywords: micro-diamonds, gold nanoparticles, hybrid plasmonic-dielectric material, electrochemical fabrication, electron microscopy and optical characterization.Hybrid plasmonic-dielectric material were fabricated by micro-discharge through water sols of sub-micrometer-sized diamonds mixed with HAuCl4 acid. Primary characterization of their deposits on a silicon wafer surface by means of electron microscopy and energy-dispersive x-ray spectroscopy indicate close proximity of gold nanoparticles and diamond particles, which is supported by photoluminescence studies demonstrating strong â almost two-fold â damping of diamond luminescence owing to the attachment of gold nanoparticles. UV-near IR spectroscopy of their sols consistently exhibits small red spectral shifts for the fabricated nanomaterial, comparing to bare gold nanoparticles
Two plant-associated Bacillus velezensis strains selected after genome analysis, metabolite profiling, and with proved biocontrol potential, were enhancing harvest yield of coffee and black pepper in large field trials
Elimination of chemically synthesized pesticides, such as fungicides and nematicides, in agricultural products is a key to successful practice of the Vietnamese agriculture. We describe here the route for developing successful biostimulants based on members of the Bacillus subtilis species complex. A number of endospore-forming Gram-positive bacterial strains with antagonistic action against plant pathogens were isolated from Vietnamese crop plants. Based on their draft genome sequence, thirty of them were assigned to the Bacillus subtilis species complex. Most of them were assigned to the species Bacillus velezensis. Whole genome sequencing of strains BT2.4 and BP1.2A corroborated their close relatedness to B. velezensis FZB42, the model strain for Gram-positive plant growth-promoting bacteria. Genome mining revealed that at least 15 natural product biosynthesis gene clusters (BGCs) are well conserved in all B. velezensis strains. In total, 36 different BGCs were identified in the genomes of the strains representing B. velezensis, B. subtilis, Bacillus tequilensis, and Bacillus. altitudinis. In vitro and in vivo assays demonstrated the potential of the B. velezensis strains to enhance plant growth and to suppress phytopathogenic fungi and nematodes. Due to their promising potential to stimulate plant growth and to support plant health, the B. velezensis strains TL7 and S1 were selected as starting material for the development of novel biostimulants, and biocontrol agents efficient in protecting the important Vietnamese crop plants black pepper and coffee against phytopathogens. The results of the large-scale field trials performed in the Central Highlands in Vietnam corroborated that TL7 and S1 are efficient in stimulating plant growth and protecting plant health in large-scale applications. It was shown that treatment with both bioformulations resulted in prevention of the pathogenic pressure exerted by nematodes, fungi, and oomycetes, and increased harvest yield in coffee, and pepper.Peer Reviewe
Vaccine effectiveness against COVID-19 hospitalisation in adults (â„âŻ20 years) during Alpha- and Delta-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021
Members of the I-MOVE-COVID-19 and VEBIS hospital study teams (in addition to the named authors): Svjetlana Karabuva, Petra TomaĆĄ PetriÄ, Marija MarkoviÄ, Sandra LjubiÄiÄ, Bojana MahmutoviÄ, Irena Tabain, Petra Smoljo, Iva Pem Novosel, Tanya Melillo, John Paul Cauchi, BenĂ©dicte Lissoir, Xavier Holemans, Marc Hainaut, Nicolas Dauby, Benedicte Delaere, Marc Bourgeois, Evelyn Petit, Marijke Reynders, Door Jouck, Koen Magerman, Marieke Bleyen, Melissa Vermeulen, SĂ©bastien Fierens, François Dufrasne, Siel Daelemans, Alaâa Al Kerwi, Francoise Berthet, Guy Fagherazzi, Myriam Alexandre, Charlene Bennett, Jim Christle, Jeff Connell, Peter Doran, Laura Feeney, Binita Maharjan, Sinead McDermott, Rosa McNamara, Nadra Nurdin, Salif Mamadou CissĂ©, Anne-Sophie L'Honneur, Xavier Duval, Yolande Costa, Fidouh Nadhira, Florence Galtier, Laura Crantelle, Vincent Foulongne, Phillipe Vanhems, SĂ©lilah Amour, Bruno Lina, Fabrice LainĂ©, Laetitia Gallais, GisĂšle Lagathu, Anna Maisa, Yacine Saidi, Christine Durier, Rebecca Bauer, Ana Paula Rodrigues, Adriana Silva, Raquel Guiomar, Margarida Tavares, DĂ©bora Pereira, Maria JosĂ© Manata, Heidi Gruner, AndrĂ© Almeida, Paula Pinto, Cristina BĂĄrbara, Itziar Casado, Ana Miqueleiz, Ana NavascuĂ©s, Camino Trobajo-SanmartĂn, Miguel FernĂĄndez-Huerta, MarĂa Eugenia Portillo, Carmen Ezpeleta, Nerea EgĂŒĂ©s, Manuel GarcĂa Cenoz, Eva Ardanaz, Marcela Guevara, Conchi Moreno-Iribas, Hana OrlĂkovĂĄ, Carmen Mihaela Dorobat, Carmen Manciuc, Simin Aysel Florescu, Alexandru Marin, Sorin Dinu, Catalina Pascu, Alina Ivanciuc, Iulia Bistriceanu, Mihaela Oprea, Maria Elena Mihai, Silke Buda, Ute Preuss, Marianne Wedde, AuksÄ MickienÄ, GiedrÄ GefenaitÄ, Alain Moren, Anthony NardoneIntroduction:
Two large multicentre European hospital networks have estimated vaccine effectiveness (VE) against COVID-19 since 2021.
Aim:
We aimed to measure VE against PCR-confirmed SARS-CoV-2 in hospitalised severe acute respiratory illness (SARI) patientsââ„â20 years, combining data from these networks during Alpha (MarchâJune)- and Delta (JuneâDecember)-dominant periods, 2021.
Methods:
Forty-six participating hospitals across 14 countries follow a similar generic protocol using the test-negative caseâcontrol design. We defined complete primary series vaccination (PSV) as two doses of a two-dose or one of a single-dose vaccineââ„â14 days before onset.
Results:
We included 1,087 cases (538 controls) and 1,669 cases (1,442 controls) in the Alpha- and Delta-dominant periods, respectively. During the Alpha period, VE against hospitalisation with SARS-CoV2 for complete Comirnaty PSV was 85% (95%âŻCI: 69â92) overall and 75% (95%âŻCI: 42â90) in those agedââ„â80 years. During the Delta period, among SARI patientsââ„â20 years with symptom onsetââ„â150 days from last PSV dose, VE for complete Comirnaty PSV was 54% (95%âŻCI: 18â74). Among those receiving Comirnaty PSV and mRNA booster (any product)ââ„â150 days after last PSV dose, VE was 91% (95%âŻCI: 57â98). In time-since-vaccination analysis, complete all-product PSV VE wasâ>â90% in those with their last doseâ<â90 days before onset;ââ„â70% in those 90â179 days before onset.
Conclusions:
Our results from this EU multi-country hospital setting showed that VE for complete PSV alone was higher in the Alpha- than the Delta-dominant period, and addition of a first booster dose during the latter period increased VE to over 90%.Key public health message: - What did you want to address in this study? To understand how well the COVID-19 vaccine was performing in Europe against hospitalisation during SARS-CoV-2 Alpha and Delta variant periods, we present vaccine effectiveness results from a multi-country study of complete and booster dose COVID-19 vaccination among adults (aged 20 years and over).
- What have we learnt from this study? Between March and June 2021 (Alpha period), vaccine effectiveness against hospitalisation with laboratory-confirmed SARS-CoV-2 was 43% for partial vaccination and 86% for complete vaccination. For June to December 2021 (Delta period), vaccine effectiveness for complete vaccination was lower (52%) but with addition of an mRNA booster dose, effectiveness reached 91%, and remainedâ>â90% up to 119 days after the booster dose.
- What are the implications of your findings for public health? In Europe in 2021, COVID-19 vaccine effectiveness results for the Alpha period indicated an excellent benefit for preventing hospitalisation after complete vaccination. During Delta variant circulation, however, a booster dose was required to achieve this level of effectiveness, and this was maintained for up to 4 months post booster.info:eu-repo/semantics/publishedVersio
Vaccine effectiveness against COVID-19 hospitalisation in adults (â„âŻ20 years) during Omicron-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021 to 2022
Introduction: The I-MOVE-COVID-19 and VEBIS hospital networks have been measuring COVID-19 vaccine effectiveness (VE) in participating European countries since early 2021. Aim: We aimed to measure VE against PCR-confirmed SARS-CoV-2 in patients â„ 20 years hospitalised with severe acute respiratory infection (SARI) from December 2021 to July 2022 (Omicron-dominant period). Methods: In both networks, 46 hospitals (13 countries) follow a similar test-negative case-control protocol. We defined complete primary series vaccination (PSV) and first booster dose vaccination as last dose of either vaccine received â„ 14 days before symptom onset (stratifying first booster into received < 150 and â„ 150 days after last PSV dose). We measured VE overall, by vaccine category/product, age group and time since first mRNA booster dose, adjusting by site as a fixed effect, and by swab date, age, sex, and presence/absence of at least one commonly collected chronic condition. Results: We included 2,779 cases and 2,362 controls. The VE of all vaccine products combined against hospitalisation for laboratory-confirmed SARS-CoV-2 was 43% (95% CI: 29-54) for complete PSV (with last dose received â„ 150 days before onset), while it was 59% (95% CI: 51-66) after addition of one booster dose. The VE was 85% (95% CI: 78-89), 70% (95% CI: 61-77) and 36% (95% CI: 17-51) for those with onset 14-59 days, 60-119 days and 120-179 days after booster vaccination, respectively. Conclusions: Our results suggest that, during the Omicron period, observed VE against SARI hospitalisation improved with first mRNA booster dose, particularly for those having symptom onset < 120 days after first booster dose.Key public health message: 1. What did you want to address in this study?
In order to understand how well the COVID-19 vaccine is performing in Europe against hospitalisation during the period when the SARS-CoV-2 Omicron variant was circulating, we investigated vaccine effectiveness using data from a multi-country study of complete and booster-dose COVID-19 vaccination among adults aged 20 years and over.
2. What have we learnt from this study?
Between December 2021 and July 2022, vaccine effectiveness against hospitalisation with laboratory-confirmed SARS-CoV-2 was 43% for complete vaccination. With addition of an mRNA booster dose, effectiveness was 59% overall. It was higher when onset of illness was close to the date of the last vaccination, at 85% when last booster dose was 14â59 days before onset, at 70% for 60â119 days, and falling below 40% for 120â179 days.
3. What are the implications of your findings for public health?
In European hospital settings in 2022, during the Omicron period, COVID-19 mRNA booster vaccine provided an improved benefit for preventing hospitalisation, particularly if disease onset was within 4 months of receiving the booster dose.info:eu-repo/semantics/publishedVersio
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
COVID-19 Vaccines against Omicron Variant: Real-World Data on Effectiveness
The efficacy of vaccines against coronavirus disease 2019 (COVID-19) has now been well established in phase III clinical trials. However, clinical studies based on real-world data remain critical to assess vaccines effectiveness (VE), especially in specific populations and against variants of concern (VOC). This review presents the principles and methods of VE studies and the main available results on VE of COVID-19 vaccines at the time of Omicron circulation. References for this narrative review were identified through searches of PubMed database up to 13 September 2022. The results of phase III clinical trials have been globally confirmed by VE in real-life studies, including in the elderly. Emergence of VOC Omicron emphasized the importance of booster doses to maintain a high level of protection against severe forms. There are still numerous challenges regarding booster(s) and duration of immunity, particularly in specific subpopulations, and regarding the need for adapted vaccines
Performance of two simplified HBV treatment criteria (TREAT-B score and WHO guidelines) in Burkina Faso, West Africa
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Metaâanalysis: Risk of hepatitis C virus infection associated with hospitalâbased invasive procedures
International audienceBackgroundHealthcare settings, where invasive procedures are frequently performed, may play an important role in the transmission dynamics of blood-borne pathogens when compliance with infection control precautions is suboptimal.AimsTo understand and quantify the role of hospital-based invasive procedures on hepatitis C virus (HCV) transmission.MethodsWe conducted a systematic review and meta-analysis to identify recent studies reporting association measures of HCV infection risk that are linked to iatrogenic procedures. Based on expert opinion, invasive procedures were categorised into 10 groups for which pooled measures were calculated. Finally, the relationship between pooled measures and the country-level HCV prevalence or the Healthcare Access and Quality (HAQ) index was assessed by meta-regression.ResultsWe included 71 studies in the analysis. The most frequently evaluated procedures were blood transfusion (66 measures) and surgery (43 measures). The pooled odds ratio (OR) of HCV infection varied widely, ranging from 1.46 (95% confidence interval: 1.14â1.88) for dental procedures to 3.22 (1.7â6.11) for transplantation. The OR for blood transfusion was higher for transfusions performed before 1998 (3.77, 2.42â5.88) than for those without a specified/recent date (2.20, 1.77â2.75). In procedure-specific analyses, the HCV infection risk was significantly negatively associated with the HAQ for endoscopy and positively associated with HCV prevalence for endoscopy and surgery.ConclusionsVarious invasive procedures were significantly associated with HCV infection. Our results provide a ranking of procedures in terms of HCV risk that may be used for prioritisation of infection control interventions, especially in high HCV prevalence settings
Metaâanalysis: Risk of hepatitis C virus infection associated with hospitalâbased invasive procedures
International audienceBackgroundHealthcare settings, where invasive procedures are frequently performed, may play an important role in the transmission dynamics of blood-borne pathogens when compliance with infection control precautions is suboptimal.AimsTo understand and quantify the role of hospital-based invasive procedures on hepatitis C virus (HCV) transmission.MethodsWe conducted a systematic review and meta-analysis to identify recent studies reporting association measures of HCV infection risk that are linked to iatrogenic procedures. Based on expert opinion, invasive procedures were categorised into 10 groups for which pooled measures were calculated. Finally, the relationship between pooled measures and the country-level HCV prevalence or the Healthcare Access and Quality (HAQ) index was assessed by meta-regression.ResultsWe included 71 studies in the analysis. The most frequently evaluated procedures were blood transfusion (66 measures) and surgery (43 measures). The pooled odds ratio (OR) of HCV infection varied widely, ranging from 1.46 (95% confidence interval: 1.14â1.88) for dental procedures to 3.22 (1.7â6.11) for transplantation. The OR for blood transfusion was higher for transfusions performed before 1998 (3.77, 2.42â5.88) than for those without a specified/recent date (2.20, 1.77â2.75). In procedure-specific analyses, the HCV infection risk was significantly negatively associated with the HAQ for endoscopy and positively associated with HCV prevalence for endoscopy and surgery.ConclusionsVarious invasive procedures were significantly associated with HCV infection. Our results provide a ranking of procedures in terms of HCV risk that may be used for prioritisation of infection control interventions, especially in high HCV prevalence settings
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