Wet anaerobic digestion of organic fraction of municipal solid waste: experience with long-term pilot plant operation and industrial scale-up.

This paper presents the analysis of a pilot anaerobic digestion plant that operates with organic fraction of municipal solid waste (OFMSW) from a wholesale market and can treat up to 500 kg d-1. The process was monitored for a period of 524 days during which the residue was characterized and the biogas production and methane content were recorded. The organic load rate (OLR) of volatile solids (VS) was 0.89 kg m-3 d-1 and the Hydraulic Retention Time (HRT) was 25 d during the process. The yield was 82 Nm3 tons OFMSW-1 biogas, equivalent to 586 Nm3 tons CH4 VS-1. The results obtained in the pilot plant were used to carry out a technical-economic evaluation of a plant that treats 50 tons of OFMSW from wholesale markets. A production of 3769 Nm3 d-1 of biogas and 2080 Nm3 d-1 of methane is estimated, generating 35.1 MWh d-1 when converted to electricity.

Characterization and expression analysis of WRKY genes during leaf and corolla senescence of Petunia hybrida plants.

Several families of transcription factors (TFs) control the progression of senescence. Many key TFs belonging to the WRKY family have been described to play crucial roles in the regulation of leaf senescence, mainly in Arabidopsis thaliana. However, little is known about senescence-associated WRKY members in floricultural species. Delay of senescence in leaves and petals of Petunia hybrida, a worldwide ornamental crop are highly appreciated traits. In this work, starting from 28 differentially expressed WRKY genes of A. thaliana during the progression of leaf senescence, we identified the orthologous in P. hybrida and explored the expression profiles of 20 PhWRKY genes during the progression of natural (age-related) leaf and corolla senescence as well as in the corollas of flowers undergoing pollination-induced senescence. Simultaneous visualization showed consistent and similar expression profiles of PhWRKYs during natural leaf and corolla senescence, although weak expression changes were observed during pollination-induced senescence. Comparable expression trends between PhWRKYs and the corresponding genes of A. thaliana were observed during leaf senescence, although more divergence was found in petals of pollinated petunia flowers. Integration of expression data with phylogenetics, conserved motif and cis-regulatory element analyses were used to establish a list of candidates that could regulate more than one senescence process. Our results suggest that several members of the WRKY family of TFs are tightly linked to the regulation of senescence in P. hybrida. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01243-y.

Blood pressure control is not enough to normalize endothelial repair by progenitor cells.

Patients presenting with classical cardiovascular risk factors within acceptable or average value ranges often develop cardiovascular disease, suggesting that other risk factors need to be considered. Considering that endothelial progenitor cells (EPCs) contribute to endothelial repair, we investigated whether EPCs might be such a factor. We compared the ability of peripheral blood EPCs to attach to extracellular matrix proteins and to grow and function in culture, between controlled hypertensive patients exhibiting a Framingham score (FS) of <10% while showing severe vascular impairment (intima-media thickness/diameter, carotid-femoral pulse wave velocity, brachial artery flow-mediated dilation, carotid and femoral atherosclerotic plaque presence; vulnerable group, N = 30) and those with an FS of ≥10% and scarce vascular changes (protected group, N = 30). When compared with vulnerable patients, protected patients had significantly higher early and late-EPC and early and late-tunneling nanotube (TNT) numbers. Significant negative associations were found between vascular damage severity and early EPC, late-EPC, or late-TNT numbers, whereas EPC or TNT numbers and patient characteristics or cardiovascular risk factors were not associated. Except for protected patients, in all controlled hypertensive patients, early and late-EPC and early and late-TNT counts were significantly lower than those in the normotensive subjects studied (N = 30). We found that the disparity in vascular status between patients presenting with both an FS of ≥10% and scarce vascular changes and those presenting with both an FS of <10% and severe vascular impairment is related to differences in peripheral blood EPC and TNT numbers. These observations support the role of EPCs as contributors to vascular injury repair and suggest that EPC numbers may be a potential cardiovascular risk factor to be included in the FS calculation.NEW & NOTEWORTHY As individuals who present with risk factors within acceptable or average value ranges often develop cardiovascular (CV) disease, it has been suggested that other CV risk factors need to be considered in addition to those that are commonly combined in the Framingham score (FS) to estimate the risk of general CV disease. We investigated whether peripheral endothelial progenitor cells (EPCs) and tunneling nanotubes (TNTs) deserve to be considered. Here we report that EPCs and TNTs are significantly lower in controlled hypertensive patients versus normotensive subjects and that the disparity in vascular status between patients presenting with an FS of ≥10% with scarce vascular changes and those presenting with an FS of <10% with severe vascular impairment is related to differences in EPC and TNT numbers. These data point to EPC and TNT numbers as potential CV risk factors to be included in the FS calculation.

Draft genome sequence data of Cercospora kikuchii, a causal agent of Cercospora leaf blight and purple seed stain of soybeans.

Cercospora kikuchii (Tak. Matsumoto & Tomoy.) M.W. Gardner 1927 is an ascomycete fungal pathogen that causes Cercospora leaf blight and purple seed stain on soybean. Here, we report the first draft genome sequence and assembly of this pathogen. The C. kikuchii strain ARG_18_001 was isolated from soybean purple seed collected from San Pedro, Buenos Aires, Argentina, during the 2018 harvest. The genome was sequenced using a 2 × 150 bp paired-end method by Illumina NovaSeq 6000. The C. kikuchii protein-coding genes were predicted using FunGAP (Fungal Genome Annotation Pipeline). The draft genome assembly was 33.1 Mb in size with a GC-content of 53%. The gene prediction resulted in 14,856 gene models/14,721 protein coding genes. Genomic data of C. kikuchii presented here will be a useful resource for future studies of this pathosystem. The data can be accessed at GenBank under the accession number VTAY00000000 https://www.ncbi.nlm.nih.gov/nuccore/VTAY00000000.

Identification and expression analysis of NAC transcription factors potentially involved in leaf and petal senescence in Petunia hybrida.

Progression of leaf senescence depends on several families of transcription factors. In Arabidopsis, the NAC family plays crucial roles in the modulation of leaf senescence; however, the mechanisms involved in this NAC-mediated regulation have not been extensively explored in agronomic species. Petunia hybrida is an ornamental plant that is commonly found worldwide. Decreasing the rate of leaf and petal senescence in P. hybrida is essential for maintaining plant quality. In this study, we examined the NAC-mediated networks involved in regulating senescence in this species. From 41 NAC genes, the expression of which changed in Arabidopsis during leaf senescence, we identified 29 putative orthologs in P. hybrida. Analysis using quantitative real-time-PCR indicated that 24 genes in P. hybrida changed their transcript levels during natural leaf senescence. Leaf-expressed genes were subsequently assessed in petals undergoing natural and pollination-induced senescence. Expression data and phylogenetic analysis were used to generate a list of 10-15 candidate genes; 7 of these were considered key regulatory candidates in senescence because of their consistent upregulation in the three senescence processes examined. Altogether, we identified common and distinct patterns of gene expression at different stages of leaf and petal development and during progression of senescence. The results obtained in this study will contribute to the understanding of NAC-mediated regulatory networks in petunia.

A Novel Phospholipase A2 Isolated from Palythoa caribaeorum Possesses Neurotoxic Activity.

Zoanthids of the genus Palythoa are distributed worldwide in shallow waters around coral reefs. Like all cnidarians, they possess nematocysts that contain a large diversity of toxins that paralyze their prey. This work was aimed at isolating and functionally characterizing a cnidarian neurotoxic phospholipase named A2-PLTX-Pcb1a for the first time. This phospholipase was isolated from the venomous extract of the zoanthid Palythoa caribaeorum. This enzyme, which is Ca2+-dependent, is a 149 amino acid residue protein. The analysis of the A2-PLTX-Pcb1a sequence showed neurotoxic domain similitude with other neurotoxic sPLA2´s, but a different catalytic histidine domain. This is remarkable, since A2-PLTX-Pcb1a displays properties like those of other known PLA2 enzymes.

Recombinant O-mannosylated protein production (PstS-1) from Mycobacterium tuberculosis in Pichia pastoris (Komagataella phaffii) as a tool to study tuberculosis infection.

BACKGROUND: Pichia pastoris (syn. Komagataella phaffii) is one of the most highly utilized eukaryotic expression systems for the production of heterologous glycoproteins, being able to perform both N- and O-mannosylation. In this study, we present the expression in P. pastoris of an O-mannosylated recombinant version of the 38 kDa glycolipoprotein PstS-1 from Mycobacterium tuberculosis (Mtb), that is similar in primary structure to the native secreted protein. RESULTS: The recombinant PstS-1 (rPstS-1) was produced without the native lipidation signal. Glycoprotein expression was under the control of the methanol-inducible promoter pAOX1, with secretion being directed by the α-mating factor secretion signal. Production of rPstS-1 was carried out in baffled shake flasks (BSFs) and controlled bioreactors. A production up to ~ 46 mg/L of the recombinant protein was achieved in both the BSFs and the bioreactors. The recombinant protein was recovered from the supernatant and purified in three steps, achieving a preparation with 98% electrophoretic purity. The primary and secondary structures of the recombinant protein were characterized, as well as its O-mannosylation pattern. Furthermore, a cross-reactivity analysis using serum antibodies from patients with active tuberculosis demonstrated recognition of the recombinant glycoprotein, indirectly indicating the similarity between the recombinant PstS-1 and the native protein from Mtb. CONCLUSIONS: rPstS-1 (98.9% sequence identity, O-mannosylated, and without tags) was produced and secreted by P. pastoris, demonstrating that this yeast is a useful cell factory that could also be used to produce other glycosylated Mtb antigens. The rPstS-1 could be used as a tool for studying the role of this molecule during Mtb infection, and to develop and improve vaccines or kits based on the recombinant protein for serodiagnosis.

Platelet-Poor and Platelet-Rich Plasma Stimulate Bone Lineage Differentiation in Periodontal Ligament Stem Cells.

BACKGROUND: Plasma-derived fractions have been used as an autologous source of growth factors; however, limited knowledge concerning their biologic effects has hampered their clinical application. In this study, the authors analyze the content and specific effect of both platelet-rich plasma (PRP) and platelet-poor plasma (PPP) on osteoblastic differentiation using primary cultures of human periodontal ligament stem cells (HPLSCs). METHODS: The authors evaluated the growth factor content of PRP and PPP using a proteome profiler array and enzyme-linked immunosorbent assay. HPLSCs were characterized by flow cytometry and differentiation assays. The effect of PRP and PPP on HPLSC bone differentiation was analyzed by quantifying calcium deposition after 14 and 21 days of treatment. RESULTS: Albeit at different concentrations, the two fractions had similar profiles of growth factors, the most representative being platelet-derived growth factor (PDGF) isoforms (PDGF-AA, -BB, and -AB), insulin-like growth factor binding protein (IGFBP)-2, and IGFBP-6. Both formulations exerted a comparable stimulus on osteoblastic differentiation even at low doses (2.5%), increasing calcium deposits in HPLSCs. CONCLUSIONS: PRP and PPP showed a similar protein profile and exerted comparable effects on bone differentiation. Further studies are needed to characterize and compare the effects of PPP and PRP on bone healing in vivo.

Sympathetic predominance is associated with impaired endothelial progenitor cells and tunneling nanotubes in controlled-hypertensive patients.

Early endothelial progenitor cells (early EPC) and late EPC are involved in endothelial repair and can rescue damaged endothelial cells by transferring organelles through tunneling nanotubes (TNT). In rodents, EPC mobilization from the bone marrow depends on sympathetic nervous system activity. Indirect evidence suggests a relation between autonomic derangements and human EPC mobilization. We aimed at testing whether hypertension-related autonomic imbalances are associated with EPC impairment. Thirty controlled-essential hypertensive patients [systolic blood pressure/diastolic blood pressure = 130(120-137)/85(61-88) mmHg; 81.8% male] and 20 healthy normotensive subjects [114(107-119)/75(64-79) mmHg; 80% male] were studied. Mononuclear cells were cultured on fibronectin- and collagen-coated dishes for early EPC and late EPC, respectively. Low (LF)- and high (HF)-frequency components of short-term heart rate variability were analyzed during a 5-min rest, an expiration/inspiration maneuver, and a Stroop color-word test. Modulations of cardiac sympathetic and parasympathetic activities were evaluated by LF/HF (%) and HF power (ms(2)), respectively. In controlled-hypertensive patients, the numbers of early EPC, early EPC that emitted TNT, late EPC, and late EPC that emitted TNT were 41, 77, 50, and 88% lower than in normotensive subjects (P < 0.008), respectively. In controlled-hypertensive patients, late EPC number was positively associated with cardiac parasympathetic reserve during the expiration/inspiration maneuver (rho = 0.45, P = 0.031) and early EPC with brachial flow-mediated dilation (rho = 0.655; P = 0.049); also, late TNT number was inversely related to cardiac sympathetic response during the stress test (rho = -0.426, P = 0.045). EPC exposure to epinephrine or norepinephrine showed negative dose-response relationships on cell adhesion to fibronectin and collagen; both catecholamines stimulated early EPC growth, but epinephrine inhibited late EPC growth. In controlled-hypertensive patients, sympathetic overactivity/parasympathetic underactivity were negatively associated with EPC, suggesting that reducing sympathetic/increasing parasympathetic activation might favor endothelial repair.

Effect of coastal urbanization on sandy beach coleoptera Phaleria maculata (Kulzer, 1959) in northern Chile.

The beetle Phaleria maculata is a common inhabitant of the upper intertidal fringe of Chilean beaches. Anthropogenic intervention in coastal areas has increased intensely, leading to changes in the flora and fauna of sandy beaches. To examine the impact of human activities on P. maculata, we studied several beaches along the northern Chilean coast. Beaches were characterized based on morphodynamics and the level of intervention, leading to the estimation of an "Urbanization Index" based on various indicators. The analysis showed a significant inverse correlation between the rate of urbanization and night sky quality. Larval and adult beetles were almost absent on beaches with high levels of urbanization. The results of simple and multiple correlations based on nMDS ordination showed an inverse relationship between increases in urbanization and the abundance of beetles. Because darkling beetles are very sensitive to human interventions on sandy beaches, we suggest that they are ideal indicator organisms for the health of these environments.

A Conus regularis conotoxin with a novel eight-cysteine framework inhibits CaV2.2 channels and displays an anti-nociceptive activity.

A novel peptide, RsXXIVA, was isolated from the venom duct of Conus regularis, a worm-hunting species collected in the Sea of Cortez, México. Its primary structure was determined by mass spectrometry and confirmed by automated Edman degradation. This conotoxin contains 40 amino acids and exhibits a novel arrangement of eight cysteine residues (C-C-C-C-CC-CC). Surprisingly, two loops of the novel peptide are highly identical to the amino acids sequence of ω-MVIIA. The total length and disulfide pairing of both peptides are quite different, although the two most important residues for the described function of ω-MVIIA (Lys2 and Tyr13) are also present in the peptide reported here. Electrophysiological analysis using superior cervical ganglion (SCG) neurons indicates that RsXXIVA inhibits CaV2.2 channel current in a dose-dependent manner with an EC50 of 2.8 µM, whose effect is partially reversed after washing. Furthermore, RsXXIVA was tested in hot-plate assays to measure the potential anti-nociceptive effect to an acute thermal stimulus, showing an analgesic effect in acute thermal pain at 30 and 45 min post-injection. Also, the toxin shows an anti-nociceptive effect in a formalin chronic pain test. However, the low affinity for CaV2.2 suggests that the primary target of the peptide could be different from that of ω-MVIIA.

Bioactive peptides from marine organisms: a short overview.

Marine organisms are an immense source of new biologically active compounds. These compounds are unique because the aqueous environment requires a high demand of specific and potent bioactive molecules. Diverse peptides with a wide range of biological activities have been discovered, including antimicrobial, antitumoral, and antiviral activities and toxins amongst others. These proteins have been isolated from different phyla such as Porifera, Cnidaria, Nemertina, Crustacea, Mollusca, Echinodermata and Craniata. Purification techniques used to isolate these peptides include classical chromatographic methods such as gel filtration, ionic exchange and reverse-phase HPLC. Multiple in vivo and in vitro bioassays are coupled to the purification process to search for the biological activity of interest. The growing interest to study marine natural products results from the discovery of novel pharmacological tools including potent anticancer drugs now in clinical trials. This review presents examples of interesting peptides obtained from different marine organisms that have medical relevance. It also presents some of the common methods used to isolate and characterize them.

Sodium intake is associated with parasympathetic tone and metabolic parameters in mild hypertension.

BACKGROUND: Although the impairment of parasympathetic cardiac control was described in hypertensives submitted to a high salt diet, the impact of this autonomic abnormality on metabolic and inflammation markers in patients with mild hypertension has not been explored. METHODS: Four hundred and ninety mild essential hypertensive patients (144 ± 9/94 ± 9 mm Hg, 49.5 ± 13.9 years, 67.9 % male) were studied. Dietary sodium intake was estimated by measuring 24-h urinary sodium excretion (UNa), and the patients were classified according to UNa levels as follows: low (<50 mEq/l), medium (50-99 mEq/l), and high UNa (≥100 mEq/l). Parasympathetic tone was evaluated by assessing heart rate recovery (HRR) after an exercise stress test. HRR, plasma lipids, glucose metabolism, and inflammatory biomarkers were compared across UNa groups. RESULTS: HRR and high-density lipoprotein (HDL)-cholesterol were progressively lower, and insulin (INS), homeostasis model assessment of insulin resistance (HOMAir), ultrasensitive-C-reactive protein (usCRP) were progressively higher across increasing UNa groups. In the low and medium UNa groups, HDL-cholesterol was higher and CRP was lower than that in high UNa (P < 0.01 and P < 0.05, respectively) (Dunnett post-hoc test). In the low UNa group, triglycerides (TGs), INS, and HOMAir were lower than that in high UNa (P < 0.05). Multiple linear regression analysis showed that UNa, HOMAir, and heart rate (HR) were negatively associated with HRR (P < 0.0001, P < 0.0001, and P = 0.001, respectively). CONCLUSIONS: In the essential hypertensive patients studied high sodium intake is associated with parasympathetic inhibition, lipid disturbances, and inflammation. Studies designed to assess causality between sodium intake and metabolic and autonomic status are needed to evaluate the relevance of controlling sodium intake, especially in hypertensive patients.

Turning symmetric an asymmetric hydrogen bond with the inclusion of nuclear quantum effects: the case of the [CN···H···NC]- complex.

Nuclear quantum effects (NQE) on the geometry, energy, and electronic structure of the [CN·L·NC](-) complex (L = H, D, T) are investigated with the recently developed APMO/MP2 code. This code implements the nuclear molecular orbital approach (NMO) at the Hartree-Fock (HF) and MP2 levels of theory for electrons and quantum nuclei. In a first study, we examined the H/D/T isotope effects on the geometry and electronic structure of the CNH molecule at NMO/HF and NMO/MP2 levels of theory. We found that when increasing the hydrogen nuclear mass there is a reduction of the R(N-H) bond distance and an increase of the electronic population on the hydrogen atom. Our calculated bond distances are in good agreement with experimental and other theoretical results. In a second investigation, we explored the hydrogen NQE on the geometry of [CNHNC](-) complex at the NMO/HF and NMO/MP2 levels of theory. We discovered that while a NMO/HF calculation presented an asymmetric hydrogen bond, the NMO/MP2 calculation revealed a symmetric H-bond. We also examined the H/D/T isotope effects on the geometry and stabilization energy of the [CNHNC](-) complex. We noted that gradual increases in hydrogen mass led to reductions of the R(NN) distance and destabilization of the hydrogen bond (H-bond). A discussion of these results is given in terms of the hydrogen nuclear delocalization effects on the electronic structure and energy components. To the best of our knowledge, this is the first ab initio NMO study that reveals the importance of including nuclear quantum effects in conventional electronic structure calculations for an enhanced description of strong-low-barrier H-bonded systems.

Secondary hydrogen isotope effects on the structure and stability of cation-pi complexes (cation = Li(+), Na(+), K(+) and pi = acetylene, ethylene, benzene).

Secondary hydrogen isotope effects on the geometries, electronic wave functions and binding energies of cation-pi complexes (cation = Li(+), Na(+), K(+) and pi = acetylene, ethylene, benzene) are investigated with NEO/HF and NEO/MP2 methods. These methods determine both electronic and nuclear wave functions simultaneously. Our results show that an increase of the hydrogen nuclear mass leads to the elongation of the cation-pi bond distance and the decrease in its binding energy. An explanation to this behavior is given in terms of the changes in the pi-molecule electronic structure and electrostatic potential induced by isotopic substitutions.

Implementación eel método del gradiente analítio de la energía en la teoría deel orbital molecular nuclear y electrónico / Implemetation off the analytical energygradient method in the nuclear and electronic molecular orbital theryy / Execução o métoddo de inclinação analític da energia na teoria do orbitaal molecular nuclaer e eletrônico

Con el fin optimizar las geometrías promedio de sistemas moleculares utilizando la teoría del orbital molecular nuclear y electrónico (OMNE), se dedujo la expresión para el cálculo del gradiente analítico de la energía a nivel de teoría Har-tree-Fock, para cualquier tipo de especie cuántica. La implementación computacional se realizó dentro del paquete APMO (Any-Particle Molecular Orbital), y con el fin de comprobar la correcta implementación del método se calcularon las moléculas modelo H2,HF y H2O, por medio de métodos numéricos y analíticos. El uso de derivadas analíticas dentro del formalismo OMNE permitirá el cálculo más eficiente de la estructura núcleo-electrónica de sistemas moleculares con el paquete APMO.

In order to optimize the average geometries of molecular systems using the nuclear and electronic molecular orbital theory (NEMO), we have deducted the expression for calculating the analytical gradient of the energy in the Hartree-Fock theory, for any kind quantum specie. The implementation was done within the computational package APMO (Any-Particle Molecular Orbital) and in order to verify the correct implementation of the method, we have calculated the model molecules H2, HF and H2O, with numerical and analytical methods. With the use of analytical derivatives within of the OMME formalism, we will have a more efficient calculation of the nuclear-electronic structure of molecular systems with the APMO package.

Com a finalidade de otimizar as geometrias médias de sistemas moleculares utilizando a teoria do orbital molecular nuclear e eletrônico (OMNE), se deduziu a expressão para o cálculo do gradiente Analítico da energia a nível de Hartree-Fock, para qualquer tipo de espécie quântica. A implementação computacional se realizou dentro do pacote APMO (Any-Particle Molecular Orbital), e com a finalidade de comprovar a correta implementação do método foram calculadas as moléculas modelo H2,HFeH2O, por meio de métodos numéricos e analíticos. O uso de derivadas analíticas dentro do formalismo OMNE vai permitir um cálculo mais eficiente da estrutura núcleo-eletrônica de sistemas moleculares com o pacote AMPO.

Estudio teóricoddel efecto isotópico de hidrógeno en el aducto borano-carbonilo / Theoretical study of the hydrogen isotope effect on the borane-carbonile adduct / Estudo teorico do efeito isotopico de hidrogeno no aducto borano-carbonilo

Se estudió el efecto de la sustitución isotópica de hidrógeno sobre la geometría, la estructura electrónica y la estabilidad del aducto borano-carbonilo, mediante el método de orbitales moleculares nucleares y electrónicos (OMNE) implementado en el paquete computacional APMO. Se encontró que el aumento de la masa isotópica acorta las distancias de enlace boro-isótopo y carbono-oxígeno, mientras que alarga la distancia boro-carbono. Se determinó además la estabilidad del aducto a partir de las energías de formación y las distancias de enlace B-C. Se encontró que el aumento de la masa isotópica debilita el enlace B-C. Una primera explicación de este fenómeno en términos del concepto de acidez de Lewis predijo resultados contrarios a los encontrados, mientras que un modelo de reactividad basado en las diferencias de las energías de los orbitales LUMO del borano permitió dar cuenta de este efecto.

We have investigated the hydrogen isotope effect on the geometry, the electronic structure and the stability of the borane-carbonile adduct, by using the nuclear-electronic molecular orbital method (NEMO) which has been implemented in the APMO software. We have found that an increase of the mass of the hydrogen isotope reduces the boron-hydrogen and carbon-oxygen bond lengths while increasing the boron-carbon distance. In this study, the stability of the adduct has been analyzed in terms of formation energies and B-C bond distances. We have found that the increase of the isotope mass weakens the B-C bond. We tried to give an explaination to this phenomenon based on Lewis acidity concept but it predicted the wrong results. A reactivity model based on the energy differences of borane LUMO orbitais offered a correct explaination to this effect.

Temos estudado o efeito da substituição de isótopos de hidrogénio sobre a geometria, estrutura electrónica e da estabilidade do aduto Borana-carbonil, através do mêtodo de orbitais moleculares-core versões (OMNE) implementado no pacote computacional APMO. Descobrimos que um aumento da isótopo massa encurta as distâncias de ligação boro-carbono-isotópica de oxigênio e aumenta a distância, enquanto boro-carbono. Foi ainda determinada a estabilidade do aduto de as energias de formação e distâncias de ligação BC. Nós descobrimos que o aumento da massa isotópica minar a relação BC. Uma explicação para este fenômeno em termos de conceito de acidez de Lewis predita resultados contrários aos encontrados enquanto um modelo baseado em diferenças de reatividade nas energias dos orbitais LUMO do Borana autorizados a conta para este efeito.

ESTUDIO DEL EFECTO DE ISOTÓPO DE HIDRÓGENO EN LOS COMPLEJOS M-HH-F (M=Li, Na) / INVESTIGATION OF THE HYDROGEN ISOTOPE EFFECT ON THE M-HH-F (M=Li, Na) COMPLEXES / ESTUDO DO EFEITO DO ISÓTOPO DO HIDROGÊNIO NO COMPLEXOS M-HH-F (M=Li, Na)

Se estudió teóricamente el efecto de isotópo de hidrógeno sobre la geometría, la distribución de carga electrónica, la estabilidad relativa y la energía de formación de complejos lineales tipo M-X-Y-F y todos sus isotopólogos de hidrógeno (M=Li, Na; X, Y= H, D, T). Estos estudios fueron realizados con el paquete computacional APMO a un nivel de teoría Hartree-Fock electrónico y nuclear. Los resultados obtenidos son acordes con resultados reportados por otros autores que usan métodos de estructura electrónica convencional.

We have carried out a theoretical investigacion of the hydrogen isotope effects on the geometry, the electronic charge distribution, the relative stability and the energy of formation of linear complexes of the type M-X-Y-F and all their hydrogen istopologues (M = Li, Na; X, Y= H, D, T). For this study we have utilized the APMO software at a nucleo-electronic Hartree-Fock level of theory. Our results are agreement with other reported theoretical data based on conventional electronic structure methods.

Foi estudado teoricamente o efeito do isótopo de hidrogênio sobre geometria, distribuição do carga eletrônica, a estabilidade relativa da energia e da formação do complexos lineares do tipo M-X-Y-F e todos os seus isotopólogos do hidrogênio (M = Li, Na, X, Y = H, D, T). Estes estudos foram realizados com o pacote computacional APMO para um nível da teoria Hartree-Fock eletrônica e nuclear. Os resultados são do acordo com os resultados relatados por outros autores que utilizam métodos do estrutura eletrônica convencionais.

Apmo: un prograaa computacional para el estudiode efectos cuánticos nucleares mediante la teoría del orbital molecular electrónico y no electrónico / Apmo: a comuter program based on the electronic and non-electronic molecular orbital theory for studies of nuclear quantum effetts / Apmo: umprogramaa computacional para o estudo dos efeito quânticos nuclleares por meio do teoria do orbital molecular eletrônico e não - elerôônico

Con el fin de estudiar teóricamente fenómenos en donde los núcleos atómicos presentan comportamiento cuántico, hemos desarrollado el paquete computacional APMO (Any-Particle Molecular Orbital). Éste implementa el método de orbitales moleculares nucleares y electrónicos (OMNE) a un nivel de teoría Hartree- Fock (HF), en el que tanto núcleos como electrones se representan como funciones de onda. Para comprobar la correcta implementación del método se realizaron cálculos de estructura electrónica regular y núcleo- electrónica de las moléculas H2 y LiH. Las componentes de energía calculadas siguen las tendencias y están en el mismo orden de magnitud de cálculos similares reportados en la literatura. A diferencia de otros paquetes que implementan el método OMNE, el nuestro fue diseñado para estudiar sistemas con cualquier número de especies cuánticas.

With the aim of studying phenomena where atomic nuclei have a quantal behavior, we have developed the APMO (Any-Particle Molecular Orbital) software package. This implements the nuclear and electronic molecular orbital approach (NEMO) at a Hartree-Fock level of theory, where both nuclei and electrons are represented as wave functions. To verify the correct implementation of the method, a number of electronic and nuclear-electronic calculations were carried out on H2 and LiH molecules. The calculated energy components follow the trends and are of the same order of magnitude of similar calculations reported in the literature. In contrast to other packages that implement the NEMO approach, ours is designed to allow for studying systems with any number of quantum particles.

Com a finalidade de estudar teoricamente fenômenos cujos núcleos atômicos apresentam comportamento quântico, desenvolvemos o pacote computacional APMO (Any-Particle Molecular Orbital). Este implementa o método de orbitais moleculares nucleares e eletrônicos (OMNE) no nível da teoria Hartree-Fock (HF), onde tanto núcleos como elétrons se apresentam como funções de onda. Para comprovar a utilização correta do método, se realizaram cálculos da estrutura eletrônica regular e do núcleo eletrônico das moléculas H_2 y LiH. Os componentes de energia calculados seguem as tendências e estão na mesma ordem de magnitude de cálculos similares reportados na literatura. Diferentemente de outros pacotes que utilizam o método OMNE, o nosso foi desenhado para estudar sistemas de qualquer número de espécies quânticas.

Wide phylogenetic distribution of Scorpine and long-chain beta-KTx-like peptides in scorpion venoms: identification of "orphan" components.

Scorpine and toxins specific for potassium channels of the family beta (beta-Ktx) are two types of structurally related scorpion venom components, characterized by an unusually long extended N-terminal segment, followed by a Cys-rich domain with some resemblance to other scorpion toxins. In this communication, we report evidence supporting the ubiquitous presence of Scorpine and beta-KTx-like polypeptides and their precursors in scorpions of the genus Tityus of the family Buthidae, but also included is the first example of such peptides in scorpions from the family Iuridae. Seven new beta-KTxs or Scorpine-like peptides and precursors are reported: five from the genus Tityus (T. costatus, T. discrepans and T. trivittatus) and two from Hadrurus gertschi. The cDNA precursors for all of these peptides were obtained by molecular cloning and their presence in the venoms were confirmed for various peptides. Analysis of the sequences revealed the existence of at least three distinct groups: (1) beta-KTx-like peptides from buthids; (2) Scorpine-like peptides from scorpionid and iurid scorpions; (3) heterogeneous peptides similar to BmTXKbeta of buthids and iurids. The biological function for most of these peptides is not well known; that is why they are here considered "orphan" peptides.