广西北部湾地区生态足迹动态分析

生态足迹方法为定量计算地区可持续性发展提供了一种简单易行的方法。论文将在传统生态足迹方法的基础上结合目前国外最新生态足迹动态分析方法对广西北部湾地区从1998年到2005年的生态足迹进行了计算。结果表明:结合万元GDP占用生态足迹、生态足迹多样性指数和经济系统发展能力指数等指标的生态足迹动态分析方法,加强了传统生态足迹方法对地区可持续发展状况的反应。1998～2005年期间,广西北部湾地区,土地生产效率不断提高,经济发展能力在逐步增强,但是人均生态足迹呈逐年增加趋势,出现生态赤字,处于不可持续发展状态,仅林地资源与建筑用地资源还有少量人均盈余。     

Facile syntheses of <Emphasis Type="SmallCaps">l</Emphasis>-β-haloalanine derivatives from <Emphasis Type="SmallCaps">l</Emphasis>-cysteine or <Emphasis Type="SmallCaps">l</Emphasis>-cystine

l-β-Haloalanines are physiologically active unnatural amino acids and they are useful intermediates for the synthesis of natural and unnatural amino acids, S-linked glycopeptides, and lanthionines. In general l-β-haloalanines were prepared predominantly from l-serine via functional group transformation. Here we reported an alternative approach for the preparation of l-β-haloalanines via halogenation of protected l-cysteine esters which was obtained from l-cysteine or l-cystine, respectively. The mercapto group of protected l-cysteine esters was efficiently transformed to halo groups by triphenylphosphine/N-halosuccinimides. It has been proved to be a versatile desulfurization strategy via this functional group transformation.     

Micro-CT检测中等强度跑台运动对去卵巢大鼠腰椎微结构的影响

目的用micro-CT方法,评估中等强度跑台运动对去卵巢大鼠腰椎微结构的影响。方法将30只3月龄雌性SD大鼠按体重分层后随机分为假手术、去卵巢静止和去卵巢运动三个组。运动组每周进行4次45min、速度18 m/min、坡度5°的跑台训练。正式运动处理14周时,取第2腰椎检测骨密度,取第4腰椎行micro-CT分析及三维结构重建;取第3腰椎椎体进行椎体压缩实验。结果去卵巢运动组第2腰椎骨密度、第3腰椎最大载荷、最大应力和弹性模量以及第4腰椎骨小梁体积和骨小梁数目显著高于去卵巢静止组,骨小梁分离度显著低于去卵巢静止组,而骨小梁厚度无显著变化。结论中等强度跑台运动能改善去卵巢大鼠腰椎的微结构。     

流式细胞术在水体微型生物研究中的应用

综述了流式细胞术（flow cytometry)在水体微型生物研究中的应用。包括微型生物的识别、记数和生物量研究,微型生物的细胞周期分析以及生态与生理学研究。讨论了FCM在淡水微型生物和环境生物学中的应用。FCM技术与食品的改进将促进水体微型生物的研究,从而有助于对水生生态系统的深入认识。     

Dichotomous effects of IFN-γ on dendritic cell function determine the extent of IL-12-driven antitumor T cell immunity

Sustained intratumoral delivery of IL-12 and GM-CSF can overcome tumor immune suppression and promote T cell-dependent eradication of established disease in murine tumor models. However, the antitumor effector response is transient and rapidly followed by a T suppressor cell rebound. The mechanisms that control the switch from an effector to a regulatory response in this model have not been defined. Because dendritic cells (DC) can mediate both effector and suppressor T cell priming, DC activity was monitored in the tumors and the tumor-draining lymph nodes (TDLN) of IL-12/GM-CSF-treated mice. The studies demonstrated that therapy promoted the recruitment of immunogenic DC (iDC) to tumors with subsequent migration to the TDLN within 24-48 h of treatment. Longer-term monitoring revealed that iDC converted to an IDO-positive tolerogenic phenotype in the TDLN between days 2 and 7. Specifically, day 7 DC lost the ability to prime CD8(+) T cells but preferentially induced CD4(+)Foxp3(+) T cells. The functional switch was reversible, as inhibition of IDO with 1-methyl tryptophan restored immunogenic function to tolerogenic DC. All posttherapy immunological activity was strictly associated with conventional myeloid DC, and no functional changes were observed in the plasmacytoid DC subset throughout treatment. Importantly, the initial recruitment and activation of iDC as well as the subsequent switch to tolerogenic activity were both driven by IFN-γ, revealing the dichotomous role of this cytokine in regulating IL-12-mediated antitumor T cell immunity.     

Selection of the Maximum Spatial Cluster Size of the Spatial Scan Statistic by Using the Maximum Clustering Set-Proportion Statistic

Spatial scan statistics are widely used in various fields. The performance of these statistics is influenced by parameters, such as maximum spatial cluster size, and can be improved by parameter selection using performance measures. Current performance measures are based on the presence of clusters and are thus inapplicable to data sets without known clusters. In this work, we propose a novel overall performance measure called maximum clustering set–proportion (MCS-P), which is based on the likelihood of the union of detected clusters and the applied dataset. MCS-P was compared with existing performance measures in a simulation study to select the maximum spatial cluster size. Results of other performance measures, such as sensitivity and misclassification, suggest that the spatial scan statistic achieves accurate results in most scenarios with the maximum spatial cluster sizes selected using MCS-P. Given that previously known clusters are not required in the proposed strategy, selection of the optimal maximum cluster size with MCS-P can improve the performance of the scan statistic in applications without identified clusters.     

酒精摄入量对小鼠肠道微生物、酶活性和血常规的影响

【背景】酒是影响机体健康的一把"双刃剑",饮酒对机体肠道微生态体系具有重要影响。【目的】研究不同酒精摄入量对小鼠肠道微生物、酶活性及血常规的影响,从肠道微生态和血常规角度探讨饮酒对身体健康的影响及作用机制。【方法】将SPF(Specific pathogen free)级实验小鼠随机分为对照组、低酒精量摄入组、中酒精量摄入组和高酒精量摄入组。对照组给予蒸馏水饮用,其余各组分别给予10%、20%和30%(体积比)的酒精水溶液作为小鼠的唯一饮用水,连续1个月后采集回肠内容物进行微生物和酶活性分析,采集眼球血进行血常规分析。【结果】与对照组相比,低酒精量摄入组小鼠肠道内乳酸菌数量显著增加(P0.05),大肠杆菌和细菌总数显著降低(P0.01或P0.05);高酒精量摄入组小鼠肠道乳酸菌、双歧杆菌数量显著降低(P0.01);与低酒精量摄入组和中酒精量摄入组相比,高酒精量摄入组小鼠肠道木聚糖酶、纤维素酶、蛋白酶和淀粉酶活性显著升高(P0.01);与对照组相比,低酒精量摄入组小鼠的红细胞比容显著降低(P0.05)。【结论】高酒精摄入量小鼠肠道有益菌群数量相对减少,肠道屏障功能受到影响;低酒精摄入量能调节小鼠肠道菌群结构和消化酶相对活性。     

Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.