Search

el presente estudio describe las características de las víctimas de muertes por sofocación homicida con bolsas de plástico en el período comprendido entre 2008 y 2021, en necropsias practicadas en el Instituto Nacional de Medicina Legal y Ciencias Forenses de la ciudad de Medellín.

Language teaching is a field in constant evolution and the use of technology has boosted its development. This article explores the design and the implementation of synchronous and asynchronous learning activities to develop oral skills in an online English course. The article uses a mix-methods approach that combines qualitative and quantitative research methods. The participants in the study were 6 graduate students. The main findings of this investigation show that the synchronous learning activities prompt errors that translate into opportunities for learning. These results show that the use of asynchronous learning activities produce errors despite the fact that the participants have time to prepare and anticipate language inaccuracies. The results suggest that the use of asynchronous learning activities promotes the development of language awareness as participants can identify general categories of errors.

The cross-linking process of natural rubber (NR) is studied for the first time by a unique combination of rheology and time-domain (TD) NMR, two methods that are commonly conducted separately. The combined setup consists of a high-end rheometer and a compact 25 MHz 1H NMR relaxometer (rheo-NMR), which allows rheological characterization and NMR relaxometry to be operated simultaneously on the same sample. During vulcanization, the elastic modulus G′(t), representing the macroscopic elasticity, was directly correlated to the molecular dynamic parameters derived from NMR, including the population-averaged transverse relaxation rate, 1/T2ave, and the logarithmic mean of the residual dipolar coupling constant, D̅res. It is found that, at the same level of macroscopic elasticity, the conformational flexibility of network chains in NR cross-linked with the so-called efficient vulcanization (EV) is more restricted than that with conventional vulcanization (CV). This can be attributed to the shorter and consequently less flexible (monosulfidic) cross-links formed by EV, whereas polysulfidic links dominate in the CV vulcanizate as confirmed by high-field 13C NMR spectroscopy.

Background: The present systematic review and meta-analysis of diagnostic test accuracy summarizes the last three decades in advances on diagnosis of Alzheimer’s disease (AD) in developed and developing countries.Objective: To determine the accuracy of biomarkers in diagnostic tools in AD, for example, cerebrospinal fluid, positron emission tomography (PET), and magnetic resonance imaging (MRI), etc.Methods: The authors searched PubMed for published studies from 1990 to April 2020 on AD diagnostic biomarkers. 84 published studies were pooled and analyzed in this meta-analysis and diagnostic accuracy was compared by summary receiver operating characteristic statistics.Results: Overall, 84 studies met the criteria and were included in a meta-analysis. For EEG, the sensitivity ranged from 67 to 98%, with a median of 80%, 95% CI [75, 91], tau-PET diagnosis sensitivity ranged from 76 to 97%, with a median of 94%, 95% CI [76, 97]; and MRI sensitivity ranged from 41 to 99%, with a median of 84%, 95% CI [81, 87]. Our results showed that tau-PET diagnosis had higher performance as compared to other diagnostic methods in this meta-analysis.Conclusion: Our findings showed an important discrepancy in diagnostic data for AD between developed and developing countries, which can impact global prevalence estimation and management of AD. Also, our analysis found a better performance for the tau-PET diagnostic over other methods to diagnose AD patients, but the expense of tau-PET scan seems to be the limiting factor in the diagnosis of AD in developing countries such as those found in Asia, Africa, and Latin America.

This paper presents a framework for teaching English in synchronous computer-mediated environments. This research shows the components of the framework, how it materializes in the teachers' pedagogical practices, and in the students' perceptions of lessons designed using the framework. The sources of data for this investigation are a questionnaire for students, in-depth interviews with teachers, and an analysis of the transcripts of synchronous sessions that were planned and executed using the framework. This investigation presents suitable guidelines to plan, carry out, and close lessons delivered synchronously. This study shows that when the framework is used, it helps teachers plan activities, and it supports the creation of a suitable environment for learning English online. This investigation also shows that when the framework is employed, it promotes a risk-free environment. It encourages collaboration, and it fosters the linking of ideas and the comprehension of fundamental concepts.

The transferable potential for a phase equilibria force field in its united-atom version, TraPPE_UA, is evaluated for 41 polar liquids that include alcohols, thiols, ethers, sulfides, aldehydes, ketones, and esters to determine its ability to reproduce experimental properties that were not included in the parametrization procedure. The intermolecular force field parameters for pure components were fit to reproduce experimental boiling temperature, vapor–liquid coexisting densities, and critical point (temperature, density, and pressure) using Monte Carlo simulations in different ensembles. The properties calculated in this work are liquid density, heat of vaporization, dielectric constant, surface tension, volumetric expansion coefficient, and isothermal compressibility. Molecular dynamics simulations were performed in the gas and liquid phases, and also at the liquid–vapor interface. We found that relative error between calculated and experimental data is 1.2% for density, 6% for heat of vaporization, and 6.2% for surface tension, in good agreement with the experimental data. The dielectric constant is systematically underestimated, and the relative error is 37%. Evaluating the performance of the force field to reproduce the volumetric expansion coefficient and isothermal compressibility requires more experimental data.

G protein-coupled receptors (GPCR) are responsible for modulating various physiological functions and are thus related to the pathophysiology of different diseases. Being potential therapeutic targets, multiple computational methodologies have been developed to analyze their behavior and interactions with other species. The solvent, on the other hand, has received much less attention. In this work, we analyzed the effect of four explicit water models on the structure and interactions of the GPR40 receptor in its apo form. We employed the rigid SPC/E and TIP4P models, and their flexible versions, the FBA/ϵ and TIP4P/ϵflex. We explored the structural changes and their correlation with some bulk dynamic properties of water. Our results showed an adverse effect on the conservation of the secondary structure of the receptor with all the models due to the breaking of the intramolecular hydrogen bond network, being more evident for the TIP4P models. Notably, all four models brought the receptor to states similar to the active one, modifying the intracellular part of the TM5 and TM6 domains in a “hinge” type movement, allowing the opening of the structure. Regarding the dynamic properties, the rigid models showed results comparable to those obtained in other studies on membrane systems. However, flexible models exhibit disparities in the molecular representation of systems. Surprisingly, the FBA/ϵ model improves the molecular picture of several properties, even though their agreement with bulk diffusion is poorer. These findings reinforce our idea that exploring other water models or improving the current ones, to better represent the membrane interface, can lead to a positive impact on the description of the signal transduction mechanisms and the search of new drugs by targeting these receptors.

The Hirshfeld charges are linearly increased to reproduce the experimental dielectric constant of 10 polar solvents having values between 13 (pyridine) and 182 (N-methylformamide). The OPLS/AA force field is used to obtain the new parameters. The surface tension and liquid density are also target properties to determine the new nonbonding parameters. The charge scaling factor is between 1.2 and 1.3. In addition, properties that were not used in the parametrization procedure, such as the heat of vaporization, self-diffusion coefficient, shear viscosity, isothermal compressibility, and volumetric expansion coefficient are obtained. Binary mixtures of amide/water and amide/amide are also studied. The original parameters of OPLS/AA, CGenFF, and GAFF force fields are evaluated. The TIP4P/ε force field is used to simulate water. The results from this work with the new parameters, for both pure components and binary mixtures, are in better agreement with experimental data than those obtained with the original values for most of the calculated properties. The maximum density of N-methylformamide in aqueous solutions is correctly predicted only with the new parameters. The high value of the dielectric constant of acetamide, formamide, and N-methylformamide is discussed in terms of the chain formation from the hydrogen bond interactions.

While most of research on chemotherapy-induced peripheral neuropathy (CIPN) has focused on somatic symptoms at hands and feet, clinical data suggest divergent persistent cognitive and visceral symptoms may have the most deleterious impact on the quality of life in cancer survivors. Because of the nature of the persistent symptoms and our data suggesting unique features on a subpopulation of somatic afferents vulnerable to chemotherapeutics, we hypothesized that persistent cognitive and visceral symptoms reflect a chemotherapeutic-induced "visceral” neuropathy with cognitive symptoms secondary to changes in the GI microbiome. To test this hypothesis, we assessed different endpoints in rodents a week after the last of six alternated IV infusions of the combination of paclitaxel (2 mg/kg) and carboplatin (30 mg/kg). Combination-treated rats developed 1) mechanical and cold sensitivity; 2) ∼50% reduction in the conduction velocity of A- and C-fibers in sciatic and vagal nerves; 3) an increase MCP-1 in a subpopulation of neurons in L4/L5 dorsal root (DRG) and nodose ganglia; 4) an increase in the mitochondria protein TOM-20 in a subpopulation of DRG and nodose neurons; 5) changes in GI motility, 6) changes in the phenotype of the GI microbiome. In a murine ovarian cancer model receiving the same chemotherapy regimen there were also alterations in the spleen and colon morphology, visceral hypersensitivity, a disruption in the spontaneous contractions in the colon, and a decrease in spatial memory performance. Our results are consistent with our initial hypothesis and suggest restoring normal GI function may have therapeutic utility for cancer survivors. R01 DK124955.

Dorsal root ganglion (DRG) stimulation is used to manage chronic pain, but the mechanism remains unknown. Given that GABA is released within the DRG, sensory neurons express GABAA receptors, and GABAA receptor activation blocks action potential propagation, one of the explanations for the efficacy of DRG stimulation, is that it is due to the release and subsequent activation of GABAA receptors within the DRG. To test this hypothesis, we recorded compound action potentials (CAP) in the sensory nerve central to the DRG, that were evoked with electrical stimulation of the nerve peripheral to the DRG before and after DRG stimulation. To test the role of GABAA receptors, action potential propagated through the ganglia were recorded before and after the application of bicuculline (100 μM), a GABAA receptor antagonist, to the DRG. We analyzed the A- and C-wave of the CAP because sensory neurons with rapidly conducting axons (A-fibers) carry largely non-nociceptive information while those with slowly conducting axons (C-fibers) carry largely nociceptive information. DRG stimulation (21Hz for 2 min) inhibited both the A- and the C-wave of the CAP. Bicuculline increased both the A- and C-wave of the CAP. Importantly, bicuculline reversed the DRG stimulation-induced block of the C-wave, and to a lesser extent, the A-wave. Ongoing experiments are designed to identify the fiber types inhibited by DRG stimulation. These results are consistent with GABA underlying the therapeutic efficacy of DRG stimulation and suggest ways to increase the efficacy of this intervention. 1RM1 NS128775.

Chemical weathering processes, such as decomposition and dissolution, are fairly well-understood phenomena as they relate to the formation of residual and saprolitic soils in the tropics. However, the effects that weathering intensity has on the physical characteristics and mechanical properties of weathered soil/rock materials, particularly their dynamic properties, are not yet fully understood. This paper presents the results of an experimental investigation conducted to assess the dynamic response of residual and saprolitic soils derived from a granodiorite rock in the central mountain range of Colombia and how this response relates to the soil microstructure and weathering intensity. Key dynamic properties, namely, shear modulus and material damping, were obtained via a fixed-free resonant column apparatus suitable for shear strain amplitudes ranging from 0.001 % to 0.1 %. Results from a short series of triaxial and oedometer tests substantiated the patterns of weathering intensity observed for each test soil. Soil fabric studies based on scanning electron microscopy observations, mercury intrusion porosimetry tests, and pore space distributions were also performed to identify the most relevant characteristics of the soil skeleton, as determined by the corresponding weathering intensity, that affect the dynamic response of each test soil. The residual soil, as the most altered/weathered material, was found to have a more rigid fabric, and thus greater stiffness, due to the presence of sesquioxides acting as cementing agents. In the saprolitic soil, a less weathered material, the soil fabric was dominated by distinct clay bridges formed between particle aggregations of partially decomposed primary minerals, resulting in less rigidity. The influence of confinement level on the shear modulus was found to be more pronounced in the saprolitic soil, which can be directly attributed to the changes in fabric of uncemented bonds during isotropic loading. Finally, and consistent with these general trends, the material damping of saprolitic soil was observed to be slightly less than that of residual soil, whereas the normalized shear moduli (G/Gmax) degradation curve was more pronounced in residual soil samples beyond a threshold value of shear strain amplitude.

We report a study of the relation between dust and gas over a 100 deg2 area in the Taurus molecular cloud. We compare the H2 column density derived from dust extinction with the CO column density derived from the 12CO and 13CO J = 1 - 0 lines. We derive the visual extinction from reddening determined from 2MASS data. The comparison is done at an angular size of 200'' corresponding to 0.14 pc at a distance of 140 pc. We find that the relation between visual extinction A V and N(CO) is linear between A V [?] 3 and 10 mag in the region associated with the B213-L1495 filament. In other regions, the linear relation is flattened for A V[?] 4 mag. We find that the presence of temperature gradients in the molecular gas affects the determination of N(CO) by [?]30%-70% with the largest difference occurring at large column densities. Adding a correction for this effect and accounting for the observed relation between the column density of CO and CO2 ices and A V, we find a linear relationship between the column of carbon monoxide and dust for observed visual extinctions up to the maximum value in our data [?]23 mag. We have used these data to study a sample of dense cores in Taurus. Fitting an analytical column density profile to these cores we derive an average volume density of about 1.4 x 104 cm-3 and a CO depletion age of about 4.2 x 105 yr. At visual extinctions smaller than [?]3 mag, we find that the CO fractional abundance is reduced by up to two orders of magnitude. The data show a large scatter suggesting a range of physical conditions of the gas. We estimate the H2 mass of Taurus to be about 1.5 x 104 M , independently derived from the A V and N(CO) maps. We derive a CO integrated intensity to H2 conversion factor of about 2.1 x 1020 cm-2 (K km s-1)-1, which applies even in the region where the [CO]/[H2] ratio is reduced by up to two orders of magnitude. The distribution of column densities in our Taurus maps resembles a log-normal function but shows tails at large and low column densities. The length scale at which the high column density tail starts to be noticeable is about 0.4 pc.

New $^{12}$CO $J =$4–3 and $^{13}$CO $J =$3–2 observations of the N 159 region, an active site of massive star formation in the Large Magellanic Cloud, have been made with the NANTEN2 and ASTE submillimeter telescopes, respectively. The $^{12}$CO $J =$4–3 distribution is separated into three clumps, each associated with N 159 W, N 159 E, and N 159 S. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the $^{12}$CO $J =$1–0, $J =$2–1, $J =$3–2, and $J =$7–6 as well as the isotope transitions of $^{13}$CO $J =$1–0, $J =$2–1, $J =$3–2, and $J =$4–3. The $^{13}$CO $J =$3–2 data were newly taken for the present work. The temperatures and densities were found to be $\sim$70&x2013;80 K and $\sim$3 $\times$10$^{3}$cm$^{-3}$in N 159 W and N 159 E, and $\sim$30 K and $\sim$1.6 $\times$10$^{3}$cm$^{-3}$in N 159 S. These results were compared with the star-formation activity based on data of young stellar clusters and HII regions as well as midinfrared emission obtained with the Spitzer MIPS. The N 159 E clump is associated with cluster(s) embedded, as observed at 24$\mu$m by the Spitzer MIPS, and the derived high temperature, 80 K, is interpreted as being heated by these sources. The N 159 E clump is likely to be responsible for a dark lane in a large H II region by dust extinction. On the other hand, the N 159 W clump is associated with clusters embedded mainly toward the eastern edge of the clump only. These clusters show offsets of 20${}^{\prime\prime}$–40${}^{\prime\prime}$from the $^{12}$CO $J =$4–3 peak, and are probably responsible for heating indicated by the derived high temperature, 70 K. The N 159 W clump exhibits no sign of star formation toward the $^{12}$CO $J =$4–3 peak position and its western region that shows enhanced $R_{4-3/1-0}$and $R_{3-2/1-0}$ratios. We therefore suggest that the N 159 W peak represents a pre-star-cluster core of $\sim$10$^{5} M_{\odot}$which deserves further detailed studies. The N 159 S clump shows little sign of star formation, as is consistent with the lower temperature, 30 K, and has a somewhat lower density than N 159 W and N 159 E. The N 159 S clump is also a candidate for future star formation.

We present a complete 12CO J = 1 - 0 map of the prominent molecular ridge in the Large Magellanic Cloud (LMC) obtained with the 22 m ATNF Mopra Telescope. The region stretches southward by [?]2deg (or 1.7 kpc) from 30 Doradus, the most vigorous star-forming region in the Local Group. The location of this molecular ridge is unique insofar as it allows us to study the properties of molecular gas as a function of the ambient radiation field in a low-metallicity environment. We find that the physical properties of CO-emitting clumps within the molecular ridge do not vary with the strength of the far-ultraviolet radiation field. Since the peak CO brightness of the clumps shows no correlation with the radiation field strength, the observed constant value for CO-to-H2 conversion factor along the ridge seems to require an increase in the kinetic temperature of the molecular gas that is offset by a decrease in the angular filling factor of the CO emission. We find that the difference between the CO-to-H2 conversion factor in the molecular ridge and the outer Milky Way is smaller than has been reported by previous studies of the CO emission: applying the same cloud identification and analysis methods to our CO observations of the LMC molecular ridge and CO data from the outer Galaxy survey by Dame et al., we find that the average CO-to-H2 conversion factor in the molecular ridge is X CO [?] (3.9 +- 2.5) x 1020 cm-2 (K km s-1)-1, approximately twice the value that we determine for the outer Galaxy clouds. The mass spectrum and the scaling relations between the properties of the CO clumps in the molecular ridge are similar, but not identical, to those that have been established for Galactic molecular clouds.

The antiepileptic drug carbamazepine is effective in a subpopulation of trigeminal neuralgia patients, in particular those suffering from pain associated with vascular compression of a trigeminal nerve. However, carbamazepine has failed in clinical trials for other neuropathic pain conditions, even those associated with peripheral nerve compression injuries. Carbamazepine is both a GABAA receptor (GAR) agonist and a blocker of voltage-gated Na+ channels (VGSC), and our recent data suggest that differences between trigeminal and somatic nerves with respect to the VGSC present are not sufficient to account for the therapeutic selectivity of carbamazepine. Therefore, we hypothesized that these observations reflected a differential involvement of GARs in somatic and trigeminal nerves. To test this, we employed a combination of electrophysiological and behavioral experiments in rat models of somatic (sciatic nerve, SN) and trigeminal (infraorbital nerve, ION) nerve compression (CCI). We observed that the potency of carbamazepine-induced compound action potential (CAP) block was increased by CCI of the ION but not the SN, and this increase in potency was reduced by the GAR blocker picrotoxin. The potency of the GAR agonist muscimol-induced block of the ION was greater than the SN, and CCI produced a further increase in efficacy. The GABAA-rho subunit mRNA and protein was increased by CCI of the ION, but not SN. The GABAA-rho receptor selective antagonist TPMPA reduced carbamazepine-induced CAP block of the ION. CCI was also associated with an increase in the potency of the GABAA-rho receptor preferring agonist TACA-induced block of the ION, but not SN. Finally, local administration of TACA to the ION but not SN, dose-dependently reversed CCI-induced mechanical sensitivity. Taken altogether, our results suggest GABAA-rho receptors are present and functional in ION, but not SN. This differential distribution of GABAA receptors could account for the therapeutic selectivity of carbamazepine for the treatment of TN. The work was supported by generous donations from TN patients and family members as well as NIH grant R01NS064988.

Here, we present a protocol to culture primary human vascular smooth muscle cells (VSMCs) under Alzheimer's disease (AD)-like conditions, including steps for morphological characterization with microscopy. We then describe functional assays, including wound healing, transwell, coculture, and supernatant assays, to evaluate the effect of dysfunctional VSMCs on the induction of the AD-associated microglial phenotype. Our approach can be applied to assess the effects of dysfunctional VSMCs on other cerebral cell lines including pericytes, astrocytes, and neurons under AD-like conditions in vitro.

In the last five years angio-interventional techniques have been applied to the recanalization of proximally occluded fallopian tubes in infertile women. The reported technical success of 90% and subsequent pregnancies in up to 54% of patients has led to considerable interest in this technique. This article will discuss current methodologies and review the reported results of this procedure.

To compare basal body temperature (BBT) graphs and urinary luteinizing hormone (LH) monitoring in scheduling therapeutic donor insemination.

The level of tumor necrosis factor (TNF) in peritoneal fluid (PF-TNF) of 74 women undergoing laparoscopy was determined. The difference between the mean concentration of PF-TNF of women with normal pelvic anatomy and women with moderate or severe endometriosis was significant (P<0.01). The proportion of PF-TNF-positive women with PID and those with moderate or severe endometriosis was also significantly higher when compared to women with normal pelvic anatomy (P<0.05; P<0.02). The proportion of PF-TNF positive women among nulligravid and nulliparous women was significantly higher than that of women with two or more pregnancies (P<0.01) and two or more deliveries (P<0.005). These results indicate that the presence of PF-TNF is associated with primary infertility and endometriosis.

One hundred twenty-two infertility patients with endometriosis were evaluated and treated using laparoscopy and laser vaporization to provide immediate elimination of all intraperitoneal disease. Ninety-five couples (77.8%) had one or more infertility factors (other than endometriosis) contributing to their infertility. Cervical factors, male factors, and luteal defects were associated with significantly decreased pregnancy rates, despite the use of laser vaporization. The number of contributing factors seemed to be unrelated to the likelihood of success in achieving pregnancy. The authors emphasize the need for total evaluation of other infertility factors in these patients. Such factors should be corrected prior to the use of laser laparoscopy, if possible, and dealt with on a continuing basis following use of this technique.

In an effort to understand the biochemical changes responsible for the decreased incidence of neonatal RDS observed in premature infants delivered after maternal glucocorticoid therapy we have compared quantitative changes in L/S ratio and qualitative changes in dipalmitoyl lecithin in serial amniotic fluid samples from 20 pregnant women treated with betamethasone and 11 patients who had repeated amniocentesis at similar gestational age but did not receive glucocorticoids. Initial L/S ratio values were not significantly different between treated (1.24 ± 0.24 [S.D.]) and control (1.09 ± 0.29 [S.D.]) groups but the values obtained within 1 week after therapy (1.49 ± 0.21 [S.D.]) were significantly higher (t = 3.8; p < 0.01) than those obtained after a similar period in the untreated group (1.24 ± 0.29 [S.D.]). However, only one of the treated patients reached a mature L/S ratio (2.0 or more). Simultaneously, 10 of 17 treated patients exhibited increases in the amount of dipalmitoyl lecithin within the first week after treatment, whereas no change was detected in serial samples from six control patients (p = 0.016). These results indicate that qualitative changes in amniotic fluid lecithin composition are a part of the fetal response to glucocorticoids which may be responsible for the decreased incidence of RDS observed after treatment.

A number of studies in sterilized animals have shown that ovarian grafts are able to restore ovarian function and fertility. Today, more women are surviving cancer, but some are made sterile by radiotherapy or gonadotoxic chemotherapy. Should it prove safe and effective to transplant ovarian tissue in humans, it may be possible to preserve fertility in these women and also those who want to delay childbearing for either medical or social reasons. The investigators report an attempt at ovarian transplantation between healthy monozygotic twins, one of whom had premature menopause.