Efecto de la pandemia Covid - 19 en las características y gravedad de apendicitis aguda, Hospital III José Cayetano Heredia, 2019-2020, Piura

Comparar las características y gravedad de pacientes con apendicitis aguda, durante el aislamiento social obligatorio por la COVID-19; Contra una cohorte del año anterior. Métodos: La presente investigación es observacional analítico, El número de pacientes incluidos con apendicitis aguda fue 136, que fueron separados en dos periodos prepandemico y pandémico Resultados: El tiempo de espera fue menor durante el periodo pandémico [9.5 horas vs 5.8 horas, p=0.003], tipo de intervención laparoscópica fue menos frecuente durante el periodo pandémico (52.11% vs 10.77%, p<0.001), el tiempo de intervención y estancia hospitalaria también fueron menos frecuentes (60 minutos vs 45 minutos, p=0.007 y 4 días vs 3 días, p=0.01 respectivamente), el tipo de anestesia general fue menos frecuente durante el periodo de pandemia (42.3% vs 7.7%, p<0.001) y la frecuencia de apendicitis aguda complicada según reporte histopatológico fue menor durante el periodo pandémico, pero esta diferencia no fue significativa (42.26% vs 26.16%, p=0.05). Se identificó como factores asociados a apendicitis aguda complicada un tiempo de enfermedad >72 horas con un RPa de 2.2 (IC95%:1.05 a 4.62) y recuento de leucocitosis ≥17 000 con un RPa de 1.59 (IC95%:1.03 a 2.45). Además, para tipo de intervención laparoscópica se identificó como factores asociados el año 2020 con un RPa de 0.19 (IC95%: 0.09 a 0.41), un tiempo de enfermedad de 24-48 horas con un RPa de 0.47 (IC95%:0.29 a 0.76) y recuento de leucocitosis ≥17 000 con un RPa de 1.77 (IC95%:1.16 a 2.72). Conclusiones: El periodo de confinamiento por la pandemia de la COVID-19 durante el año 2020 se asoció con un menor tiempo de espera, de intervención quirúrgica, de estancia hospitalaria. Asimismo, una menor frecuencia de intervención laparoscópica y de anestesia general. Sin embargo, no tuvo impacto en la gravedad de apendicitis aguda. Los factores asociados a apendicitis aguda complicada fueron leucocitos >17 000 y tiempo de enfermedad >72 horas. Los factores asociados para intervención laparoscópica fueron leucocitos >17 000, año 2020 y tiempo de enfermedad de 24 a 48 horas.To compare the characteristics and severity of patients with acute appendicitis, during mandatory social isolation due to COVID-19; Against a cohort from the previous year. Methods: The present investigation is analytical observational. The number of patients included with acute appendicitis was 136, which were separated into two pre-pandemic and pandemic periods. Results: The waiting time was shorter during the pandemic period [9.5 hours vs 5.8 hours, p=0.003], the type of laparoscopic intervention was less frequent during the pandemic period (52.11% vs 10.77%, p<0.001), the waiting time intervention and hospital stay were also less frequent (60 minutes vs 45 minutes, p=0.007 and 4 days vs 3 days, p=0.01 respectively), the type of general anesthesia was less frequent during the pandemic period (42.3% vs 7.7% , p<0.001) and the frequency of complicated acute appendicitis according to histopathological report was lower during the pandemic period, but this difference was not significant (42.26% vs 26.16%, p=0.05). Factors associated with complicated acute appendicitis were identified as disease time >72 hours with an RPa of 2.2 (95% CI: 1.05 to 4.62) and a leukocytosis count ≥17,000 with an RPa of 1.59 (95% CI: 1.03 to 2.45). In addition, for the type of laparoscopic intervention, associated factors were identified in 2020 with an RPa of 0.19 (95%CI: 0.09 to 0.41), a disease time of 24-48 hours with an RPa of 0.47 (95%CI: 0.29 to 0.76) and leukocytosis count ≥17,000 with an RPa of 1.77 (95% CI: 1.16 to 2.72). Conclusions: The period of confinement due to the COVID-19 pandemic during the year 2020 was associated with a shorter waiting time, intervention time, hospital stay, laparoscopic intervention, and general anesthesia. However, it had no impact on the severity of acute appendicitis. Factors associated with complicated acute appendicitis were leukocytes >17,000 and disease time >72 hours. The associated factors for laparoscopic intervention were leukocytes >17,000, year 2020 and disease time of 24 to 48 hoursTesi

Applications of Peer Assessment and Self-Assessment in Music

Feedback is crucial to students’ growth as musicians. Fortunately, the teacher is not the sole source of feedback in the music classroom. Under the right conditions, students can provide actionable feedback to themselves and each other. This article showcases the work of three elementary music specialists who have innovatively incorporated formative peer assessment and self-assessment in their music lessons to promote student learning and self-direction

Spectroscopy of Giant Stars in the Pyxis Globular Cluster

The Pyxis globular cluster is a recently discovered globular cluster that lies in the outer halo (R_{gc} ~ 40 kpc) of the Milky Way. Pyxis lies along one of the proposed orbital planes of the Large Magellanic Cloud (LMC), and it has been proposed to be a detached LMC globular cluster captured by the Milky Way. We present the first measurement of the radial velocity of the Pyxis globular cluster based on spectra of six Pyxis giant stars. The mean heliocentric radial velocity is ~ 36 km/sec, and the corresponding velocity of Pyxis with respect to a stationary observer at the position of the Sun is ~ -191 km/sec. This radial velocity is a large enough fraction of the cluster's expected total space velocity, assuming that it is bound to the Milky Way, that it allows strict limits to be placed on the range of permissible transverse velocities that Pyxis could have in the case that it still shares or nearly shares an orbital pole with the LMC. We can rule out that Pyxis is on a near circular orbit if it is Magellanic debris, but we cannot rule out an eccentric orbit associated with the LMC. We have calculated the range of allowed proper motions for the Pyxis globular cluster that result in the cluster having an orbital pole within 15 degrees of the present orbital pole of the LMC and that are consistent with our measured radial velocity, but verification of the tidal capture hypothesis must await proper motion measurement from the Space Interferometry Mission or HST. A spectroscopic metallicity estimate of [Fe/H] = -1.4 +/- 0.1 is determined for Pyxis from several spectra of its brightest giant; this is consistent with photometric determinations of the cluster metallicity from isochrone fitting.Comment: 22 pages, 5 figures, aaspp4 style, accepted for publication in October, 2000 issue of the PAS

4-Styrylquinolines from cyclocondensation reactions between (2-aminophenyl)chalcones and 1,3-diketones : crystal structures and regiochemistry

Funding for this research was provided by: Vicerrectoría de Investigación y Extensión de la Universidad Industrial de Santander (proyecto No. 2497, to AP); Universidad de Jaén, the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía, Spain) and Centro de Instrumentación Científico–Técnica of the Universidad de Jaén (UJA) (to JC).Structures are reported for two matched sets of substituted 4-styryl­quino­lines which were prepared by the formation of the heterocyclic ring in cyclo­condensation reactions between 1-(2-amino­phen­yl)-3-aryl­prop-2-en-1-ones with 1,3-dicarbonyl com­pounds. (E)-3-Acetyl-4-[2-(4-meth­oxy­phen­yl)ethen­yl]-2-methyl­quino­line, C21H19NO2, (I), (E)-3-acetyl-4-[2-(4-bromo­phen­yl)ethen­yl]-2-methyl­quino­line, C20H16BrNO, (II), and (E)-3-acetyl-2-methyl-4-{2-[4-(tri­fluoro­meth­yl)phen­yl]ethen­yl}quino­line, C21H16F3NO, (III), are isomorphous and in each structure the mol­ecules are linked by a single C—H...O hydrogen bond to form C(6) chains. In (I), but not in (II) or (III), this is augmented by a C—H...π(arene) hydrogen bond to form a chain of rings; hence, (I)–(III) are not strictly isostructural. By contrast with (I)–(III), no two of ethyl (E)-4-[2-(4-meth­oxy­phen­yl)ethen­yl]-2-methyl­quino­line-3-carboxyl­ate, C22H21NO3, (IV), ethyl (E)-4-[2-(4-bromo­phen­yl)ethen­yl]-2-methyl­quino­line-3-carboxyl­ate, C21H18BrNO2, (V), and ethyl (E)-2-methyl-4-{2-[4-(tri­fluoro­meth­yl)phen­yl]ethen­yl}quino­line-3-carboxyl­ate, C22H18F3NO2, (VI), are isomorphous. The mol­ecules of (IV) are linked by a single C—H...O hydrogen bond to form C(13) chains, but cyclic centrosymmetric dimers are formed in both (V) and (VI). The dimer in (V) contains a C—H...π(pyrid­yl) hydrogen bond, while that in (VI) contains two independent C—H...O hydrogen bonds. Comparisons are made with some related structures, and both the regiochemistry and the mechanism of the heterocyclic ring formation are discussed.Publisher PDFPeer reviewe

Electrostatic effects of inhomogeneous strain in monolayer transition metal dichalcogenides

Two-dimensional materials are only a few atoms thick, exhibiting novel properties due to their reduced dimensionality. Strain engineering can be used to modify optical and electronic properties, and highly inhomogeneous strain distributions in two-dimensional materials can be easily realized, allowing for their properties to be tuned on the nanoscale. This work is primarily focused on transition metal dichalcogenides, which have received much attention owing to their semiconducting nature, placing them in a key role among two-dimensional materials. Monolayer transition metal dichalcogenides exhibit a significant piezoelectric effect that can couple with spatially inhomogeneous strain distributions to influence electronic and optical behavior. In this work, inhomogeneous strain and piezoelectricity in transition metal dichalcogenides are studied. We first examine the luminescence behavior of monolayer MoS₂ and WSe₂ in the presence of strain and strain gradients generated via nanoindentation. The strain distribution and piezoelectricity resulting from indentation of monolayer MoS₂ and WSe₂ is modeled, and the interaction between the piezoelectric effect and strain distribution is demonstrated to result in charge densities reaching 10¹² e/cm², with electrostatic potential variations on the order of ±0.1V across the suspended monolayer in the modeled geometry. These results have potential implications for luminescence and exciton transport behavior in monolayer transition metal dichalcogenides with spatially varying strain. We then characterize monolayer MoS₂ which is inhomogeneously strained via a nanopatterned substrate. Kelvin probe force microscopy and electrostatic gating are used to measure the spatial distribution of the conduction band edge energy which can be correlated to in-plane hydrostatic strain. This method demonstrates the capability to resolve the strain distribution on length scales less than 100nm. A method for determining the distribution of the full in-plane strain tensor from the in-plane hydrostatic strain distribution is also presented. The combination of these methods is able to successfully calculate the spatial distribution of the electrostatic potential resulting from piezoelectricity that agrees well with experimental results. These methods present a powerful way to characterize inhomogeneous strain distributions and piezoelectricity that can be extended towards characterization of a variety of 2D materials.Materials Science and Engineerin

The Multi-phase Absorption Systems Toward PG 1206+459

A high-resolution HST/STIS spectrum (R=30,000) is presented of the three MgII-selected absorption systems (A, B, and C, clustered within 1500km/s) at z~0.93 toward the quasar PG 1206+459. A WIYN Gunn i-band image of the quasar field and spectroscopy of two galaxy candidates are also presented. A multi-phase medium is seen in all three systems, consistent with smaller, denser clouds producing low-ionization transitions (MgII, FeII, and SiII) and larger, diffuse clouds giving rise to high-ionization transitions (CIV, NV, and/or OVI). (1) System A, a multi-cloud, weak MgII absorber at z=0.9254, requires a super-solar metallicity in both low- and high-ionization phases, unless an alpha-group enhancement is included. With the unusually complex velocity structure resolved in the NV profiles, this system is unlikely to represent a traditional galaxy disk/corona. The most likely candidate host galaxy is a ~2L^*, apparently warped, spiral at an impact parameter of 43h^-1 kpc. (2) System B, at z=0.9276, has the strongest MgII absorption and has an approximately solar metallicity in the low-ionization phase. The smooth, broad high-ionization profiles may indicate a coronal structure similar to that of the Milky Way. The redshift of an L^* galaxy (z=0.9289), at an impact parameter of 38h^-1 kpc is consistent with the redshift of this system. (3) System C, at z=0.9342, has a single component in MgII, separated from the other two systems by ~1000km/s. It lacks the small, low-ionization cloud characteristic of an isolated single-cloud, weak MgII absorber. Its absorption properties are similar to the ``satellite clouds'' of classic strong MgII absorbers, so this could be a high-velocity cloud in the galaxy group responsible for the systems, possibly related to a 0.2L^* galaxy at an impact parameter of 43h^-1 kpc.Comment: 52 pages, 9 figures; to appear in ApJ, June 20, 200

Synthesis and spectroscopic and structural characterization of three new 2-methyl-4-styrylquinolines formed using Friedlander reactions between (2-aminophenyl)chalcones and acetone

Funding for this research was provided by: Vicerrectoría de Investigación y Extensión of the Industrial University of Santander (grant No. 2680 to AP); Universidad de Jaén and the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucá, Spain) (award to JC).Three new 2-methyl-4-styryl­quinoline derivatives have been synthesized in high yields using Friedländer reactions between chalcones [1-(2-amino­phen­yl)-3-aryl­prop-2-en-1-ones] and acetone, and characterized using IR, 1H and 13C NMR spectroscopy, and mass spectrometry, and by crystal structure analysis. In (E)-4-(4-fluoro­styr­yl)-2-methyl­quinoline, C18H14FN, (I), the mol­ecules are joined into cyclic centrosymmetric dimers by C—H⋯N hydrogen bonds and these dimers are linked into sheets by π–π stacking inter­actions. The mol­ecules of (E)-2-methyl-4-[4-(tri­fluoro­meth­yl)styr­yl]quinoline, C19H14F3N, (II), are linked into cyclic centrosymmetric dimers by C—H⋯π hydrogen bonds and these dimers are linked into chains by a single π–π stacking inter­action. There are no significant hydrogen bonds in the structure of (E)-4-(2,6-di­chloro­styr­yl)-2-methyl­quinoline, C18H13Cl2N, (III), but mol­ecules related by translation along [010] form stacks with an inter­molecular spacing of only 3.8628 (2) Å. Comparisons are made with the structures of some related com­pounds.Publisher PDFPeer reviewe

Synthesis, and spectroscopic and structural characterization of three new styrylquinoline–benzimidazole hybrids

Funding for this research was provided by: Vicerrectoría de Investigación y Extensión of the Industrial University of Santander (grant No. 2680)Three new 4-styryl­quinoline–benzimidazole hybrids have been synthesized using a reaction sequence in which 2-methyl­quinoline precursors first undergo selective oxidation by selenium dioxide to form the corresponding 2-formyl­quinoline inter­mediates, followed by oxidative cyclo­condensation reactions with benzene-1,2-diamine to yield the hybrid products. The formyl inter­mediates and the hybrid products have all been fully characterized using a combination of IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry, and the structures of the three hybrid products have been determined using single-crystal X-ray diffraction. Ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-chloro­styr­yl)quinoline-3-carboxyl­ate, C27H20ClN3O2, (IIIa), and ethyl (E)-2-(1H-ben­zo[d]imidazol-2-yl)-4-(2-meth­oxy­styr­yl)quinoline-3-carboxyl­ate, C28H23N3O3, (IIIb), both crystallize in the solvent-free form with Z′ = 1, but ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-methyl­styr­yl)quinoline-3-carboxyl­ate, C28H23N3O2, (IIIc), crystallizes as a partial hexane solvate with Z′ = 3, and the ester group in one of the independent mol­ecules is disordered over two sets of atomic sites having occupancies of 0.765 (7) and 0.235 (7). The mol­ecules of (IIIc) enclose continuous channels which are occupied by disordered solvent mol­ecules having partial occupancy. In all of the mol­ecules of (IIIa)–(IIIc), the styryl­quinoline fragment is markedly nonplanar. Different combinations of N—H⋯O and C—H⋯π hydrogen bonds generate supra­molecular assemblies which are two-dimensional in (IIIb) and (IIIc), but three-dimensional in (IIIa). Comparisons are made with the structures of some related com­pounds.Publisher PDFPeer reviewe