25 research outputs found
Microfluidics in gas sensing and artificial olfaction
SCENT-ERC-2014-STG-639123 (2015-2020) UIDB/04378/2020 PTDC/BII-BIO/28878/2017Rapid, real-time, and non-invasive identification of volatile organic compounds (VOCs) and gases is an increasingly relevant field, with applications in areas such as healthcare, agriculture, or industry. Ideal characteristics of VOC and gas sensing devices used for artificial olfaction include portability and affordability, low power consumption, fast response, high selectivity, and sensitivity. Microfluidics meets all these requirements and allows for in situ operation and small sample amounts, providing many advantages compared to conventional methods using sophisticated apparatus such as gas chromatography and mass spectrometry. This review covers the work accomplished so far regarding microfluidic devices for gas sensing and artificial olfaction. Systems utilizing electrical and optical transduction, as well as several system designs engineered throughout the years are summarized, and future perspectives in the field are discussed.publishersversionpublishe
Stable and oriented liquid crystal droplets stabilized by imidazolium ionic liquids
SCENT-ERC-2014-STG-639123(2015-2022) UIDP/04378/2020 UIDB/04378/2020 LA/P/0140/2020Liquid crystals represent a fascinating intermediate state of matter, with dynamic yet or-ganized molecular features and untapped opportunities in sensing. Several works report the use of liquid crystal droplets formed by microfluidics and stabilized by surfactants such as sodium do-decyl sulfate (SDS). In this work, we explore, for the first time, the potential of surface-active ionic liquids of the imidazolium family as surfactants to generate in high yield, stable and oriented liquid crystal droplets. Our results show that [C12MIM][Cl], in particular, yields stable, uniform and mon-odisperse droplets (diameter 74 ± 6 µm; PDI = 8%) with the liquid crystal in a radial configuration, even when compared with the standard SDS surfactant. These findings reveal an additional application for ionic liquids in the field of soft matter.publishersversionpublishe
Cytokines and neutrophil extracellular traps in the equine endometrium: friends or foes?
Articles in International JournalsCytokines may play a dual role in the reproductive tract – either involved in physiologic processes or mediating inflammation and other
pathologic processes. Physiologic secretory and angiogenic function in the equine endometrium appears to be regulated by cytokines
TNFa, FasL, IFNg through their receptors. These receptors are present in glandular epithelium, and stroma cells and their mRNA expression
changes throughout the estrous cycle. Besides, interleukins (IL-1a and IL-1b) and their receptors mRNA expression vary according to
various degrees of endometrium inflammation (endometritis) and fibrosis (endometrosis). A novel paradigm in innate immunity and neutrophils
(PMN) hyperactivation is PMN ability to cast out their DNA in response to infectious stimuli. These PMN extracellular traps (NETs)
bind and kill pathogens, at the infection site. The intriguing dilemma is that even though NETs may function as a first line of defense, they
also release molecules that may contribute to tissue damage. Thus, we postulate that PMN present in the endometrium at estrus, mating
or infection, might form NETs, and release nucleic and cytoplasmic proteins with immunomodulatory properties. Equine PMN stimulated in
vitro showed NETs formation capacity when in contact with some bacteria strains obtained from mares with endometritis, such as Streptococcus
zooepidemicus, Escherichia coli and Staphylococus capitis. In this regard, even though NETs and cytokines function as an effective
antimicrobial first line of defense or modulate physiologic endometrial function, respectively (friends), they may also be involved in endometrial
fibrosis pathogenesis and endometrial secretory function impairment, due to enhanced NETs formation and/or a decrease on NETs
degradation (foes)
Uncovering the kiloparsec-scale stellar ring of NGC5128
We reveal the stellar light emerging from the kiloparsec-scale, ring-like
structure of the NGC5128 (Centaurus A) galaxy in unprecedented detail. We use
arcsecond-scale resolution near infrared images to create a "dust-free" view of
the central region of the galaxy, which we then use to quantify the shape of
the revealed structure. At the resolution of the data, the structure contains
several hundreds of discreet, point-like or slightly elongated sources. Typical
extinction corrected surface brightness of the structure is K_S = 16.5
mag/arcsec^2, and we estimate the total near infrared luminosity of the
structure to be M = -21 mag. We use diffraction limited (FWHM resolution of ~
0.1", or 1.6 pc) near infrared data taken with the NACO instrument on VLT to
show that the structure decomposes into thousands of separate, mostly
point-like sources. According to the tentative photometry, the most luminous
sources have M_K = -12 mag, naming them red supergiants or relatively low-mass
star clusters. We also discuss the large-scale geometry implied by the
reddening signatures of dust in our near infrared images.Comment: 5 pages, 4 figures, accepted for publication in A&A Letters. A
version with high resolution images can be downloaded from
http://www.helsinki.fi/~jtkainul/CenALette
The In vitro inhibitory effect of sivelestat on elastase induced collagen and metallopeptidase expression in equine endometrium
Research Areas: Agriculture ; Veterinary Sciences ; ZoologyAbstract: Neutrophil extracellular traps (NETs) fight endometritis, and elastase (ELA), a protease
found in NETs, might induce collagen type I (COL1) accumulation in equine endometrium.
Metallopeptidases (MMPs) are involved in extracellular matrix balance. The aim was to evaluate
the e ects of ELA and sivelestat (selective elastase inhibitor) on MMP-2 and MMP-9 expression and
gelatinolytic activity, as well as the potential inhibitory e ect of sivelestat on ELA-induced COL1 in
equine endometrium. Endometrial explants from follicular (FP) and mid-luteal (MLP) phases were
treated for 24 or 48 h with ELA, sivelestat, and their combination. Transcripts of COL1A2, MMP2, and
MMP9 were evaluated by qPCR; COL1 protein relative abundance by Western blot, and MMP-2 and
MMP-9 gelatinolytic activity by zymography. In response to ELA treatment, there was an increase in
MMP2 mRNA transcription (24 h) in active MMP-2 (48 h), both in FP, and in MMP9 transcripts in FP
(48 h) and MLP (24 h) (p < 0.05). Sivelestat inhibited ELA-induced COL1A2 transcripts in FP (24 h)
and MLP (24 h, 48 h) (p < 0.05). The sivelestat inhibitory e ect was detected in MMP9 transcripts
in FP at 48 h (p < 0.05), but proteases activity was unchanged. Thus, MMP-2 and MMP-9 might be
implicated in endometrium fibrotic response to ELA. In mare endometrium, sivelestat may decrease
ELA-induced COL1 deposition and hinder endometrosis development.info:eu-repo/semantics/publishedVersio
Enzymes present in neutrophil extracellular traps may stimulate the fibrogenic PGF(2 alpha) pathway in the mare endometrium
Research Areas: AgricultureVeterinary SciencesEndometrosis is a fibrotic disease in mare endometrium whose pathological
mechanisms remain obscure. Prostaglandin (PG)F2α, despite modulating reproductive physiological
processes, may also provoke local pathological collagen deposition (fibrogenesis). Neutrophil extracellular traps (NETs) released during inflammation have been linked to fibrogenesis in several
tissues. We have previously shown that enzymes found in NETs increase in vitro collagen production
in mare endometrium. In this study, activation of PGF2α-pathway in equine endometrial explants
challenged in vitro by enzymes found in NETs is shown. Our results indicate that both endocrine
microenvironment (estrous cycle phase) and healthy or pathological conditions of endometrial tissues
play an important role in PGF2α-pathway activation. In the endometrium of the follicular phase,
we have observed both high production of PGF2α and/or PGF2α receptor gene transcription under
the action of enzymes found in NETs, both conditions associated with fibrogenesis in other tissues.
Nevertheless, transcription of the PGF2α receptor gene does not appear to be hormone-dependent,
albeit their levels seem to be dependent on endometrial category in the mid-luteal phase. This study
suggests that enzymes existing in NETs may instigate changes on PGF2α mediators, which may
become an additional mechanism of fibrogenesis in mare endometrium.info:eu-repo/semantics/publishedVersio
Metallopeptidades 2 and 9 genes epigenetically modulate equine endometrial fibrosis
Endometrium type I (COL1) and III (COL3) collagen accumulation, periglandular fibrosis and mare infertility characterize endometrosis. Metalloproteinase-2 (MMP-2), MMP-9 and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) are involved in collagen turnover. Since epigenetic changes may control fibroproliferative diseases, we hypothesized that epigenetic mechanisms could modulate equine endometrosis. Epigenetic changes can be reversed and therefore extremely promising for therapeutic use. Methylation pattern analysis of a particular gene zone is used to detect epigenetic changes. DNA methylation commonly mediates gene repression. Thus, this study aimed to evaluate if the transcription of some genes involved in equine endometrosis was altered with endometrial fibrosis, and if the observed changes were epigenetically modulated, through DNA methylation analysis. Endometrial biopsies collected from cyclic mares were histologically classified (Kenney and Doig category I, n = 6; category IIA, n = 6; category IIB, n = 6 and category III, n = 6). Transcription of COL1A1, COL1A2, COL3A1, MMP2, MMP9, TIMP1, and TIMP2 genes and DNA methylation pattern by pyrosequencing of COL1A1, MMP2, MMP9, TIMP1 genes were evaluated. Both MMP2 and MMP9 transcripts decreased with fibrosis, when compared with healthy endometrium (category I) (P < 0.05). TIMP1 transcripts were higher in category III, when compared to category I endometrium (P < 0.05). No differences were found for COL1A1, COL1A2, COL3A1 and TIMP2 transcripts between endometrial categories. There were higher methylation levels of (i) COL1A1 in category IIB (P < 0.05) and III (P < 0.01), when compared to category I; (ii) MMP2 in category III, when compared to category I (P < 0.001) and IIA (P < 0.05); and (iii) MMP9 in category III, when compared to category I and IIA (P < 0.05). No differences in TIMP1 methylation levels were observed between endometrial categories. The hypermethylation of MMP2 and MMP9, but not of COL1A1 genes, occurred simultaneously with a decrease in their mRNA levels, with endometrial fibrosis, suggesting that this hypermethylation is responsible for repressing their transcription. Our results show that endometrosis is epigenetically modulated by anti-fibrotic genes (MMP2 and MMP9) inhibition, rather than fibrotic genes activation and therefore, might be promising targets for therapeutic use.info:eu-repo/semantics/publishedVersio
Collagen Type III as a Possible Blood Biomarker of Fibrosis in Equine Endometrium
Research Areas:Agriculture ; Veterinary Sciences ; ZoologyCollagen pathological deposition in equine endometrium (endometrosis) is responsible for infertility. Kenney and Doig’s endometrial biopsy histopathological classification is the gold standard method for endometrosis evaluation, whereby blood biomarkers identification would be less invasive and could provide additional information regarding endometrosis diagnosis and fertility prognosis. This study aimed to identify blood biomarkers for endometrosis diagnosis (42 mares were used in experiment 1), and fertility assessment (50 mares were used in experiment 2). Reproductive examination, endometrial biopsy histopathological classification (Kenney and Doig) and blood collection were performed. Endometrium and serum collagen type I (COL1) and type III (COL3), and hydroxyproline concentrations were measured (ELISA). Serum COL3 cut-off value of 60.9 ng/mL allowed healthy endometria (category I) differentiation from endometria with degenerative/fibrotic lesions (categories IIA, IIB or III) with 100% specificity and 75.9% sensitivity. This cut-off value enabled category I + IIA differentiation from IIB + III (76% specificity, 81% sensitivity), and category III differentiation from others (65% specificity, 92.3% sensitivity). COL1 and hydroxyproline were not valid as blood biomarkers. Serum COL3 cut-off value of 146 ng/mL differentiated fertile from infertile mares (82.4% specificity, 55.6% sensitivity), and was not correlated with mares’ age. Only COL3 may prove useful as a diagnostic aid in mares with endometrial fibrosis and as a fertility indicator.info:eu-repo/semantics/publishedVersio
A precise architecture characterization of the Men planetary system
The bright star Men was chosen as the first target for a radial
velocity follow-up to test the performance of ESPRESSO, the new high-resolution
spectrograph at the ESO's Very-Large Telescope (VLT). The star hosts a
multi-planet system (a transiting 4 M planet at 0.07 au, and a
sub-stellar companion on a 2100-day eccentric orbit) which is
particularly appealing for a precise multi-technique characterization. With the
new ESPRESSO observations, that cover a time span of 200 days, we aim to
improve the precision and accuracy of the planet parameters and search for
additional low-mass companions. We also take advantage of new photometric
transits of Men c observed by TESS over a time span that overlaps with
that of the ESPRESSO follow-up campaign. We analyse the enlarged spectroscopic
and photometric datasets and compare the results to those in the literature. We
further characterize the system by means of absolute astrometry with Hipparcos
and Gaia. We used the spectra of ESPRESSO for an independent determination of
the stellar fundamental parameters. We present a precise characterization of
the planetary system around Men. The ESPRESSO radial velocities alone
(with typical uncertainty of 10 cm/s) allow for a precise retrieval of the
Doppler signal induced by Men c. The residuals show an RMS of 1.2 m/s,
and we can exclude companions with a minimum mass less than 2 M
within the orbit of Men c). We improve the ephemeris of Men c using
18 additional TESS transits, and in combination with the astrometric
measurements, we determine the inclination of the orbital plane of Men b
with high precision ( deg). This leads to the precise
measurement of its absolute mass M, and
shows that the planetary orbital planes are highly misaligned.Comment: Accepted for publication on A&
ESPRESSO@VLT -- On-sky performance and first results
ESPRESSO is the new high-resolution spectrograph of ESO's Very-Large
Telescope (VLT). It was designed for ultra-high radial-velocity precision and
extreme spectral fidelity with the aim of performing exoplanet research and
fundamental astrophysical experiments with unprecedented precision and
accuracy. It is able to observe with any of the four Unit Telescopes (UT) of
the VLT at a spectral resolving power of 140,000 or 190,000 over the 378.2 to
788.7 nm wavelength range, or with all UTs together, turning the VLT into a
16-m diameter equivalent telescope in terms of collecting area, while still
providing a resolving power of 70,000. We provide a general description of the
ESPRESSO instrument, report on the actual on-sky performance, and present our
Guaranteed-Time Observation (GTO) program with its first results. ESPRESSO was
installed on the Paranal Observatory in fall 2017. Commissioning (on-sky
testing) was conducted between December 2017 and September 2018. The instrument
saw its official start of operations on October 1st, 2018, but improvements to
the instrument and re-commissioning runs were conducted until July 2019. The
measured overall optical throughput of ESPRESSO at 550 nm and a seeing of 0.65
arcsec exceeds the 10% mark under nominal astro-climatic conditions. We
demonstrate a radial-velocity precision of better than 25 cm/s during one night
and 50 cm/s over several months. These values being limited by photon noise and
stellar jitter show that the performanceis compatible with an instrumental
precision of 10 cm/s. No difference has been measured across the UTs neither in
throughput nor RV precision. The combination of the large collecting telescope
area with the efficiency and the exquisite spectral fidelity of ESPRESSO opens
a new parameter space in RV measurements, the study of planetary atmospheres,
fundamental constants, stellar characterisation and many other fields.Comment: 26 pages, 28 figure