Electronic and structural properties of rare gas cation clusters

We study structure and ground and excited state properties of rare gas cation clusters, Rg+N, for N=3-60. The main goal is to understand how the positive charge is delocalized over the cluster and the relationship between cluster geometry and delocalization. He+N, Ar+N, and Xe+N are selected as representatives of the rare gas elements. We perform Monte Carlo simulations to obtain finite temperature properties of the energy spectrum. The Hamiltonian of the system is based on a semi-empirical model whose parameters are obtained through the fitting of experimental and calculated properties such as bond length and dissociation energy of small clusters (N \u3c 6). Since rare gas cation clusters are formed by closed shell atoms with one electron deficiency, the Hamiltonian is constructed within a hole (electron deficiency) formalism, resulting in a single particle model. In addition, our model can treat polarization and dispersion energies as a many-body interaction which is very important for small clusters. We compare our results with experiments through calculations of photoabsorption cross section and magic numbers

Mejoramiento del perfil nutricional del pan

El reposicionamiento de semillas ancestrales se está difundiendo en nuestro país, debido al excelente perfil nutricional que poseen (FAO, 2011) (Luis, 2018). Por ello el objetivo fue determinar la variación del perfil nutricional de pan, por el agregado de semillas ancestrales o condimento como orégano. Se realizaron cuatro formulaciones de pan, las cuales fueron evaluadas sensorialmente y analizadas para determinar la variación en su composición por el agregado de semillas. A la preparación base realizada con harina de trigo 000, agua, levadura y sal (pan común), se le adicionó semillas de amaranto y quínoa (previamente molidas) en una proporción del 5%, resultando la mezcla (1). El panificado (2) se reemplazaron por chía y amaranto, en igual proporción y en el (3) se realizó un pan sólo con orégano. Los productos fueron analizados determinando proteínas, grasas totales, carbohidratos, fibra por técnicas analíticas oficiales. Los panes con semillas incrementaron su humedad, pasando de 26,36±0,17g% en pan común a 32,94±0,17g% en la (2). Por otra parte aumentó su contenido de fibras de 0,7±0,04 g% (pan común) a 4,7±0,03 g% (1), 5,39±0,45 g% (2) y 2,4±0,15 g% (3). Si bien se incrementa su contenido proteico a 11 g%, y su contenido graso a 3,50±0,15 g% (1) y 5,21±0,12 g% (2). Su valor calórico total se vio disminuido por el aporte de fibra y el incremento de humedad, pasando de 291±1,02 kcal (común) a 259±1,27 kcal (1) y 262±2,05 kcal (1). En todos los casos la aceptabilidad fue superior al 93%. Aplicando análisis de la varianza (ANOVA) se determinó que todas las formulaciones presentaron diferencias estadísticamente significativas (a<0,05), en sus nutrientes. Se concluye que con la incorporación de semillas se incrementó la humedad y la fibra, disminuyendo el contenido calórico total, mejorando el aporte de proteínas y grasas totales. El pan con orégano sólo mejoró el aporte de fibra

A measurement of the CP asymmetry difference between Λc + → pK − K + and pπ−π+ decays

The difference between the CP asymmetries in the decays Λ + c → pK−K+ and Λ + c → pπ−π + is presented. Proton-proton collision data taken at centre-of-mass energies of 7 and 8 TeV collected by the LHCb detector in 2011 and 2012 are used, corresponding to an integrated luminosity of 3 fb−1 . The Λ + c candidates are reconstructed as part of the Λ 0 b → Λ + c µ −X decay chain. In order to maximize the cancellation of production and detection asymmetries in the difference, the final-state kinematic distributions of the two samples are aligned by applying phase-space-dependent weights to the Λ + c → pπ−π + sample. This alters the definition of the integrated CP asymmetry to A wgt CP (pπ−π +). Both samples are corrected for reconstruction and selection efficiencies across the five-dimensional Λ + c decay phase space. The difference in CP asymmetries is found to be ∆A wgt CP = ACP (pK−K+) − A wgt CP (pπ−π +) = (0.30 ± 0.91 ± 0.61) %, where the first uncertainty is statistical and the second is systemati

Observation of the decay Bs0→D¯0K+K−

The first observation of the B0 s → D¯ 0KþK− decay is reported, together with the most precise branching fraction measurement of the mode B0 → D¯ 0KþK−. The results are obtained from an analysis of pp collision data corresponding to an integrated luminosity of 3.0 fb−1. The data were collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction of the B0 → D¯ 0KþK− decay is measured relative to that of the decay B0 → D¯ 0πþπ− to be BðB0→D¯ 0KþK−Þ BðB0→D¯ 0πþπ−Þ ¼ ð6.9 0.4 0.3Þ%, where the first uncertainty is statistical and the second is systematic. The measured branching fraction of the B0 s → D¯ 0KþK− decay mode relative to that of the corresponding B0 decay is BðB0 s→D¯ 0KþK−Þ BðB0→D¯ 0KþK−Þ ¼ ð93.0 8.9 6.9Þ%. Using the known branching fraction of B0 → D¯ 0πþπ−, the values of BðB0 →D¯ 0KþK−Þ¼ð6.10.40.30.3Þ×10−5 and BðB0 s →D¯ 0KþK−Þ¼ð5.70.50.40.5Þ×10−5 are obtained, where the third uncertainties arise from the branching fraction of the decay modes B0 → D¯ 0πþπ− and B0 → D¯ 0KþK−, respectively

Measurement of Z → τ + τ − production in proton-proton collisions at √s=8 TeV

A measurement of Z → τ +τ − production cross-section is presented using data, corresponding to an integrated luminosity of 2 fb−1 , from pp collisions at √ s = 8 TeV collected by the LHCb experiment. The τ +τ − candidates are reconstructed in final states with the first tau lepton decaying leptonically, and the second decaying either leptonically or to one or three charged hadrons. The production cross-section is measured for Z bosons with invariant mass between 60 and 120 GeV/c2 , which decay to tau leptons with transverse momenta greater than 20 GeV/c and pseudorapidities between 2.0 and 4.5. The crosssection is determined to be σpp→Z→τ+τ− = 95.8 ± 2.1 ± 4.6 ± 0.2 ± 1.1 pb, where the first uncertainty is statistical, the second is systematic, the third is due to the LHC beam energy uncertainty, and the fourth to the integrated luminosity uncertainty. This result is compatible with NNLO Standard model predictions. The ratio of the cross-sections for Z → τ +τ − to Z → µ +µ − (Z → e +e −), determined to be 1.01 ± 0.05 (1.02 ± 0.06), is consistent with the lepton-universality hypothesis in Z decays

Novel purine chemotypes with activity against Plasmodium 2 falciparum and Trypanosoma cruzi

Malaria and Chagas disease, caused by Plasmodium spp. and Trypanosoma cruzi parasites, remain important global health problems. Available treatments for those diseases present several limitations, such as lack of efficacy, toxic side effects, and drug resistance. Thus, new drugs are urgently needed. The discovery of new drugs may be benefited by considering the significant biological differences between hosts and parasites. One of the most striking differences is found in the purine metabolism, because most of the parasites are incapable of de novo purine biosynthesis. Herein, we have analyzed the in vitro anti-P. falciparum and anti-T. cruzi activity of a collection of 81 purine derivatives and pyrimidine analogs. We firstly used a primary screening at three fixed concentrations (100, 10, and 1 µM) and progressed those compounds that kept the growth of the parasites < 30% at 100 µM to dose–response assays. Then, we performed two different cytotoxicity assays on Vero cells and human HepG2 cells. Finally, compounds specifically active against T. cruzi were tested against intracellular amastigote forms. Purines 33 (IC50 = 19.19 µM) and 76 (IC50 = 18.27 µM) were the most potent against P. falciparum. On the other hand, 6D (IC50 = 3.78 µM) and 34 (IC50 = 4.24 µM) were identified as hit purines against T. cruzi amastigotes. Moreover, an in silico docking study revealed that P. falciparum and T. cruzi hypoxanthine guanine phosphoribosyltransferase enzymes could be the potential targets of those compounds. Our study identified two novel, purine-based chemotypes that could be further optimized to generate potent and diversified anti-parasitic drugs against both parasites.SAF2016-76080-R (Spanish Ministry of Economy (AEI/FEDER, UE))PID2019-110810RB-I00 (Spanish Ministry of Science and Innovation)Generalitat of Catalonia Universities and Research Department, Spain (AGAUR; 2017SGR00924)Carlos III Health Institute (ISCIII)RICET Network for Cooperative Research in Tropical Diseases (ISCIII; RD12/0018/0010)Generalitat of Catalonia Department of Health (PERIS 2016–2010 SLT008/18/00132)Spanish Ministry of Education, Culture, and Sports (FPU grant ref. 14/00818)Spanish Ministry of Science, Innovation, and Universities through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018-000806-S)CERCA Progra

First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease

Real-Time PCR (qPCR) testing is recommended as both a diagnostic and outcome measurement of etiological treatment in clinical practice and clinical trials of Chagas disease (CD), but no external quality assurance (EQA) program provides performance assessment of the assays in use. We implemented an EQA system to evaluate the performance of molecular biology laboratories involved in qPCR based follow-up in clinical trials of CD. An EQA program was devised for three clinical trials of CD: the E1224 (NCT01489228), a pro-drug of ravuconazole; the Sampling Study (NCT01678599), that used benznidazole, both conducted in Bolivia; and the CHAGASAZOL (NCT01162967), that tested posaconazole, conducted in Spain. Four proficiency testing panels containing negative controls and seronegative blood samples spiked with 1, 10 and 100 parasite equivalents (par. eq.)/mL of four Trypanosoma cruzi stocks, were sent from the Core Lab in Argentina to the participating laboratories located in Bolivia and Spain. Panels were analyzed simultaneously, blinded to sample allocation, at 4-month intervals. In addition, 302 random blood samples from both trials carried out in Bolivia were sent to Core Lab for retesting analysis. The analysis of proficiency testing panels gave 100% of accordance (within laboratory agreement) and concordance (between laboratory agreement) for all T. cruzi stocks at 100 par. eq./mL; whereas their values ranged from 71 to 100% and from 62 to 100% at 1 and 10 par. eq./mL, respectively, depending on the T. cruzi stock. The results obtained after twelve months of preparation confirmed the stability of blood samples in guanidine-EDTA buffer. No significant differences were found between qPCR results from Bolivian laboratory and Core Lab for retested clinical samples. This EQA program for qPCR analysis of CD patient samples may significantly contribute to ensuring the quality of laboratory data generated in clinical trials and molecular diagnostics laboratories of CD

Identification of Trypanosoma cruzi Discrete Typing Units (DTUs) in Latin-American migrants in Barcelona (Spain)

Trypanosoma cruzi, the causative agent of Chagas disease, is divided into six Discrete Typing Units (DTUs): TcI-TcVI. We aimed to identify T. cruzi DTUs in Latin-American migrants in the Barcelona area (Spain) and to assess different molecular typing approaches for the characterization of T. cruzi genotypes. Seventy-five peripheral blood samples were analyzed by two real-time PCR methods (qPCR) based on satellite DNA (SatDNA) and kinetoplastid DNA (kDNA). The 20 samples testing positive in both methods, all belonging to Bolivian individuals, were submitted to DTU characterization using two PCR-based flowcharts: multiplex qPCR using TaqMan probes (MTq-PCR), and conventional PCR. These samples were also studied by sequencing the SatDNA and classified as type I (TcI/III), type II (TclI/IV) and type I/II hybrid (TcV/VI). Ten out of the 20 samples gave positive results in the flowcharts: TcV (5 samples), TcII/V/VI (3) and mixed infections by TcV plus TclI (1) and TcV plus Tcll/VI (1). By SatDNA sequencing, we classified the 20 samples, 19 as type I/II and one as type I. The most frequent DTU identified by both flowcharts, and suggested by SatDNA sequencing in the remaining samples with low parasitic loads, TcV, is common in Bolivia and predominant in peripheral blood. The mixed infection by TcV-TclI was detected for the first time simultaneously in Bolivian migrants. PCR-based flowcharts are very useful to characterize DTUs during acute infection. SatDNA sequence analysis cannot discriminate T. cruzi populations at the level of a single DTU but it enabled us to increase the number of characterized cases in chronically infected patients. (C) 2016 Elsevier Ireland Ltd. All rights reserved

HTLV-1 infection in solid organ transplant donors and recipients in Spain

HTLV-1 infection is a neglected disease, despite infecting 10-15 million people worldwide and severe illnesses develop in 10% of carriers lifelong. Acknowledging a greater risk for developing HTLV-1 associated illnesses due to immunosuppression, screening is being widely considered in the transplantation setting. Herein, we report the experience with universal HTLV testing of donors and recipients of solid organ transplants in a survey conducted in Spain. All hospitals belonging to the Spanish HTLV network were invited to participate in the study. Briefly, HTLV antibody screening was performed retrospectively in all specimens collected from solid organ donors and recipients attended since the year 2008. A total of 5751 individuals were tested for HTLV antibodies at 8 sites. Donors represented 2312 (42.2%), of whom 17 (0.3%) were living kidney donors. The remaining 3439 (59.8%) were recipients. Spaniards represented nearly 80%. Overall, 9 individuals (0.16%) were initially reactive for HTLV antibodies. Six were donors and 3 were recipients. Using confirmatory tests, HTLV-1 could be confirmed in only two donors, one Spaniard and another from Colombia. Both kidneys of the Spaniard were inadvertently transplanted. Subacute myelopathy developed within 1 year in one recipient. The second recipient seroconverted for HTLV-1 but the kidney had to be removed soon due to rejection. Immunosuppression was stopped and 3 years later the patient remains in dialysis but otherwise asymptomatic. The rate of HTLV-1 is low but not negligible in donors/recipients of solid organ transplants in Spain. Universal HTLV screening should be recommended in all donor and recipients of solid organ transplantation in Spain. Evidence is overwhelming for very high virus transmission and increased risk along with the rapid development of subacute myelopathy

ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.</p> <p>Methods</p> <p>A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb) and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease.</p> <p>Results</p> <p>Heterogeneity was high within each test (ELISA and PCR) and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% [96.7%-98.5%] and 96.3% [94.6%-97.6%] respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% [97.9%-99.9%] and 97.5% [88.5%-99.5%] respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied.</p> <p>Conclusions</p> <p>Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in this review and therefore correctly order and interpret test results. Currently, PCR should not be used in clinical practice for chronic Chagas disease diagnosis and there is no PCR test commercially available for this purpose. Tests limitations and directions for future research are discussed.</p