Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 200
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 121(26): e2317945121, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38889154

RESUMEN

Chaperone-mediated autophagy (CMA) is part of the mammalian cellular proteostasis network that ensures protein quality control, maintenance of proteome homeostasis, and proteome changes required for the adaptation to stress. Loss of proteostasis is one of the hallmarks of aging. CMA decreases with age in multiple rodent tissues and human cell types. A decrease in lysosomal levels of the lysosome-associated membrane protein type 2A (LAMP2A), the CMA receptor, has been identified as a main reason for declined CMA in aging. Here, we report constitutive activation of CMA with calorie restriction (CR), an intervention that extends healthspan, in old rodent livers and in an in vitro model of CR with cultured fibroblasts. We found that CR-mediated upregulation of CMA is due to improved stability of LAMP2A at the lysosome membrane. We also explore the translational value of our observations using calorie-restriction mimetics (CRMs), pharmacologically active substances that reproduce the biochemical and functional effects of CR. We show that acute treatment of old mice with CRMs also robustly activates CMA in several tissues and that this activation is required for the higher resistance to lipid dietary challenges conferred by treatment with CRMs. We conclude that part of the beneficial effects associated with CR/CRMs could be a consequence of the constitutive activation of CMA mediated by these interventions.


Asunto(s)
Restricción Calórica , Autofagia Mediada por Chaperones , Proteína 2 de la Membrana Asociada a los Lisosomas , Lisosomas , Animales , Ratones , Proteína 2 de la Membrana Asociada a los Lisosomas/metabolismo , Proteína 2 de la Membrana Asociada a los Lisosomas/genética , Lisosomas/metabolismo , Humanos , Envejecimiento/metabolismo , Fibroblastos/metabolismo , Proteostasis , Hígado/metabolismo , Ratones Endogámicos C57BL , Masculino , Autofagia
2.
Faraday Discuss ; 251(0): 509-522, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-38766758

RESUMEN

The exploration of the fundamental formation mechanisms of polycyclic aromatic hydrocarbons (PAHs) is crucial for the understanding of molecular mass growth processes leading to two- and three-dimensional carbonaceous nanostructures (nanosheets, graphenes, nanotubes, buckyballs) in extraterrestrial environments (circumstellar envelopes, planetary nebulae, molecular clouds) and combustion systems. While key studies have been conducted exploiting traditional, high-temperature mechanisms such as the hydrogen abstraction-acetylene addition (HACA) and phenyl addition-dehydrocyclization (PAC) pathways, the complexity of extreme environments highlights the necessity of investigating chemically diverse mass growth reaction mechanisms leading to PAHs. Employing the crossed molecular beams technique coupled with electronic structure calculations, we report on the gas-phase synthesis of phenanthrene (C14H10)-a three-ring, 14π benzenoid PAH-via a phenylethynyl addition-cyclization-aromatization mechanism, featuring bimolecular reactions of the phenylethynyl radical (C6H5CC, X2A1) with benzene (C6H6) under single collision conditions. The dynamics involve a phenylethynyl radical addition to benzene without entrance barrier leading eventually to phenanthrene via indirect scattering dynamics through C14H11 intermediates. The barrierless nature of reaction allows rapid access to phenanthrene in low-temperature environments such as cold molecular clouds which can reach temperatures as low as 10 K. This mechanism constitutes a unique, low-temperature framework for the formation of PAHs as building blocks in molecular mass growth processes to carbonaceous nanostructures in extraterrestrial environments thus affording critical insight into the low-temperature hydrocarbon chemistry in our universe.

3.
Phys Chem Chem Phys ; 26(26): 18256-18265, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38904382

RESUMEN

Alkynyl radicals and cations are crucial reactive intermediates in chemistry, but often evade direct detection. Herein, we report the direct observation of the phenylethynyl radical (C6H5CC˙) and its cation (C6H5CC+), which are two of the most reactive intermediates in organic chemistry. The radical is generated via pyrolysis of (bromoethynyl)benzene at temperatures above 1500 K and is characterized by photoion mass-selected threshold photoelectron spectroscopy (ms-TPES). Photoionization of the phenylethynyl radical yields the phenylethynyl cation, which has never been synthesized due to its extreme electrophilicity. Vibrationally-resolved ms-TPES assisted by ab initio calculations unveiled the complex electronic structure of the phenylethynyl cation, which appears at an adiabatic ionization energy (AIE) of 8.90 ± 0.05 eV and exhibits an uncommon triplet (3B1) ground state, while the closed-shell singlet (1A1) state lies just 2.8 kcal mol-1 (0.12 eV) higher in energy. The reactive phenylethynyl radical abstracts hydrogen to form ethynylbenzene (C6H5CCH) but also isomerizes via H-shift to the o-, m-, and p-ethynylphenyl isomers (C6H4CCH). These radicals are very reactive and undergo ring-opening followed by H-loss to form a mixture of C8H4 triynes, along with low yields of cyclic 3- and 4-ethynylbenzynes (C6H3CCH). At higher temperatures, dehydrogenation from the unbranched C8H4 triynes forms the linear tetraacetylene (C8H2), an astrochemically relevant polyyne.

4.
Phys Chem Chem Phys ; 26(26): 18321-18332, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38912536

RESUMEN

The biphenyl molecule (C12H10) acts as a fundamental molecular backbone in the stereoselective synthesis of organic materials due to its inherent twist angle causing atropisomerism in substituted derivatives and in molecular mass growth processes in circumstellar environments and combustion systems. Here, we reveal an unconventional low-temperature phenylethynyl addition-cyclization-aromatization mechanism for the gas-phase preparation of biphenyl (C12H10) along with ortho-, meta-, and para-substituted methylbiphenyl (C13H12) derivatives through crossed molecular beams and computational studies providing compelling evidence on their formation via bimolecular gas-phase reactions of phenylethynyl radicals (C6H5CC, X2A1) with 1,3-butadiene-d6 (C4D6), isoprene (CH2C(CH3)CHCH2), and 1,3-pentadiene (CH2CHCHCHCH3). The dynamics involve de-facto barrierless phenylethynyl radical additions via submerged barriers followed by facile cyclization and hydrogen shift prior to hydrogen atom emission and aromatization to racemic mixtures (ortho, meta) of biphenyls in overall exoergic reactions. These findings not only challenge our current perception of biphenyls as high temperature markers in combustion systems and astrophysical environments, but also identify biphenyls as fundamental building blocks of complex polycyclic aromatic hydrocarbons (PAHs) such as coronene (C24H12) eventually leading to carbonaceous nanoparticles (soot, grains) in combustion systems and in deep space thus affording critical insight into the low-temperature hydrocarbon chemistry in our universe.

5.
Int J Mol Sci ; 25(16)2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39201365

RESUMEN

Despite efforts to elucidate the cellular adaptations induced by obesity, cellular bioenergetics is currently considered a crucial target. New strategies to delay the onset of the hazardous adaptations induced by obesity are needed. Therefore, we evaluated the effects of 4 weeks of melatonin treatment on mitochondrial function and lipid metabolism in the livers of leptin-deficient mice. Our results revealed that the absence of leptin increased lipid storage in the liver and induced significant mitochondrial alterations, which were ultimately responsible for defective ATP production and reactive oxygen species overproduction. Moreover, leptin deficiency promoted mitochondrial biogenesis, fusion, and outer membrane permeabilization. Melatonin treatment reduced the bioenergetic deficit found in ob/ob mice, alleviating some mitochondrial alterations in the electron transport chain machinery, biogenesis, dynamics, respiration, ATP production, and mitochondrial outer membrane permeabilization. Given the role of melatonin in maintaining mitochondrial homeostasis, it could be used as a therapeutic agent against adipogenic steatosis.


Asunto(s)
Leptina , Metabolismo de los Lípidos , Melatonina , Mitocondrias Hepáticas , Animales , Melatonina/farmacología , Leptina/metabolismo , Leptina/deficiencia , Ratones , Mitocondrias Hepáticas/metabolismo , Mitocondrias Hepáticas/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Especies Reactivas de Oxígeno/metabolismo , Adenosina Trifosfato/metabolismo , Obesidad/metabolismo , Obesidad/tratamiento farmacológico , Metabolismo Energético/efectos de los fármacos , Hígado/metabolismo , Hígado/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados
6.
Gac Med Mex ; 160(2): 186-195, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39116852

RESUMEN

BACKGROUND: The follow-up of health sciences graduates is relevant due to the commitment of universities to train professionals who contribute to solve the country's health problems. The National Autonomous University of Mexico (UNAM) has health sciences graduates who join the workforce every year. OBJECTIVE: To identify the perception of health sciences graduates regarding the curriculum and their incorporation into the labor market from 1994 to 2015, and compare it according to the degree program and campus. MATERIAL AND METHODS: Observational, cross-sectional, comparative, quantitative study. The sample of 26,866 graduates was obtained from information of three decades of the institutional questionnaire for graduates applied by the General Directorate of Planning of the UNAM. RESULTS: Most graduates were females (68.4%), with admission to the degree course at between 19 and 20 years of age (65.4%). At least 47% had a job; incorporation into the labor market depended on not having an income, a higher grade point average, not having presented extraordinary exams, or failed subjects, among others. CONCLUSIONS: Adequate job insertion is associated with starting the degree course at age 18, having financial support, having an average of 8.1 or higher and perceiving low academic and teaching training.


ANTECEDENTES: El seguimiento de egresados en ciencias de la salud es de relevancia debido al compromiso de las universidades de formar profesionales que contribuyan a resolver los problemas de salud del país. La Universidad Nacional Autónoma de Mexico (UNAM) cuenta con egresados en ciencias de la salud que cada año se incorporan al campo laboral. OBJETIVO: Identificar la percepción de los egresados de ciencias de la salud de 1994 a 2015 respecto su formación académica y su incorporación laboral, y compararla según licenciatura y plantel. MATERIAL Y MÉTODOS: Estudio observacional, transversal, comparativo y cuantitativo. La muestra de 26 866 graduados se obtuvo de la información de tres décadas del cuestionario institucional para egresados de la Dirección General de Planeación de la UNAM. RESULTADOS: La mayoría de los egresados fue del sexo femenino (68.4 %), con ingreso a la licenciatura entre los 19 y 20 años (65.4 %). Al menos 47 % trabajaba; la incorporación laboral dependió de no contar con ingresos, mayor promedio, no haber presentado exámenes extraordinarios ni recursado materias, entre otros. CONCLUSIONES: La inserción laboral adecuada se asocia a iniciar la licenciatura a los 18 años, contar con apoyo económico, tener promedio de 8.1 o más y percibir la formación académica y docente baja.


Asunto(s)
Curriculum , Humanos , Femenino , Estudios Transversales , Masculino , México , Adulto , Adulto Joven , Encuestas y Cuestionarios
7.
World J Urol ; 41(11): 2905-2914, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37171477

RESUMEN

PURPOSE: To determine the risk factors associated with major complications in patients with histologically confirmed Xanthogranulomatous pyelonephritis (XGP) who underwent nephrectomy. METHODS: A multicenter retrospective study was performed including patients who underwent nephrectomy between 2018 and 2022 with histopathological diagnosis of XGP. Clinical and laboratory parameters at the initial presentation were evaluated. Data on extension of XGP was recorded as per the Malek clinical-radiological classification. Characteristics of nephrectomy and perioperative outcomes were obtained. The primary outcome was major complications, defined as a CD ≥ grade 3 and the need for intensive care unit (ICU) admission. Secondary outcomes included the comparison of complications evaluating the nephrectomy approach (transperitoneal, retroperitoneal, and laparoscopic). A sub-analysis stratifying patients who needed ICU admission and Malek classification was performed. RESULTS: A total of 403 patients from 10 centers were included. Major complications were reported in 98 cases (24.3%), and organ injuries were reported in 58 patients (14.4%), being vascular injuries the most frequent (6.2%). Mortality was reported in 5 cases (1.2%). A quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥ 2, increased creatinine, paranephric extension of disease (Malek stage 3), a positive urine culture, and retroperitoneal approach were independent factors associated with major complications. CONCLUSION: Counseling patients on factors associated with higher surgical complications is quintessential when managing this disease. Clinical-radiological staging, such as the Malek classification may predict the risk of major complications in patients with XGP who will undergo nephrectomy. A transperitoneal open approach may be the next best option when laparoscopic approach is not feasible.


Asunto(s)
Laparoscopía , Pielonefritis Xantogranulomatosa , Humanos , Estudios Retrospectivos , Pielonefritis Xantogranulomatosa/epidemiología , Pielonefritis Xantogranulomatosa/cirugía , Pielonefritis Xantogranulomatosa/diagnóstico , Factores de Riesgo , Nefrectomía/efectos adversos
8.
Phys Chem Chem Phys ; 25(45): 31146-31152, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37947458

RESUMEN

2-Cyanoindene has recently been identified in the interstellar medium, however current models cannot fully account for its formation pathways. Herein, we identify and characterize 2-naphthylnitrene, which is prone to rearrange to 2- and 3-cyanoindene, in the gas phase using photoion mass-selective threshold photoelectron spectroscopy (ms-TPES). The adiabatic ionization energies (AIE) of triplet nitrene (3A'') to the radical cation in its lowest-energy doublet X̃+(2A') and quartet ã+(4A') electronic states were determined to be 7.72 ± 0.02 and 8.64 ± 0.02 eV, respectively, leading to a doublet-quartet energy splitting (ΔED-Q) of 0.92 eV (88.8 kJ mol-1). A ring-contraction mechanism yields 3-cyanoindene, which is selectively formed under mild pyrolysis conditions (800 K), while the lowest-energy isomer, 2-cyanoindene, is also observed under harsh pyrolysis conditions at 1100 K. The isomer-selective assignment was rationalized by Franck-Condon spectral modeling and by measuring the AIEs at 8.64 ± 0.02 and 8.70 ± 0.02 eV for 2- and 3-cyanoindene, respectively, in good agreement with quantum chemical calculations.

9.
J Phys Chem A ; 127(41): 8574-8583, 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37734109

RESUMEN

The thermal decomposition of 2- and 4-iodobenzyl iodide at high temperatures was investigated by mass-selective threshold photoelectron spectroscopy (ms-TPES) in the gas phase, as well as by matrix isolation infrared spectroscopy in cryogenic matrices. Scission of the benzylic C-I bond in the precursors at 850 K affords 2- and 4-iodobenzyl radicals (ortho- and para-IC6H4CH2•), respectively, in high yields. The adiabatic ionization energies of ortho-IC6H4CH2• to the X̃+(1A') and ã+(3A') cation states were determined to be 7.31 ± 0.01 and 8.78 ± 0.01 eV, whereas those of para-IC6H4CH2• were measured to be 7.17 ± 0.01 eV for X̃+(1A1) and 8.98 ± 0.01 eV for ã+(3A1). Vibrational frequencies of the ring breathing mode were measured to be 560 ± 80 and 240 ± 80 cm-1 for the X̃+(1A') and ã+(3A') cation states of ortho-IC6H4CH2•, respectively. At higher temperatures, subsequent aryl C-I cleavage takes place to form α,2- and α,4-didehydrotoluene diradicals, which rapidly undergo ring contraction to a stable product, fulvenallene. Nevertheless, the most intense vibrational bands of the elusive α,2- and α,4-didehydrotoluene diradicals were observed in the Ar matrices. In addition, high-energy and astrochemically relevant C7H6 isomers 1-, 2-, and 5-ethynylcyclopentadiene are observed at even higher pyrolysis temperatures along with fulvenallene. Complementary quantum chemical computations on the C7H6 potential energy surface predict a feasible reaction cascade at high temperatures from the diradicals to fulvenallene, supporting the experimental observations in both the gas phase and cryogenic matrices.

10.
J Phys Chem A ; 127(27): 5723-5733, 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37401904

RESUMEN

The bimolecular gas-phase reactions of the phenylethynyl radical (C6H5CC, X2A1) with allene (H2CCCH2), allene-d4 (D2CCCD2), and methylacetylene (CH3CCH) were studied under single-collision conditions utilizing the crossed molecular beams technique and merged with electronic structure and statistical calculations. The phenylethynyl radical was found to add without an entrance barrier to the C1 carbon of the allene and methylacetylene reactants, resulting in doublet C11H9 collision complexes with lifetimes longer than their rotational periods. These intermediates underwent unimolecular decomposition via atomic hydrogen loss through tight exit transition states in facile radical addition─hydrogen atom elimination mechanisms forming predominantly 3,4-pentadien-1-yn-1-ylbenzene (C6H5CCCHCCH2) and 1-phenyl-1,3-pentadiyne (C6H5CCCCCH3) in overall exoergic reactions (-110 kJ mol-1 and -130 kJ mol-1) for the phenylethynyl-allene and phenylethynyl-methylacetylene systems, respectively. These barrierless reaction mechanisms mirror those of the ethynyl radical (C2H, X2Σ+) with allene and methylacetylene forming predominantly ethynylallene (HCCCHCCH2) and methyldiacetylene (HCCCCCH3), respectively, suggesting that in the aforementioned reactions the phenyl group acts as a spectator. These molecular mass growth processes are accessible in low-temperature environments such as cold molecular clouds (TMC-1) or Saturn's moon Titan, efficiently incorporating a benzene ring into unsaturated hydrocarbons.

11.
Postgrad Med J ; 99(1172): 599-604, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37319154

RESUMEN

INTRODUCTION: Performance and selection rate of non-newly graduated physicians in a medical residency admission test as an indicator for the need of continuing education. METHODS: A database comprising 153 654 physicians who took a residency admission test in the period 2014-2018 was analysed. Performance and selection rates were assessed in relation to year of graduation and performance in medical school. RESULTS: The whole sample scored at a mean of 62.3 (SD ±8.9; range 1.11-91.11). Examinees who took the test in their year of graduation performed better (66.10) than those who took the test after their year of graduation (61.84); p<0.001.Selection rates differed accordingly; 33.9% for newly graduated physicians compared with 24.8% in those who took the test at least 1 year after graduation; p<0.001. An association between selection test performance and medical school grades was established using Pearson's correlation: r=0.40 for newly graduated physicians and r=0.30 for non-newly graduated physicians. There were statistically significant differences in selection rates for every ranking group of grades in medical school based on the χ2 test (p<0.001). The selection rates are decreased years after graduation even for candidates with high grades in medical school. DISCUSSION: There is an association between performance in a medical residency admission test and academic variables of the candidates: medical school grades and time elapsed from graduation to test taking. The evidence of decrease in retention of medical knowledge since graduation highlights the pertinence of continuing education interventions.


Asunto(s)
Rendimiento Académico , Internado y Residencia , Médicos , Humanos , Facultades de Medicina
12.
Salud Publica Mex ; 65(3, may-jun): 227-235, 2023 Apr 21.
Artículo en Español | MEDLINE | ID: mdl-38060875

RESUMEN

OBJETIVO: Comparar el control glucémico entre pacientes con diabetes mellitus tipo 2 prepandemia vs pandemia de Covid-19 que acudieron a unidades de salud de primer nivel de atención de la Ciudad de México. Material y métodos. Se analizaron los registros de 23 912 pacientes con diabetes; 78.7% fueron del grupo prepandemia (2016 a 2020) y 21.3% del grupo pandemia (marzo 2020 a julio 2021). Se calcularon medidas de tendencia central y de dispersión, pruebas t de Student y se ajustó un modelo de regresión logística múltiple. RESULTADOS: La mayoría de los pacientes con diabetes fueron mujeres (66.6 y 62.6%) con edad promedio de 59 y 58 años, respectivamente, y con hemoglobina glucosilada (HbA1) final de 7.7 vs el grupo pandemia (8.0). Las variables asociadas con el descontrol glucémico incluyeron periodo, nivel de HbA1, sobrepeso, obesidad, antecedente de padres con diabetes, número de medicamentos y tipo de insulina. CONCLUSIONES: La mayoría de los pacientes con diabetes en ambos grupos tuvieron descontrol glucémico. Los pacientes del grupo pandemia tuvieron mayor descontrol glucémico de HbA1 comparados con los del grupo prepandemia. Después de recibir atención médica en ambos grupos, los pacientes mejoraron su control glucémico.

13.
Int J Mol Sci ; 24(6)2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36982444

RESUMEN

The metabolic syndrome (MS) is a cluster of risk factors, such as central obesity, hyperglycemia, dyslipidemia, and arterial hypertension, which increase the probability of causing premature mortality. The consumption of high-fat diets (HFD), normally referred to high-saturated fat diets, is a major driver of the rising incidence of MS. In fact, the altered interplay between HFD, microbiome, and the intestinal barrier is being considered as a possible origin of MS. Consumption of proanthocyanidins (PAs) has a beneficial effect against the metabolic disturbances in MS. However, there are no conclusive results in the literature about the efficacy of PAs in improving MS. This review allows a comprehensive validation of the diverse effects of the PAs on the intestinal dysfunction in HFD-induced MS, differentiating between preventive and therapeutic actions. Special emphasis is placed on the impact of PAs on the gut microbiota, providing a system to facilitate comparison between the studies. PAs can modulate the microbiome toward a healthy profile and strength barrier integrity. Nevertheless, to date, published clinical trials to verify preclinical findings are scarce. Finally, the preventive consumption of PAs in MS-associated dysbiosis and intestinal dysfunction induced by HFD seems more successful than the treatment strategy.


Asunto(s)
Microbioma Gastrointestinal , Síndrome Metabólico , Proantocianidinas , Humanos , Animales , Ratones , Síndrome Metabólico/tratamiento farmacológico , Síndrome Metabólico/etiología , Síndrome Metabólico/prevención & control , Proantocianidinas/farmacología , Proantocianidinas/uso terapéutico , Obesidad/metabolismo , Intestinos , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BL , Disbiosis/complicaciones
14.
Molecules ; 28(2)2023 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-36677623

RESUMEN

During the 20th century, modern painters experimented with different mediums and painting techniques, one of them was Rafael Coronel in his mural painting, Paisaje Abstracto (Abstract landscape). The painting was created with a peculiar pouring technique and an unknown binding medium; ageing produced fractures and severe conservation problems. Therefore, the characterization of the painting medium became an urgent matter in order to understand the current condition of the painting and to develop a proper treatment. The aim of this research was to characterize the chemical composition and painting technique of Paisaje Abstracto. To approach this goal two microsamples were taken and analyzed by optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), nuclear magnetic resonance (NMR) spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), micro attenuated total reflection Fourier transform infrared spectroscopy (micro-ATR-FTIR) and gas chromatography/mass spectrometry (GC/MS). The analysis allowed for the identification of cadmium sulfide (CdS) and titanium dioxide (TiO2) as inorganic pigments; aluminosilicate fillers; poly(methyl methacrylate) (pMMA) as a binder; MMA monomer, red organic pigment PR181; benzoyl peroxide, dibutyl phthalate and 1-octadecanol as organic additives. This study presents an innovative painting technique with pMMA, a medium not commonly used by artists, which was probably polymerized onto the painting support.

15.
Gac Med Mex ; 159(3): 233-239, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37494718

RESUMEN

BACKGROUND: Academic track record analysis is essential for evaluating the training of students and the structure of higher education study programs, which allows diagnosing and preventing educational lag and school dropout. OBJECTIVE: To analyze the differences in academic track records of UNAM health sciences undergraduate students from generations 2001 to 2016. MATERIAL AND METHODS: Study of real cohorts; graduation and lag rates were calculated. ANOVA was used to contrast the graduation rates between campuses by undergraduate program and time. To identify critical periods, survival functions were used with Kaplan-Meier's method. RESULTS: The lowest percentages of lag were observed in nursing and medicine students; nursing students had the highest graduation rates, especially at Zaragoza campus; dentistry students had the lowest graduation rates and the highest dropout and lag rates. Women showed higher graduation rates and lower risk of dropout and lag. CONCLUSIONS: Nursing, medicine and psychology undergraduate students at Zaragoza and Iztacala campuses, with modular programs, achieved the highest graduation percentages and the lowest dropout and lag rates.


ANTECEDENTES: El análisis de las trayectorias académicas es fundamental para evaluar la formación de los estudiantes y la estructura de los programas de estudio de educación superior, lo que permite diagnosticar y prevenir el rezago y abandono escolar. OBJETIVO: Analizar las diferencias en las trayectorias académicas de los estudiantes de las licenciaturas en ciencias de la salud de la UNAM de las generaciones 2001 a 2016. MATERIAL Y MÉTODOS: Estudio de cohortes reales; se calcularon tasas de egreso y rezago. Se realizó ANOVA para contrastar el egreso entre planteles por carrera y tiempo. Para identificar los períodos críticos se utilizaron funciones de supervivencia con el método de Kaplan-Meier. RESULTADOS: En las licenciaturas en enfermería y medicina se observaron los menores porcentajes de rezago; enfermería presentó los mayores porcentajes de egreso, sobre todo en la Facultad de Estudios Superiores Zaragoza; odontología mostró los menores índices de egreso y mayores índices de abandono y rezago. Las mujeres mostraron mayor egreso y menor riesgo de abandono y rezago. CONCLUSIONES: Los estudiantes de las licenciaturas en enfermería, medicina y psicología de las facultades de estudios superiores Zaragoza e Iztacala, con programas modulares, alcanzaron los mayores porcentajes de egreso y menores índices de abandono y rezago.


Asunto(s)
Medicina , Estudiantes de Medicina , Humanos , Femenino , Escolaridad
16.
Gac Med Mex ; 159(4): 280-286, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37699223

RESUMEN

Innovative technologies such as the metaverse and chat GPT-4 (based on artificial intelligence) are present in the daily discourse of society; recently, they have been introduced into medical practice and are bringing about important changes. In the case of the metaverse ("beyond the universe"), various medical schools and departments around the world are beginning to use it as an innovative strategy for teaching subjects such as anatomy, histology, ophthalmology, and simulation in parallel (virtual) worlds for learning and supervision of surgeries, as well as for other applications in medical education and in the doctor-patient relationship. Although it should be regarded as an area of opportunity for the transformation of medicine, it is important to consider the various limitations and risks of the metaverse in medical practice, student training, and physicians' relationship with the health problems they have to deal with in their practice.


Las innovadoras tecnologías del metaverso y el chat GPT4 (basado en inteligencia artificial) están presentes en el discurso cotidiano de la sociedad; recientemente se han introducido en la práctica médica y están provocando importantes cambios. En cuanto al metaverso ("después del universo"), diversas escuelas y facultades de medicina del mundo comienzan a utilizarlo como una estrategia innovadora dirigida a la enseñanza de materias como anatomía, histología, oftalmología y simulación en mundos paralelos (virtuales) para el aprendizaje y supervisión de cirugías, así como para otras aplicaciones en educación médica y en la relación médico-paciente. Si bien debe tomarse en cuenta como un área de oportunidad para la transformación de la medicina, es importante considerar las diversas limitaciones y riesgos del metaverso en la práctica médica, la formación de estudiantes y la relación del médico con los problemas de salud a los que se enfrenta en su práctica.


Asunto(s)
Educación Médica , Medicina , Humanos , Inteligencia Artificial , Relaciones Médico-Paciente , Aprendizaje
17.
Org Biomol Chem ; 20(18): 3703-3707, 2022 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-35262542

RESUMEN

The supramolecular assembly of DNA conjugates, functionalized with tetraphenylethylene (TPE) sticky ends, into vesicular structures is described. The aggregation-induced emission (AIE) active TPE units allow monitoring the assembly process by fluorescence spectroscopy. The number of TPE modifications in the overhangs of the conjugates influences the supramolecular assembly behavior. A minimum of two TPE residues on each end are required to ensure a well-defined assembly process. The design of the presented DNA-based nanostructures offers tailored functionalization with applications in DNA nanotechnology.


Asunto(s)
ADN , Estilbenos , Secuencia de Bases , Nanotecnología , Estilbenos/química
18.
Curr Urol Rep ; 23(10): 235-244, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36053406

RESUMEN

PURPOSE OF REVIEW: Greater availability of sequencing methods has broadened the knowledge of the urinary microbiome in an environment previously believed to be sterile. This review discusses internal and external influences that promote either a balance or a dysbiosis of the urinary tract and the future perspectives in understanding lower urinary tract infections. RECENT FINDINGS: Efforts have been made to identify a "core" urinary microbiome in which Firmicutes and Bacteroidetes account for most of the bacterial representations. A shift to a Proteobacteria-dominant representation shapes the fingerprint of the infectious urinary microbiome; furthermore, the virome and the mycobiome are important modulators of the urinary microbiome, which have been recently explored to determine their role in the health-disease process of the lower urinary tract. A disturbance of bacterial representation and diversity triggers a transition from health to disease; conversely, a functional cooperative interplay between the host and microbiome allows for basic metabolic and immune functions to take place.


Asunto(s)
Microbiota , Infecciones Urinarias , Sistema Urinario , Humanos
19.
BMC Med Educ ; 22(1): 456, 2022 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-35701813

RESUMEN

BACKGROUND: A large portion of prescribing errors can be attributed to deficiencies in medication knowledge. These errors are preventable and most often occur at the time of prescription. Antimicrobials are the drug class most common incorrectly prescribed. OBJECTIVE: To characterize the relationship between clinical competence and antibiotic prescription errors. We also investigated the frequency and severity of antibiotic prescription errors to identify items and attributes of clinical competence which are correlated with the antibiotic prescription error ratio. METHOD: A cross-sectional study was applied to assess clinical competence of junior medical residents in two reference academic hospitals and a regional hospital in Mexico City. It was conducted during February 2019. We used an infectious disease Objective Structured Clinical Examination (OSCE) to assess clinical competence and a measure of frequency, and severity of antibiotic prescription errors. RESULTS: The number of eligible participants was ~ 255 (hospital meeting attendance), and the number of residents in this study were 51 (~ 20%), 31 were female (60.8%). The mean OSCE score was 0.692 ± 0.073. The inter-item (Cronbach's alpha = 0.927) and inter-station internal consistency was adequate (Cronbach's alpha = 0.774). The G coefficient in generalizability theory analysis was 0.84. The antibiotic prescription error ratio was 45.1% ± 7%. The most frequent category of severity of antibiotic prescription errors was category E (errors that may contribute to or result in temporary harm to the patient and require intervention), 235 (65.2%). We observed a negative and significant correlation between clinical competence and antibiotic prescription errors (r = -0.33, p < 0.05, CI95% -0.57 to -0.07), which remained significant after controlling for the effect of gender and time since graduation from medical school (r = -0.39, p < 0.01, CI95% -0.625 to -0.118). Using exploratory factor analysis we identified two factors, which explained 69% of the variance in clinical competence, factor 1 evaluated socio-clinical skills and factor 2 evaluated diagnostic-therapeutic skills. Factor 2 was correlated with antibiotic prescription error ratio (r = -0.536, p < 0.001). CONCLUSIONS: We observed a negative correlation between clinical competence and antibiotic prescription error ratio in graduated physicians who have been accepted in a medical specialty. The therapeutic plan, which is a component of the clinical competence score, and the prescription skills had a negative correlation with antibiotic prescription errors. The most frequent errors in antibiotic prescriptions would require a second intervention.


Asunto(s)
Competencia Clínica , Internado y Residencia , Antibacterianos/uso terapéutico , Estudios Transversales , Prescripciones de Medicamentos , Femenino , Humanos , Masculino
20.
Sensors (Basel) ; 22(23)2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36502235

RESUMEN

Visualizing two variables in the fluid flow requires a complex optical system to fulfill such a purpose. Furthermore, in these applications, measuring the temperature fields of the fluid is sometimes necessary. In this work, we use a color digital camera to record in one snapshot shadowgraph and two direction sensitivity Schlieren images. Furthermore, the Schlieren images obtained are used to measure temperature fields. The optical system, as main components, employs an rgb Light Emitting Diode (LED), two knife edges represented by shortpass and longpass ultra-thin filters, and a color digital camera. The results of this study show that shadowgraph images are contaminated with the crosstalk effect, and correction against it was applied. On the other hand, the reached resolution of the optical system to measure temperature values is approximately one degree.


Asunto(s)
Dispositivos Ópticos , Temperatura , Fenómenos Físicos , Reacciones Cruzadas , Extremidad Superior
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA