6,708 research outputs found
On interrelations between Sibgatullin's and Alekseev's approaches to the construction of exact solutions of the Einstein-Maxwell equations
The integral equations involved in Alekseev's "monodromy transform" technique
are shown to be simple combinations of Sibgatullin's integral equations and
normalizing conditions. An additional complex conjugation introduced by
Alekseev in the integrands makes his scheme mathematically inconsistent;
besides, in the electrovac case all Alekseev's principal value integrals
contain an intrinsic error which has never been identified before. We also
explain how operates a non-trivial double-step algorithm devised by Alekseev
for rewriting, by purely algebraic manipulations and in a different (more
complicated) parameter set, any particular specialization of the known
analytically extended N-soliton electrovac solution obtained in 1995 with the
aid of Sibgatullin's method.Comment: 7 pages, no figures, section II extende
The unprecedented flaring activities around Mrk 421 in 2012 and 2013: The test for neutrino and UHECR event connection
Since its mission, Fermi Collaboration reported the highest flux observed
during July - September 2012 for the BL Lac Markarian 421 (Mrk 421). The
integrated flux was eight times greater than the average flux reported in the
second Fermi catalog. During April 2013, Mrk 421 exhibited the highest TeV
-ray and optical fluxes recorded. The Telescope Array (TA)
collaboration reported the arrival of 72 ultra-high-energy cosmic rays
(UHECRs), two in temporal and positional coincidence with the flaring activity
observed in 2012 and one with the flaring activity in 2013. The IceCube
collaboration has reported around 100 neutrino events in the High-Energy
Starting Events (HESE) catalog. Although no neutrino track-like event has been
associated with this source, a neutrino shower-like event (IC31) is in temporal
and positional coincidence with the flare in 2012. Describing the broadband
spectral energy distribution during the flaring activities exhibited in 2012
and 2013 with one- and two-zone lepto-hadronic scenarios and one-zone SSC
model, we study a possible correlation between the neutrino event IC31 and the
three UHECRs. We estimate the number of neutrino and UHECR events generated
from the proposed models, and show that while the neutrino events are low to
associate the event IC31 with Mrk 421, the number of UHECRs are similar to
those reported by TA collaboration.Comment: 20 pages, 5 figures, 7 Table
Prevalence of and Risk Factors for Biliary Carriage of Bacteria Showing Worrisome and Unexpected Resistance Traits
Data on biliary carriage of bacteria and, specifically, of bacteria with worrisome and unexpected resistance traits (URB) are lacking.
A prospective study (April 2010 to December 2011) was performed that included all patients admitted for<48 h for elective
laparoscopic cholecystectomy in a Spanish hospital. Bile samples were cultured and epidemiological/clinical data recorded. Logistic
regression models (stepwise) were performed using bactobilia or bactobilia by URB as dependent variables. Models (P<
0.001) showing the highest R2 values were considered. A total of 198 patients (40.4% males; age, 55.3 17.3 years) were included.
Bactobilia was found in 44 of them (22.2%). The presence of bactobilia was associated (R2 Cox, 0.30) with previous biliary endoscopic
retrograde cholangiopancreatography (ERCP) (odds ratio [OR], 8.95; 95% confidence interval [CI], 2.96 to 27.06; P<
0.001), previous admission (OR, 2.82; 95% CI, 1.10 to 7.24; P 0.031), and age (OR, 1.09 per year; 95% CI, 1.05 to 1.12; P<
0.001). Ten out of the 44 (22.7%) patients with bactobilia carried URB: 1 Escherichia coli isolate (CTX-M), 1 Klebsiella pneumoniae
isolate (OXA-48), 3 high-level gentamicin-resistant enterococci, 1 vancomycin-resistant Enterococcus isolate, 3 Enterobacter
cloacae strains, and 1 imipenem-resistant Pseudomonas aeruginosa strain. Bactobilia by URB (versus those by non-URB)
was only associated (R2 Cox, 0.19) with previous ERCP (OR, 11.11; 95% CI, 1.98 to 62.47; P 0.006). For analyses of patients
with bactobilia by URB versus the remaining patients, previous ERCP (OR, 35.284; 95% CI, 5.320 to 234.016; P<0.001), previous
intake of antibiotics (OR, 7.200; 95% CI, 0.962 to 53.906; P 0.050), and age (OR, 1.113 per year of age; 95% CI, 1.028 to
1.206; P 0.009) were associated with bactobilia by URB (R2 Cox, 0.19; P<0.001). Previous antibiotic exposure (in addition to
age and previous ERCP) was a risk driver for bactobilia by URB. This may have implications in prophylactic/therapeutic
measures
One-step facial feminization surgery: The importance of a custom-made preoperative planning and patient satisfaction assessment
Background: The availability of more accurate techniques used for transgender surgery has resulted in an increased number of patients requesting facial feminization surgery (FFS). The aim of this study was to present the FFS pre-operative planning of the authors’ male-to-female transsexual patients using photo-editing software, computer-aided design (CAD), modeling, and three-dimensional (3D) printing. Material and Methods: Twenty-five patients underwent FFS between November 2015 and May 2018. They were retrospectively included in this study, and their records were analyzed. Patients’ 3D facial models were printed and used for an accurate preoperative planning and shown to the patients. To assess patient satisfaction, the preoperative, six-month, and one-year postoperative scores obtained using Satisfaction With Life Scale (SWLS) and Subjective Happiness Scale (SHS) were compared. The scores following a normal distribution obtained for each patient were compared using a paired t-test. Results: The 3D model preparation mean time was 145±13.2 min. A total of 114 surgical procedures were carried out. The mean operative time was 420±23 min. Patients experienced no postoperative complication. All patients were very satisfied after surgery, with a significant difference between pre- and postoperative scores (p = 0.002; p = 0.03). Conclusion: With use of 3D modeling, surgeons are nearing a custom-made surgery era, especially required for complex procedures such as FFS. We suggest using 3D technology for a more accurate preoperative planning
Hydrothermal–microwave processing for starch extraction from mexican avocado seeds: operational conditions and characterization
Avocado seeds are an agroindustrial residue widely produced in Mexico that are causing various environmental problems due to their accumulation. The evaluation of avocado residues to recover biopolymers by microwave-assisted extraction (MAE) and the characterization of avocado starch properties were studied in the present work. A central-composite design was used to optimize the MAE process. Moreover, a comparison was performed between MAE non-isothermal mode (NO–ISO) and conventional extraction. Starch optimization by MAE was obtained at 161.09 °C for 56.23 min with an extraction yield of 49.52% ± 0.69%, while with NO–ISO at 161 °C was obtained 45.75% ± 2.18%. Conventional extraction was 39.04% ± 2.22%. Compared with conventional starch, MAE starch showed similar proprieties and molecular spectra. In contrast, MAE starch showed high solubility, low water absorption capacity, a non-granular structure with small particle size (<2 μm) and polydispersity of fragments at different sizes of polymers. Therefore, MAE is a viable technology to extract the starch, and avocado seed can be considered an excellent starch source for the development of novel functional foods, contributing to promoting sustainability
across the food chain.N/Ainfo:eu-repo/semantics/publishedVersio
La distribución espacial de los suelos del sector occidental de la Sierra de Gador (AlmerÃa)
Enterobacteriaceas strains isolated in the Mycrobiology Department of the Universitary Hospital in Granade (Spain) containing β-lactamases determinated by plasmids R were studied. Three types of these enzymes, TEM (71,72 %), SHV (12,04 %) and OXA (16,23 %), has been identified and theirs relatives percentages were similar to the other workers. Epidemiological interest of the β-lactamases clasifications are discussed in the last part o this article.Se estudia la presencia de β-lactamasas en las enterobacterias que se aislan en el Servicio de MicrobiologÃa del Hospital Universitario de Granada. Se detectaron tres tipos de enzimas, TEM (71,72 %), SHV (12,04 %) y OXA (16,23 %), cuyas proporciones relativas coinciden con las obtenidas por otros autores. El interés epidemiológico de la detección de β-lactamasas se discute en el último apartado de este trabajo
Dielectric Characterization of Breast Biopsied Tissues as Pre-Pathological Aid in Early Cancer Detection: A Blinded Feasibility Study
Dielectric characterization has significant potential in several medical applications, providing valuable insights into the electromagnetic properties of biological tissues for disease diagnosis, treatment planning, and monitoring of therapeutic interventions. This work presents the use of a custom-designed electromagnetic characterization system, based on an open-ended coaxial probe, for discriminating between benign and malignant breast tissues in a clinical setting. The probe’s development involved a well-balanced compromise between physical feasibility and its combined use with a reconstruction algorithm known as the virtual transmission line model (VTLM). Immediately following the biopsy procedure, the dielectric properties of the breast tissues were reconstructed, enabling tissue discrimination based on a rule-of-thumb using the obtained dielectric parameters. A comparative analysis was then performed by analyzing the outcomes of the dielectric investigation with respect to conventional histological results. The experimental procedure took place at Complejo Hospitalario Universitario de Toledo—Hospital Virgen de la Salud, Spain, where excised breast tissues were collected and subsequently analyzed using the dielectric characterization system. A comprehensive statistical evaluation of the probe’s performance was carried out, obtaining a sensitivity, specificity, and accuracy of 81.6%, 61.5%, and 73.4%, respectively, compared to conventional histological assessment, considered as the gold standard in this investigation
Nitrogen compounds removal from oil-derived middle distillates by MIL-101(Cr) and its impact on ULSD production by hydrotreating
Es un articulo sobre sintesis caracterizacion de catalizadoresoil) for ultra-low sulfur diesel (ULSD) production by hydrotreating (HDT) were pretreated by selective nitrogen organic compounds (NOC) adsorption. Highly crystalline metal-organic framework (MOF) MIL-101(Cr) prepared with propylene oxide (proton scavenger) as textural improver was employed to that end. MOF was characterized by N2 physisorption, X-ray diffraction, thermal analysis, infrared, Raman and UV-vis spectroscopies, and electron microscopy (SEM and HR-TEM). NOC removal was performed at room temperature and atmospheric pressure, the adsorbent being easily regenerable under mild conditions. Extruded MOF efficiently removed NOC from real feedstocks to concentrations ~ 80 ppm, allowing ULSD production at much milder conditions to those used during pristine feedstocks HDT. Operating temperature could be greatly diminished (from 350°C to 330°C, at 56 kg/sq cm (5.77 MPa), LHSV = 1.5/h, H2/oil = 2500 cy ft/bbl (445 cu m/cu m)) which could notably prolong cycle life of NiMo/Al2O3 formulation used.SENER-CONACYT-HIDROCARBUROS FUND
IMP 00117, 6105
Searching for sterile neutrinos in ice
Oscillation interpretation of the results from the LSND, MiniBooNE and some
other experiments requires existence of sterile neutrino with mass eV
and mixing with the active neutrinos . It has
been realized some time ago that existence of such a neutrino affects
significantly the fluxes of atmospheric neutrinos in the TeV range which can be
tested by the IceCube Neutrino Observatory. In view of the first IceCube data
release we have revisited the oscillations of high energy atmospheric neutrinos
in the presence of one sterile neutrino. Properties of the oscillation
probabilities are studied in details for various mixing schemes both
analytically and numerically. The energy spectra and angular distributions of
the events have been computed for the simplest mass, and
mixing schemes and confronted with the IceCube data. An
illustrative statistical analysis of the present data shows that in the
mass mixing case the sterile neutrinos with parameters required by
LSND/MiniBooNE can be excluded at about level. The
mixing scheme, however, can not be ruled out with currently available IceCube
data.Comment: 41 pages, 16 figures. Accepted for publication in JHEP. Minor changes
from the previous versio
Hydrogen-ion driven molecular motions in Cu2+-complexes of a ditopic phenanthrolinophane ligand
One of the first kinetic evaluations of a metal ion interchange between the two coordination sites of a ditopic macrocycle is presented.Garcia-España Monsonis, Enrique, [email protected] ; Soriano Soto, Concepción, [email protected] ; Verdejo Viu, Begoña, [email protected]
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