17 research outputs found
Theory and phenomenology of two-Higgs-doublet models
We discuss theoretical and phenomenological aspects of two-Higgs-doublet
extensions of the Standard Model. In general, these extensions have scalar
mediated flavour changing neutral currents which are strongly constrained by
experiment. Various strategies are discussed to control these flavour changing
scalar currents and their phenomenological consequences are analysed. In
particular, scenarios with natural flavour conservation are investigated,
including the so-called type I and type II models as well as lepton-specific
and inert models. Type III models are then discussed, where scalar flavour
changing neutral currents are present at tree level, but are suppressed by
either specific ansatze for the Yukawa couplings or by the introduction of
family symmetries. We also consider the phenomenology of charged scalars in
these models. Next we turn to the role of symmetries in the scalar sector. We
discuss the six symmetry-constrained scalar potentials and their extension into
the fermion sector. The vacuum structure of the scalar potential is analysed,
including a study of the vacuum stability conditions on the potential and its
renormalization-group improvement. The stability of the tree level minimum of
the scalar potential in connection with electric charge conservation and its
behaviour under CP is analysed. The question of CP violation is addressed in
detail, including the cases of explicit CP violation and spontaneous CP
violation. We present a detailed study of weak basis invariants which are odd
under CP. A careful study of spontaneous CP violation is presented, including
an analysis of the conditions which have to be satisfied in order for a vacuum
to violate CP. We present minimal models of CP violation where the vacuum phase
is sufficient to generate a complex CKM matrix, which is at present a
requirement for any realistic model of spontaneous CP violation.Comment: v3: 180 pages, 506 references, new chapter 7 with recent LHC results;
referee comments taken into account; submitted to Physics Report
An optimized protocol for combined fluorescent lectin/immunohistochemistry to characterize tissue-specific glycan distribution in human or rodent tissues
: Lectin histochemical analysis of tissues combined with immunohistochemistry is a valuable tool to characterize and correlate the spatial distribution of glycans with the presence of specific cell types or antigens of interest. The current protocol describes the application of monosaccharide motif specificity of lectin binding to glycan residues to different tissue types. In addition, we describe stereological methods to provide further quantification of the analyzed tissues. For complete details on the use and execution of this protocol, please refer to Mohd Isa et al. (2018), Contessotto et al. (2020), and Samal et al. (2020)
Capacidade antioxidante e atividade biológica do óleo essencial e extrato metanólico de Hyptis crenata Pohl ex Benth
The essential oils of fresh and dried leaves and fine stems of Hyptis crenata furnished the following yields: 1.4% and 0.9%. The main volatile constituents were α-pinene (22.0%; 19.5%), 1,8-cineole (17.6%; 23.2%), β-pinene (17.0%; 13.8%), camphor (4.7%; 11.6%), limonene (5.4%; 4.4%) and γ-terpinene (3.5%; 2.4%), totalizing more than 70% in the oils. The DPPH radical scavenging activity (EC50, 16.7 + 0.4 µg/mL) of the methanol extract was comparable to BHT (19.8 ± 0.5 µg/mL) showing a significant antioxidant activity. The oils showed low activities. The amount of total phenolics (TP, 373.0 + 15.9 mg GAE/g) and trolox equivalent (TEAC, 226.8 + 0.5 mg TE/g) confirmed the antioxidant activity of the methanol extract that can be attributed to the presence of polar phenolic compounds. In the brine shrimp bioassay the lethal concentrations (LC50) for the oil and methanol extract were 6.7 + 0.2 µg/mL and 13.0 + 3.7 µg/mL, respectively, providing important evidence of their biological activities.O óleo essencial das folhas e ramos finos frescos e secos de Hyptis crenata forneceu os seguintes rendimentos, 1,4% e 0,9%. Os constituintes voláteis principais foram α-pineno (22,0%; 19,5%), 1,8-cineol (17,6%; 23,2%), β-pineno (17,0%: 13,8%), cânfora (4,7%; 11,6%), limoneno (5,4%; 4,4%) e γ-terpineno (3,5%; 2,4%), totalizando mais de 70% nos óleos. A atividade de seqüestro do radical DPPH para o extrato metanólico (CE50, 16,7 + 0,4 µg/mL) foi comparável ao do BHT (19,8 ± 0,5 µg/mL) mostrando uma significante atividade antioxidante. Os óleos apresentaram baixa atividade. O teor de fenólicos totais (TP, 373,0 + 15,9 mg GAE/g) e equivalente trolox (TEAC, 226,8 + 0,5 mg TE/g) confirmaram a atividade antioxidante do extrato metanólico, que pode ser atribuída à presença de compostos fenólicos polares. No teste com larvas de camarão as concentrações letais para o óleo e extrato metanólico foram 6,7 + 0,2 µg/mL e 13,0 + 3,7 µg/mL, respectivamente, fornecendo importante evidência de suas atividade biológicas
Antioxidant capacity and biological activity of essential oil and methanol extract of Conobea scoparioides (Cham. & Schltdl.) Benth
The essential oils of the sub-aquatic plant Conobea scoparioides (fresh and dried previously) showed yields of 3.4 and 3.3%, respectively. The main identified constituents were thymol methyl ether (39.6 and 47.7%), thymol (40.0 and 26.4%), α-phellandrene (12.1 and 14.3%) and p-cymene (1.5 and 1.7%), totalizing more than 90% of the oils. The DPPH radical scavenging activity (EC50) of the oils and extract was 46.7 ± 3.6 µg mL-1 in the fresh plant (CsO-f), 56.1 ± 2.4 µg mL-1 in the dried plant (CsO-d), and 23.0 ± 2.2 µg mL -1 in the methanol extract. The extract (CsE-d)value is comparable to BHT (19.8 ± 0.5 µg mL-1) used as antioxidant standard. The mean value of the oils is twice smaller but equally important as antioxidant agent. The mean amount of Total Phenolics (TP, 124.6 ± 8.7 mg GAE per g) and the Trolox Equivalent (TEAC, 144.1 ± 4.9 mg TE per g) of the methanol extract confirmed the significant antioxidant activity of C. scoparioides. Similarly, in the brine shrimp bioassay (Artemia salina) the mean value of the lethal concentration for the oils (CL50, 7.7 ± 0.3 µg mL-1) was ten times higher than the methanol extract (CL50, 77.6 ± 7.1 µg mL-1) showing important biological activity.Os óleos essenciais da planta sub-aquática Conobea scoparioides (fresca e previamente seca) apresentaram rendimentos de 3,4 e 3,3%, respectivamente. Os principais constituintes identificados foram o éter metílico do timol (39,6 e 47,7%), timol (40,0 e 26,4%), α-felandreno (12,1 e 14,3%) e p-cimeno (1,5 e 1,7%), totalizando mais de 90% nos referidos óleos. A concentração de seqüestro do radical DPPH (CE50) dos óleos e extrato foi de 46,7 ± 3,6 µg mL-1 para a planta fresca (CsO-f), de 56,1 ± 2,4 µg mL-1 para a planta seca (CsO-d), e de 23,0 ± 2,2 µg mL-1 para o extrato metanólico (CsE-d). O valor do extrato é comparável ao BHT (19,8 ± 0,5 µg mL-1), usado como padrão antioxidante. O valor médio dos óleos é duas vezes menor, mas igualmente importante como agente antioxidante. O teor de Fenólicos Totais (TP, 124,6 ± 8,7 mg GAE per g) e o Trolox Equivalente (TEAC, 144,1 ± 4,9 mg TE per g) do extrato metanólico confirmaram a significativa atividade antioxidante de C. scoparioides. Da mesma forma, nos bioensaios com larva de camarão (Artemia salina) o valor médio da concentração letal dos óleos (CL50, 7,7 ± 0,3 µg mL-1) foi dez vezes maior que no extrato metanólico (CL50, 77,6 ± 7,1 µg mL-1) mostrando importante atividade biológica
Genetic analysis of patients with familial and sporadic amyotrophic lateral sclerosis in a Brazilian Research Center
<p><i>Objective</i>: To investigate gene mutations in familial form (FALS) and sporadic form (SALS) of amyotrophic lateral sclerosis (ALS) in a highly miscegenated population. <i>Methods</i>: Frequencies of mutations in the <i>C9orfF72</i>, <i>TARDBP</i>, <i>SOD1</i>, <i>FUS</i> and <i>VAPB</i> genes were investigated in a cohort of FALS (<i>n</i> = 39) and SALS (<i>n</i> = 189) subjects from the Research Centre of the University of São Paulo School of Medicine. All patients were subjected to <i>C9orf72</i> and <i>TARDBP</i> analyses. <i>SOD1</i>, <i>FUS</i> and <i>VAPB</i> were also evaluated in FALS subjects. <i>Results</i>: Mutations were identified in FALS (61.3%) and SALS (5.3%) patients. Mutations in <i>C9orf72</i> (12.8%, >45 GGGGCC hexanucleotide repeats), <i>VAPB</i> (43.6%, P56S) and <i>SOD1</i> (7.7%, <i>L145S</i>) were identified in FALS subjects. Pathogenic <i>C9orf72</i> expansions (2.64%) were identified in some SALS patients. Similar changes of <i>TARDBP</i> were found in SALS (2.64%) but not in FALS subjects. No <i>FUS</i> mutations were seen in any FALS subjects. <i>Conclusions</i>: <i>TARDBP</i> and <i>C9orf72</i> mutations in this cohort were similar to those found in other centres worldwide. <i>VAPB</i> mutation (P56S) was highly prevalent in Brazilian FALS patients.</p