Calorie restriction and calorie-restriction mimetics activate chaperone-mediated autophagy.

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.

Exploring the chemical dynamics of phenanthrene (C14H10) formation via the bimolecular gas-phase reaction of the phenylethynyl radical (C6H5CC) with benzene (C6H6).

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.

The elusive phenylethynyl radical and its cation: synthesis, electronic structure, and reactivity.

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.

Unconventional gas-phase synthesis of biphenyl and its atropisomeric methyl-substituted derivatives.

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.

Perioperative outcomes and risk factors for major complications associated with nephrectomy for Xanthogranulomatous pyelonephritis: a multicenter study.

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.

Photoelectron spectroscopic study of 2-naphthylnitrene and its thermal rearrangement to cyanoindenes.

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.

Thermal Decomposition of 2- and 4-Iodobenzyl Iodide Yields Fulvenallene and Ethynylcyclopentadienes: A Joint Threshold Photoelectron and Matrix Isolation Spectroscopic Study.

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.

Exploring the Chemical Dynamics of Phenylethynyl Radical (C6H5CC; X2A1) Reactions with Allene (H2CCCH2; X1A1) and Methylacetylene (CH3CCH; X1A1).

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.

National examination for medical residency admission: academic performance in a high-stakes test and the need for continuing education.

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.

Descontrol glucémico: desafío de salud pública en prepandemia y pandemia.

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.

Proanthocyanidins: Impact on Gut Microbiota and Intestinal Action Mechanisms in the Prevention and Treatment of Metabolic Syndrome.

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.

Microanalytical Characterization of an Innovative Modern Mural Painting Technique by SEM-EDS, NMR and Micro-ATR-FTIR among Others.

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.

Health sciences undergraduate students academic track records.

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.

Medicine and the metaverse: current applications and future.

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.

Tetraphenylethylene-DNA conjugates: influence of sticky ends and DNA sequence length on the supramolecular assembly of AIE-active vesicles.

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.

A Perspective of the Urinary Microbiome in Lower Urinary Tract Infections - A Review.

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.

Antibiotic prescription errors: the relationship with clinical competence in junior medical residents.

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.

Simultaneous Schlieren-Shadowgraph Visualization and Temperature Measurement Fields of Fluid Flow Using One Color CCD Camera.

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.

Diffusion of Lipid Nanovesicles Bound to a Lipid Membrane Is Associated with the Partial-Slip Boundary Condition.

During diffusion of nanoparticles bound to a cellular membrane by ligand-receptor pairs, the distance to the laterally mobile interface is sufficiently short for their motion to depend not only on the membrane-mediated diffusivity of the tethers but also in a not yet fully understood manner on nanoparticle size and interfacial hydrodynamics. By quantifying diffusivity, velocity, and size of individual membrane-bound liposomes subjected to a hydrodynamic shear flow, we have successfully separated the diffusivity contributions from particle size and number of tethers. The obtained diffusion-size relations for synthetic and extracellular lipid vesicles are not well-described by the conventional no-slip boundary condition, suggesting partial slip as well as a significant diffusivity dependence on the distance to the lipid bilayer. These insights, extending the understanding of diffusion of biological nanoparticles at lipid bilayers, are of relevance for processes such as cellular uptake of viruses and lipid nanoparticles or labeling of cell-membrane-residing molecules.

Chronic Treatment with Melatonin Improves Hippocampal Neurogenesis in the Aged Brain and Under Neurodegeneration.

Adult hippocampal neurogenesis is altered during aging and under different neuropsychiatric and neurodegenerative diseases. Melatonin shows neurogenic and neuroprotective properties during aging and neuropathological conditions. In this study, we evaluated the effects of chronic treatment with melatonin on different markers of neurodegeneration and hippocampal neurogenesis using immunohistochemistry in the aged and neurodegenerative brains of SAMP8 mice, which is an animal model of accelerated senescence that mimics aging-related Alzheimer's pathology. Neurodegenerative processes observed in the brains of aged SAMP8 mice at 10 months of age include the presence of damaged neurons, disorganization in the layers of the brain cortex, alterations in neural processes and the length of neuronal prolongations and ß-amyloid accumulation in the cortex and hippocampus. This neurodegeneration may be associated with neurogenic responses in the hippocampal dentate gyrus of these mice, since we observed a neurogenic niche of neural stem and progenitor/precursors cells in the hippocampus of SAMP8 mice. However, hippocampal neurogenesis seems to be compromised due to alterations in the cell survival, migration and/or neuronal maturation of neural precursor cells due to the neurodegeneration levels in these mice. Chronic treatment with melatonin for 9 months decreased these neurodegenerative processes and the neurodegeneration-induced neurogenic response. Noticeably, melatonin also induced recovery in the functionality of adult hippocampal neurogenesis in aged SAMP8 mice.