Abstract Tires are a critical component of military wheeled vehicles and are exposed to the threat of fragment caused by explosion of warhead on the battlefield. To study the ballistic impact response of military vehicle tires under fragment, experiments and numerical simulations of spherical fragments impacting tires were carried out. The damage mode of the tires was analyzed. The effects of obliquity, tire thickness, and fragment mass on the dynamic response of tires, as well as the ballistic limit velocity, were analyzed. The results indicate that: (1) The main failure modes of the tire comprise local erosion near the center of the perforation, elastic deformation surrounding the perforation, and tensile fracture of the steel cords. (2) The process of fragment penetration into a tire can be divided into four stages: the entry stage, stable penetration stage, cord layer penetration stage, and fragment exit stage. (3) The cord structure demonstrates its ability to undergo plastic deformation to a certain extent and its restraining effect on the rubber.

Abstract: Video-assisted self-reflection (VASR) has been identified as an effective pedagogical tool in teacher education, and yet it has been rarely researched in the context of teaching EFL students to make oral presentations (OPs). This study aimed at investigating the effectiveness of VASR in teaching EFL students to make OPs and the students’ perceptions of its pedagogical use. A quasi-experimental two-group pre-test post-test comparison design was used. The experimental group (n = 14) and the control group (n = 15) experienced the same instructional procedures for 14 weeks, while only the experimental group made VASRs. Two questionnaires were used as instruments, one completed by both groups first as the pre-test and then as post-test to investigate the effectiveness of VASR, and the other completed by the experimental group to examine students’ perceptions. The results suggested that VASR was effective in developing students’ use of non-verbal elements in communication and that students perceived VASRs as beneficial activities. A structured protocol was recommended to facilitate students’ VASRs and maximize its pedagogical effect. The findings have implications for the design of VASRs in teaching EFL students to make OPs.

Resumen: Se ha identificado a la autorreflexión asistida por video como una herramienta efectiva en la formación de profesores, pero casi nunca ha sido investigada en el contexto de enseñar a esos estudiantes de inglés como lengua extranjera al hacer presentaciones orales. Esta investigación pretende investigar la eficacia de la autorreflexión asistida por video como método de enseñar a estudiantes de inglés como lengua extranjera a hacer presentaciones orales, y las percepciones de estudiantes acerca del uso pedagógico de videos. Hemos empleado un diseño cuasi-experimental de pre-test/post-test, con dos grupos. El grupo experimental (n = 14) y el grupo de control (n = 15) recibieron la misma enseñanza durante 14 semanas, pero solo el grupo experimental hizo autorreflexión asistida por video. Se usan dos cuestionarios como instrumentos, uno rellenado por ambos grupos en la pre-test y de nuevo en la post-test para investigar la eficacia de autorreflexión asistida por video, y el otro completado por el grupo experimental solamente, para examinar las percepciones de esos estudiantes. Los resultados sugirieron que la autorreflexión asistida por video resultó efectiva para desarrollar el uso de elementos no verbales en la comunicación, y que los estudiantes pensaron que la autorreflexión asistida por video fue una actividad beneficiosa para ellos. Se sugirió un protocolo estructurado que puede facilitar la autorreflexión y aumentar sus efectos. Los hallazgos son importantes a la hora de diseñar la autorreflexión asistida por video para enseñar estudiantes de inglés como lengua extranjera cuando se hacen presentaciones orales.

Abstract This study aimed to use gene chips to investigate differential gene expression profiles in the occurrence and development of acute myocardial infarction (AMI). The study included 12 AMI patients and 12 healthy individuals. Total mRNA of peripheral bloodwas extracted and reversed-transcribed to cDNA for microarray analysis. After establishing two pools with three subjects each (3 AMI patients and 3 healthy individuals), the remaining samples were used for RT-qPCR to confirm the microarray data. From the microarray results, seven genes were randomly selected for RT-qPCR. RT-qPCR results were analyzed by the 2-ΔΔCt method. Microarray analysis showed that 228 genes were up- regulated and 271 were down-regulated (p ≤ 0.05, |logFC| > 1). Gene ontology showed that these genes belong to 128 cellular components, 521 biological processes, and 151 molecular functions. KEGG pathway analysis showed that these genes are involved in 107 gene pathways. RT-qPCR results for the seven genes showed expression levels consistent with those obtained by microarray. Thus, microarray data could be used to select the pathogenic genes for AMI. Investigating the abnormal expression of these differentially expressed genes might suggest efficient strategies for the prevention, diagnosis, and treatment of AMI.

BACKGROUND: Mitogen-activated protein kinase (MAPK) signaling pathway plays an important role in response to viral infection. The aim of this study was to explore the function and mechanism of MAPK signaling pathway in enterovirus 71 (EV71) infection of human rhabdomyosarcoma (RD) cells. METHODS: Apoptosis of RD cells was observed using annexin V-FITC/PI binding assay under a fluorescence microscope. Cellular RNA was extracted and transcribed to cDNA. The expressions of 56 genes of MAPK signaling pathway in EV71-infected RD cells at 8 h and 20 h after infection were analyzed by PCR array. The levels of IL-2, IL-4, IL-10, and TNF-α in the supernatant of RD cells infected with EV71 at different time points were measured by ELISA. RESULTS: The viability of RD cells decreased obviously within 48 h after EV71 infection. Compared with the control group, EV71 infection resulted in the significantly enhanced releases of IL-2, IL-4, IL-10 and TNF-α from infected RD cells (p < 0.05). At 8 h after infection, the expressions of c-Jun, c-Fos, IFN-i, MEKK1, MLK3 and NIK genes in EV71-infected RD cells were up-regulated by 2.08-6.12-fold, whereas other 19 genes (e.g. AKT1, AKT2, E2F1, IKK and NF-κB1) exhibited down-regulation. However, at 20 h after infection, those MAPK signaling molecules including MEKK1, ASK1, MLK2, MLK3, NIK, MEK1, MEK2, MEK4, MEK7, ERK1, JNK1 and JNK2 were up-regulated. In addition, the expressions of AKT2, ELK1, c-Jun, c-Fos, NF-κB p65, PI3K and STAT1 were also increased. CONCLUSION: EV71 infection induces the differential gene expressions of MAPK signaling pathway such as ERK, JNK and PI3K/AKT in RD cells, which may be associated with the secretions of inflammatory cytokines and host cell apoptosis.

Um novo sistema de quimioluminescência (CL), sensível, (reação [Ag(HIO6)2]5--luminol), acoplado com injeção em fluxo, é introduzido para determinação de d-penicilamina. O sistema é baseado no efeito do aumento da reação de quimioluminescência por penicilamina em meio alcalino. Sob condições ótimas, a intensidade de CL é proporcional às concentrações de d-penicilamina com uma boa linearidade. O intervalo linear é de 1,5-150 ng mL-1 e o limite de detecção do método, 0,8 ng mL-1. O desvio padrão relativo é 0,23% para 11 repetições de 0,06 µg mL-1 de d-penicilamina. O método tem sido aplicado com sucesso às determinações de d-penicilamina em preparações farmacêuticas e amostras de urina, proporcionando resultados satisfatórios. Com base nos espectros de quimioluminescência e no experimento de aprisionamento de radicais livres realizado neste trabalho, um possível mecanismo de reação para esse sistema reacional é sugerido.

A novel sensitive chemiluminescence (CL) system ([Ag(HIO6)2]5--luminol reaction system), coupled with a flow injection, is introduced for determination of d-penicillamine. The system is based on the enhancement effect of chemiluminescence reaction by penicillamine in alkaline medium. Under the optimum conditions, the CL intensity is proportional to the concentrations of d-penicillamine with a good linearity. The linear range covers 1.5-150 ng mL-1 and the limit of detection of the method is 0.8 ng mL-1. The relative standard deviation is 0.23% for 11 repeated measurements of 0.06 µg mL-1 d-penicillamine. The method has been successfully applied to the determinations of d-penicillamine in pharmaceutical preparations and urine samples, giving rise to satisfactory results. Based on the chemiluminescent spectra and free radical trapping experiment performed in this work, a possible reaction mechanism for this reaction system is suggested.