Safety and efficacy of preoperative chemoradiotherapy in fit older patients with intermediate or locally advanced rectal cancer evaluated by comprehensive geriatric assessment: A planned interim analysis of a multicenter, phase II trial.

BACKGROUND AND PURPOSE: Comprehensive geriatric assessment (CGA) is a diagnostic method to assess the physical and mental health status of older patients. The purpose of this study was to assess the safety and efficacy of preoperative concurrent chemoradiotherapy (preCRT) for intermediate or locally advanced rectal cancer in older people who were classified as "fit" by CGA. The interim analysis focusing on safety was reported here as the first part of this trial. METHODS AND MATERIALS: This is a single arm, multicenter, phase II trial. The eligible patients for this study were aged 70 years or above that fulfilled the standard of intermediate or locally advanced risk category, and met the standard of fit (SIOG1) evaluated by CGA. All patients received preCRT (50 Gy) with Raltitrexed (3 mg/m2 on d1 and d22). Qualitative and quantitative variables were described using descriptive statistics. The surgery adherence predicting was analyzed by multivariate logistic regression. RESULTS: Thirty-nine fit patients were enrolled. All patients except one finished radiotherapy without dose reduction. Thirty-two patients finished the prescribed Raltitrexed therapy as scheduled. A serious toxicity was observed in 12 patients (30.8%), and only six patients (15.4%) experienced non-hematological side effects. CONCLUSION: Overall, our results showed that preCRT was feasible and safe in older patients with rectal cancer who were evaluated as fit based on CGA, supporting the use of CGA to tailor oncological treatment and predict the tolerance of a specific therapy. Completing this trial as planned would provide further valuable insights.

[Long-term changes of land use/cover in the Three Gorges Reservoir Area of the Yangtze River, China.] / 长江三峡库区土地利用/覆盖的长期变化.

Understanding the temporal and spatial dynamics of land use/cover (LUC) can contri-bute to reveal the impacts of climate change and human activities on ecosystems and thus be an important prerequisite for ecosystem management. As an ecologically vulnerable area in China, the Three Gorges Reservoir Area (TGRA) of the Yangtze River presented significant complexity in the response to environmental changes. However, there is a general lack of understanding in the underlying mechanism. In this study, we interpreted the time series remote sensing images derived from the Landsat sensors to map the LUC of the TGRA, and aimed to analyze the long-term changes in the distribution and structure of LUC and elucidate the evolution process of LUC, which could provide a scientific basis to understand the complexity of ecosystem changes and regional ecosystem management in ecologically fragile regions. The results showed that the TGRA presented the significant changes in spatial heterogeneity of LUC structure from 1990 to 2015. Meanwhile, the landscape changed from farmland to woodland (forest and shrubland). Farmland decreased from 66.2% to 40.4%, but woodland increased from 31.3% to 53.5%, buildings and water area increased gradually. Forest gradually spread to the middle of the TGRA, while the buildings presented a scattered expansion. In the altitude zone of 500-1000 m and slope zone of 15°-25°, woodland increased noticeably, and the coniferous forest, mixed forest and shrubland had a higher growth rate. In the study period, due to the urban construction and the various ecological restoration projects in the TGRA, the LUC structure varied with the dam's impoundment and was characterized by the ecosystem restoration. Ecological restoration projects were helpful to reduce the negative impacts of urban construction and economic development on the environment.

[Ecological risk assessment of typical karst basin based on land use change: A case study of Lijiang River basin, Southern China]. / åŸºäºŽåœŸåœ°åˆ©ç”¨å˜åŒ–çš„å ¸åž‹å–€æ–¯ç‰¹æµåŸŸç”Ÿæ€é£Žé™©è¯„ä¼°­­ä»¥æ¼“江流域为例.

Taking Lijiang River basin as study area, and based on the remote sensing images of 1973, 1986, 2000 and 2013, the land-use data were extracted, the ecological risk index was constructed, and the characteristics of spatiotemporal variation of ecological risk were analyzed by "3S" technique. The results showed that land use structure of Lijiang River basin was under relatively reasonable state and it was constantly optimizing during 1973-2013. Overall, the ecological risk of Lijiang River basin was maintained at a low level. Lowest and lower ecological risk region was dominant in Lijiang River basin, but the area of highest ecological risk expanded quickly. The spatial distribution of ecological risk was basically stable and showed an obvious ring structure, which gra-dually decreased from the axis of Xingan County Town-Lingchuan County Town-Guilin City-Yangshuo County Town to other regions. Region with lowest ecological risk mainly distributed in natural mountain forest area of the north and mid-eastern parts of Lijiang River basin, and region with highe-st ecological risk concentrated in Guilin City. The ecological risk distribution of Lijiang River basin presented significant slope and altitude differences, and it decreased with increasing slope and altitude. During the study period, the area of low ecological risk converted to high ecological risk gra-dually decreased and vice versa. On the whole, the ecological risk tended to decline rapidly in the Lijiang River basin.

[Evaluation of landscape connectivity based on least-cost model].

Landscape connectivity, as a dominant factor affecting species dispersal, reflects the degree to which the landscape facilitates or impedes organisms' movement among resources patches. It is also an important indicator in sustainable land use and biological conservation. Least-cost model originates from graph theory, and integrates the detailed geographical information with organisms' behavioral characteristics in the landscape. Through cost distance analysis, this model can describe the species connectivity in heterogeneous landscape intuitively and visually. Due to the simple algorithm performed in GIS packages and the demand of moderate data information, least-cost model has gained extensive attention in the evaluation of large-scale landscape connectivity. Based on the current studies of landscape connectivity, this paper elaborated the significance, principles, and operation processes of least-cost model in evaluating landscape connectivity, and discussed the existing problems of the model in its practical applications, which would benefit the further related studies and biodiversity conservation.