3,321 research outputs found

    Positive Influence Of A Dental Anaesthesia Simulation Model On The Perception Of Learning By Mexican Dental Students

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    Introduction: This study evaluated the influence of 3-repetition training with a dental anesthesia simulation model (DASM) on the perception of learning by dental students. Materials and methods: Dental students who had never used a dental anesthesia technique were randomly divided into 2 groups that were taught the anterior superior alveolar nerve infiltrative anesthesia technique. Group 1 (G1, N=10) followed a 3-stage learning method: 1st) theoretical lecture, 2nd) clinical demonstration, and 3rd) DASM training, including 3 repetitions of the anesthesia technique. Group 2 (G2, N=10) followed only the 1st and 2nd stages. The students in both groups then performed the anesthesia technique. The perception of the students was evaluated by 4 learning concepts. Each was evaluated with a 5-point Likert Scale questionnaire. The average score of each item of the questionnaire for G1 was compared with that of G2. Statistically significant differences were identified with the Mann-Whitney test. The average working time of each group was timed and compared by Student’s t-test to identify possible statistically significant differences. Results: Students in G1 showed higher average scores of perception in controlling the handling of the dental syringe and confidence in performing the injection (p\u3c0.05), and showed an average working time shorter than that of the students in G2 (p\u3c0.05). Conclusion: The DASM positively influenced the perception learning of the dental students; it increased their confidence and syringe handling ability, as well as skills to perform the injection of anesthesia more quickly

    Physiological Responses of Species to Microclimate Help explain Population Dynamics along Succession in a Tropical Dry Forest of Yucatan, Mexico

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    We investigated relationships between population dynamics and microclimate, physiology, and the degree of mycorrhizal colonization, for three species (Piscidia piscipula L.(Sarg.)) (Fabaceae), Bunchosia swartzianaGriseb. (Malpighiaceae) and Psidium sartorianum (Bergius) Nied. (Myrtaceae)) of a tropical sub deciduous forest in Yucatan, Mexico that were growing in plots of different successional ages. We hypothesized that abundance and persistence were related to increased plasticity in CO2assimilation. We found that Piscidia piscipula had greater abundance in intermediate plots (18 to 21 years), presented higher levels of plasticity in CO2 assimilation (greater variability among individuals, plots, and seasons), presented the highest CO2 assimilation rates, and presented greater drought resistance (higher water potentials and capacitance). Conversely, Psidium sartorianum had greater abundance in older plots (more than 50 years of secondary succession), lower assimilation rates, and low levels of plasticity in CO2 assimilation. Bunchosia had intermediate values. Locally, the degree of mycorrhizal colonization was consistent with abundance across plots. Regionally (but not locally), plasticity in CO2 assimilation was consistent with abundance. We found differences in microclimates among plots and within plots among species. Physiological adjustments appeared to play an important role in the capacity to regenerate and in the successional persistence of these species in this tropical dry forest

    Transcriptome analyses throughout chili pepper fruit development reveal novel insights into the domestication process

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    Chili pepper (Capsicum spp.) is an important crop, as well as a model for fruit development studies and domestication. Here, we performed a time-course experiment to estimate standardized gene expression profiles with respect to fruit development for six domesticated and four wild chili pepper ancestors. We sampled the transcriptomes every 10 days from flowering to fruit maturity, and found that the mean standardized expression profiles for domesticated and wild accessions significantly differed. The mean standardized expression was higher and peaked earlier for domesticated vs. wild genotypes, particularly for genes involved in the cell cycle that ultimately control fruit size. We postulate that these gene expression changes are driven by selection pressures during domestication and show a robust network of cell cycle genes with a time shift in expression, which explains some of the differences between domesticated and wild phenotypes

    Desenvolvimento de um instrumento para medir a cibervitimização em adolescentes

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    There is sufficient evidence on the existence of traditional bullying and its effects, but the increasing use of technologies as a way of coexistence among students has given rise to the need to study a new form of harassment: cybervictimization. The objective of this study was to determine the psychometric properties of a scale to measure cybervictimization reports in high school students. A non-probabilistic sample of 286 high school students who reported having been victims of cybervictimization was selected. The exploratory and confirmatory factorial analysis evidenced the empirical sustainability of a measurement model by means of three factors: harassment, invasion of privacy and denigration. In addition, the test showed evidence of concurrent validity by correlating the results with the reports of traditional victimization. It is concluded that, although it must be improved, the scale constitutes an instrument to measure the construct.Existe suficiente evidencia sobre la existencia del bullying tradicional y sus efectos, pero el uso cada vez mayor de las tecnologías como forma de convivencia entre los estudiantes, ha dado lugar a la necesidad de estudiar una nueva forma de hostigamiento: la cibervictimización. El objetivo de este estudio fue determinar las propiedades psicométricas de una escala para medir reportes de cibervictimización en estudiantes de educación media superior. Se seleccionó una muestra no probabilística de 286 estudiantes de bachillerato que reportaron haber sido víctimas de cibervictimización. El análisis factorial exploratorio y confirmatorio evidenciaron la sustentabilidad empírica de un modelo de medición mediante tres factores: acoso, invasión a la privacidad y denigración. Además, la prueba mostró evidencias de validez concurrente al correlacionarse los resultados con los reportes de victimización tradicional. Se concluye que, aunque debe ser mejorada, la escala constituye un instrumento para medir el constructo.Há provas suficientes da existência de bullying tradicional e os seus efeitos, mas o uso crescente de tecnologias como uma forma de convivência entre os alunos, levou à necessidade de estudar uma nova forma de assédio: cybervictimization. O objetivo deste estudo foi determinar as propriedades psicométricas de uma escala para medir os relatórios de cibervitimização em estudantes do ensino médio. Foi selecionada uma amostra não probabilística de 286 estudantes do ensino médio que relataram ter sido vítimas de cibervitimização. A análise fatorial exploratória e confirmatória evidenciou a sustentabilidade empírica de um modelo de mensuração por meio de três fatores: assédio, invasão de privacidade e denigração. Além disso, o teste mostrou evidências de validade concorrente, correlacionando os resultados com os relatos de vitimização tradicional. Conclui-se que, embora deva ser melhorada, a escala constitui um instrumento para medir o construto

    Comparación de la percepción social en playas recreativas arenosas de dos bahías localizadas en el Pacífico Mexicano

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    En el presente trabajo se desarrollaron dos formatos de encuesta, para incorporar la percepción de los usuarios a la evaluación de la calidad de las playas (Cervantes, 2006 y Silva-Iñiguez, 2006); ambos basados en un modelo cuantitativo para revelar la percepción social de las playas localizadas en la bahía de Santiago, Manzanillo, Col (MZO) y en Acapulco, Gro (ACA). Se aplicaron un total de 790 encuestas (ACA: 390 y MZO: 400), que permitieron conocer el perfil de los usuarios, sus hábitos de recreación y sus opiniones sobre las condiciones biofísicas y de infraestructura de cada playa. En ambas playas la mayoría prefirieron asistir acompañados por sus familias; las principales actividades recreativas fueron nadar, descansar, comer y beber. En general las demandas en ambos sitios coincidieron con incrementar el número de botes de basura, la frecuencia en el servicio de recolección y limpieza, baños y regaderas. Las razones por la que los usuarios seleccionaron la playa a visitar fueron la seguridad y vigilancia, así como las características biofísicas de la misma. La incorporación de esta información a modelos y/o esquemas de evaluación y gestión de playa (a través de índices ambientales) permitió realizar la valoración integral de la playa.In this paper it was developed two survey formats, to include the perception of users on the assessment of the quality of the beaches (Cervantes, 2006 and Silva-Iñiguez, 2006), both based on a quantitative model to reveal the social perception of the beaches on Santiago Bay, Manzanillo, Col (MZO) and Acapulco, Guerrero (ACA). We did a total of 790 surveys (ACA: 390 and MZO: 400), which allowed the user profile, recreation habits and their views on the biophysical and infrastructure of each beach. In both beaches, most people, attended with their families, the main recreational activities were swimming, resting, eating and drinking. In general the demands on both sites agreed to increase the number of waste baskets, the frequency of collection service and cleaning bathrooms and showers. The reasons why the users selected to visit the beach were the safety and security, as well as the biophysical characteristics of the same. Incorporating this information to models and / or evaluation schemes and beach management (through environmental ratings) allowed the comprehensive assessment of the beach

    Descriptive analysis of histological types in women undergoing post mastectomy breast reconstruction

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    Background: Breast cancer is a pathological entity that widely compromises the life and quality of life of affected women; in addition to the great affectation to the current health services. Therefore, maintaining an accurate and complete cancer registry program is one of the most important factors in implementing national cancer control programs and evaluating the results of screening, diagnosis, and treatment. Among the current limitations in the studies, there is a gap in the study of the population undergoing breast reconstruction. Methods: A retrospective study was carried out at hospital general de México “Dr. Eduardo Licéaga” with the information from the clinical records of the period 2019-2020. Patients undergoing breast reconstruction after mastectomy with histological report were included. Through non-probabilistic sampling, a population of 138 women was formed. For data analysis, frequencies and percentages were calculated for the qualitative variables; while for the quantitative variables, mean and standard deviation were calculated. Results: 138 women who underwent breast reconstruction were included, the mean age was 49.9±10.85 years, the mean BMI was 26.80±4.62 kg/m2, the secondary educational level predominated (34.8%), radiotherapy was applied to 34.1%, reconstruction was late in 75.4%, the most frequent reconstruction technique was TRAM flap (44.2%), the histological type of invasive ductal carcinoma predominated (68.1%). Conclusions: In women undergoing post-mastectomy breast reconstruction, the histological type of invasive ductal carcinoma predominates.

    Synthesis of Nylon 6/Modified Carbon Black Nanocomposites for Application in Uric Acid Adsorption

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    High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the absorption of toxins and hemocompatibility. MBC and nanocomposites showed excellent uric acid removal (78–82%) and hemocompatibility (1.6–1.8%). These results suggest that Nylon 6/MCB nanocomposites with low loading percentages can be used on a large scale without compatibility problems with blood

    Urethro-cutaneous fistula: a rare complication in anti-incontinence surgery with trans-obturator tapes sling

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    This case report presents a rare complication of tension-free mid-urethral tape surgery by the obturator approach (TOT) in the form of a urethro-cutaneous fistula. The patient underwent successful surgical repair, highlighting the importance of intraoperative cystoscopy to minimize surgical risks and complications. Tension-free mid-urethral tape surgery is a commonly performed procedure for the treatment of stress urinary incontinence (SUI). However, complications can occur, albeit rarely. In this case, a 52-year-old female patient developed a urethro-cutaneous fistula following TOT surgery. The fistula was identified by the presence of urine leakage at the right inguinal level, leading to significant distress and discomfort for the patient. Prompt diagnosis and appropriate management are crucial in such cases. The patient underwent surgical repair, which involved excision of the fistulous tract. The procedure was successful, resulting in complete resolution of the fistula and restoration of normal urinary function. In conclusion, this case report highlights the occurrence of a rare complication, namely a urethro-cutaneous fistula, following TOT surgery. The successful surgical repair emphasizes the importance of prompt diagnosis and appropriate management. Furthermore, the authors propose that an intraoperative cystoscopic evaluation be considered, even after a TOT procedure. Especially in cases that present risk factors or in hospital-school institutions. By implementing this practice, surgeons can enhance patient safety and improve surgical outcomes in anti-incontinence procedures
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