Resumo: A participação efetiva dos estudantes de medicina tem contribuído muito para o próspero desenvolvimento da pesquisa clínica nas escolas médicas da China nos últimos anos. No entanto, com o aumento do número e tipos de projetos de pesquisa clínica dos quais os estudantes de medicina participam, questões relacionadas à ética e à alfabetização são gradualmente expostas. Este artigo lista as questões éticas que surgiram na participação de estudantes de medicina em pesquisas clínicas nos últimos anos, analisa as causas subjacentes e propõe soluções para as questões éticas acima mencionadas, com o objetivo de fornecer referência para o ensino de ética médica e gestão de projetos de pesquisa para escolas médicas.

Resumen: La participación efectiva de los estudiantes de medicina ha contribuido en gran medida al desarrollo exitoso de la investigación clínica en las escuelas de medicina de China en los últimos años. Sin embargo, con el creciente número y tipos de proyectos de investigación clínica en los que participan estudiantes de medicina, las cuestiones éticas se exponen gradualmente. Este trabajo enumera las cuestiones éticas que han surgido en la participación de los estudiantes de medicina en la investigación clínica en los últimos años, analiza las causas subyacentes y propone soluciones a las cuestiones éticas mencionadas anteriormente, con el objetivo de proporcionar referencia para la enseñanza de la ética médica y la gestión de proyectos de investigación para las escuelas de medicina.

Abstract: In recent years, the vigorous development of clinical researches carried out by medical schools is inseparable from the effective participation of medical students. However, as the number and categories of clinical research projects that medical students participate in increase, medical ethics related issues gradually occur. This article sorts out the ethical issues that arose in clinical researches, in which medical students participated, analyzes the underlying causes, and proposes solutions for the above-mentioned ethical issues, aiming to provide reference for medical ethics education and research project management for medical schools.

RESUMO Introdução: O confronto físico nos jogos de futebol apresenta maiores exigências quanto à aptidão física dos atletas. A velocidade, força, flexibilidade, coordenação, resistência e explosividade de um jogador de futebol podem afetar a capacidade de combate corporal. Objetivo: Este estudo visa analisar a relação entre o treinamento de força no core abdominal dos jogadores de futebol e sua aptidão física. Métodos: O efeito do treinamento de força da estabilidade do core abdominal sobre a melhoria do desempenho nos jogadores de futebol voluntários selecionados como objetos de pesquisa foi verificado por divisão aleatória em dois grupos (grupos experimentais e grupos de controle). Ambos os grupos realizavam treinamentos diários. O grupo experimental acrescentou treinamento especial de core abdominal. Foram utilizados algoritmos matemáticos-estatísticos para analisar os indicadores físicos dos dois grupos de voluntários de forma estatística. Resultados: Os índices de aptidão física e explosividade corporal dos dois grupos de atletas foram significativamente melhorados (P<0,05). Após o treinamento sistemático, o desempenho de competição do grupo experimental e os indicadores fisiológicos e bioquímicos foram melhores que os do grupo de controle (P<0,05). Conclusão: Após o treinamento do core abdominal, a aptidão física dos jogadores de futebol e os índices de potência explosiva foram melhorados. Pesquisas mostram que o treinamento da força pode ajudar a melhorar o desempenho do core abdominal nos jogadores de futebol. Recomenda-se aos treinadores a implementação do treino de força no core abdominal ao treinamento diário dos atletas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

ABSTRACT Introduction: Physical confrontation in soccer games presents greater demands on athletes’ physical fitness. A soccer player’s speed, strength, flexibility, coordination, endurance, and explosiveness can affect the body’s fighting capacity. Objective: This study analyzes the relationship between strength training in soccer players’ abdominal core and physical fitness. Methods: The effect of abdominal core stability strength training on performance improvement in volunteer soccer players selected as research subjects was verified by random division into two groups (experimental and control groups). Both groups performed daily training. The experimental group added special abdominal core training. Mathematical-statistical algorithms were used to statistically analyze the physical indicators of the two groups of volunteers. Results: The indices of physical fitness and body explosiveness of the two groups of athletes were significantly improved (P<0.05). After systematic training, the competition performance of the experimental group and the physiological and biochemical indicators were better than the control group (P<0.05). Conclusion: After abdominal core training, soccer players’ physical fitness and explosive power indexes were improved. Research shows that strength training can help improve abdominal core performance in soccer players. It is recommended that coaches implement abdominal core strength training in the daily training of athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMEN Introducción: El enfrentamiento físico en los partidos de fútbol presenta mayores exigencias a la aptitud física de los atletas. La velocidad, la fuerza, la flexibilidad, la coordinación, la resistencia y la explosividad de un jugador de fútbol pueden afectar a la capacidad de combate del cuerpo. Objetivo: Este estudio tiene como objetivo analizar la relación entre el entrenamiento de la fuerza en el core de los jugadores de fútbol y su condición física. Métodos: El efecto del entrenamiento de la fuerza de la estabilidad del core abdominal sobre la mejora del rendimiento en jugadores de fútbol voluntarios seleccionados como sujetos de la investigación se verificó mediante la división aleatoria en dos grupos (grupo experimental y grupo de control). Ambos grupos realizaron un entrenamiento diario. El grupo experimental añadió un entrenamiento especial del core abdominal. Se utilizaron algoritmos matemático-estadísticos para analizar de forma estadística los indicadores físicos de los dos grupos de voluntarios. Resultados: Los índices de aptitud física y explosividad corporal de los dos grupos de atletas mejoraron significativamente (P<0,05). Tras el entrenamiento sistemático, el rendimiento en competición del grupo experimental y los indicadores fisiológicos y bioquímicos fueron mejores que los del grupo de control (P<0,05). Conclusión: Tras el entrenamiento del core abdominal, mejoraron la condición física y los índices de potencia explosiva de los futbolistas. Las investigaciones demuestran que el entrenamiento de fuerza puede ayudar a mejorar el rendimiento del core abdominal en los jugadores de fútbol. Se recomienda que los entrenadores implementen el entrenamiento de fuerza en el core abdominal al entrenamiento diario de los atletas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

RESUMO Introdução O treinamento em suspensão desenvolve a aptidão física de um nadador e aprimora suas habilidades. A aptidão física específica de um nadador é a capacidade corporal de adaptação à carga na natação. Isto é também um reflexo abrangente de sua função física, condicionamento, habilidade atlética e saúde geral. Objetivo Este estudo teve como objetivo analisar o efeito do treinamento em suspensão no equilíbrio da força do centro abdominal e no desempenho atlético dos nadadores. Métodos Este artigo seleciona vários nadadores como voluntários de pesquisa. Eles foram divididos aleatoriamente em grupo experimental e grupo de controle. Ambos foram submetidos a treinamento físico durante três meses. O grupo experimental adotou o método de treinamento em suspensão. O grupo de controle utilizou métodos de treinamento tradicionais. A análise dos dados nos dois grupos foi executada por estatísticas matemáticas. Resultados A aptidão física dos dois grupos de nadadores foi aprimorada substancialmente após o experimento (P<0,05). A capacidade de equilíbrio de força do grupo experimental demonstrou um melhor desempenho(P<0,05). Houve uma diferença significativa entre os grupos experimental e de controle nos resultados dos testes de índice de aptidão física (P<0,01). Conclusão O treinamento de suspensão tem um efeito destacado sobre o desenvolvimento físico dos nadadores. Esta modalidade comprovou uma melhor eficácia sobre o desempenho dos nadadores.Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

ABSTRACT Introduction Suspension training develops the physical fitness of a swimmer and improves his or her abilities. The specific fitness of a swimmer is the body's ability to adapt to load in swimming. This is also a comprehensive reflection of their physical function, conditioning, athletic ability, and overall health. Objective This study aimed to analyze the effect of suspension training on swimmers’ balance, abdominal center strength, and athletic performance. Methods This paper selects several swimmers as research volunteers. They were randomly divided into experimental and control groups. Both of them underwent physical training for three months. The experimental group adopted the suspension training method. The control group used traditional training methods. Mathematical statistics performed data analysis in both groups. Results The physical fitness of the two groups of swimmers was improved substantially after the experiment (P<0.05). The strength balance ability of the experimental group showed better performance(P<0.05). There was a significant difference between the experimental and control groups in the results of fitness index tests (P<0.01). Conclusion Suspension training has a prominent effect on the physical development of swimmers. This modality proved a better efficacy on swimmers’ performance. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMEN Introducción El entrenamiento en suspensión desarrolla la aptitud física de un nadador y mejora sus habilidades. La condición física específica de un nadador es la capacidad del cuerpo para adaptarse a la carga en la natación. También es un reflejo exhaustivo de su función física, su acondicionamiento, su capacidad atlética y su salud en general. Objetivo Este estudio tiene como objetivo analizar el efecto del entrenamiento en suspensión sobre el equilibrio de la fuerza del centro abdominal y el rendimiento deportivo de los nadadores. Métodos Este trabajo selecciona a varios nadadores como voluntarios para la investigación. Se dividieron aleatoriamente en grupo experimental y grupo de control. Ambos fueron sometidos a un entrenamiento físico durante tres meses. El grupo experimental adoptó el método de entrenamiento en suspensión. El grupo de control utilizó métodos de entrenamiento tradicionales. El análisis de los datos en ambos grupos se realizó mediante estadística matemática. Resultados La aptitud física de los dos grupos de nadadores mejoró sustancialmente después del experimento (P<0,05). La capacidad de equilibrio de la fuerza del grupo experimental mostró un mejor rendimiento (P<0,05). Hubo una diferencia significativa entre los grupos experimental y de control en los resultados de las pruebas del índice de aptitud física (P<0,01). Conclusión El entrenamiento en suspensión tiene un efecto destacado en el desarrollo físico de los nadadores. Esta modalidad demostró una mayor eficacia en el rendimiento de los nadadores. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Abstract Objective: Necrotizing enterocolitis (NEC) is characterized by a rich infiltration of macrophages in the intestines, which is derived from monocytes in the blood. The authors aimed to explore the changing trend of absolute monocyte counts (AMC) over time in NEC infants and to verify whether the reduction of AMC correlates with the severity of NEC and whether it can be used to identify infants who need surgery. Method: The authors collected the clinical data of 66 control and 222 NEC infants. The NEC infants were divided into medical NEC (M-NEC) and surgical NEC (S-NEC). The counting of mono-cyte and their percentage change were compared at the time of birth, before NEC (baseline), the onset of NEC and after NEC (recovery). In addition, the same comparison was made among stages 1, 2 and 3 of Bell’s staging, respectively. Results: The authors found that the AMC in NEC infants decreased sharply at the onset. Further comparison was made between 172 cases of M-NEC and 50 cases of S-NEC. It was discovered that the AMC reduced more in S-NEC infants at onset, but it increased more at recovery. In addition, the authors found that among stage 1,2 and 3, stage 3 had the lowest AMC and the largest percentage decrease at the onset. Conclusion: The AMC decreases sharply in NEC infants at onset, and the degree of decline is associated with the severity of NEC. AMC is expected to be a marker of NEC and provide a reference for clinicians in the diagnosis and treatment of NEC.

Abstract Lactic acid bacteria (LAB) can produce extracellular polysaccharides that can be used as thickeners, emulsifiers, and gels in foods. The immobilization technology can effectively simplify and improve the separation and regeneration of extracellular polysaccharides. In this study, six strains of LAB, including the extracellular polysaccharide-producing strain Lactobacillus plantarum, were screened. The different immobilized carriers of sodium alginate, agar, gelatin-glutaraldehyde, and carrageenan were assessed for fermentation by these six LAB. Different diameters of beads were selected, and the optimum culture temperature, carrier concentration, and inoculum volume were evaluated. The results showed that the agar-embedding method was the best immobilization method and the optimum process conditions were as follows: 3% inoculum of L. plantarum, 30 g/L of agar as immobilization carrier with a particle diameter of 1 cm, and fermentation at 37 °C for 24 h. Through orthogonal experiments, the maximum exopolysaccharide (EPS) yield obtained was 1489.9 mg/L.

Abstratc This work reports the production of low-tin Cu-Sn alloy coatings on carbon steel substrates using a bath containing CuCl2, SnCl2, and sodium citrate. In the first part of this study, the coatings were electrodeposited by direct and simple pulse current processes (DC and SPC, respectively). Different current density values were used, while the pulse frequency and duty cycle remained constant. Independent of the current mode used, low-tin Cu-Sn coatings, showing globular surface morphology and Cu6Sn5 as the main compositional phase, were produced. Both the current mode and the applied current density affected the anticorrosive properties of the coatings. The most protective DC and SPC coatings, showing Sn content < 3 wt.% and compact morphology, were prepared using j = 80 A m-2 and jc = 167 A m-2, respectively. High charge transfer resistance values were verified even after immersion for 24 h in 0.5 mol L-1 NaCl solution.

This study aimed to examine and summarize clinical characteristics of Kawasaki disease (KD) at different ages to further strengthen clinicians understanding of children with KD, improving the level of diagnosis, and reducing coronary artery complications of KD. A total of 398 patients with KD who were diagnosed between January 2016 and December 2017 were reviewed retrospectively. These participants were allocated into three groups according to age: group A (<1 year, n=62), group B (≥1 and <5 years, n=286), and group C (≥5 years, n=50). Clinical manifestations, laboratory results, and echocardiographic findings were compared among the groups. Most (71.86%) patients with KD were aged 1-5 years. The prevalence of cervical lymphadenopathy was lowest in group A. The duration of fever before admission was longest in group A. The rate of cervical lymphadenopathy and laboratory data were different among the groups. Group A had higher frequencies of gastrointestinal involvement, neurological symptoms, and redness at the Bacillus Calmette-Guerin inoculation site than the other groups. Infants aged <1 year with KD often have a longer duration of fever before admission, a lower prevalence of cervical lymphadenopathy, and a higher prevalence of gastrointestinal and neurological symptoms.

OBJECTIVES: Hypoxia leads to endothelial cell inflammation, apoptosis, and damage, which plays an important role in the complications associated with ischemic cardiovascular disease. As an oxidoreductase, p66Shc plays an important role in the regulation of reactive oxygen species (ROS) production and apoptosis. Ketamine is widely used in clinics. This study was designed to assess the potential protective effect of ketamine against hypoxia-induced injury in human umbilical vein endothelial cells (HUVECs). Moreover, we explored the potential mechanism by which ketamine protected against hypoxia-induced endothelial injury. METHODS: The protective effects of ketamine against hypoxia-induced injury was assessed using cell viability and adhesion assays, quantitative polymerase chain reaction, and western blotting. RESULTS: Our data showed that hypoxia reduced HUVEC viability, increased the adhesion between HUVECs and monocytes, and upregulated the expression of endothelial adhesion molecules at the protein and mRNA levels. Moreover, hypoxia increased ROS accumulation and upregulated p66Shc expression. Furthermore, hypoxia downregulated sirt1 expression in HUVECs. Alternatively, ketamine was shown to reverse the hypoxia-mediated reduction of cell viability and increase in the adhesion between HUVECs and monocytes, ameliorate hypoxia-induced ROS accumulation, and suppress p66Shc expression. Moreover, EX527, a sirt1 inhibitor, reversed the protective effects of ketamine against the hypoxia-mediated reduction of cell viability and increase in adhesion between HUVECs and monocytes. CONCLUSION: Ketamine reduces hypoxia-induced p66Shc expression and attenuates ROS accumulation via upregulating sirt1 in HUVECs, thus attenuating hypoxia-induced endothelial cell inflammation and apoptosis.

This paper discusses a new method for identification and simulation of the hydrocarbon expulsion history of Effective Source Rocks (ESR) in the Dongying Formation (Ed), Bohai sea area, Bohai Bay basin, eastern China. This new method enables us to reliably identify the distribution and quantitatively determine the hydrocarbon expulsion history of ESR in petroliferous basins. ESR are the material basis for hydrocarbon accumulation, having important implications for oil and gas exploration prospects. The Bohai Bay basin is one of the most petroliferous basins in China, with nearly one third of the total oil production of the country. However, insufficient research on the ESR in the Dongying Formation (Ed), Bohai sea area, Bohai Bay basin obstructs further exploration. In this paper, ESR of Ed are identified with the new "two-stage and three-step" method, and their planar distribution is predicted by combining well data with sedimentary facies, and structure distribution. On that basis, the hydrocarbon expulsion history of ESR in the 2nd Member (E3d2) and 3rd Member (E3d3) of Ed was systematically simulated by using the hydrocarbon generation potential method. The results show that the ESR of E3d2 are distributed in four sags of Bohai Sea area, while the ESR of E3d3 occur in seven sags. Hydrocarbon expulsion from the ESR of E3d2 began during the deposition period of the Minghuazhen Formation Nm) (12 Ma) with a hydrocarbon expulsion quantity of 42 x10(8) t. The hydrocarbon expulsion centers were located in the Bozhong, Huanghekou, Qikou and Bodong sags. Hydrocarbon expulsion from the ESR of E3d3 began around 16.6 Ma ago (hydrocarbon expulsion quantity of 84x10(8) t), and the hydrocarbon expulsion centers were located in the Bozhong, Qinnan, Huanghekou, Liaozhong, Nanpu and Qikou sags. In conclusion, the hydrocarbon expulsion centers of the ESR of E3d are mainly located in Bozhong, Huanghekou, Qikou and Bodong sags, with late-stage hydrocarbon expulsion (16.6-2 Ma), which is advantageous to hydrocarbon accumulation and preservation. The uplifts and slope belts around the hydrocarbon expulsion centers would be favorable exploration targets.

En este artículo se discute un nuevo método para la identificación y simulación de la historia de expulsión de hidrocarburos de la Roca Madre Efectiva (RME) en la Formación Dongying (E3d), área del Mar de Bohai, cuenca de la Bahía de Bohai, este de China. Este nuevo método permite identificar de manera confiable la distribución y determinar cuantitativamente la historia de expulsión de hidrocarburos de las RME en cuencas petrolíferas. Las RME son la base material para la acumulación de hidrocarburos y tienen implicaciones importantes para prospectos de exploración de petróleo y gas. La cuenca de la Bahía de Bohai es una de las más ricas en petróleo de China, con cerca de un tercio de la producción total de petróleo en el país. Sin embargo, la investigación de las RME de la Formación Dongying (E3d) en la cuenca de la Bahía de Bohai es aún insuficiente, lo que ha obstruido el avance de la exploración. En este trabajo, se indentifican las RME de E3d con el nuevo método de "dos etapas y tres pasos", y su distribución planar se predice por medio de la combinación de datos de pozos con facies sedimentarias y distribución de estructuras. Con base en lo anterior se simuló sistemáticamente la historia de expulsión de hidrocarburos de las RME en el 2°Miembro (E3d2) y el 3er Miembro (E3d3) de E3dpor medio de la aplicación del método de potencial de generación de hidrocarburos. Los resultados muestran que las RME de E3d2 están distribuidas en cuatro depresiones ("sags") del área del Mar de Bohai, mientras que las RME de E3d3 se presentan en siete depresiones. La expulsión de hidrocarburos de las RME de E3d2 inició en el periodo de depósito de la Formación Minghuazhen (N1m) (12 Ma) con la expulsión de 42x 10(8) t. Los centros de expulsión se localizan en las depresiones de Bozhong, Huanghekou, Qikou y Bodong. La expulsión de hidrocarburos de las RME de E3d3 inició a ~16.6 Ma con la expulsión de 84x10(8) t, y los centros de expulsión se localizaron en las depresiones Bozhong, Qinnan, Huanghekou, Liaozhong, Nanpu y Qikou. En conclusión, los centros de expulsión de hidrocarburos de las RME de E3d se localizan principalmente en las depresiones Bozhong, Huanghekou, Qikou y Bodong, con expulsión de hidrocarburos tardía (16.6-2 Ma), lo cual es ventajoso para la acumulación y preservación de hidrocarburos. Los levantamientos ("uplifts") y cinturones de talud que rodean a los centros de expulsión de hidrocarburos serían blancos de exploración favorables.