ABSTRACT Purpose: To explore the effect of different gastrointestinal reconstruction techniques on laparoscopic distal gastrectomy of gastric cancer on the nutritional and anemia status, and quality of life (QoL) of patients. Methods: Eligible patients were randomly divided into three groups (n=36/group): Billroth I anastomosis group, Billroth II combined with Braun anastomosis group, and Roux-en-Y anastomosis group. Related indicators were compared and analyzed. Results: The general data were comparable among the three groups (all P>0.05). Among the surgical-related indicators and postoperative recovery indicators, only the comparison of the operation time was statistically significant (P=0.004). The follow-up time was 5~36 months (average 27.9 months). In terms of nutritional and anemia indicators, only the differences in the levels of prealbumin, hemoglobin and serum ferritin in 24 months after operation showed significant differences (P=0.015, P=0.003, P=0.005, respectively). There were no significant differences in hospital readmission rate, overall survival, and QoL among the three groups (all P>0.05). Conclusions: In laparoscopic gastrectomy for stage II~III distal gastric cancer, Billroth I anastomosis has shorter operation time than Billroth II combined with Braun anastomosis and Roux-en-Y anastomosis and advantages in the improvement of nutritional status and anemia recovery.

A novel [FeII2L3]4+ metallo-organic helicate results from subcomponent self-assembly of a C3-symmetric triamine (4,4',4''- (1,3,5-triazine-2,4,6-triyl) trianiline), octahedral iron(II) and 2-formyl pyridine in CH3CN solution. The constitution of this supramolecular helicate was confirmed by ESI-MS and 1H NMR spectra. Different planar aromatic guests were selected to investigate host-guest interactions by shifts of 1H NMR signals. The results show that electron-rich aromatic molecules with matched size and symmetry, such as pyrene, are subject to be bound with the outstretched arms of the helicate ligand via aromatic p–p interactions.

A novel helicate complex [FeII2L3]4+ resulted from subcomponent self-assembly of a C3-symmetric triamine, 2-formylpyridine and octahedral iron(II) in CH3CN, which was confirmed by ESI-MS measurement. After the addition of selected planar aromatic molecules in CD3CN solution, shifts of 1H NMR signals of the helicate were investigated. The results revealed that the size, functional group and symmetry of guest molecules remarkably influence the interaction patterns.

Abstract A balanced-to-single-ended (BTSE) Wilkinson power divider of planar microstrip structure is proposed in this paper. It has a balanced input and two single-ended outputs. Cascade of a balun and a conventional power divider can be replaced by this proposed structure. Based on the theory of mixed-mode S parameters and the admittance matrix method, the critical parameters are determined. The four-port network is analyzed by simplifying it to two-port network with other ports matched at the central frequency. Then the key parameters are derived and the impact of a freely selected variable on the bandwidth is also discussed. An example of 2.4GHz BTSE power divider is designed. The simulated and measured results show the effectiveness of the method: differential-mode transmissions are better than −3.25dB, common-mode transmissions are lower than −28.6dB, common-mode return loss is −0.10dB, differential-mode return loss and isolation is lower than −23.7dB. While the operating bandwidth is 20%.

A new noninvasive screening tool for colorectal neoplasia detects epigenetic alterations exhibited by gastrointestinal tumor cells shed into stool. There is insufficient existing data to determine temporal associations between colorectal cancer (CRC) progression and aberrant DNA methylation. To evaluate the feasibility of using fecal DNA methylation status to determine CRC progression, we collected stool samples from 14 male SD rats aged six weeks, and administered subcutaneous injections of either 1,2-dimethylhydrazine or saline weekly. p16 DNA methylation statuses in tumorous and normal colon tissue, and from stool samples were determined using methylation-specific PCR. Additionally, p16 methylation was detected in stool DNA from 85.7% of the CRC rats. The earliest change in p16 methylation status in the DMH-treated group stool samples occurred during week nine; repeatabilities were 57.1% in week 19 (p = 0.070) and 85.7% in week 34 (p = 0.005). A temporal correlation was evidenced between progression of CRC and p16 methylation status, as evidenced by DMH-induced rat feces. Using fecal DNA methylation status to determine colorectal tissue methylation status can reveal CRC progression. Our data suggests that p16 promoter methylation is a feasible epigenetic marker for the detection and may be useful for CRC screening.

Learning fundamental concepts in science in order to develop deep understanding of complex scientific concepts is an essential task. However, research that uses rigorous methods to investigate how students' concepts develop over time is limited. In this article, we answer two key questions about learning progressions for the concept of phase transitions: (1) what mental models of matter and phase change do students possess across grades, and (2) what conceptual pathways do students follow for these concepts? We describe the results from a study involving fourth, fifth, and seventh through twelfth grade students (N = 832). Our work led to two main findings. First, students' mental models of the targeted concepts gradually shifted from direct and sensory to synthetic and then to scientific-like. Second, based on our cladistics analysis, we found that some crucial concepts developed before students possessed scientific models. Our results provide a novel perspective from which to revisit learning progressions associated with the development of core scientific knowledge.

El aprendizaje de conceptos fundamentales en ciencia con el fin de facilitar la comprensión de conceptos más complejos es una tarea educativa esencial. Sin embargo, las investigaciones que se basan en el uso de métodos rigurosos para estudiar cómo se desarrollan los conceptos de los estudiantes a través tiempo son limitadas. En este artículo respondemos a dos preguntas claves sobre progresiones de aprendizaje del concepto de transiciones de fase: (1) ¿Qué modelos mentales sobre la materia y los cambios de fase poseen los estudiantes de diferentes grados escolares? y (2) ¿Qué trayectorias conceptuales siguen los estudiantes al aprender estos conceptos? Presentamos los resultados de un estudio que involucró estudiantes en los grados cuarto, quinto y de séptimo a doceavo (N = 832). Nuestro trabajo dio lugar a dos resultados principales. Primero, los modelos mentales de los estudiantes sobre los conceptos estudiados cambiaron gradualmente de directos y sensoriales a sintéticos, y después a de tipo científico. Segundo, con base en un análisis de cladística, encontramos conceptos cruciales que deben desarrollarse antes de que los estudiantes posean los conceptos científicos. Nuestros resultados proporcionan una perspectiva novedosa desde la cual abordar el estudio de progresiones de aprendizaje sobre conocimientos científicos fundamentales.