Sensor Noise in LISA Pathfinder: In-Flight Performance of the Optical Test Mass Readout.

We report on the first subpicometer interferometer flown in space. It was part of ESA's Laser Interferometer Space Antenna (LISA) Pathfinder mission and performed the fundamental measurement of the positional and angular motion of two free-falling test masses. The interferometer worked immediately, stably, and reliably from switch on until the end of the mission with exceptionally low residual noise of 32.0_{-1.7}^{+2.4} fm/sqrt[Hz], significantly better than required. We present an upper limit for the sensor performance at millihertz frequencies and a model for the measured sensitivity above 200 mHz.

Study of nitrogen implantation in Ti surface using plasma immersion ion implantation & deposition technique as biocompatible substrate for artificial membranes.

The present investigation reports the modification of Ti substrates by a plasma technique to enhance their physio-chemical properties as biocompatible substrates for the deposition of artificial membranes. For that purpose, nitrogen ions are implanted into Ti substrate using the plasma immersion ion implantation & deposition (PIII&D) technique in a capacitively coupled radio frequency plasma. The plasma was characterized using optical emission spectroscopy, together with radio frequency compensated Langmuir probe, while the ion current towards the substrate was measured during the implantation process using an opto-electronic device. X-ray photoelectron spectroscopy (XPS) was used for chemical analysis of the surface, confirming the presence of δ-TiN. The penetration depth of the nitrogen ions into the Ti substrate was measured using secondary ions mass spectroscopy (SIMS) while the morphological changes were observed using atomic force microscopy (AFM). A calorimetric assay was used to prove that the TiN samples maintain the biocompatibility of the untreated Ti surface with its native oxide layer. The ion implantation increases the load bearing ability of Ti surface by the formation of α-Ti(N) and δ-TiN phases on the sub-surface of Ti, and maintains the bio compatibility of Ti surface. After the plasma treatment a thin layer of chitosan (CH) was deposited in order to provide a moisturizing matrix for the artificial membrane of 1,2-dipalmitoyl-sn-3- phosphor glycerocholine (DPPC). The CH and subsequently the DPPC were deposited on the plasma deposited TiN substrate by using physical vapor deposition. The formation of artificial membranes was confirmed by AFM, measuring the topography at different temperatures and performing force curves.

Reference values of leukocyte and lymphocytes populations in umbilical cord and capillary blood in healthy Mexican newborns

INTRODUCTION: In newborns, dramatic changes occur in the blood and bone marrow during the first hours; there are rapid fluctuations in the quantities of leukocytes populations. In this work, we investigated leukocytes subsets counts in two types of blood samples (cord blood and capillary blood) extracted from healthy newborns. METHODS: Blood samples from Mexican neonates were collected by Instituto Nacional de Pediatría with written informed consent. For all samples we determined leukocytes populations; neutrophils, monocytes, total lymphocytes, and populations: T CD3+ cells, TCD4+ cells, T CD8+ cells, B CD19+ cells and NK CD16+56 cells by flow cytometry. We used the Mann-Whitney U test to compare leukocytes of cord and capillary blood; also to analyze the differences between gender and we obtained reference values of the cord and capillary blood in neonates. RESULTS: We observed higher absolute counts and frequencies of total lymphocyte in capillary blood compared with cord blood. In absolute numbers, the capillary blood showed significant differences in neutrophils, monocytes, lymphocytes, T CD3+ cells, T CD4+ cells, T CD8+ cells, B CD19+ cells, and NK cells; no significant differences were observed between genders. DISCUSSION: Our data contribute to newborn Mexican reference values for all these populations of leukocytes. We found that the dispersal range differs between the two types of blood, suggesting a different fate in the immune response. Immunophenotyping of the blood cell population to identify these cells is an essential tool in the diagnosis and follow-up of neonates with immunodeficiencies and other immune disorders

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Reference values of leukocyte and lymphocytes populations in umbilical cord and capillary blood in healthy Mexican newborns.

INTRODUCTION: In newborns, dramatic changes occur in the blood and bone marrow during the first hours; there are rapid fluctuations in the quantities of leukocytes populations. In this work, we investigated leukocytes subsets counts in two types of blood samples (cord blood and capillary blood) extracted from healthy newborns. METHODS: Blood samples from Mexican neonates were collected by Instituto Nacional de Pediatría with written informed consent. For all samples we determined leukocytes populations; neutrophils, monocytes, total lymphocytes, and populations: T CD3+ cells, TCD4+ cells, T CD8+ cells, B CD19+ cells and NK CD16+56 cells by flow cytometry. We used the Mann-Whitney U test to compare leukocytes of cord and capillary blood; also to analyze the differences between gender and we obtained reference values of the cord and capillary blood in neonates. RESULTS: We observed higher absolute counts and frequencies of total lymphocyte in capillary blood compared with cord blood. In absolute numbers, the capillary blood showed significant differences in neutrophils, monocytes, lymphocytes, T CD3+ cells, T CD4+ cells, T CD8+ cells, B CD19+ cells, and NK cells; no significant differences were observed between genders. DISCUSSION: Our data contribute to newborn Mexican reference values for all these populations of leukocytes. We found that the dispersal range differs between the two types of blood, suggesting a different fate in the immune response. Immunophenotyping of the blood cell population to identify these cells is an essential tool in the diagnosis and follow-up of neonates with immunodeficiencies and other immune disorders.

π-Extended push-pull azo-pyrrole photoswitches: synthesis, solvatochromism and optical band gaps.

A new family of push-pull biphenyl-azopyrrole compounds 3b-g and 4b-d was efficiently obtained via a Suzuki cross-coupling reaction between 2-(4'-iodophenyl-azo)-N-methyl pyrrole (1a) or 3-(4'-iodophenyl-azo)-1,2,5-trimethyl pyrrole (2a) and 4'-substituted phenyl boronic acids in excellent yields. The influence of the π-biphenyl backbone and pyrrole pattern substitution was correlated with their optical properties. Solvatochromic studies via UV-visible spectrophotometry revealed that the inclusion of a 4'-nitro-biphenyl fragment favors a red-shift of the main absorption band in these azo compounds compared with their non-substituted analogues. Likewise, optical band-gaps were estimated by means of electronic absorption spectra and correlated with TD-DFT studies. The pyrrole pattern substitution and the π-conjugated backbone exhibit a clear influence on their thermal isomerization kinetics at room temperature. In all cases, biphenylazo-pyrrole compounds lead to the formation of J-type aggregates in binary MeOH : H2O solvents. Under these conditions, compounds 3b-c undergo a water-assisted cis-to-trans isomerization at room temperature.

Bioinformatic analysis of post-transmission viral readaptation in Argentine patients with acute HIV-1 infection.

During the acute phase of HIV-1 infection, a strong readaptation occurs in the viral population. Our objective was to analyze the post-transmission mutations associated with escape to the cytotoxic immune response and its relationship with the progression of the infection. In this study, a total of 17 patients were enrolled during acute/early primary HIV infection and 8 subjects that were the HIV positive partner resulting in 8 transmission pairs. Genotyping of the genetic polymorphisms of HLA class I A and B was performed using PCR-SSOP. Viral RNA extraction was from plasma. 570 single Gag-gene amplifications were obtained by limiting-dilution RT-PCR. Epitope prediction was performed with NetMHC CBS prediction server for the 19 HLA-A and B alleles. Cytotoxic response prediction was performed by using the IEDB Analysis Resource. From our results, we deduce that the transmitted CTL / gag escape frequency in the founder virus was at least double compared to the post-transmission events. Additionally, by means of an algorithm that combines these frequencies, we observed that the founder viruses better adapted to the HLA A / B alleles of the recipient could contribute to a greater progression of the infection. Our results suggest that there is a large adaptation of HIV-1 to the HLA A / B alleles prevalent in our population. However, despite this adaptive advantage, the virus needs to make "readjustments" through new escape and compensatory mutations. Interestingly, according to our results, this readaptation could have a role in the progression of the infection.

Cáncer de próstata, el problema del diagnóstico: ¿es la resonancia multiparamétrica de próstata la solución? / Prostate cancer, the problem of diagnosis: is multiparametric prostate magnetic resonance imaging the solution?

Junto con un aumento sostenido en la incidencia de cáncer de próstata en los países desarrollados ha habido un cambio en el enfrentamiento diagnóstico en estos pacientes. El diagnóstico tradicional basado en la medición del antígeno prostático específico y la biopsia randomizada ha mostrado tener muchas falencias ya que sobre-diagnostica cánceres no significativos y sub-diagnostica cánceres clínicamente significativos. La resonancia magnética de próstata multiparamétrica ha demostrado ser útil ya que disminuye este tipo de falencias. En este artículo se revisará la historia de la resonancia magnética de próstata y del PI-RADS, con el objeto de revisar el rendimiento de estos métodos y sus indicaciones actuales.

Along with a sustained increase in the incidence of prostate cancer in developed countries, there has been a change in the diagnostic approach in these patients. The traditional diagnosis based on the measurement of the specific prostate antigen and randomized biopsy has shown to have many shortcomings as it leads to overdiagnosis of non-significant cancers and underdiagnosis of clinically significant cancers. The multiparametric prostate magnetic resonance imaging has proven to be useful since it diminishes these shortcomings. In this article we will review part of the history of prostate magnetic resonance imaging and PI-RADS, in order to review the performance of these methods and their current indications.

De novo assembly of Vriesea carinata leaf transcriptome to identify candidate cysteine-proteases.

Vriesea carinata is an endemic bromeliad from the Brazilian Atlantic Forest. It has trichome and tank system in their leaves which allows to absorb water and nutrients. It belongs to Bromeliaceae family, which includes several species highly enriched of cysteine-proteases (CysPs). These proteolytic enzymes regulate processes as senescence, cell differentiation, pathogen-linked programmed cell death and mobilization of proteins. Although, their biological importance, there are not genomic resources in V. carinata that can help to identify and understand their molecular mechanisms involved in different biological processes. Thus high-throughput transcriptome sequencing of V. carinata is necessary to generate sequences for the purpose of gene discovery and functional genomic studies. In the present study, we sequenced and assembled the V. carinata transcriptome to the identification of CysPs. A total of 43,232 contigs were assembled for the leaf tissue. BLAST analysis indicated that 23,803 contigs exhibited similarity to non-redundant Viridiplantae proteins. 28.24% of the contigs were classified into the COG database, and gene ontology categorized them into 61 functional groups. A metabolic pathway analysis with KEGG revealed 9679 contigs assigned to 31 metabolic pathways. Among 16 full-length CysPs identified, 11 were evaluated in respect to their expression patterns in the leaf apex, base and inflorescence tissues. The results showed differential expression levels of legumain, metacaspase, pyroglutamyl and papain-like CysPs depending of the leaf region. These results provide a global overview of V. carinata gene functions and expression activities of CysPs in those tissues.

Estrongiloidiasis gastrointestinal en paciente inmunocompetente: a propósito de un caso / Gastrointestinal strongyloidosis in an immunocompetent patient: a case report

Intestinal parasitic infections cause a not insignificant number of chronic diarrhea in children, however, with the sociodemographic change that our country has experienced, the number of cases and new parasites (immigration from tropical endemic areas) could increase. We report the case of an immunocompetent patient who presents with chronic diarrhea associated with Strongyloides stercoralis infection. The patient migrated two years ago from an endemic area for this helminth. The diagnosis is challenging, and the chances of a successful outcome depend on the administration of the antiparasitic.

Las infecciones parasitarias intestinales provocan un número no despreciable de causas de diarrea crónica en niños, sin embargo, con el cambio sociodemográfico que ha vivido nuestro país se podría incrementar el número de casos y de nuevos parásitos (inmigración de áreas endémicas tropicales). Reportamos el caso de un paciente inmunocompetente, que presenta cuadro de diarrea crónica asociada a infección por Strongyloides stercoralis. El paciente habría migrado hace dos años desde zona endémica para este helminto. El diagnóstico es desafiante y las posibilidades de un resultado exitoso dependen de la administración del antiparasitario.

Charmonium: comparison between potential models / Charmonio: comparación entre modelos potenciales

Abstract Heavy quark c c ¯ has been studied in the non relativistic framework using a quark-quark potential as a sum of power of the corresponding distance. The form of potential is based on phenomenological facts. The problem was solved numerically using a program written on C++. Mass spectra and the expectation value of the radius have been estimated for different quantum-mechanical states for c c ¯ system. The results have been compared with other similar and recent works. The mass spectra obtained is in acceptable agreement with the experimental data for c c ¯.

Resumen El sistema de quarks pesados c c ¯ ha sido estudiado en el marco no relativista usando un potencial quark-quark de la forma de la suma de potencias de la distancia entre las partículas. El problema se resolvió numéricamente usando un programa escrito en C++. Se estimaron el espectro de masa y el valor esperado del radio para diferentes estados de excitación. Los resultados fueron comparados con otros trabajos similares recientes. El espectro de masa obtenido concuerda de manera aceptable con los datos experimentales para el sistema c c ¯.

Study of light-particle multiplicities in p + non-fissionable nuclei events in the 0.5 - 2 GeV energy range / Estudio de la multiplicidad de partículas ligeras en proto-reacciones con núcleos no fisionables en el rango energético 0.5 - 2 GeV

Abstract In recent years, the investigation of spallation reactions have caught the attention of scientific community due to their application in the transmutation of nuclear waste by using the Accelerator Driven System (ADS) reactors. Due to the experimental difficulties that nuclear reactions researches face; the study of spallation reaction by using simulation codes is more suitable for generating more complete database for different energy ranges. This work aims to study spallation reactions induced by protons at intermediate energies 0.5 - 2 GeV on non-fissionable nuclei by using the Monte Carlo code: CRISP (Collaboration Rio-Ilhéus-São Paulo). The target nuclei studied were: 184 W, 197 Au and 208 Pb, focusing on the last one. Multiplicity of light particles obtained with CRISP was compared with the available experimental data and other Monte Carlo codes involved in the study of spallation reactions, resulting on a quite satisfactory agreement.

Resumen En años recientes la investigación de las reacciones nucleares de "espalación" han causado atención en la comunidad científica debido a su aplicación en la transmutación de los residuos nucleares usando reactores ADS (AcceleratorDriven System). Debido a las dificultades experimentales en el estudio de las reacciones nucleares, su estudio vía simulación es adecuado para generar una base de datos más completa en un amplio rango de energía. Este trabajo tiene como objetivo principal el estudio de reacciones nucleares inducidas por protones a energías intermedias, 0.5 - 2 GeV, en núcleos no fisionables, utilizando el código de Monte Carlo: CRISP (Collaboration Rio-Ilhéus-São Paulo). Los núcleos estudiados fueron: 184W, 197Au y 208Pb, con un enfoque en el último. La multiplicidad de partículas ligeras obtenida con el CRISPfue comparada con los datos experimentales disponibles y con otros códigos de Monte Carlo y se obtuvieron resultados satisfactorios.

Inkjet printable-photoactive all inorganic perovskite films with long effective photocarrier lifetimes.

Photoactive perovskite quantum dot films, deposited via an inkjet printer, have been characterized by x-ray diffraction and x-ray photoelectron spectroscopy. The crystal structure and bonding environment are consistent with CsPbBr3 perovskite quantum dots. The current-voltage (I-V) and capacitance-voltage (C-V) transport measurements indicate that the photo-carrier drift lifetime can exceed 1 ms for some printed perovskite films. This far exceeds the dark drift carrier lifetime, which is below 50 ns. The printed films show a photocarrier density 109 greater than the dark carrier density, making these printed films ideal candidates for application in photodetectors. The successful printing of photoactive-perovskite quantum dot films of CsPbBr3, indicates that the rapid prototyping of various perovskite inks and multilayers is realizable.

Understanding the antimicrobial properties/activity of an 11-residue Lys homopeptide by alanine and proline scan.

Previous work demonstrated that lysine homopeptides adopt a polyproline II (PPII) structure. Lysine homopeptides with odd number of residues, especially with 11 residues (K11), were capable of inhibiting the growth of a broader spectrum of bacteria than those with an even number. Confocal studies also determined that K11 was able to localize exclusively in the bacterial membrane, leading to cell death. In this work, the mechanism of action of this peptide was further analyzed focused on examining the structural changes in bacterial membrane induced by K11, and in K11 itself when interacting with bacterial membrane lipids. Moreover, alanine and proline scans were performed for K11 to identify relevant positions in structure conformation and antibacterial activity. To do so, circular dichroism spectroscopy (CD) was conducted in saline phosphate buffer (PBS) and in lipidic vesicles, using large unilamellar vesicles (LUV), composed of 2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) or bacterial membrane lipid. Antimicrobial activity of K11 and their analogs was evaluated in Gram-positive and Gram-negative bacterial strains. The scanning electron microscopy (SEM) micrographs of Staphylococcus aureus ATCC 25923 exposed to the Lys homopeptide at MIC concentration showed blisters and bubbles formed on the bacterial surface, suggesting that K11 exerts its action by destabilizing the bacterial membrane. CD analysis revealed a remarkably enhanced PPII structure of K11 when replacing some of its central residues by proline in PBS. However, when such peptide analogs were confronted with either DMPG-LUV or membrane lipid extract-LUV, the tendency to form PPII structure was severely weakened. On the contrary, K11 peptide showed a remarkably enhanced PPII structure in the presence of DMPG-LUV. Antibacterial tests revealed that K11 was able to inhibit all tested bacteria with an MIC value of 5 µM, while proline and alanine analogs have a reduced activity on Listeria monocytogenes. Besides, the activity against Vibrio parahaemolyticus was affected in most of the alanine-substituted analogs. However, lysine substitutions by alanine or proline at position 7 did not alter the activity against all tested bacterial strains, suggesting that this position can be screened to find a substitute amino acid yielding a peptide with increased antibacterial activity. These results also indicate that the PPII secondary structure of K11 is stabilized by the interaction of the peptide with negatively charged phospholipids in the bacterial membrane, though not being the sole determinant for its antimicrobial activity.

Importancia de la semiología en la era tecnológica / Relevance of medical semiology in the technological era

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Antimicrobial activity of a new synthetic peptide loaded in polylactic acid or poly(lactic-co-glycolic) acid nanoparticles against Pseudomonas aeruginosa, Escherichia coli O157:H7 and methicillin resistant Staphylococcus aureus (MRSA).

Nanocarrier systems are currently being developed for peptide, protein and gene delivery to protect them in the blood circulation and in the gastrointestinal tract. Polylactic acid (PLA) and poly(lactic-co-glycolic) acid (PLGA) nanoparticles loaded with a new antimicrobial GIBIM-P5S9K peptide were obtained by the double emulsion solvent extraction/evaporation method. PLA- and PLGA-NPs were spherical with sizes between 300 and 400 nm for PLA and 200 and 300 nm for PLGA and <0.3 polydispersity index as determined by dynamic light scattering and scanning electron microscopy), having the zeta potential of >20 mV. The peptide-loading efficiency of PLA-NP and PLGA-NPs was 75% and 55%, respectively. PLA- and PLGA-NPs released around 50% of this peptide over 8 h. In 10% human sera the size of peptide loaded PLA- and PLGA-NPs increased between 25.2% and 39.3%, the PDI changed from 3.2 to 5.1 and the surface charge from -7.15 to 14.6 mV. Both peptide loaded PLA- and PLGA-NPs at 0.5 µM peptide concentration inhibited the growth of Escherichia coli O157:H7 (E. coli O157:H7), methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas. aeruginosa (P. aeruginosa). In contrast, free peptide inhibited at 10 µM but did not inhibit at 0.5 and 1 µM. These PLA- and PLGA-NPs presented <10% hemolysis indicating that they are hemocompatible and promising for delivery and protection system of GIBIM-P5S9K peptide.

Variations of B cell subpopulations in peripheral blood of healthy Mexican population according to age: Relevance for diagnosis of primary immunodeficiencies

BACKGROUND: Peripheral blood B cells include lymphocytes at various stages of differentiation, each with a specific function in the immune response. All these stages show variations in percentage and absolute number throughout human life. The numbers and proportions of B subpopulation are influenced by factors such as gender, age, ethnicity, and lifestyle. This study establishes reference values according to age of peripheral blood B cell subtypes in healthy Mexican population. METHODS: Peripheral blood from healthy new-borns and adults were analysed for total B cell subpopulations, using surface markers such as CD19, IgM, IgD, CD21, CD24, CD27, and CD38, to identify naïve, memory with and without isotype switch, double-negative, transitional, and plasmablast cells. RESULTS: We observed a significant variation in terms of frequency and absolute counts between all groups analysed. Values from each B cell subpopulation show variations according to age. CONCLUSIONS: In order to attempt to elucidate reference values for B cell subpopulation, the present study evaluated a population sample of healthy blood donors from this region. Values reported here can also be used as a tool for diagnosis of diseases in which B cell maturation is affected

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Variations of B cell subpopulations in peripheral blood of healthy Mexican population according to age: Relevance for diagnosis of primary immunodeficiencies.

BACKGROUND: Peripheral blood B cells include lymphocytes at various stages of differentiation, each with a specific function in the immune response. All these stages show variations in percentage and absolute number throughout human life. The numbers and proportions of B subpopulation are influenced by factors such as gender, age, ethnicity, and lifestyle. This study establishes reference values according to age of peripheral blood B cell subtypes in healthy Mexican population. METHODS: Peripheral blood from healthy new-borns and adults were analysed for total B cell subpopulations, using surface markers such as CD19, IgM, IgD, CD21, CD24, CD27, and CD38, to identify naïve, memory with and without isotype switch, double-negative, transitional, and plasmablast cells. RESULTS: We observed a significant variation in terms of frequency and absolute counts between all groups analysed. Values from each B cell subpopulation show variations according to age. CONCLUSIONS: In order to attempt to elucidate reference values for B cell subpopulation, the present study evaluated a population sample of healthy blood donors from this region. Values reported here can also be used as a tool for diagnosis of diseases in which B cell maturation is affected.

On the sources of PBDEs in coastal marine sediments off Baja California, Mexico.

Polybrominated diphenyl ethers (PBDEs) are widely distributed compounds in all types of matrices. In the northern portion of the Southern California Bight (SCB), there were reports of some of the largest PBDE concentrations in marine mammals and mussels. Because of this, we decided to analyze the status of PBDEs in the southern part of the SCB. An analysis of 91 samples of marine surface sediment was carried out. All of the 91 samples contained measurable amounts of PBDEs, which is a manifestation of the widespread distribution of these chemical substances. However, the levels detected are between one and two orders of magnitude smaller than those reported in southern California. Currents appear to control the distribution of PBDEs along the coast and the sedimentation sites with largest concentrations are favored by local bathymetry. Maximum concentrations were located in the middle and deeper platforms ranging from 0.02 to 5.90 (with a median 0.71) ng·g(-1) d.w. Deca-BDE mixture is largely predominant in the sediments followed by the penta-BDE mixture. The mass balance for the latitudinal strata shows the largest concentrations in the north where the largest population centers are present and with a very clear southward gradient. The mass balance calculation values showed about 36kg of PBDEs for the north, 22kg for the center, and 10kg for the south strata. In terms of depth, the PBDEs are mainly located on the middle and deep platforms rather than near point discharges, which is different than that reported by other authors.

Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results.

We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2±0.1 fm s^{-2}/sqrt[Hz], or (0.54±0.01)×10^{-15} g/sqrt[Hz], with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8±0.3) fm/sqrt[Hz], about 2 orders of magnitude better than requirements. At f≤0.5 mHz we observe a low-frequency tail that stays below 12 fm s^{-2}/sqrt[Hz] down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.