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1.
Thromb Haemost ; 120(2): 262-276, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31901221

RESUMEN

C-type lectin-like receptor 2 (CLEC-2) plays a crucial role in different platelet-related physiological and pathological processes. It signals through a tyrosine kinase-mediated pathway that is highly dependent on the positive feedback exerted by the platelet-derived secondary mediators, adenosine diphosphate (ADP) and thromboxane A2 (TXA2). Here, we aimed to analyze the tyrosine phosphoproteome of platelets activated with the CLEC-2 agonist rhodocytin to identify relevant phosphorylated tyrosine residues (p-Tyr) and proteins involved in platelet activation downstream of this receptor. We identified 363 differentially p-Tyr residues, corresponding to the majority of proteins previously known to participate in CLEC-2 signaling and also novel ones, including adaptors (e.g., DAPP1, Dok1/3, CASS4, Nck1/2), kinases/phosphatases (e.g., FAK1, FES, FGR, JAK2, SHIP2), and membrane proteins (e.g., G6F, JAM-A, PECAM-1, TLT-1). To elucidate the contribution of ADP and TXA2 at different points of the CLEC-2 signaling cascade, we evaluated p-Tyr levels of residues identified in the analysis and known to be essential for the catalytic activity of kinases Syk(p-Tyr525+526) and Src(p-Tyr419), and for PLCγ2 activity (p-Tyr759). We demonstrated that Syk phosphorylation at Tyr525+526 also happens in the presence of ADP and TXA2 inhibitors, which is not the case for Src-pTyr419 and PLCγ2-pTyr759. Kinetics studies for the three phosphoproteins show some differences in the phosphorylation profile. Ca2+ mobilization assays confirmed the relevance of ADP and TXA2 for full CLEC-2-mediated platelet activation. The present study provides significant insights into the intracellular events that take place following CLEC-2 activation in platelets, contributing to elucidate in detail the CLEC-2 signalosome.


Asunto(s)
Plaquetas/metabolismo , Lectinas Tipo C/metabolismo , Glicoproteínas de Membrana/metabolismo , Fosfoproteínas/química , Transducción de Señal , Tirosina/química , Adenosina Difosfato/química , Adulto , Calcio/química , Calcio/metabolismo , Femenino , Humanos , Cinética , Masculino , Persona de Mediana Edad , Fosforilación , Fosfotirosina/química , Activación Plaquetaria , Agregación Plaquetaria , Proteoma , Tromboxano A2/química , Adulto Joven
2.
Opt Express ; 26(15): 19445-19455, 2018 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-30114116

RESUMEN

In this paper, we evaluate by means of simulation and experimentally the simultaneous coupling of the LP01x-LP11ax fiber modes and the TE0-TE1 nanophotonic SOI waveguide modes using a grating coupler for a two-mode fiber at 1550 nm. Both the grating width (ranging from 10 µm to 15 µm) and the grating vertical profile have been considered in the design procedure. The optimum design (14 µm width and 609 nm grating period) has been selected in terms of coupling efficiency (both LP01x-TE0 and LP11ax-TE1), compactness and tolerance to lateral misalignments between fiber and coupler. The LP01x-TE0 and LP11ax-TE1 modes achieved coupling efficiencies of 49% and 45%, respectively.

3.
Opt Lett ; 43(11): 2491-2494, 2018 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29856412

RESUMEN

The supermode analysis of asymmetrical directional couplers (ADC) based on SOI technology for strip and ridge structures at 1550 nm is herein reported, targeting to reduce ADC device fabrication requirements. The reported analysis based on supermodes permits us to assess the sensitivity of the ADC coupling efficiency by calculating the index difference between even and odd supermodes. Optimum designs have been found for 100 and 400 nm gaps, respectively, capable of converting and (de) multiplexing both TE0 and TE1 modes taking into account the width, gap, height, and slab thickness variations produced with respect to the nominal design.

4.
Opt Express ; 26(3): 3013-3019, 2018 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-29401834

RESUMEN

We investigate partial response signaling (PRS) as a way of increasing the transmission length achievable by direct detection optical systems. The performance of the duobinary and PRS modulations is evaluated against that of conventional on-off-keying (OOK). We prove by simulation and experimentally that duobinary increases the link distance by up to 1.5 times and PRS by up to 3 times, when no signal processing is employed. The gain is preserved even when equalization is used. PRS is employed also with 4-level pulse-amplitude modulation (PAM-4) and is shown to improve the transmission distance by almost 3 times.

5.
Front Microbiol ; 8: 723, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28522991

RESUMEN

The spirochetes Brachyspira hyodysenteriae and B. pilosicoli are pig intestinal pathogens that are the causative agents of swine dysentery (SD) and porcine intestinal spirochaetosis (PIS), respectively. Although some inactivated bacterin and recombinant vaccines have been explored as prophylactic treatments against these species, no effective vaccine is yet available. Immunoproteomics approaches hold the potential for the identification of new, suitable candidates for subunit vaccines against SD and PIS. These strategies take into account the gene products actually expressed and present in the cells, and thus susceptible of being targets of immune recognition. In this context, we have analyzed the immunogenic pattern of two B. pilosicoli porcine isolates (the Spanish farm isolate OLA9 and the commercial P43/6/78 strain) and one B. hyodysenteriae isolate (the Spanish farm V1). The proteins from the Brachyspira lysates were fractionated by preparative isoelectric focusing, and the fractions were analyzed by Western blot with hyperimmune sera from challenged pigs. Of the 28 challenge-specific immunoreactive bands detected, 21 were identified as single proteins by MS, while the other 7 were shown to contain several major proteins. None of these proteins were detected in the control immunoreactive bands. The proteins identified included 11 from B. hyodysenteriae and 28 from the two B. pilosicoli strains. Eight proteins were common to the B. pilosicoli strains (i.e., elongation factor G, aspartyl-tRNA synthase, biotin lipoyl, TmpB outer membrane protein, flagellar protein FlaA, enolase, PEPCK, and VspD), and enolase and PEPCK were common to both species. Many of the identified proteins were flagellar proteins or predicted to be located on the cell surface and some of them had been previously described as antigenic or as bacterial virulence factors. Here we report on the identification and semiquantitative data of these immunoreactive proteins which constitute a unique antigen collection from these bacteria.

6.
Opt Lett ; 42(7): 1221-1224, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28362734

RESUMEN

The use of an integrated asymmetrical directional coupler for two-mode transmission at 1550 nm is analyzed. The design is based on silicon-on-insulator (SOI) technology and permits mode conversion and mode multiplexing/demultiplexing. In the nominal design, mode conversion and mode (de)multiplexing are achieved with 97% efficiency and a 23.4 dB crosstalk level in the 1540-1560 nm band using a 0.1 µm gap. The dimension tolerance of the SOI process has been taken into account in the selection of the optimum design, and the coupling efficiency would remain above 82.3% (corresponding to 0.8 dB excess loss) with 3σ accuracy. A 90% efficiency has been experimentally obtained.

7.
Anal Chem ; 89(7): 3840-3846, 2017 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-28260372

RESUMEN

Protein ubiquitination regulates key cellular functions, including protein homeostasis and signal transduction. The digestion of ubiquitinated proteins with trypsin yields a glycine-glycine remnant bound to the modified lysine residue (K-ε-GG) that can be recognized by specific antibodies for immunoaffinity purification (IAP) and subsequent identification of ubiquitination sites by mass spectrometry. Previous ubiquitinome studies based on this strategy have consistently digested milligram amounts of protein as starting material using in-solution digestion protocols prior to K-ε-GG enrichment. Filter-aided sample preparation (FASP) surpasses in-solution protein digestion in cleavage efficiency, but its performance has thus far been shown for digestion of sample amounts on the order of micrograms. Because cleavage efficiency is pivotal in the generation of the K-ε-GG epitope recognized during IAP, here we developed a large-scale FASP method (LFASP) for digestion of milligram amounts of protein and evaluated its applicability to the study of the ubiquitinome. Our results demonstrate that LFASP-based tryptic digestion is efficient, robust, reproducible, and applicable to the study of the ubiquitinome. We benchmark our results with state-of-the-art ubiquitinome studies and show a ∼3-fold reduction in the proportion of miscleaved peptides with the method presented here. Beyond ubiquitinome analysis, LFASP overcomes the general limitation in sample capacity of standard FASP-based protocols and can therefore be used for a variety of applications that demand a large(r) amount of starting material.

8.
Opt Express ; 24(19): 21415-34, 2016 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-27661883

RESUMEN

In this paper, we evaluate experimentally and model theoretically the intra- and inter-core crosstalk between the polarized core modes in single-mode multi-core fiber media including temporal and longitudinal birefringent effects. Specifically, extensive experimental results on a four-core fiber indicate that the temporal fluctuation of fiber birefringence modifies the intra- and inter-core crosstalk behavior in both linear and nonlinear optical power regimes. To gain theoretical insight into the experimental results, we introduce an accurate multi-core fiber model based on local modes and perturbation theory, which is derived from the Maxwell equations including both longitudinal and temporal birefringent effects. Numerical calculations based on the developed theory are found to be in good agreement with the experimental data.

9.
Opt Express ; 23(14): 18712-20, 2015 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-26191930

RESUMEN

In this paper we evaluate experimentally and model theoretically the nonlinear crosstalk random process in multi-core fiber. The experimental results indicate that mode coupling in multi-core fibers is reduced in presence of fiber Kerr nonlinearities. An analytical study of the inter-core crosstalk probability density function in nonlinear regime is performed, where the theoretical distribution, derived from the nonlinear coupled-mode equation, is experimentally validated in homogeneous four-core fiber. The herein presented analysis includes the evaluation of the inter-core crosstalk probability density function, mean and variance evolution considering the optical power launched into the fiber.

10.
Opt Express ; 22(6): 6203-9, 2014 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-24663968

RESUMEN

In this paper the on-the-field performance of a WDM-PON optical access providing quintuple-play services using orthogonal frequency division multiplexing (OFDM) modulation is evaluated in a real fiber-to-the-home (FTTH) network deployed by Towercom operator in Bratislava (Slovakia). A bundle of quintuple-play services comprising full-standard OFDM-based signals (LTE, WiMAX, UWB and DVB-T) and an ad-hoc OFDM-GbE signal is transmitted in coexistence per single user. Both downstream and upstream transmission performances are evaluated in different on-the-field long-reach optical link distance configurations. Four wavelength multi-user transmission of quintuple-play OFDM services is demonstrated exceeding 60.8 km reach in standard single mode fiber.

11.
Int Wound J ; 11(6): 605-10, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23253894

RESUMEN

Pressure ulcers (PU) are the source of multiple complications and even death. To our knowledge, there is no available data about PU prevalence in Mexico. The objective of this study was to determine the point prevalence of PU in three second-level hospitals in Mexico. Every adult hospitalised patient was included in each hospital. Age, gender, hospitalisation ward, Braden score, and the number, location and stage of the ulcers encountered were recorded, as well as any pressure relief measures. In total, 294 patients were examined (127 were male); of these, 63 were considered to be at risk. The average age was 48·6 years. The overall prevalence of the PU was 17%. The service with the highest prevalence was the ICU. The most frequent stage was II (32%) and they were most commonly found in the sacrum (74%). The average Braden score of the patients with ulcers was 10, and 21·4% of the patients obtained moderate- to high-risk Braden scores. Of them, 60·3% had ulcers and only 46% had any preventive measures. The prevalence of PU in three hospitals in Mexico is 17%. The most common stage is II and the most commonly affected site is the sacrum. Only 46% of patients with PU had at least one pressure release measure.


Asunto(s)
Úlcera por Presión/epidemiología , Adulto , Anciano , Femenino , Hospitalización/estadística & datos numéricos , Hospitales Generales , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Úlcera por Presión/patología , Úlcera por Presión/terapia , Prevalencia , Riesgo , Centros de Atención Secundaria , Índice de Severidad de la Enfermedad
12.
Opt Express ; 20(13): 13748-61, 2012 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-22714440

RESUMEN

The simultaneous transmission of four orthogonal frequency-division multiplexing (OFDM)-based signals used to provide quintuple-play services along wavelength division multiplexing (WDM) long-reach passive optical networks (LR-PONs) is demonstrated experimentally. Particularly, the transmission performance of custom signal bearing Gigabit Ethernet data, Worldwide Interoperability for Microwave Access, Long Term Evolution and Ultra Wideband (sub-bands 2 and 3) signals is evaluated for different LR-PONs reaches, considering single-wavelength and WDM transmission, and using a centralized impairment compensation technique at the central office that is transparent to the services provided.It is shown that error vector magnitude-compliant levels are obtained for all the OFDM-based signals in WDM LR-PONs reaching 100 km and that negligible inter-channel crosstalk is obtained for a channel spacing of 100 GHz regardless the OFDM-based signal considered. The successful multi-format OFDM transmission along the 100 km-long WDM LR-PON is achieved in the absence of optical dispersion compensation or single sideband modulation, and it is enabled by the performance improvement provided by the centralized impairment compensation realized.


Asunto(s)
Redes de Comunicación de Computadores/instrumentación , Dispositivos Ópticos , Telecomunicaciones/instrumentación , Telemetría/instrumentación , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo
13.
Opt Express ; 20(28): 29769-75, 2012 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-23388804

RESUMEN

The low-cost in-home distribution of full-standard digital TV jointly with high-bitrate data using 50 m long 1 mm core diameter graded-index plastic optical fiber (GI-POF) is proposed and experimentally demonstrated. Discrete multitone (DMT) modulation is demonstrated to provide an adaptive bitrate which can spectrally coexist with digital video broadcasting-terrestrial (DVB-T) signals in 470-862 MHz. A 3 Gb/s DMT signal and two DVB-T channels are generated, transmitted and received exhibiting excellent performance.

15.
Opt Lett ; 36(6): 858-60, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21403708

RESUMEN

We propose and analyze a novel (to our knowledge) approach to implement the spectral self-imaging effect of optical frequency combs. The technique is based on time-domain multilevel phase-only modulation of a periodic optical pulse train. The method admits both infinite- and finite-duration periodic pulse sequences. We show that the fractional spectral self-imaging effect allows one to reduce by an integer factor the comb frequency spacing. Numerical simulation results support our theoretical analysis.

16.
Opt Express ; 19(26): B197-202, 2011 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-22274019

RESUMEN

Radio-over-fiber (RoF) schemes offer the possibility of permitting direct access to native format services for the domestic user. A low power requirement and cost effectiveness are crucial to both the service provider and the end user. Here, we present an ultra-low cost and power RoF scheme using direct modulation of commercially-available 1344 nm and 1547 nm VCSELs by band-group 1 UWB wireless signals (ECMA-368) at near broadcast power levels. As a result, greatly simplified electrical-optical-electrical conversion is accomplished. A successful demonstration over a transmission distance of 20.1 km is described using a SSMF, CWDM optical network. EVMs of better than -18.3 dB were achieved.

17.
Opt Express ; 19(26): B450-6, 2011 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-22274055

RESUMEN

A dual-drive LiNbO(3) architecture modulator with chirp management is proposed and developed offering SFDR > 25 dB in a 1.4 V bias excursion compared to only 0.5 V bias excursion in a conventional Mach-Zehnder electro-optical modulator (MZ-EOM). The architecture effectively extends the linear regime and enables the optical transmission of wireless systems employing orthogonal division multiplexing (OFDM) modulation such as ultra-wide band (UWB) which require high linearity over a broad frequency range due to their high peak-to-average power ratio (PARP). Radio-over-fiber UWB transmission in a passive optical network is experimentally demonstrated employing this technique, exhibiting an enhancement of 2.2 dB in EVM after 57 km SSMF when the dual-drive developed modulator is employed.

18.
Opt Express ; 19(26): B895-904, 2011 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-22274117

RESUMEN

The paper addresses the problem of distribution of high-definition video over fiber-wireless networks. The physical layer architecture with the low complexity envelope detection solution is investigated. We present both experimental studies and simulation of high quality high-definition compressed video transmission over 60 GHz fiber-wireless link. Using advanced video coding we satisfy low complexity and low delay constraints, meanwhile preserving the superb video quality after significantly extended wireless distance.

19.
Artículo en Inglés | MEDLINE | ID: mdl-20886019

RESUMEN

Pigmented tumors have similar clinical features that overlap and hamper diagnosis. Dermoscopy increases the diagnostic accuracy of doubtful melanocytic lesions and has been used as a noninvasive tool in the detection of pigmented lesions (PLs) like melanoma, basal cell carcinoma, and pigmented Bowen's disease (pBD). Our objective was to show the dermoscopic features of 2 cases of pBD and compare with the findings reported in the literature. Two dermoscopic images of biopsy proven pBD were retrospectively analyzed for dermoscopic patterns. Both cases showed brown regular globules, structureless brown and blue pigmentation, glomerular vessels, hypopigmented regression-like areas, and keratosis. These findings were similar to the cases reported previously. The dermoscopic diagnosis of pBD is based on the absence of criteria for a melanocytic lesion in the presence of glomerular vessels, regular brown globules and keratosis. Although pBD is rare, it should be included in the differential diagnosis of PLs, especially melanoma.

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