Osteosarcoma is a highly malignant tumor that occurs in the bone. Previous studies have shown that multiple microRNAs (miRNAs) regulate the development of osteosarcoma. This study aimed to explore the role of miR-629-5p and its target gene, caveolin 1 (CAV1), in osteosarcoma development. To analyze the expression of miR-629-5p and CAV1 mRNA in osteosarcoma tissues and cell lines, qRT-PCR analysis was performed. Dual-luciferase reporter experiments were subsequently performed to validate the relationship between CAV1 and miR-629-5p. CCK8 assay was used to measure osteosarcoma cell proliferation, and wound-healing assay was performed to study their migratory phenotype. Our findings revealed that miR-629-5p was overexpressed in osteosarcoma tissues and cells, and thereby enhanced cell proliferation and migration. Further, we validated that miR-629-5p targets CAV1 mRNA directly. CAV1 expression, which was negatively correlated with miR-629-5p expression, was found to be downregulated in osteosarcoma tissue samples. Moreover, our data showed that an increase in CAV1 level led to a decline in osteosarcoma cell proliferation and migration, which could be rescued by miR-629-5p upregulation. Overall, our study confirmed that miR-629-5p promoted osteosarcoma proliferation and migration by directly inhibiting CAV1.

ABSTRACT The design of the magnetic field is crucial to the performance of the hall thruster. This paper investigates the effects of magnetic field on the discharge characteristics of the low-power hall thruster in the method of combining simulation and experiment. Based on a 40-mm-diameter hall thruster (LHT-40) operating with hundreds of Watts, a two-dimensional axisymmetric model is established in fluid method to investigate the mechanism, how the magnetic field influences the performance of the thruster, and the experiments are also carried out to investigate the performance effected by magnetic field. Both the numerical and the experimental results indicate that there is an optimal magnetic flux density in which the thruster could achieve a higher efficiency compared with other conditions. And in order to maintain its high efficiency, the line of magnetic-curve inflexion inside the discharge channel should coincide with the center line of the channel to decrease the interaction between the plasma and the wall. The LHT-40 could generate about 12.2 mN of thrust at an optimal efficiency of 27% when the maximum magnetic flux density along the center line of the channel is about 200 Gs.

ABSTRACT Lifetime is a main factor restraining the application of low-power Hall thruster. Magnetic shielding configuration is regarded as a promising method to prolong the lifespan of Hall thruster. Aiming to demonstrate the feasibility and effectiveness of magnetic shielding configuration applying on low-power Hall thruster, a 60-mm diameter Hall thruster in partial magnetic shielding configuration was designated. Both the numerical and experimental methods were used to investigate the discharge characteristics of the Hall thruster and help understand the mechanism behind. The maximum anode efficiency was achieved as high as 29.7% with 1.7 mg•s–1 anode mass flow and 320 V discharge voltage. To evaluate the effectiveness of the magnetic shielding used for low-power Hall thruster, a 2000 h lifetime test has been carried out and the results indicate that the erosion rate has been decreased below 0.2 μm•h–1.

Valency is a major source of lexical errors in foreign language learning. Accordingly, the research question is how the syntactic and semantic properties of a word can be retrieved from the corpora and represented in a Chinese valency dictionary to facilitate foreign learners' vocabulary acquisition. Within the three aspects of the valency framework - logical-semantic, syntactic and semantic-pragmatic valency - this study examines 60 cases of Chinese lexical misuse extracted from the HSK (Chinese Language Proficiency Test) Dynamic Compositions Corpus. The results suggest that the majority of cases of misuse occur in the dimension of semantic-pragmatic valency and that this semantic-pragmatic misuse can be ascribed to various factors such as semantic collocations, emotive variables, text styles, registers, and other contextual factors. The results are then utilized as syntactic, semantic and pragmatic information to be presented in a Chinese valency dictionary. Specifically, the results obtained from a case study of a misused word by referring to a large-scale native Chinese speaker corpus help retrieve a relatively full list of complementation patterns, based on which the study designs a Chinese valency entry that embodies three basic elements - quantitative valency, qualitative valency and valency patterns.

Valensie is 'n groot bron van leksikale foute in die aanleer van 'n vreemde taal. Gevolglik ontstaan die vraag hoe sintaktiese en semantiese eienskappe van 'n woord uit die korpus verkry en in 'n Chinese valensiewoordeboek weergegee kan word om woordeskat-verwerwing vir vreemdetaalleerders te vergemaklik. Met inagneming van die drie aspekte van 'n valensieraamwerk - logies-semantiese, sintaktiese en semanties-pragmatiese valensie - word 60 gevalle van Chinese leksikale foute wat uit die HSK (Chinese Taalvaardigheidstoets) Dinamies Saamgestelde Korpus onttrek is, bestudeer. Die resultate dui daarop dat die meeste van die foute plaasvind in die semanties-pragmatiese valensie-dimensie en dat hierdie semanties-pragmatiese foute toegeskryf kan word aan verskeie faktore soos semantiese kollokasies, emotiewe verander-likes, teksstyle, registers, en ander kontekstuele faktore. Die resultate word dan benut as sintak-tiese, semantiese en pragmatiese inligting wat in 'n Chinese valensiewoordeboek weergegee moet word. Meer spesifiek, die resultate wat verkry word uit 'n gevallestudie van 'n verkeerd gebruikte woord wat onttrek is uit 'n grootskaalse Chinese moedertaalssprekerskorpus, help om 'n relatief volledige lys aanvullingspatrone, wat gebaseer is op die studieontwerpe van 'n Chinese valensie-inskrywing wat drie basiese elemente insluit - kwantitatiewe valensie, kwalitatiewe valensie en valensiepatrone - te verkry.

Abstract In this work, the vapor-liquid equilibrium experimental data for the systems of isopropyl chloroacetate + isopropanol, isopropyl chloroacetate + cyclohexane and isopropyl chloroacetate + benzene were measured by a modified Rose-type recirculating still under the pressure of 101.3 kPa. The thermodynamic consistency of the measured data was verified by the Herington and van Ness methods, respectively. The experimental data were correlated by the NRTL, Wilson, and UNIQUAC activity coefficient models, and the corresponding interaction parameters of the three models were obtained. The root-mean-square deviations between the experimental data and calculated results for the temperature and the mole fraction of the vapor phase were less than 0.58 K and 0.0066, respectively. In addition, the excess Gibbs energy was calculated for the three systems.

Abstract A simple and convenient procedure for the synthesis of 5Hdibenzo[b,i]xanthene-tetraones and aryl-14H-dibenzo[a,j]xanthenes is described through the condensation of aldehydes with 2-naphthol or 2-hydroxy-1, 4-naphthoquinone under solvent-free conditions in the presence of ferric chloride hexahydrate. This method has the advantages of high yields, cleaner reaction, simple work-up and cost efficiency.

Resumen Se describe una metodología simple para la síntesis de 5Hdibenzo[b,i]xanteno-tetraonas y aril-14H-dibenzo[a,j]xantenos. Los xantenos son obtenidos por condensación de aldehídos con 2-naftol o 2-hidroxi-1,4-naftoquinona en presencia de cloruro férrico hexahidratado. Las reacciones se llevan a cabo en ausencia de disolvente, son limpias, de bajo costo y con alto rendimiento.

OBJECTIVE: China has about 350 million smokers, more commonly men. Using data from National Health Service Surveys conducted in 1993, 1998 and 2003, we (i) estimated trends in smoking prevalence and cessation according to sociodemographic variables and (ii) analysed cessation rates, quitting intentions, reasons for quitting and reasons for relapsing. METHODS: Data were collected from approximately 57 000 households and 200 000 individuals in each survey year. Household members > 15 years of age were interviewed about their smoking habits, quitting intentions and attitudes towards smoking. We present descriptive data stratified by age, sex, income level and rural versus urban residence. FINDINGS: In China, current smoking in those > 15 years old declined 60-49% in men and 5-3.2% in women over 1993-2003. The decline was more marked in urban areas. However, heavy smoking (> 20 cigarettes daily) increased substantially overall and doubled in men. The average age of uptake also dropped by about 3 years. In 2003, 7.9% of smokers reported intending to quit, and 6% of people who had ever smoked reported having quit. Of former smokers, 40.6% quit because of illness, 26.9% to prevent disease and 10.9% for financial reasons. CONCLUSION: Smoking prevalence declined in China over the study period, perhaps due to the combined effect of smoking cessation, reduced uptake in women and selective mortality among men over 40 years of age. However, heavy smoking increased. People in China rarely quit or intend to quit smoking, except at older ages. Further tobacco control efforts are urgently needed, especially in rural areas.

OBJETIVO: China cuenta con unos 350 millones de fumadores, la mayoría, hombres. Utilizando datos de las encuestas llevadas a cabo por el Servicio Nacional de Salud en 1993, 1998 y 2003, (i) calculamos las tendencias en la prevalencia del tabaquismo y la deshabituación tabáquica según variables socio-demográficas y (ii) analizamos las tasas de deshabituación, los intentos de dejar de fumar, los motivos para dejar de fumar y los motivos para recaer. MÉTODOS: Se recopilaron datos de aproximadamente 57 000 hogares y 200 000 individuos en cada año de encuesta. Se entrevistó a los miembros menores de 15 años de dichos hogares acerca de sus hábitos tabáquicos, sus intenciones de dejar de fumar y sus actitudes frente al tabaquismo. Presentamos datos descriptivos estratificados por edad, sexo, nivel de ingresos y residencia rural frente a urbana. RESULTADOS: En China, el tabaquismo actual en menores de 15 años cayó entre el 60% y el 49% en hombres y entre el 5% y el 3,2% en mujeres durante el periodo entre 1993 y 2003. La caída fue más acusada en áreas urbanas. Sin embargo, el tabaquismo agudo (>20 cigarrillos al día) aumentó sustancialmente en general y se duplicó en hombres. El promedio de edad de consumo también cayó en unos 3 años. En 2003, el 7,9% de los fumadores indicó que tenía intención de dejar el tabaco y el 6% de las personas que habían fumado alguna vez señaló haberlo dejado. De los ex-fumadores, el 40,6% había dejado el tabaco por una enfermedad; el 26,9%, para prevenir una enfermedad; y el 10,9%, por motivos económicos. CONCLUSIÓN: La prevalencia del tabaquismo cayó en China durante el periodo del estudio, quizá debido al efecto combinado de la deshabituación tabáquica, la reducción del consumo en mujeres y la mortalidad selectiva en hombres mayores de 40 años. Sin embargo, el tabaquismo agudo se incrementó. En China, las personas rara vez dejan o tienen intención de dejar de fumar, salvo en edades más avanzadas. Se necesitan más iniciativas para controlar el tabaquismo, especialmente en las áreas rurales.

OBJECTIF: La Chine compte près de 350 millions de fumeurs, qui sont le plus souvent des hommes. Utilisant les données des enquêtes du Service national de la Santé, menées en 1993, 1998 et 2003, nous avons (i) estimé les tendances de prévalence et d'arrêt du tabagisme en fonction des variables sociodémographiques et (ii) analysé les taux d'arrêt, les intentions d'arrêter, les raisons d'arrêter et les raisons de rechuter. MÉTHODES: Les données ont été recueillies auprès d'environ 57 000 ménages et 200 000 individus par année d'enquête. Les membres des ménages âgés de plus de plus de 15 ans ont été interrogés sur leurs habitudes de fumeurs, sur leurs intentions d'arrêter et sur leur attitude à l'égard du tabagisme. Nous présentons des données descriptives stratifiées par âge, sexe, niveau de revenu et résidence rurale ou urbaine. RÉSULTATS: En Chine, entre 1993 et 2003, le nombre de fumeurs chez les plus de 15 ans a chuté de 60 à 49% chez les hommes et de 5 à 3,2% chez les femmes. Cette baisse est plus marquée dans les régions urbaines. Toutefois, le tabagisme lourd (plus de 20 cigarettes par jour) a considérablement augmenté au total et a doublé chez les hommes. L'âge moyen de la première cigarette a également diminué de près de 3 ans. En 2003, 7,9% des fumeurs ont déclaré avoir l'intention d'arrêter et 6% de ceux ayant déclaré avoir fumé ont arrêté. Parmi les anciens fumeurs, 40,6% d'entre eux stoppent pour cause de maladie, 26,9% pour prévenir une maladie et 10,9% pour des raisons financières. CONCLUSION: La prévalence du tabagisme a diminué en Chine au cours de la période d'étude, sans doute à cause d'un effet combiné de l'arrêt de la cigarette, de la réduction de la consommation chez les femmes et d'une mortalité sélective chez les hommes de plus de 40 ans. Cependant, le tabagisme lourd a quant à lui augmenté. Les Chinois arrêtent ou décident rarement d'arrêter de fumer, à l'exception des plus âgés. Des efforts en matière de contrôle du tabagisme sont nécessaires d'urgence, surtout dans les régions rurales.