Production of cadmium sulfide quantum dots by the lithobiontic Antarctic strain Pedobacter sp. UYP1 and their application as photosensitizer in solar cells

Indexación ScopusBackground: Microbes are present in almost every environment on Earth, even in those with extreme environmental conditions such as Antarctica, where rocks may represent the main refuge for life. Lithobiontic communities are composed of microorganisms capable of colonizing rocks and, as it is a not so well studied bacterial community, they may represent a very interesting source of diversity and functional traits with potential for biotechnological applications. In this work we analyzed the ability of Antarctic lithobiontic bacterium to synthesize cadmium sulfide quantum dots (CdS QDs) and their potential application in solar cells. Results: A basaltic andesite rock sample was collected from Fildes Peninsula, King George Island, Antarctica, and processed in order to isolate lithobiontic bacterial strains. Out of the 11 selected isolates, strain UYP1, identified as Pedobacter, was chosen for further characterization and analysis due to its high cadmium tolerance. A protocol for the biosynthesis of CdS QDs was developed and optimized for this strain. After 20 and 80 min of synthesis, yellow-green and orange-red fluorescent emissions were observed under UV light, respectively. QDs were characterized through spectroscopic techniques, dynamic light scattering analysis, high-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. Nanostructures of 3.07 nm, composed of 51.1% cadmium and 48.9% sulfide were obtained and further used as photosensitizer material in solar cells. These solar cells were able to conduct electrons and displayed an open circuit voltage of 162 mV, a short circuit current density of 0.0110 mA cm−2, and had an efficiency of conversion up to 0.0016%, which is comparable with data previously reported for solar cells sensitized with biologically produced quantum dots. Conclusions: We report a cheap, rapid and eco-friendly protocol for the production of CdS QDs by an Antarctic lithobiontic bacterium, Pedobacter, a genus that was not previously reported as a quantum dot producer. The application of the biosynthesized QDs as sensitizer material in solar cells was validated. © 2021, The Author(s).https://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-021-01531-

The immunogenicity and safety of a reduced PRP-content DTPw-HBV/Hib vaccine when administered according to the accelerated EPI schedule

<p>Abstract</p> <p>Background</p> <p>Combination vaccines improve coverage, compliance and effectively introduce new antigens to mass vaccination programmes. This was a phase III, observer-blind, randomized study of GSK Biologicals diphtheria-tetanus-whole cell pertussis vaccine combined with hepatitis B and <it>Haemophilus influenzae </it>type b vaccines, containing a reduced amount of polyribosyl-ribitol-phosphate (PRP) and a DTPw component manufactured at a different site (DTPw-HBV/Hib_2.5[Kft]). The primary aim of this study was to demonstrate that DTPw-HBV/Hib_2.5[Kft] was not inferior to the licensed DTPw-HBV/Hib (<it>Tritanrix</it>(tm)-HepB/<it>Hiberix</it>(tm)) vaccine or the DTPw-HBV/Hib_2.5vaccine, also containing a reduced amount of PRP, with respect to the immune response to the PRP antigen, when administered to healthy infants, according to the Expanded Programme for Immunization (EPI) schedule at 6, 10 and 14 weeks of age.</p> <p>Methods</p> <p>299 healthy infants were randomised to receive either DTPw-HBV/Hib_2.5[Kft] DTPw-HBV/Hib_2.5or DTPw-HBV/Hib according to the 6-10-14 week EPI schedule. Blood samples were analysed prior to the first dose of study vaccine and one month after the third vaccine dose for the analysis of immune responses. Solicited local and general symptoms such as pain, redness and swelling at the injection site and drowsiness and fever, unsolicited symptoms (defined as any additional adverse event) and serious adverse events (SAEs) were recorded up to 20 weeks of age.</p> <p>Results</p> <p>One month after the third vaccine dose, 100% of subjects receiving DTPw-HBV/Hib_2.5[Kft] or DTPw-HBV/Hib and 98.8% of subjects receiving DTPw-HBV/Hib_2.5vaccine had seroprotective levels of anti-PRP antibodies (defined as anti-PRP antibody concentration ≥0.15 μg/ml). Seroprotective antibody concentrations were attained in over 98.9% of subjects for diphtheria, tetanus and hepatitis B. The vaccine response rate to pertussis antigen was at least 97.8% in each group. Overall, the DTPw-HBV/Hib_2.5[Kft] vaccine was well tolerated in healthy infants; no SAEs were reported in any group.</p> <p>Conclusions</p> <p>The DTPw-HBV/Hib_2.5[Kft] vaccine was immunogenic and well-tolerated when administered according to the EPI schedule to Indian infants.</p> <p>Trial registration</p> <p><url>http://www.clinicaltrials.gov</url> NCT00473668</p

Primary and booster vaccination in Latin American children with a DTPw-HBV/Hib combination: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Diphtheria-tetanus-whole-cell pertussis (DTPw)-based combination vaccines are an attractive option to rapidly achieve high coverage and protection against other important pathogens, such as hepatitis B virus (HBV) and <it>Haemophilus influenzae </it>type B (Hib). To ensure adequate antigen supply, GlaxoSmithKline Biologicals has introduced a new DTPw antigen source and developed a new DTPw-HBV/Hib combination vaccine containing a reduced amount of Hib polyribosylribitol phosphate (PRP). This study was undertaken to compare the immunogenicity and reactogenicity of this new DTPw-HBV/Hib vaccine with a licensed DTPw-HBV/Hib vaccine (<it>Tritanrix</it>™-HBV/Hib).</p> <p>Methods</p> <p>This was a randomized, partially-blind, multicenter study in three countries in Latin America (Argentina, Chile and Nicaragua). Healthy children received either the new DTPw-HBV/Hib vaccine (1 of 3 lots; n = 439; double-blind) or Tritanrix™-HBV/Hib (n = 146; single-blind) co-administered with oral poliovirus vaccine (OPV) at 2, 4 and 6 months, with a booster dose at 18-24 months.</p> <p>Results</p> <p>One month after the end of the 3-dose primary vaccination course, the new DTPw-HBV/Hib vaccine was non-inferior to Tritanrix™-HBV/Hib in terms of seroprotection/vaccine response rates for all component antigens; ≥97.3% and ≥93.9% of subjects in the two groups, respectively, had seroprotective levels of antibodies against diphtheria, tetanus, hepatitis B and Hib and a vaccine response to the pertussis component. Persistence of antibodies against all vaccine antigens was comparable between groups, with marked increases in all antibody concentrations after booster administration in both groups. Both vaccines were generally well-tolerated as primary and booster doses.</p> <p>Conclusions</p> <p>Results confirm the suitability of this new DTPw-HBV/Hib vaccine comprising antigens from a new source and a reduced PRP content for inclusion into routine childhood vaccination programs.</p> <p>Trial registration</p> <p><url>http://www.clinicaltrials.gov</url> NCT00332566</p

Adaptación cultural al español del instrumento de evaluación de funcionalidad física en Unidad de Paciente Crítico: “The Chelsea Critical Care Physical Assessment Tool (CPAx)”

Las Unidades de Cuidados Intensivos (UCI), presentan una sobrevida cada vez mayor de los pacientes que ingresan a ellas, donde se ven enfrentados a una nueva entidad fisiopatológica llamada Debilidad Muscular Adquirida en UCI (DAUCI). Algunos test desarrollados para la evaluación de función motriz, que permiten objetivar la progresión del paciente, son la escala de fuerza muscular del Medical Research Council (MRC), el Functional status score for the intensive care unit (FSS-ICU) y el “Chelsea Critical Care Physical Assessment Tool (CPAx). La ventaja del CPAx radica en que este test incluye mayor información asociada al funcionamiento humano como recomienda la OMS, incorporando tanto el componente ventilatorio (que también se ve deteriorado por DAUCI) como neuromuscular lo que permite al profesional kinesiólogo tener una herramienta objetiva más completa del nivel funcional del paciente. Para que sea confiable, todo test debe ser validado en el país donde quiere aplicarse, pero antes de esto debe ser adaptado culturalmente. El objetivo de este trabajo fue efectuar la adaptación transcultural (AT) al español del test de funcionalidad física de aplicación kinésica CPAx. Se utilizó el proceso establecido por Beaton y cols que incluye la formación de un comité de expertos multidisciplinario que da una visión integral a la adaptación y una prueba piloto en que kinesiólogos de UCI sin capacitación previa del test lo lean, posteriormente lo apliquen y entreguen sus observaciones. Conclusiones: Realizar la AT permite dimensionar la importancia que tiene cada una de las etapas de este proceso. El test es el mismo, equivalente al original, pero contiene nuestras características culturales y condiciones técnicas, que lo hace ser comprensible y aplicable en nuestro país. Esta adaptación transcultural también es útil a nivel latinoamericano; para los países de habla hispana que quieran validarlo tenerlo adaptado al español, hace el proceso menos complejo. Palabras clave: Evaluación funcional, Unidad de cuidados intensivos, CPAx, adaptación transcultural