ABSTRACT: Pork price fluctuations are closely related to the national economy and people’s livelihoods in China. Based on the monthly pork price fluctuations in China from January 2011 to August 2022, this study uses ARCH family models to assess the characteristics and laws of these fluctuations in China. The pork price fluctuations show obvious clustering, with external shock information from the previous month affecting the pork price in the following period; the pork market price is characterized by risk compensation, with the high risk of pork supply driving the pork price up. In addition, the pork price fluctuations are characterized by asymmetry, with a greater impact of good than of bad news on the pork price. Due to the pork industry’ low entry threshold and the existence of sunk costs, positive information on the pork market has a stronger impact on price fluctuations than negative information. To guide pork supply, we recommend improving monitoring and early-warning mechanisms in the pork market to identify the pork price volatility threshold and measure the price volatility. In addition, price index insurance products should be constantly strengthened, with different types of insurance products being offered to meeting the insurance demand of various sectors in the pig meat supply chain.

RESUMO: As flutuações do preço da carne suína estão intimamente relacionadas à economia nacional e à subsistência das pessoas. Com base na flutuação mensal do preço da carne suína na China de a janeiro de 2011 a agosto de 2022, este estudo usa os modelos da família ARCH para avaliar as características e as leis das flutuações do preço da carne suína na China. Nossos estudos mostraram que as flutuações do preço da carne suína apresentam agrupamento óbvio, e as informações de choque externo do mês anterior irão interferir no preço da carne suína no período seguinte. O preço de mercado da carne suína tem as características de “risco de recompensa”, e o “alto risco” do preço da carne suína. Observa-se uma tendência de alta, mostrando que as oscilações do preço da carne suína são caracterizadas por assimetria. Devido ao baixo limiar de entrada da indústria de suínos e à existência de “sinking cost”, as informações positivas sobre o mercado de suínos têm um impacto mais forte nas flutuações de preços do que as informações negativas. Recomenda-se melhorar o monitoramento do mercado de carne suína e o mecanismo de alerta precoce, esclarecer e identificar o limite de volatilidade do preço da carne suína e melhorar o sistema de seguro financeiro da indústria suína.

RESUMO Introdução A taxa máxima de consumo de oxigênio (VO2max) pode refletir diretamente o metabolismo aeróbico corporal e o sistema de fornecimento de oxigênio. Esta é uma medida da capacidade aeróbica empregada para monitorar o nível do nadador, e seu desempenho em força e velocidade. Objetivo Verificar as alterações de VO2max ao incorporar o treinamento com exercícios aeróbicos no treino padrão dos nadadores. Métodos 12 nadadores voluntários foram divididos em duas categorias: grupo de treinamento de força e grupo de treinamento regular. Ambos os grupos realizaram um teste de aptidão física na pista de 200 metros antes de iniciar o treinamento. O VO2 máximo foi mensurado e trabalhado estatisticamente para verificar os resultados desta competição. Os efeitos do exercício aeróbico sobre a força e o status competitivo dos atletas foi investigado segundo uma revisão bibliográfica atualizada. Resultados Houve uma mudança significativa na ingestão máxima de oxigênio dos atletas após o protocolo experimental. Os atletas do grupo de treinamento de força aumentaram seu VO2 máximo quando comparados ao grupo de treinamento regular. Os resultados mostraram uma diferença significativa no índice VO2max antes e depois do treinamento de força (P<0,05). Isto sugere que o treinamento de força tem um efeito significativo no consumo máximo de oxigênio. Conclusão As intervenções de treinamento de força afetam significativamente a intensidade máxima de consumo de oxigênio e a capacidade de exercício dos atletas. A intervenção do exercício aeróbico demonstrou evidencias em melhorar o nível competitivo dos atletas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

ABSTRACT Introduction The maximal oxygen consumption rate (VO2max) can directly reflect the body's aerobic metabolism and oxygen delivery system. This is a measure of aerobic capacity used to monitor swimmers’ levels and their strength and speed performance. Objective Verify the changes in VO2max when incorporating aerobic exercise training into swimmers’ regular training. Methods 12 volunteer swimmers were divided into two categories: strength training group and regular training group. Both groups performed a fitness test on the 200-meter track before starting the training. VO2 maximal was measured and worked out statistically to verify the results of this competition. The effects of aerobic exercise on the strength and competitive status of the athletes were investigated according to an updated literature review. Results There was a significant change in the maximal oxygen uptake of the athletes after the experimental protocol. The athletes in the strength training group increased their VO2 max compared to the regular training group. The results showed a significant difference in the VO2max index before and after strength training (P<0.05). This suggests that strength training has a significant effect on maximal oxygen consumption. Conclusion Strength training interventions significantly affect athletes’ maximal oxygen consumption intensity and exercise capacity. The aerobic exercise intervention showed evidence of improving the competitive level of athletes. Level of evidence II; Therapeutic studies -investigation of treatment outcomes.

RESUMEN Introducción La tasa máxima de consumo de oxígeno (VO2máx) puede reflejar directamente el metabolismo aeróbico del cuerpo y el sistema de suministro de oxígeno. Se trata de una medida de la capacidad aeróbica que sirve para controlar el nivel del nadador y su rendimiento en fuerza y velocidad. Objetivo Verificar los cambios en el VO2máx al incorporar el entrenamiento de ejercicio aeróbico en el entrenamiento habitual de los nadadores. Métodos 12 nadadores voluntarios fueron divididos en dos categorías: grupo de entrenamiento de fuerza y grupo de entrenamiento regular. Ambos grupos realizaron una prueba de aptitud física en 200 metros de pista antes de comenzar el entrenamiento. Se midió el VO2 máximo y se trabajó estadísticamente para verificar los resultados de esta competición. Se investigaron los efectos del ejercicio aeróbico en la fuerza y el estado competitivo de los atletas según una revisión bibliográfica actualizada. Resultados Hubo un cambio significativo en el consumo máximo de oxígeno de los atletas después del protocolo experimental. Los atletas del grupo de entrenamiento de fuerza aumentaron su VO2 máximo en comparación con el grupo de entrenamiento regular. Los resultados mostraron una diferencia significativa en el índice VO2max antes y después del entrenamiento de fuerza (P<0,05). Esto sugiere que el entrenamiento de fuerza tiene un efecto significativo en el consumo máximo de oxígeno. Conclusión Las intervenciones de entrenamiento de fuerza afectan significativamente a la intensidad del consumo máximo de oxígeno y a la capacidad de ejercicio de los atletas. La intervención de ejercicio aeróbico mostró evidencia de mejorar el nivel competitivo de los atletas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

RESUMEN La contaminación por neblina, caracterizada principalmente por la baja visibilidad, es uno de los principales problemas ambientales a los que se enfrenta China en la actualidad. El pronóstico exacto de la neblina es útil para la aplicación de medidas preventivas orientadas a controlar emisiones de contaminantes atmosféricos y aliviar la contaminación por neblina. Sin embargo, no es fácil predecir con precisión los acontecimientos de baja visibilidad causados por neblina, lo cual requiere no sólo un pronóstico riguroso de los factores meteorológicos, sino también una actualización detallada y en tiempo real de los inventarios de emisiones de las fuentes. Con el fin de obtener una herramienta de predicción fiable, se estudian varios métodos populares de aprendizaje automático, como la máquina vectorial de apoyo (SVM, por su sigla en inglés), el k-vecino más próximo, el bosque aleatorio y varios métodos de aprendizaje profundo. A partir de los principales factores que influyen en la visibilidad, se analizan las relaciones entre velocidad y dirección del viento, temperatura, humedad y visibilidad. El método de aprendizaje automático se utiliza para entrenamiento y pronóstico. La precisión de estos métodos para pronosticar la visibilidad se verifica mediante varios parámetros (error de raíz cuadrada media, error absoluto medio y error porcentual absoluto medio). Los resultados muestran que: 1) entre todos los parámetros meteorológicos, la velocidad del viento puede reflejar mejor la variación de la visibilidad; 2) el rendimiento de las redes neuronales recurrentes de memoria a largo-corto plazo (LSTM RNN) y el método de unidades recurrentes cerradas (GRU) en la predicción de visibilidad a corto plazo (es decir, 1, 3 y 6 h) es casi igual; 3) el método clásico de aprendizaje automático (SVM) funciona bien para el pronóstico de visibilidad a medio y largo plazo, y 4) el método de aprendizaje automático también tiene cierto grado de precisión en el pronóstico, incluso en un periodo de tiempo más largo (p. ej., 72 h).

ABSTRACT Haze pollution, mainly characterized by low visibility, is one of the main environmental problems currently faced by China. Accurate haze forecasts facilitate the implementation of preventive measures to control the emission of air pollutants and thereby mitigate haze pollution. However, it is not easy to accurately predict low visibility events induced by haze, which requires not only accurate prediction for weather elements, but also refined and real-time updated source emission inventory. In order to obtain reliable forecasting tools, this paper studies the usability of several popular machine learning methods, such as support vector machine (SVM), k-nearest neighbor, and random forest, as well as several deep learning methods, on visibility forecasting. Starting from the main factors related to visibility, the relationships between wind speed, wind direction, temperature, humidity, and visibility are discussed. Training and forecasting were performed using the machine learning methods. The accuracy of these methods in visibility forecasting was confirmed through several parameters (i.e., root-mean-square error, mean absolute error, and mean absolute percentage error). The results show that: (1) among all meteorological parameters, wind speed was the best at reflecting the visibility change patterns; (2) long short-term memory recurrent neural networks (LSTM RNN), and gated recurrent unit (GRU) methods perform almost equally well on short-term visibility forecasts (i.e., 1, 3, and 6 h); (3) a classical machine learning method (i.e., the SVM) performs well in mid- and long-term visibility forecasts; (4) machine learning methods also have a certain degree of forecast accuracy even for long time periods (e.g., 7 2h).

ABSTRACT Introduction: Basketball is a combative sport, very popular among college students. However, it requires many periods of running, interspersed with emergency breaks, tackling, and other actions prone to ankle injuries. Objective: Investigate the causes of ankle joint injuries in college basketball, raising countermeasures to prevent these sports injuries. Methods: 413 college students who regularly participate in basketball games at 10 colleges and universities were selected as research objects. The causes of ankle joint injuries in the process of this sport were investigated through questionnaires, and the main causes of injuries were analyzed using statistical methods. Results: The causes of ankle joint injuries in college basketball include subjective and objective factors. Subjective factors include inadequate psychological preparation, warm-up exercise, cushioning, and excessive exercise, among others listed; objective factors mainly contemplate local injury and accidental injury. Conclusion: The participation of college students in basketball is beneficial to improve their physical health, requiring effective measures to prevent possible ankle injuries, both related to subjective and objective aspects. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMEN Introducción: El baloncesto es una modalidad deportiva combativa, muy popular entre los estudiantes universitarios. Sin embargo, requiere muchos periodos de carrera, intercalados con pausas de emergencia, enfrentamientos y otras acciones propensas a las lesiones de tobillo. Objetivo: Investigar las causas de las lesiones de la articulación del tobillo en el baloncesto universitario, planteando contramedidas para prevenir estas lesiones deportivas. Métodos: Se seleccionaron como objeto de investigación un total de 413 estudiantes universitarios que participaban regularmente en partidos de baloncesto en 10 colegios y universidades. Las causas de las lesiones de la articulación del tobillo en el proceso de este deporte se investigaron mediante cuestionarios, y las principales causas de las lesiones se analizaron mediante métodos estadísticos. Resultados: Las causas de las lesiones de la articulación del tobillo en el baloncesto universitario incluyen principalmente factores subjetivos y objetivos. Los factores subjetivos incluyen una preparación psicológica inadecuada, un ejercicio de calentamiento inadecuado, una amortiguación inadecuada, un ejercicio excesivo, entre otros enumerados; los factores objetivos contemplan principalmente la lesión local y la lesión accidental. Conclusión: La participación de los estudiantes universitarios en el baloncesto es beneficiosa para mejorar su salud física, requiriendo medidas eficaces para prevenir posibles lesiones de tobillo, tanto las relacionadas con aspectos subjetivos como objetivos. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

RESUMO Introdução: o basquetebol é uma modalidade esportiva combativa, muito popular entre os universitários. No entanto, necessita de muitos períodos de corrida, intercalados por pausas emergenciais, enfrentamentos e outras ações propensas a lesões no tornozelo. Objetivo: Investigar as causas de lesões nas articulações do tornozelo no basquetebol universitário, levantando contramedidas para prevenir essas lesões desportivas. Métodos: O total de 413 estudantes universitários que participam regularmente em jogos de basquetebol em 10 faculdades e universidades foram selecionados como objetos de pesquisa. As causas das lesões nas articulações do tornozelo no processo desse esporte foram investigadas através de questionários, sendo analisadas as principais causas das lesões através de métodos estatísticos. Resultados: as causas das lesões nas articulações do tornozelo dentro do basquetebol universitário incluem principalmente fatores subjetivos e objetivos. Os fatores subjetivos incluem a preparação psicológica inadequada, o exercício de aquecimento inadequado, o amortecimento inadequado, o exercício excessivo, entre outros listados; os fatores objetivos contemplam principalmente a lesão local e a lesão acidental. Conclusão: A participação dos estudantes universitários no basquetebol é benéfica para melhorar a sua saúde física, requerendo medidas eficazes para prevenir possíveis lesões no tornozelo, tanto as relacionadas aos aspectos subjetivos como objetivos. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

Astragaloside IV is a biologically active substance derived from the traditional Chinese medicine Astragalus mambranaceus Bunge, and has antioxidant, anti-inflammatory, and anti-apoptotic properties. In this study, we aimed to investigate the effects of astragaloside IV on Klebsiella pneumonia rats and the underlying mechanisms. Klebsiella pneumoniae (K. pneumoniae) rats were treated with different dosages of astragaloside IV (5, 10, and 20 mg/kg) by intragastric administration. The levels of pro-inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in bronchoalveolar lavage fluid (BALF) were determined. Pathological changes of lung tissue were inspected by HE staining. The expression of transforming growth factor (TGF)-β1 in lung tissue was determined with immunohistochemistry, and the expression levels of TGF-β1, p-Smad2/Smad2, p-Smad3/Smad3, IκBα/p-IκBα, and p65/p-p65 in lung tissue were determined by western blot. The mechanism was further investigated with TGF-β1 inhibitor SB-431542. Astragaloside IV reduced the elevated levels of pro-inflammatory cytokines caused by K. pneumoniae and improved lung tissue damage in a dose-dependent manner. Astragaloside IV also decreased the expression of TGF-β1/Smad signaling pathway-related proteins and decreased the protein levels of inflammation-related p-IκBα and p65 in lung tissues induced by K. pneumoniae. Additionally, it was found that the effects of 20 mg/kg astragaloside IV were similar to SB-431542, which could improve pulmonary fibrosis induced by K. pneumoniae, decrease the levels of TGF-β1/Smad signaling pathway-related proteins in lung, and reduce inflammation at the same time. Astragaloside IV could alleviate the inflammation of rat pneumonia induced by K. pneumoniae through suppressing the TGF-β1/Smad pathway.

ABSTRACT Purpose: Over-activation of nuclear factor kappa B (NF-κB) was proven to be involved in the pathogenesis of preeclampsia. However, its regulation mechanism is not clear yet. This paper explored the role of WD repeat domain 5 (WDR5) in the development of late-onset preeclampsia and its relationship with NF-κB. Methods: WDR5 expression was detected in normal placentas and placentas from late-onset preeclampsia patients. CCK-8 and colony formation assays were conducted to appraise the proliferative ability of trophoblast. Migration and invasion were observed by wound healing and transwell assays. The interaction between WDR5 and NF-κB inhibitor I-kappa-B-alpha (IkBa) was verified by Co-immunoprecipitation analysis. Immunofluorescence was used to analyze the activation of NF-κB. Finally, we tested the role of WDR5 using the mice late-onset preeclampsia model. Results: WDR5 was highly expressed in the placentas of late-onset preeclampsia patients. WDR5 overexpression suppressed cell proliferation, migration, and invasion in trophoblast. WDR5 could interact with IkBa to activate NF-κB. Knockdown of NF-κB counteracted the anti-proliferative and anti-metastatic effects of WDR5 overexpression in trophoblast. In-vivo studies suggested that targeting WDR5 combated late-onset preeclampsia development. Conclusions: Our finding provides new insights into the role of WDR5 in late-onset preeclampsia development.

Abstract Terpenoids are one of the secondary metabolites of plants and are the most widely distributed in nature with a diverse skeleton and significant biological activity, among which sesquiterpenoids are the most abundant. Sesquiterpenoids and triterpenoids are mainly synthesized by the mevalonate pathway, and the processes involve a variety of key enzymes and are regulated by transcription factors. They play important roles in plant growth and development, environmental adaptation, and resistance to pests and diseases. It is important to understand the gene functions of key enzymes to increase the production of sesquiterpenoids and triterpenoids to meet the market demand and to study the mevalonate biosynthesis pathway in depth. In this paper, the progress of gene cloning and transcription factor regulation of sesquiterpenes, triterpenoids and key enzymes of mevalonate synthesis pathway will be briefly reviewed. activity abundant factors development adaptation diseases depth paper sesquiterpenes reviewed

Abstract In herbal markets, an overwhelming majority the Dendrobium nobile are sold in dried strips form, and this product type would lead to the incomplete release of the active ingredient. To increase the bioaccessibility of Dendrobium nobile, we obtained powders of different particle sizes by shear-breaking and superfine-grinding to further compare its sensory properties, physical properties, the leaching rate of active ingredients and antioxidant activity in vitro. The results showed that the superfine-grinding changed the sensory properties and physical properties of Dendrobium nobile, with an increase in bulk density, a decrease in swelling capacity and water-holding capacity and an increase in water solubility index. The method also contributed to the release of total polysaccharides, dendrobine, total polyphenols and total flavonoids components, thereby increasing ABTS, DPPH and nitrite ion scavenging activity. In addition, scanning electron microscopy and infrared spectroscopy analyses showed that superfine-grinding had no effect on the primary structure of the fractions as with decreasing particle size. This study suggested that superfine-grinding could be a promising method for producing Dendrobium nobile powders with higher contents of bioactive compounds and bioactivity. markets form ingredient shearbreaking shear breaking superfinegrinding superfine grinding vitro density waterholding holding index polysaccharides dendrobine components ABTS addition size bioactivity

Abstract Background and objectives: Nerve block or neurolysis is an important approach in the treatment of spastic equinovarus foot. To illustrate the accurate location of the nerve branch to the tibialis posterior muscle (TP) in clinical practice, 21 adult cadavers were dissected and 14 complete both lower limb specimens were obtained. A total of 28 lower limbs were included. Methods: We measured the length of the motor branch nerve (LM) of the tibialis posterior muscle, the length of the fibula (LF), the vertical distance (D1) from the midpoint of LM to the fibula tip as well as the horizontal distance (D2) from the midpoint of LM to the inner edge of the fibula. Results: The LM was higher (35.74 ± 7.28 mm) in male than in female (30.40 ± 6.88 mm) specimens but there was no significant correlation between LM and gender (> 0.05). Additionally, among male specimens, the LM on the right side was longer than that on the left (p ≤ 0.05) while among female specimens, the D1 on the left side was longer than that on the right (p ≤ 0.05). The LF in male specimen was significantly longer than that in female (p ≤ 0.05). The midpoint of the nerve to the motor branch of the tibialis posterior muscle was about 50 mm distal to the fibular head and 10 mm at the inner edge of the fibula. Conclusion: Using this coordinate, the midpoint of the nerve branch to the TP could be accurately located.

Abstract Proanthocyanidins were extracted and purified from grape seeds, and the protective effect and mechanism of proanthocyanidins on spinal cord injury were explored. After extraction optimization and purification, the proanthocyanidins with purity of 92.53% were obtained. The rats were divided into control, model and treatment groups. The spinal cord injury model was established in model and treatment groups. Then, the treatment group was treated with 40 mg/kg proanthocyanidins. On the 1st, 3rd and 7th day after modeling, compared with model group, in model group the Basso-Beattie-Bresnahan scores were significantly decreased (p < 0.05). On the 7th day after modeling, compared with model group, in treatment group the spinal cord tissue superoxide dismutaseand glutathione peroxidase levels were significantly increased (p < 0.05), the malondialdehyde level was significantly decreased (p < 0.05), the necrosis factor α and interleukin 1βlevels were significantly decreased (p < 0.05), and the interleukin 10 level was significantly increased (p < 0.05). In conclusion, proanthocyanidins have protective effect on spinal cord injury in rats. The mechanisms may be related to its reducing oxidative stress and inflammation in spinal cord tissue.

Abstract In this study, we aimed to compare clinical efficacy of laparoscopic surgery and open surgery for colorectal cancer in the Huaihe River Basin in China. A total of 92 patients with colorectal cancer were selected as subjects. Patients were divided into control group (open surgery, n = 27 cases) and test group (laparoscopic surgery, n = 28 cases). Our results showed that the duration of operation (122.54 ± 14.85) min and length of incision (4.51 ± 1.065) cm were shorter in the experimental group than those in the control group. The intraoperative blood loss of the experimental group was (161.12 ± 10.694) ml, which was less than that of the control group (218.53 ± 15.369) ml (P < 0.05). Patients in the experimental group have higher Five-year survival rate and lower incidence of postoperative complications than those in the control group (all P < 0.05). In conclusion, in the treatment of colorectal cancer, laparoscopic surgery has a better clinical effect than open surgery, which is worthy of clinical application.

ABSTRACT Oil is a non-renewable resource, and it is essential to improve oil recovery. Surfactant flooding is a key technology in enhancing oil recovery. The present work aims to develop a new surfactant to the combination flooding system in oil displacement. The Aminosulfonic Acid Gemini Surfactant was prepared by using Hexadecylamine, 1-Butanaminium,N,N,N-tributyl-,bromide (1:1) and Sodium 2-chloroethyl sulfonate. The AminoSulfonic Acid Gemini Surfactant Sodium N,N’-Dihexadecyl-2-propanol- 1,3-ethylsulfonate SNNDPE) has better reaction temperature at 80℃. The best reaction time of SNNDPE is 12 h. Next, We made a characterization of SNNDPE. A new gemini surfactant was developed, which is beneficial to the research of material science. Then the performance of the new Gemini surfactant was tested. The surface tension tests suggested that the newly synthesized Aminosulfonic Acid Gemini Surfactant has higher surface activity. The resistance temperature of the Aminosulfonic Acid Gemini Surfactant solution is 80℃. Moreover, the oil-water interfacial tension experiment suggested that the minimum aqueous solution of the combination flooding system reaches an ultra-low level of 9.4 × 10−4 mN/m. The combination flooding system experiment results can be considered as a guidance in the design and studies of the combination flooding system for a selective.

Inconel 718 alloy which was prepared using selective laser melting (SLM) forming technology underwent various annealing treatments. Optical microscope, scanning electron microscope, electron backscattered diffraction and MTS testing machine were used to study the microstructure, mechanical and fatigue properties of Inconel 718 alloy melted by selective laser melting under different annealing treatments. The results show that the microstructure of Inconel 718 alloy after homogenization and doubleaging annealing is the most obvious, and the microstructure of the alloy is mainly recrystallized. The microstructure contains a large number of annealing twins and the grain boundaries are flat. The yield strength, tensile strength and microhardness of Inconel 718 alloy formed by selective laser melting after different annealing treatments are greatly increased, while the elongation after fracture is significantly decreased. The fatigue properties of Inconel 718 alloy after double aging annealing and solution dual aging annealing are improved slightly, while the fatigue properties after uniform double aging annealing are decreased slightly.

RESUMO Introdução: A dança esportiva é amplamente conhecida como um jogo competitivo, mas como atividade de lazer, existem poucas pesquisas sobre sua eficácia na saúde e forma física humana. A dança esportiva, como exercício físico popular em âmbito nacional, tem importantes efeitos na promoção da saúde. Atualmente, a pesquisa nacional e estrangeira está focada principalmente no impacto da dança esportiva em jovens de ambos os sexos. Objetivo: Este estudo irá explorar a influência dos exercícios regulares de dança física na forma, função e qualidade do corpo de adultos mais velhos e de meia-idade, e fornecerá uma base científica para o papel da dança física no fitness nacional. Métodos: Este estudo recrutou 20 pessoas saudáveis, de meia-idade e idosos de um clube esportivo sem experiência profissional em dança durante três meses de treinamento. As primeiras duas semanas foram pré-experimentos cinco vezes por semana. Cada tempo de exercício foi de 60 minutos. As últimas dez semanas foram experimentos formais, duas vezes por semana, 90 minutos cada vez, sem nenhum outro exercício físico na vida cotidiana. Ao comparar a forma corporal, a função física e o índice de aptidão física antes e depois do experimento, o impacto da dança esportiva na aptidão física saudável de adultos mais velhos e de meia-idade é avaliado. Resultados: Após três meses de exercício físico de dança com diferentes estilos de dança, nos homens, o índice de IMC, o percentual de gordura corporal, a circunferência da cintura, a circunferência do quadril e a circunferência da coxa diminuíram, mas não houve diferença significativa. Nas mulheres, o índice de IMC, o percentual de gordura corporal (P <0,01), a circunferência da cintura (P <0,05), a pressão arterial diastólica (P <0,01), o corpo sentado inclinado para frente (P <0,05) e com um pés e olhos fechados aumentaram. Nas mulheres, os índices de força de preensão (P <0,01), de inclinação para a frente na posição sentada (P <0,055) e com um pé com os olhos fechados aumentaram. Conclusões: Sugere-se que o exercício de dança esportiva aeróbica de intensidade moderada de longa duração pode melhorar a forma corporal de adultos mais velhos e de meia idade e ajudar a aumentar a aptidão física; enquanto isso, a dança esportiva pode efetivamente melhorar a função cardiovascular de indivíduos de meia-idade e idosos. Nível de evidência II; Estudos terapêuticos: investigação dos resultados do tratamento.

ABSTRACT Introduction: Sports dance is widely known as a competitive game, but as a leisure activity, there is little research on the efficacy of human health and fitness. Sports dance, as a popular national fitness exercise, has sound health promotion effects. At present, domestic and foreign researches mostly focus on the impact of sports dance on young men and women. Objective: This study will explore the influence of regular physical dance exercises on the body shape, function, and quality of middle-aged and older adults, provide a scientific basis for the role of physical dance in national fitness. Methods: This study recruited 20 healthy middle-aged and elderly members of a leisure sports dance club without professional dance experience for three months of dance training. The first two weeks are pre-experiments five times a week. Each exercise time is 60 minutes. The last ten weeks are formal experiments, two times a week, 90 minutes each time, and no other physical exercises are involved in everyday life. By comparing part of the body shape, physical function, and physical fitness index before and after the experiment, the impact of sports dance on middle-aged and older adults’ healthy physical fitness is evaluated. Results: After three months of physical dance exercise with different dance styles, in male, BMI index, body fat percentage, waist circumference, hip circumference, and thigh circumference indicators all decreased, but there was no significant difference. In women, BMI index, body fat percentage (P<0.01), waist circumference (P<0.05), diastolic blood pressure (P<0.01), sitting body forward bending (P<0.05), and standing with one foot and closed eyes all increased. In women, the indexes of grip strength (P<0.01), forward bending in sitting position (P<0.055), and standing with eyes closed on one foot all increased. Conclusions: It is suggested that long-term moderate-intensity aerobic sport dance exercise can improve the body shape of middle-aged and older adults and help increase physical fitness; meanwhile, sports dance can effectively improve the cardiovascular function of middle-aged and elderly subjects. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMEN Introducción: La danza deportiva es ampliamente conocida como un juego competitivo, pero como actividad de ocio hay poca investigación sobre la eficacia en la salud y el estado físico humanos. La danza deportiva, como ejercicio físico popular a nivel nacional, tiene importantes efectos en la promoción de la salud. En la actualidad, las investigaciones nacionales y extranjeras se centran principalmente en el impacto de la danza deportiva en hombres y mujeres jóvenes. Objetivo: Este estudio explorará la influencia de los ejercicios regulares de danza física en la forma, función y calidad del cuerpo de los adultos mayores y de mediana edad, y proporcionará una base científica para el papel de la danza física en la aptitud nacional. Métodos: Este estudio reclutó a 20 miembros sanos de mediana edad y ancianos de un club deportivo sin experiencia profesional en danza durante tres meses de entrenamiento. Las dos primeras semanas eran experimentos previos cinco veces por semana. Cada tiempo de ejercicio fue de 60 minutos. Las últimas diez semanas eran experimentos formales, dos veces por semana, 90 minutos cada vez, sin otros ejercicios físicos en la vida cotidiana. Al comparar la forma del cuerpo, la función física y el índice de aptitud física antes y después del experimento, se evalúa el impacto de la danza deportiva en la aptitud física saludable de los adultos mayores y de mediana edad. Resultados: Después de tres meses de ejercicio físico de baile con diferentes estilos de baile, en los hombres, el índice de IMC, el porcentaje de grasa corporal, la circunferencia de la cintura, la circunferencia de la cadera y la circunferencia del muslo disminuyeron, pero no hubo diferencia significativa. En las mujeres, el índice de IMC, el porcentaje de grasa corporal (P <0.01), la circunferencia de la cintura (P <0.05), la presión arterial diastólica (P <0.01), el cuerpo sentado inclinado hacia adelante (P <0.05) y con un pie y ojos cerrados aumentaron. En las mujeres, aumentaron los índices de fuerza de agarre (P <0.01), de inclinación hacia adelante en posición sentada (P <0.055) y con un pie con los ojos cerrados. Conclusiones: Se sugiere que el ejercicio de danza deportiva aeróbica de intensidad moderada a largo plazo puede mejorar la forma del cuerpo de los adultos mayores y de mediana edad y ayudar a aumentar la aptitud física; mientras tanto, la danza deportiva puede mejorar eficazmente la función cardiovascular de sujetos de mediana edad y ancianos. Nivel de evidencia II;Estudios terapéuticos: investigación de los resultados del tratamiento.