Metabolites Profile of Extracts and Fractions of Erythroxylum mexicanum Kunth by UHPLC-QTOF-MS/MS and its Antibacterial, Cytotoxic and Nitric Oxide Inhibitory Activities.

The present study shows the untargeted metabolite profiling and in vitro antibacterial, cytotoxic, and nitric oxide (NO) inhibitory activities of the methanolic leaves extract (MLE) and methanolic stem extract (MSE) of Erythroxylum mexicanum, as well as the fractions from MSE. Using ultra-high performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS), a total of 70 metabolites were identified; mainly alkaloids in the MLE, while the MSE showed a high abundance of diterpenoids. The MSE fractions exhibited differential activity against Gram-positive bacteria. Notably, the hexane fraction (HSF) against Streptococcus pyogenes ATCC 19615 (MIC=62.5 µg/mL) exhibited a bactericidal effect. The MSE fractions exhibited cytotoxicity against all cancer cell lines tested, with selectivity towards them compared to a noncancerous cell line. Particularly, the HSF and chloroform fraction (CSF) showed the highest cytotoxicity against prostate cancer (PC-3) cells, with IC50 values of 19.9 and 18.1 µg/mL and selectivity indexes of 3.8 and 4.2, respectively. Both the HSF and ethyl acetate (EASF) fractions of the MSE inhibited NO production in RAW 264.7 macrophages, with NO production percentages of 50.0 % and 51.7 %, respectively, at a concentration of 30 µg/mL. These results indicated that E. mexicanum can be a source of antibacterial, cytotoxic, and anti-inflammatory metabolites.

KI effects on corrosion inhibition for 1018 steel in acid media using Medicago sativa.

Medicago sativa (M. sativa) extract is a safe and eco-friendly corrosion inhibitor of 1018 steel in acid media. The inhibitor reached a maximum efficiency of 85% by using 500 ppm. In this work, we study the use of KI as an add-on to increase the inhibition efficiency of M. sativa, as well as making the natural inhibitor competitive with the commercial ones. We evaluated the effect of halide ions through the variation of different concentrations of KI and its synergy with the extract of M. sativa as a corrosion inhibitor of carbon steel in 0.5 M sulfuric acid and at different temperatures. The results were obtained through electrochemical techniques such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) curves, and weight loss gravimetric technique. It was found that halide ions increase the inhibition efficiency of M. sativa from 85 to 95% when 5 mM concentration of KI was used. The efficiency of the inhibition increases proportionally with the immersion time but reduces when the temperature increases. The addition of iodide ions (I-) revealed that it exerts a synergistic effect on the inhibition of corrosion with the extract of M. sativa. However, when studying the metal surface using a scanning electron microscope, pitting corrosion was found.

Triterpenes and limonoids of Cedrela: Distribution, biosynthesis, and 1 H and 13 C NMR data.

Cedrela genus, a member of the Meliaceae family, presents both chemical characteristics associated with and those that distinguish it from the rest of its members. The presence of triterpenes and limonoids is the characteristic of the Meliaceae family, but the class and type of these chemical constituents are distinctive for each genus. Cedrela includes cycloartane, ursane, oleanane, tirucallane, butyrospermane, and apotirucallane triterpenes, and its limonoids belongs to six class and nine types, known as class Ia-type havanensines, class Ib-type delevoyin, class II-type gedunin, class IIIb-type andirobin, class IIIg-type mexicanolide, class IVa-type evoludone, class Va-type obacunol, class V-type limonin, and class VIII. Each of these structural arrangements includes specific traits, defined by their biosynthetic origin, which can be established by means of structural elucidation techniques, particularly 1 H and 13 C NMR, which assisted by 2D NMR techniques, allowing to deduce their structures unequivocally. The constant presence of these skeletal arrangements in Cedrela ensures that they are its chemophenetic markers and their recurrence is an important criterion for their identity. This review is a compilation of the occurrence of triterpenes and limonoids in Cedrela genus, detailing their biosynthetic association and collecting and organizing their NMR data, with the purpose of facilitating its location, analysis, and use in the phytochemical study of species from this genus.

Metabolomic Profile and Cytotoxic Activity of Cissus incisa Leaves Extracts.

Cissus incisa leaves have been traditionally used in Mexican traditional medicine to treat certain cancerous illness. This study explored the metabolomic profile of this species using untargeted technique. Likewise, it determined the cytotoxic activity and interpreted all data by computational tools. The metabolomic profile was developed through UHPLC-QTOF-MS/MS for dereplication purposes. MetaboAnalyst database was used in metabolic pathway analysis and the network topological analysis. Hexane, chloroform/methanol, and aqueous extracts were evaluated on HepG2, Hep3B, HeLa, PC3, A549, and MCF7 cancer cell lines and IHH immortalized hepatic cells, using Cell Titer proliferation assay kit. Hexane extract was the most active against Hep3B (IC50 = 27 ± 3 µg/mL), while CHCl3/MeOH extract was the most selective (SI = 2.77) on the same cell line. A Principal Component Analysis (PCA) showed similar profiles between the extracts, while a Venn diagram revealed 80 coincident metabolites between the bioactive extracts. The sesquiterpenoid and triterpenoid biosynthesis pathway was the most significant identified. The Network Pharmacology (NP) approach revealed several targets for presqualene diphosphate, phytol, stearic acid, δ-tocopherol, ursolic acid and γ-linolenic acid, involved in cellular processes such as apoptosis. This work highlights the integration of untargeted metabolomic profile and cytotoxic activity to explore plant extracts, and the NP approach to interpreting the experimental results.

Efficiency of integrated electrooxidation and anaerobic digestion of waste activated sludge.

BACKGROUND: Most of the organic content of waste activated sludge (WAS) comprises microbial cells hard to degrade, which must be pre-treated for energy recovery by anaerobic digestion (AD). Electrooxidation pre-treatment (EOP) with boron-doped diamond (BDD) electrode have been considered a promising novel technology that increase hydrolysis rate, by the disintegrating cell walls from WAS. Although electrochemical oxidation could efficiently solubilize organic substances of macromolecules, limited reports are available on EOP of WAS for improving AD. In this endeavour, the mathematical optimization study and the energy analysis of the effects of initial total solids concentrations [TS] of WAS and current density (CD) during EOP on the methane production and removal of chemical oxygen demand (COD) and volatile solids (VS) were investigated. Because limited reports are available on EOP of WAS for improving biogas production, it is not well understood; however, it has started to attract interest of scientists and engineers. RESULTS: In the present work, the energy recovery as biogas and WAS conversion were comprehensively affected by CD and [TS], in an integrated EOP and AD system. When working with WAS at 3% of [TS] pre-treated at current density of 24.1 mA/cm2, the highest COD and VS removal were achieved, making it possible to obtain the maximum methane (CH4) production of 305 N-L/kg VS and a positive energy balance of 1.67 kWh/kg VS. Therefore, the current densities used in BDD electrode are adequate to produce the strong oxidant (hydroxyl radical, ·OH) on the electrode surface, allow the oxidation of organic compounds that favours the solubilization of particulate matter and VS from WAS. CONCLUSIONS: The improvement of VS removal and COD solubilization were due to the effects of pre-treatments, which help to break down the microbial cells for faster subsequent degradation; this allows a decomposition reaction that leads to biodegrade more compounds during AD. The balance was positive, suggesting that even without any optimization the energy used as electricity could be recovered from the increased methane production. It is worth noting that this kind of analysis have not been sufficiently studied so far. It is therefore important to understand how operational parameters can influence the pre-treatment and AD performances. The current study highlights that the mathematical optimization and energy analysis can make the whole process more convenient and feasible.

Conocimiento de la composición y efectos secundarios de las bebidas energéticas en alumnos de medicina: estudio transversal / Knowledge of energy drinks composition and side effects in medical students: a cross-sectional study

INTRODUCCIÓN: En los últimos 20 años se ha producido un incremento del consumo de bebidas energéticas, con un alto contenido de cafeína, en especial en la población de adolescentes. Pocos estudios han investigado qué saben los estudiantes de medicina sobre este producto y sus posibles efectos secundarios. SUJETOS Y MÉTODOS: Estudio observacional y transversal. Se incluyeron todos los alumnos de primer y segundo curso de medicina en la Universidad Europea de Madrid en los cursos 2017-2018 y 2018-2019. Se elaboró una encuesta con 20 ítems: 7 preguntas sobre datos sociodemográficos y de estilo de vida y 13 sobre conocimiento y hábitos de consumo de bebidas energéticas. Los alumnos cumplimentaron la encuesta de forma voluntaria, anónima y autoadministrada Se realizó una estadística descriptiva y para la comparación de variables cualitativas se utilizó la prueba de chi cuadrado o el test exacto de Fisher. RESULTADOS: Respondieron a la encuesta 353 alumnos (80% de la muestra). De ellos, 115 (32,6%) señalaron que consumían al menos una lata al mes (consumidores). El 79% conocían algún componente: el 67,1%, que contenían taurina; el 51,9%, cafeína, y el 31,2%, azúcares. En cuanto a los efectos secundarios derivados del consumo, los más conocidos eran taquicardia/palpitaciones, insomnio, nerviosismo e irritabilidad e incremento de la diuresis. CONCLUSIONES: Los alumnos de primer y segundo de medicina conocen mayoritariamente que las bebidas energéticas contienen taurina, pero solo la mitad, que contienen cafeína. Los efectos secundarios más conocidos son la sensación de palpitaciones/taquicardia y la dificultad para dormir

INTRODUCTION: The consumption of energy drinks, drinks with a high caffeine content, has increased exponentially in the last decade. Several studies have been carried out especially in the adolescent population, but there are not many studies in medical students. SUBJECTS AND METHODS: Observational and cross-sectional study where all students of 1st and 2nd year of Medicine at Universidad Europea de Madrid were included in the 2017-2018 and 2018-2019 academic years. A questionnaire was done with 20 items: 7 questions about sociodemographic and lifestyle aspects and 13 questions about knowledge and consumption habits of energy drinks. Questionnaire fill in was voluntary, anonymous and self-administered. A descriptive statistic analysis was performed and squared chi test or Fisher's exact test was used for the comparison of qualitative variables. RESULTS: 353 students (80%) filled in the questionnaire. 115 of them (32.6%) indicated that they consumed at least one can per month (consumers). 79% knew at least one components of these drinks: 67.1% said they contained taurine, 51.9% caffeine and 31.2% sugars. Best known side effects were tachycardia/palpitations, insomnia, nervousness and irritability and increased diuresis. CONCLUSIONS: Most of 1st and 2nd year medical students knows that energy drinks contain taurine but only half of them knows they contain caffeine. Best known side effects are: palpitations/tachycardia and difficulty sleeping

Dietary consumption and serum pattern of bioactive fatty acids in NAFLD patients.

INTRODUCTION AND OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome. Some dietary fatty acids have showed different bioactive functions in metabolic syndrome. The aim of this study is to determine the dietary consumption patterns and serum percentage of bioactive fatty acids in NAFLD patients. PATIENTS AND METHODS: Cross-sectional study with NAFLD patients and non-NAFLD patients. Dietary consumption of bioactive fatty acids was assessed by a food frequency questionnaire. NAFLD and liver fibrosis were diagnosed by transient elastography. The identification of serum bioactive fatty acids was achieved by gas chromatography-mass spectrometry (%). Bioactive fatty acids consumption was correlated with NAFLD clinical characteristics with the Spearman correlation analysis. RESULTS: A total of 299 patients were included, whose mean of age and body mass index were 44.2±9.9 years and 25.9±3.8kg/m2, respectively. The consumption of bioactive fatty acids was no different regarding the presence of NAFLD; however, the consumption of stearic and linoleic fatty acids was higher in relation with NAFLD severity (p≤0.05). The consumption of myristic acid was higher in patients with fibrosis (p=0.02). Serum percentage and dietary consumption did not show correlations. CONCLUSION: Dietary consumption of bioactive fatty acids is different according to NAFLD severity. Individualized diets according to NAFLD severity could be successful in order to prevent liver injury-related outcomes.

Furofuranone Lignans from Leucophyllum ambiguum.

Eight furofuranone lignans with an endo,endo relationship between the oxygen atoms, an exo,exo relationship between the aryl groups, and a chair,chair conformation (1-4 and 6-9), in addition to the α-amino acid (3S)-hydroxy-3',4'-dimethoxy-L-phenylalanine (5), veratric acid (10), and ß-sitosterol (11), were isolated from the powdered and defatted air-dried aerial parts of Leucophyllum ambiguum. Four of these lignans, ciquitins A-D, 1-4, were isolated for the first time as natural products. The structures of these compounds were established based on their spectrometric/spectroscopic data. Additionally, single-crystal X-ray crystallography confirmed the structure of ciquitin A (1), and derivatization with (9S)-naproxen and X-ray diffraction crystallography data established its absolute configuration. Ciquitins A (1) and B (2) possess a 9-hydroxy group; this chemical characteristic grants these species conformational isomerism not seen in the other six lignans. The conformers of 1 and 2 are distinguishable via their 1H and 13C NMR spectroscopic data. This is the first report of this phenomenon, and hence, a complete assignment of the signals in both spectra of each conformer for each compound is presented. Compounds 1-9 were found to exhibit potent inhibitory activity in the 1.0 × 10-3 to 2.2 µM range against acetylcholinesterase, an enzyme directly involved in the etiology of Alzheimer's disease and senile dementia. Thus, these natural products are promising agents that are potentially useful for the treatment of neurological degeneration.

Metabolic Profile and Evaluation of Biological Activities of Extracts from the Stems of Cissus trifoliata.

Cissus trifoliata (L.) L belongs to the Vitaceae family and is an important medicinal plant used in Mexico for the management of infectious diseases and tumors. The present study aimed to evaluate the metabolic profile of the stems of C. trifoliata and to correlate the results with their antibacterial and cytotoxic activities. The hexane extract was analyzed using gas chromatography coupled with mass spectrometry (GC-MS) and the CHCl3-MeOH and aqueous extracts by ultraperformance liquid chromatography quadrupole time of fly mass spectrometry (UPLC-QTOF-MS). The antibacterial activity was determined by broth microdilution and the cytotoxicity was evaluated using MTS cell proliferation assay. Forty-six metabolites were putatively identified from the three extracts. Overall, terpenes, flavonoids and stilbenes characterize the metabolic profile. No antibacterial activity was found in any extract against the fifteen bacteria strains tested (MIC >500 µg/mL). However, high cytotoxic activity (IC50 ≤ 30 µg/mL) was found in the hexane and aqueous extracts against hepatocarcinoma and breast cancer cells (Hep3B, HepG2 and MCF7). This is the first report of the bioactive compounds of C. trifoliata stems and their antibacterial and cytotoxic properties. The metabolic profile rich in anticancer compounds correlate with the cytotoxic activity of the extracts from the stems of C. trifoliata. This study shows the antitumor effects of this plant used in the traditional medicine and justifies further research of its anticancer activity.

Suspended LRSPP for the development of highly integrated active plasmonic devices.

We present a novel long-range surface plasmon polariton (LRSPP) device consisting of a suspended dielectric matrix in which an electrically active, millimeter-long metallic waveguide is embedded. We show that, by opening an air gap under the lower cladding, the influence of the substrate is suppressed and the symmetry of the thermo-optical distribution around the LRSPP waveguide is preserved over extended ranges of applied electrical current with minimal optical losses. Experimental results show that, compared to a standard nonsuspended structure, our device allows either the induction of a phase change that is three times larger, for a fixed electrical power, or, equivalently, a scaling down of the device to one-tenth of its original length, for a fixed phase change.

Chemical composition of Helietta parvifolia and its in vitro anticholinesterase activity.

The chemical composition of the essential oil and the n-hexane (Hex), Ethyl Acetate (EtOAc) and butanol (BuOH) extracts from the leaves of Helietta parvifolia were determined by detailed GC-MS analysis, spectroscopic and spectrometric data. Eighty-four compounds were identified, revealing a furoquinoline alkaloid-rich composition. The phytochemical analysis of the extracts allowed the isolation of eigth furoquinoline alkaloids. Retention indices in GC-MS for six of this alkaloids are reported for the first time. Furoquinoline alkaloids are acethylcholinesterase inhibitors. Thus, the essential oil and extracts were submitted to this in vitro assay. The EtOAc and BuOH extracts showed potent activity, with IC50 of 9.7 and 12.9 µg mL-1, respectively. Additionaly, a correlation of their chemical constituents, established by principal component analysis (PCA) demostrated a similar profile and a high content of alkaloids. It is for these reasons that we can assume that the alkaloid content in these extracts could be responsible for their anticholinesterase activity.

In vitro nematicidal effect of Chenopodium ambrosioides and Castela tortuosa n-hexane extracts against Haemonchus contortus (Nematoda) and their anthelmintic effect in gerbils.

The in vitro nematicidal effect of Chenopodium ambrosioides and Castela tortuosa n-hexane extracts (E-Cham and E-Cato, respectively) on Haemonchus contortus infective larvae (L3) and the anthelmintic effect of these extracts against the pre-adult stage of the parasite in gerbils were evaluated using both individual and combined extracts. The in vitro confrontation between larvae and extracts was performed in 24-well micro-titration plates. The results were considered 24 and 72 h post confrontation. The in vivo nematicidal effect was examined using gerbils as a study model. The extracts from the two assessed plants were obtained through maceration using n-hexane as an organic agent. Gerbils artificially infected with H. contortus L3 were treated intraperitoneally with the corresponding extract either individually or in combination. The results showed that the highest individual lethal in vitro effect (96.3%) was obtained with the E-Cham extract at 72 h post confrontation at 40 mg/ml, followed by E-Cato (78.9%) at 20 mg/ml after 72 h. The highest combined effect (98.7%) was obtained after 72 h at 40 mg/ml. The in vivo assay showed that the individual administration of the E-Cato and E-Cham extracts reduced the parasitic burden in gerbils by 27.1% and 45.8%, respectively. Furthermore, the anthelmintic efficacy increased to 57.3% when both extracts were administered in combination. The results of the present study show an important combined nematicidal effect of the two plant extracts assessed against L3 in gerbils.

Phytotoxic Potential of Zanthoxylum affine and Its Major Compound Linarin as a Possible Natural Herbicide.

Four compounds, the flavone linarin (1), the triterpene lupenone (2), the tocopherol (vitamin E, 3), and the new natural alkaloid 1,2,3,4-tetrahydro-1,1-dimethyl-6,7-isoquinolindiol (affineine, 4), were the major natural products isolated from Zanthoxylum affine (syn. Zanthoxylum fagara, Rutaceae). Compound 1 is highly abundant in this plant and was isolated as a white precipitate obtained from the acetone and methanol extracts. The structure of these four compounds was established by 1D and 2D NMR spectroscopy including 1H, 13C, DEPT, COSY, HSQC, and HMBC experiments. The hexane, acetone, and methanol extracts, as well as 1, were evaluated for their potential phytotoxic effects in pre- and post-emergent assays, as well as to identify their mechanisms of action. As pre-emergent phytotoxic agents, the hexane, acetone, and methanol extracts inhibited germination and residual growth (root and stem elongation) of Lactuca sativa (lettuce) and Lolium perenne (perennial ryegrass). As post-emergent agents, they inhibited dry biomass. Compound 1 acts as a pre-emergent herbicide, by inhibiting germination, seed respiration, residual seedling growth and, notably, root hair development. Furthermore, 1 inhibited the synthesis of ATP and the electron transport chain of isolated spinach chloroplasts; in this way, it behaves as a Hill reaction inhibitor. The site of inhibition was located at the donor site of PSII from the oxygen evolving complex to QA, thus acting as a multisite compound. These results suggest that compound 1 can be used as a lead for a potential green herbicide with different targets.

Sulfur-Containing Aristoloxazines and Other Constituents of the Roots of Aristolochia orbicularis.

Six new compounds, aristoloxazine A (1), aristoloxazine B (2), 7-methoxytaliscanine (3), humul-7-en-1,4,11-triol (4), 8-hydroxy-ß-logipinene (5), and 1ß-hydroxy-4(14)-eudesmene (6), corresponding to two sulfur-containing aristoloxazines (1 and 2), an aristolactam (3), and three sesquiterpenes (4-6) were isolated, along with 26 known compounds, from the roots of Aristolochia orbicularis. The structures of the new compounds were established based on their spectroscopic and spectrometric data and in the case of aristoloxazine A (1) by single-crystal X-ray crystallography. This is the first report of sulfur-containing aristoloxazines from a natural source. Furthermore, aristoloxazine A (1) was found to possess potent in vitro antimicrobial activity against all resistant Staphylococcus aureus and several fungal strains in which it was evaluated.

Hadamard circular masks: high focal depth with high throughput.

We present a class of binary masks that encode, in polar coordinates, the values of a Hadamard matrix of order N. For order N ≥ 2, the binary masks increase the Strehl ratio vs. focus error by the factor N, with the highest possible light throughput. Since a Strehl ratio with high tolerance to defocus does not guarantee a modulation transfer function (MTF) with low sensitivity to focus errors, then, we show that for N = 16 the binary mask reduces also the impact of focus error on the MTF. Equivalently, the discrete binary mask has Fisher information with low variations to defocus.

In vitro COX-1 and COX-2 enzyme inhibitory activities of iridoids from Penstemon barbatus, Castilleja tenuiflora, Cresentia alata and Vitex mollis.

A group of sixteen iridoids isolated from plants used as anti-inflammatory remedies in Mexican folk medicine were evaluated for their potential to inhibit cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes. From these assays, loganic acid (10) was identified as the most promising compound with both COX-1 (36.0 ± 0.6%) and COX-2 (80.8 ± 4.0%) inhibition at 10 µM. Compound 10 shows a better inhibition against the COX-2 enzyme. Other iridoids tested in the present study showed weak or no inhibition against these enzymes. Furthermore, herein are presented key interactions of iridoid 10 with COX-1 and COX-2 enzymes through molecular docking studies. These studies suggest that 10 exhibits anti-inflammatory activity due to COX inhibition.

Supercontinuum optimization for dual-soliton based light sources using genetic algorithms in a grid platform.

We present a numerical strategy to design fiber based dual pulse light sources exhibiting two predefined spectral peaks in the anomalous group velocity dispersion regime. The frequency conversion is based on the soliton fission and soliton self-frequency shift occurring during supercontinuum generation. The optimization process is carried out by a genetic algorithm that provides the optimum input pulse parameters: wavelength, temporal width and peak power. This algorithm is implemented in a Grid platform in order to take advantage of distributed computing. These results are useful for optical coherence tomography applications where bell-shaped pulses located in the second near-infrared window are needed.

Clinical and immunological features of common variable immunodeficiency in Mexican patients

BACKGROUND: Common variable immunodeficiency (CVID) is characterised by hypogammaglobulinaemia and a broad clinical spectrum, mainly showing recurrent bacterial infections accompanied sometimes by increased susceptibility to chronic lung disease, autoimmunity, and neoplastic diseases. OBJECTIVES: To evaluate the clinical and immunological characteristics of patients with CVID in Mexico. METHODS: This is a retrospective analysis of 43 patients with CVID from the Immunology Division of seven different reference centres in Mexico. Patients were diagnosed according to the diagnostic criteria of the European Society for Immunodeficiency Diseases. We collected demographics, clinical and immunological data from each patient and a statistical analysis was performed. RESULTS: There were 23 (53.5%) male and 20 (46.5%) female patients. Median age at onset of disease was 13.7 years, and median age at diagnosis was 19 years. Average delay in diagnosis was 12.5 years. The median total serum levels of IgG, IgM, and IgA at diagnosis were 175, 18, and 17.8 mg/dL, respectively. The mean percentage of CD19+ B cells was 8.15%. Sinusitis (83%), pneumonia (83%), gastrointestinal infection (70%), and acute otitis media (49%) were the most common manifestations. Bronchiectasis was present in 51% of the patients, 44% manifested non-infectious chronic diarrhoea, and 70% experienced weight loss. Autoimmunity was present in 23% of the patients; haemolytic anaemia and autoimmune thrombocytopenic purpura were the most common presentations. Allergy was present in 30.2% of patients, with allergic rhinitis and asthma being the most frequent types. Two patients developed malignancy. All the patients received Intravenous immunoglobulin (IVIG) as a fundamental part of the treatment at a mean dose of 408 mg/kg. CONCLUSION: This is the first cohort of CVID reported in Mexico We found that infection diseases were the most frequent presentations at onset. Moreover, patients had an average diagnosis delay of twelve years and thus a major prevalence of bronchiectasis. We suggest performing an extended analysis of patients with CVID patients in other Latin American countries

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Multi-peak-spectra generation with Cherenkov radiation in a non-uniform single mode fiber.

We propose, by means of numerical simulations, a simple method to design a non-uniform standard single mode fiber to generate spectral broadening in the form of "ad-hoc" chosen peaks from dispersive waves. The controlled multi-peak generation is possible by an on/off switch of Cherenkov radiation, achieved by tailoring the fiber dispersion when decreasing the cladding diameter by segments. The interplay between the fiber dispersion and the soliton self-frequency shift results in discrete peaks of efficiently emitted Cherenkov radiation from low order solitons, despite the small amount of energy contained in a pulse. These spectra are useful for applications that demand low power bell-shaped pulses at specific carrier wavelengths.

Clinical and immunological features of common variable immunodeficiency in Mexican patients.

BACKGROUND: Common variable immunodeficiency (CVID) is characterised by hypogammaglobulinaemia and a broad clinical spectrum, mainly showing recurrent bacterial infections accompanied sometimes by increased susceptibility to chronic lung disease, autoimmunity, and neoplastic diseases. OBJECTIVES: To evaluate the clinical and immunological characteristics of patients with CVID in Mexico. METHODS: This is a retrospective analysis of 43 patients with CVID from the Immunology Division of seven different reference centres in Mexico. Patients were diagnosed according to the diagnostic criteria of the European Society for Immunodeficiency Diseases. We collected demographics, clinical and immunological data from each patient and a statistical analysis was performed. RESULTS: There were 23 (53.5%) male and 20 (46.5%) female patients. Median age at onset of disease was 13.7 years, and median age at diagnosis was 19 years. Average delay in diagnosis was 12.5 years. The median total serum levels of IgG, IgM, and IgA at diagnosis were 175, 18, and 17.8mg/dL, respectively. The mean percentage of CD19+ B cells was 8.15%. Sinusitis (83%), pneumonia (83%), gastrointestinal infection (70%), and acute otitis media (49%) were the most common manifestations. Bronchiectasis was present in 51% of the patients, 44% manifested non-infectious chronic diarrhoea, and 70% experienced weight loss. Autoimmunity was present in 23% of the patients; haemolytic anaemia and autoimmune thrombocytopenic purpura were the most common presentations. Allergy was present in 30.2% of patients, with allergic rhinitis and asthma being the most frequent types. Two patients developed malignancy. All the patients received Intravenous immunoglobulin (IVIG) as a fundamental part of the treatment at a mean dose of 408mg/kg. CONCLUSION: This is the first cohort of CVID reported in Mexico We found that infection diseases were the most frequent presentations at onset. Moreover, patients had an average diagnosis delay of twelve years and thus a major prevalence of bronchiectasis. We suggest performing an extended analysis of patients with CVID patients in other Latin American countries.