188 research outputs found
Managing Psoriasis Consultations During the COVID-19 Pandemic : Recommendations From the Psoriasis Group of the Spanish Academy of Dermatology and Venereology (AEDV)
Ye
Optical Trapping of Single Nanostructures in a Weakly Focused Beam. Application to Magnetic Nanoparticles
"This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [insert ACS Articles on Request author-directed link to Published Work, see https://pubs.acs.org/doi/10.1021/acs.jpcc.8b04676."[EN] Optical trapping of individual particles is believed to be only effective under highly focused beams because these conditions strengthen the gradient forces. This is especially critical in the beam propagating direction, where the scattering and absorption forces must be counterbalanced. Here, we demonstrate that optical trapping of nanostructures is also possible in a weakly focused beam. We study the theoretical conditions for effective three-dimensional optical confinement and verify them experimentally on iron-oxide-based nanoparticles with and without a silica coating, for which scattering, absorption, and gradient forces exist. This chemical approach to their all-optical control is, in turn, convenient for making magnetic nanostructures biocompatible. Weakly focused beams reduce the irradiance in the focal region and therefore the photon damage to the samples, which is further important to delay quantum dot quenching in the trap or to prevent artifacts in the study of biomolecular motor dynamics.We are grateful to Dr. Maria Acebron and Dr. Beatriz H. Juarez for their support in the silica encapsulation of the nano particles. This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Grant MAT2015-71806-R). IMDEA Nanociencia acknowledges support from the "Severo Ochoa" Programme for Centers of Excellence in R&D (MINECO, Grant SEV-2016-0686). H.R.-R. is supported by an FPI-UAM fellowship.RodrĂguez-RodrĂguez, H.; De Lorenzo, S.; De La Cueva, L.; Salas, G.; Arias-Gonzalez, JR. (2018). Optical Trapping of Single Nanostructures in a Weakly Focused Beam. Application to Magnetic Nanoparticles. The Journal of Physical Chemistry C. 122(31):18094-18101. https://doi.org/10.1021/acs.jpcc.8b04676S18094181011223
Spatial variation of trace elements in the peri-urban soil of Madrid
Purpose The peri-urban region to the south east of Madrid contains a mixture of housing, manufacturing industry and farming, some of which disperse metals, in particular cadmium, copper, lead, and zinc, into the soil. We have mapped the concentrations of these elements and identified the major influences on their distributions. Material and methods We sampled the topsoil at 125 sites across 1,050 km2 of peri-urban land to the south east of the city on two grids, one nested inside the other. At each site, we measured the current contents of the four trace elements in the soil. We used robust geostatistical methods to model the complex spatial distributions of the data as mixtures of fixed and random effects. The empirical best linear unbiased predictor was used to map the elements. Site descriptors (lithology, land cover, cultivation, relief, erosion, and stoniness) were then included as covariates to identify significant effects on trace element concentrations. Results and discussion The complex spatial distributions of the elements seem to arise from several sources. The concentrations generally increase from southeast to northwest, i.e.;with increasing proximity to Madrid itself, the main potential source of pollution. This pattern is clear for lead and similar for copper and zinc, though with "hot spots" at or near industrial sites. The spatial pattern of cadmium is more complex and depends on varied lithology, industry, and land use such as irrigation and cultivation. In general, the concentrations of the four elements appear to decrease with increases in stoniness and erosion, and to be largest on the valley floors. Conclusions Robust geostatistical methods enabled us to analyze and map the complex patterns of spatial variation of trace elements in a peri-urban region of Madrid. They show that distance to the city center, lithology, manufacturing industry, and cultivation all play their parts in loading the soil with lead, copper, zinc, and cadmium. In the event, none of the metals has yet exceeded the legislative thresholds, but some concentrations are already substantially greater than would arise from natural sources, especially closest to Madrid itself. © 2013 The Author(s)
Study of the anticancer properties of optically active titanocene oximato compounds
New water soluble and optically active cyclopentadienyl titanium derivatives [(¿5-C5H5)2Ti{(1R, 4S)-¿ON, (R)NH}Cl] (R = Bn (Benzyl) 1a’, 2-pic (2-picolylamine) 1b’) have been synthesized. The novel compounds along with those previously described [(¿5-C5H5)2Ti{(1S, 4R)-¿ON, (R)NH}Cl] (R = Bn 1a, 2-pic 1b) were evaluated by polarimetry, ultra-violet and circular dichroism spectroscopy. The structure of 1b was determined by single crystal X-ray crystallography and showed a unique terminal monohapto Ti–O disposition of the oximato ligand. All enantiomers have been tested against several cancer cell lines in vitro: prostate PC-3 and DU-145, lung A-549, pancreas MiaPaca-2, colorectal HCT-116, leukemia Jurkat and cervical HeLa. In addition, 1a, 1b and 1b’ were tested against non-tumorigenic prostate RWPE-1 cell line. After 24 h of incubation, 1b and 1b’ were moderately active against Jurkat and A-549 cells. The anti-proliferative effect of titanium compounds on prostate PC-3, DU-145 and RWPE-1 cell lines was also assessed after 72 h of drug exposure. The cytotoxic profile of the enantiomers was similar, exception made for the PC-3 cells, with S, R-isomers exhibiting cytotoxicities 2 to 3 times higher than R, S-compounds. Under these conditions, derivative 1b showed calculated IC50 values better than those of Tacke''s Titanocene-Y (bis-[(p-methoxybenzyl)cyclopentadienyl]titanium(IV) dichloride) on both the prostate PC-3 and DU-145 cells. 1a and 1b cytotoxic behaviour shows certain selectiveness, with activities 2–4 times lower on normal prostate RWPE-1 than on cancer PC-3 cells. Furthermore, 1b produces higher cytotoxicity on prostate PC-3, DU-145 and RWPE-1 cells than the additive dose of titanocene dichloride and pro-ligand b·HCl. Additionally, compound-DNA interactions have been investigated by equilibrium dialysis, Fluorescence Resonance Energy Transfer (FRET) melting assays and viscometric titrations, which suggest that these metal complexes and/or their hydrolysis products bind DNA either in the minor groove or externally
Biological evaluation of water soluble arene Ru(II) enantiomers with amino-oxime ligands
New water soluble, enantiopure arene ruthenium compound SRuSN-(1R, 4S)-[(Âż6-p-cymene)Ru{ÂżNH(Bn), ÂżNOH}Cl]Cl (Bn = benzyl, 1a') has been synthesized. The novel compound along with that previously described RRuRN-(1S, 4R)-[(Âż6-p-cymene)Ru{ÂżNH(Bn), ÂżNOH}Cl]Cl (1a) was evaluated by polarimetry, ultra-violet and circular dichroism spectroscopy. The structure of novel ruthenium derivative 1a' was determined by single crystal X-ray crystallography. Both enantiomers have been tested against several cancer cell lines in vitro: prostate PC-3, lung A-549, pancreas MIA PaCa-2, colorectal HCT-116, leukemia Jurkat and cervical HeLa. Both enantiomers are active and versatile cytotoxic agents, showing IC50 values from 2 to 12 times lower than those found for cisplatin in the different cell lines evaluated. The mechanism of cell death induced by the metal compounds was analyzed in A-549 and Jurkat cell lines. Derivatives 1a and 1a' induced apoptotic cell death of A-549 cells while dose-dependent cell death mechanisms have been found in the Jurkat cell line. Compound-DNA interactions have been investigated by equilibrium dialysis, Fluorescence Resonance Energy Transfer (FRET) melting assays and viscometric titrations, revealing moderate binding affinity of 1a and 1a' towards duplex DNA. Finally, the efficacy of 1a in a preliminary in vivo assay of PC-3 xenografts in nude mice has been evaluated, resulting in a promising inhibition of tumor growth by 45%. Analysis of tumor tissue also showed a significant decrease of levels of crucial molecules in the invasive phenotype of PC-3 cells
A mid-term astrometric and photometric study of trans-Neptunian object (90482) Orcus
From time series CCD observations of a fixed and large star field that contained the binary trans-Neptunian object (90482) Orcus (formerly 2004 DW), taken during a period of 33 days, we have been able to derive high-precision relative astrometry and photometry of the Orcus system with respect to background stars. The right ascension residuals of an orbital fit to the astrometric data revealed a periodicity of 9.7 ± 0.3 days, which is what one would expect to be induced by the known Orcus companion (Vanth). The residuals are also correlated with the theoretical positions of the satellite with regard to the primary. We therefore have revealed the presence of Orcus’ satellite in our astrometric measurements, although the residuals in declination did not show the expected variations. The oscillation in the residuals is caused by the photocenter motion of the combined Orcus plus satellite system around the barycenter along an orbital revolution of the satellite. The photocenter motion is much larger than the motion of Orcus around the barycenter, and we show here that detecting some binaries through a carefully devised astrometric technique might be feasible with telescopes of moderate size. We discuss the prospects for using the technique to find new binary trans-Neptunian objects (TNOs) and to study already known binary systems with uncertain orbital periods. We also analyzed the system’s mid-term photometry in order to determine whether the rotation could be tidally locked to the satellite’s orbital period. We found that a photometric variability of 9.7 ± 0.3 days is clear in our data, and is nearly coincident with the orbital period of the satellite. We believe this variability might be induced by the satellite’s rotation. In our photometry there is also a slight hint for an additional very small variability in the 10 h range that was already reported in the literature. This short-term variability would indicate that the primary is not tidally locked and therefore the system would not have reached a double synchronous state. Implications for the basic physical properties of the primary and its satellite are discussed. From angular momentum considerations we suspect that the Orcus satellite might have formed from a rotational fission. This requires that the mass of the satellite would be around 0.09 times that of the primary, close to the value that one derives by using an albedo of 0.12 for the satellite and assuming equal densities for both the primary and secondary.Facultad de Ciencias AstronĂłmicas y GeofĂsica
A mid-term astrometric and photometric study of Trans-Neptunian Object (90482) Orcus
From CCD observations of a fixed and large star field that contained the
binary TNO Orcus, we have been able to derive high-precision relative
astrometry and photometry of the Orcus system with respect to background stars.
The RA residuals of an orbital fit to the astrometric data revealed a
periodicity of 9.7+-0.3 days, which is what one would expect to be induced by
the known Orcus companion. The residuals are also correlated with the
theoretical positions of the satellite with regard to the primary. We therefore
have revealed the presence of Orcus' satellite in our astrometric measurements.
The photocenter motion is much larger than the motion of Orcus around the
barycenter, and we show here that detecting some binaries through a carefully
devised astrometric technique might be feasible with telescopes of moderate
size. We also analyzed the system's mid-term photometry to determine whether
the rotation could be tidally locked to the satellite's orbital period. We
found that a photometric variability of 9.7+-0.3 days is clear in our data, and
is nearly coincident with the orbital period of the satellite. We believe this
variability might be induced by the satellite's rotation. There is also a
slight hint for an additional small variability in the 10 hr range that was
already reported in the literature. This short-term variability would indicate
that the primary is not tidally locked and therefore the system would not have
reached a double synchronous state. Implications for the basic physical
properties of the primary and its satellite are discussed. From angular
momentum considerations we suspect that the Orcus satellite might have formed
from a rotational fission. This requires that the mass of the satellite would
be around 0.09 times that of the primary, close to the value that one derives
by using an albedo of 0.12 for the satellite and assuming equal densities for
both objects.Comment: in Press at A&
Predictors Of Positivity Of [F-18]F-Choline PET-CT In Prostate Cancer Recurrence. Preliminary Results
EP-173
Aim/Introduction: To analyze the validity of [18F]F-Choline PET-CT results in prostate cancer recurrence in our daily practice, based on theoretical cut-off points of prostatespecific antigen (PSA), its kinetic, and PSA doubling time (PSADT), to identify predictors of positivity and modify the indication criteria. Materials and
Methods: Prior to the validity analysis, a descriptive, prospective analysis of consecutive patients with prostate cancer treated with curative intent by radical prostatectomy (RP) or radiotherapy (RT), who underwent PET-CT scan with recurrence criteria: PSA =1 or PSA 0.4-1 with PSADT Nadir + 2 after RT, was performed.
Results: From April to December 2019, 69 patients were included, 40 were treated with RP (58%) and 29 with RT (42%). In 45 patients (65%) PET-CT was able to identify recurrence of the disease (positive PET) and in 24 it was not (negative PET). Of patients treated with RP, 82, 5% (33/40) had PSA>1, and of those, 61% were positive PET. 17, 5% (7/40) had PSA6months (28/69), in 71% if PSADT6 months, in 61% and 92% if PSADT<6 months and in 77% and 100% if PSADT<3 months.
Conclusion: Preliminarily and awaiting validation, it seems that PSA>1 after RP or Nadir +2 after RT is an indicator of PET-CT. There seems to be a tendency that shows that PSA<1 after RP is an indicator of PET-CT if PSADT<3 months. PSADT <3 or <6 months could be the best predictor of positivity of PET-CT with [18F]F-Choline in recurrent prostate cancer
Correlation between the findings in the first post-transplantation Renogram and the allograft renal function twelve months after surgery
EP-061
Aim/Introduction: To study the correlation between findings in the first renogram post-trasplantation, and the evolution of the renal function of the graft twelve months after surgery.
Materials and Methods: 20-minute duration renogram with [99mTc]Tc-MAG3, performed in the first 72 hours post-kidney transplantation, of patients attended at the Nuclear Medicine Service between January-December of 2018 are reviewed, extracting: a) the concentration angle (CA) that measures the inclination of the ascent section of the concentration phase with respect to the vertical axis (cutoff thershold <40° vs =40°); b) the time, in minutes (Tmax), at which the maximum concentration occurs (<10 vs =10min); and c) the percentage of cortical retention (CR) at the end of the study (<80% vs =80%). These 3 parameters are correlated with renal function at 12 months post-transplantation, through the need or not of dialysis.
Results: A total of 62 renograms were obtained, excluding 7 due to death as a result of intercurrent diseases and 2 due to vascular complications and graft loss, before the first year after surgery. 53 patients, 15 female and 38 male, aged between 20-80 years, were included in the analysis. Functional failure (dialysis) of the graft one year after the transplantation ocurred in 15% (8/53). In patients with CA =40° the probability of failure was 28% (5/18) and in CA <40° 8.6% (3/35), with relative risk (RR) of 3.2. 7/34 (20, 6%) patients incluided in the group with Tmax =10 min were on dialysis one-year after, unlike just 1/19 (5, 3%) if Tmax<10min (RR 3, 8). Among the 37 patients with CR =80%, 8/37 (22%) were dialyzed one year after, while none of the 16 in the group of patients with CR <80% (0% probability if CR <80%). The matching of parameteres CA =40°, Tmax =10 min and CR =80% together do not improve the prediction of dialysis one year after (27%, 5/18). Conclusion: 1. Renogram parameters 72 hours post-transplantation, such as concentration phase angle =40°, time at maximun concentration =10min and percentage of cortical retention =80%, allow recognize a group of patients with greater probability of needing dialysis in the first year after surgery, but they do not are capable of indentify in which specific patients it will occur. 2. The parameter that best predicts the viability of the graft is cortical retention <80%
Acute and long-term success of ventricular tachycardia ablation in patients with ischemic heart disease in a Mexican center
Objective. To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods. We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results. Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66–6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08–5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06–5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34–6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR0.29, IC95% 0.12–0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48–0.86, p=0.013) were protective factors. Conclusions. Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it.Objective. To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods. We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results. Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66–6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08–5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06–5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34–6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR0.29, IC95% 0.12–0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48–0.86, p=0.013) were protective factors. Conclusions. Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it
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