Thermal Stability of Self-Assembled Monolayers of n-Hexanethiol on Au(111)-(1 × 1) and Au(001)-(1 × 1)

Thermal desorption in an ultrahigh vacuum of n-hexanethiol (C6T) self-assembled monolayers (SAMs) prepared from ethanolic solutions on Au(111) and Au(001) unreconstructed surfaces was investigated by X-ray photoelectron spectroscopy. The SAMs desorption was performed from room temperature (RT) to 380 K. We report that the hexanethiolate surface saturation coverage is bigger (∼0.4 ML) for the SAM on Au(001) than on Au(111) (∼0.33 ML). We identified a greater stability for C6T SAMs on Au(001). Large amounts of physisorbed species were found on preferred oriented (111) polycrystalline Au at the low coverage regime at RT, while the SAM on the Au(001) single crystal at this conditions desorbs at a steady pace. At 340 K, both SAMs remain stable at the coverage expected for the lying-down phases that maximizes the van der Waals interactions. We observe that at higher temperatures the carbon alpha-sulfur bond breaks, producing free S on both gold surfaces.Fil: Cristina, Lucila Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Ruano Sandoval, Gustavo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Salvarezza, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Ferron, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Materiales; Argentin

FLAG Review 2021

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereWe review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor f+(0) arising in the semileptonic K→ π transition at zero momentum transfer, as well as the decay constant ratio fK/ fπ and its consequences for the CKM matrix elements Vus and Vud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2) L× SU(2) R and SU(3) L× SU(3) R Chiral Perturbation Theory. We review the determination of the BK parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for mc and mb as well as those for the decay constants, form factors, and mixing parameters of charmed and bottom mesons and baryons. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant αs. We consider nucleon matrix elements, and review the determinations of the axial, scalar and tensor bilinears, both isovector and flavor diagonal. Finally, in this review we have added a new section reviewing determinations of scale-setting quantitie

Cytochrome P450 from Plants: Platforms for Valuable Phytopharmaceuticals

Cytochrome P450 enzymes are important for biotechnology due to their capacity to modify diverse secondary metabolites that may produce chemicals with pharmacological properties. Most terpenes, flavonoids and alkaloids require P450 catalytic functions to reach their biological activity. In the last ten years, several efforts have focused on the expression and production of these three main types of secondary metabolites in engineered microorganisms and plants using P450 of ethnobotanical origin. Despite this, several P450 coding sequences from plant sources are discovered yearly but only a few have been screened by functional genomics. Amongst them, only a few have shown potentials for use in sustainable production of novel drugs and highly valuable products. Cytochrome P450 involvement in the biosynthesis of these products is discussed in this work.Keywords: Biotechnological platforms, Cytochrome P450, Phytopharmaceuticals, Yield improvement, Terpenes, Flavonoids, Alkaloids, Microbial expressio

Surfactant protein D modulates HIV infection of both T-cells and dendritic cells

Surfactant Protein D (SP-D) is an oligomerized C-type lectin molecule with immunomodulatory properties and involvement in lung surfactant homeostasis in the respiratory tract. SP-D binds to the enveloped viruses, influenza A virus and respiratory syncytial virus and inhibits their replication in vitro and in vivo. SP-D has been shown to bind to HIV via the HIV envelope protein gp120 and inhibit infectivity in vitro. Here we show that SP-D binds to different strains of HIV (BaL and IIIB) and the binding occurs at both pH 7.4 and 5.0 resembling physiological relevant pH values found in the body and the female urogenital tract, respectively. The binding of SP-D to HIV particles and gp120 was inhibited by the presence of several hexoses with mannose found to be the strongest inhibitor. Competition studies showed that soluble CD4 and CVN did not interfere with the interaction between SP-D and gp120. However, soluble recombinant DC-SIGN was shown to inhibit the binding between SP-D and gp120. SP-D agglutinated HIV and gp120 in a calcium dependent manner. SP-D inhibited the infectivity of HIV strains at both pH values of 7.4 and 5.0 in a concentration dependent manner. The inhibition of the infectivity was abolished by the presence of mannose. SP-D enhanced the binding of HIV to immature monocyte derived dendritic cells (iMDDCs) and was also found to enhance HIV capture and transfer to the T-cell like line PM1. These results suggest that SP-D can bind to and inhibit direct infection of T-cells by HIV but also enhance the transfer of infectious HIV particles from DCs to T-cells in vivo

Sources of Community Health Worker Motivation: A Qualitative Study in Morogoro Region, Tanzania.

There is a renewed interest in community health workers (CHWs) in Tanzania, but also a concern that low motivation of CHWs may decrease the benefits of investments in CHW programs. This study aimed to explore sources of CHW motivation to inform programs in Tanzania and similar contexts. We conducted semi-structured interviews with 20 CHWs in Morogoro Region, Tanzania. Interviews were digitally recorded, transcribed, and coded prior to translation and thematic analysis. The authors then conducted a literature review on CHW motivation and a framework that aligned with our findings was modified to guide the presentation of results. Sources of CHW motivation were identified at the individual, family, community, and organizational levels. At the individual level, CHWs are predisposed to volunteer work and apply knowledge gained to their own problems and those of their families and communities. Families and communities supplement other sources of motivation by providing moral, financial, and material support, including service fees, supplies, money for transportation, and help with farm work and CHW tasks. Resistance to CHW work exhibited by families and community members is limited. The organizational level (the government and its development partners) provides motivation in the form of stipends, potential employment, materials, training, and supervision, but inadequate remuneration and supplies discourage CHWs. Supervision can also be dis-incentivizing if perceived as a sign of poor performance. Tanzanian CHWs who work despite not receiving a salary have an intrinsic desire to volunteer, and their motivation often derives from support received from their families when other sources of motivation are insufficient. Policy-makers and program managers should consider the burden that a lack of remuneration imposes on the families of CHWs. In addition, CHWs' intrinsic desire to volunteer does not preclude a desire for external rewards. Rather, adequate and formal financial incentives and in-kind alternatives would allow already-motivated CHWs to increase their commitment to their work

Assessment of Surfactant Protein A (SP-A) dependent agglutination

Background: Monomers of the collectin surfactant associated protein-A (SP-A) are arranged in trimers and higher oligomers. The state of oligomerization differs between individuals and likely affects SP-A's functional properties. SP-A can form aggregates together with other SP-A molecules. Here we report and assess a test system for the aggregate forming properties of SP-A in serum and broncho-alveolar lavage samples. Methods: Anti-SP-A antibodies fixed to latex beads bound SP-A at its N-terminal end and allowed the interaction with other SP-A molecules in a given sample by their C-terminal carbohydrate recognition domain (CRD) to agglutinate the beads to aggregates, which were quantified by light microscopy. Results: SP-A aggregation was dependent on its concentration, the presence of calcium, and was dose-dependently inhibited by mannose. Unaffected by the presence of SP-D no aggregation was observed in absence of SP-A. The more complex the oligomeric structure of SP-A present in a particular sample, the better was its capability to induce aggregation at a given total concentration of SP-A. SP-A in serum agglutinated independently of the pulmonary disease; in contrast SP-A in lung lavage fluid was clearly inferior in patients with chronic bronchitis and particularly with cystic fibrosis compared to controls. Conclusions: The functional status of SP-A with respect to its aggregating properties in serum and lavage samples can be easily assessed. SP-A in lung lavage fluid in patients with severe neutrophilic bronchitis was inferior

Evaluación bio-económica de alojamientos y densidades de siembra para el cultivo de caracoles comestibles de agua dulce (Pomacea flagellata Say, 1827)

Existe información limitada sobre el cultivo de caracoles de agua dulce del orden Mesogastropoda y familia Ampullaridae en El Salvador. La mayoría de la población desconoce este recurso y los beneficios potenciales que tiene para la familia de las zonas rurales. El alojamiento y la densidad del caracol Pomacea flagellata Say fue evaluado durante 180 días en la Piscigranja de la Escuela de Biología de la Universidad de El Salvador. Los tratamientos fueron: tanque de asbesto con densidad de 1 caracol / 3 litros de agua, tanque de asbesto con 1 caracol / 6 litros de agua, recipientes plásticos con 1 caracol / 3 litros de agua y recipientes plásticos con 1 caracol / 6 litros de agua. Se utilizó el diseño estadístico completamente al azar, con cinco repeticiones por tratamiento. La cantidad de caracoles por repetición varió según la densidad. La regresión lineal se usó para conocer la relación entre peso y tamaño. Además se realizó un análisis bromatológico y un parasitológico. Las variables evaluadas fueron: peso, tamaño, sobrevivencia, rendimiento de material comestible y comparación de peso con tamaño. También se realizó una comparación económica (presupuesto parcial). No se observó diferencia significativa en peso y tamaño. En el rendimiento se obtuvo significancia estadística (p=0.028) y el valor mayor fue 59.44% en recipientes plásticos con 1 caracol / 6 litros de agua. La mayor sobrevivencia correspondió al recipiente plástico con 1 caracol / 3 litros de agua con un 97.95%. Se obtuvo una relación lineal positiva entre el peso y el tamaño (r²=0.96, 0.96 y 0.95% para altura, diámetro y eje de la concha, respectivamente). En el presupuesto parcial todos los tratamientos resultaron con beneficios netos negativos, debido a las bajas densidades, el costo de los alojamientos y transporte. Según el análisis bromatológico, la proteína y grasa en base seca del material comestible fueron 51.50 % y 5.60 %, respectivamente. En el parasitológico únicamente se observaron quistes de amibas de vida libre de Endolimax nana. La principal conclusión fue: el peso y tamaño de los caracoles durante el crecimiento fue similar estadísticamente para todos los tratamientos.There is limited information about freshwater snails order Mesogastropoda and family Ampullaridae in El Salvador. The majority of people do not know this resource and its potential benefits. This research was developed at the fish farm of the School of Biology, University of El Salvador. The effect of housing and density in the production of Pomacea flagellata Say was evaluated during 180 days. The treatments were: asbestos tank with snail density of 1/3 liters of water, asbestos tank with snail density of 1/6 liters of water, plastic containers with snail density of 1/3 liters of water and plastic containers with snail density of 1/6 liters of water. Was used the statistical design completely randomized with five replicates per treatment. The variables evaluated were: weight, height, diameter, axis of the shell, yield, survival and weight compared with size. Was used an economical comparison using partial budget. There was no significant difference between weight, height, diameter and axis of the shell; while the yield of edible material was obtained statistical significance (p = 0.028). The highest value was 58.91% in plastic containers with 1 snail / 6 lt of water. The best survival results corresponded to plastic containers with 1/3 liters of water with 97.95%. In the comparison of weight and size was a positive relation between the variables (r²=0.96, 0.96 y 0.95 % for height, diameter and axis of the shell). In the partial budget showed in all treatments, net profits were negative due to low densities and high cost of the housing and transportation. The edible material analysis showed high protein and low fat in dry basis: 51.50 % y 5.60 %. The parasitological diagnosis reported Endolimax nana. The main conclusion was: the weight and size for the snails during the growth was statistically similar for all treatments

La Constitución Europea. Una visión desde Euskadi

Jornada: La Constitución Europea. Una visión desde Euskadi 15 de febrero de 200