生物质炭及过氧化钙对旱地红壤酶活性和微生物群落结构的影响

明确生物质炭等改良剂对土壤酶活性及土壤微生物群落结构的影响,对南方红壤旱地改良剂的合理施用及评价不同改良剂对旱地红壤肥力的影响具有重要意义。针对江西旱地红壤进行室内培养试验,试验设置4个处理,即CK、Ca(过氧化钙,1.72 g/kg)、C(生物质炭,21.46 g/kg)、C+Ca(过氧化钙,1.72 g/kg;生物质炭,21.46 g/kg),利用磷脂脂肪酸方法(PLFA),研究改良剂对土壤微生物量和组成以及土壤酶活性、土壤活性有机碳的影响。结果表明:旱地红壤中添加生物质炭和过氧化钙土壤提高可溶性有机碳(DOC)和微生物量碳(MBC)含量;增加蔗糖酶(INV)、淀粉酶(AMY)及脲酶(URE)活性,特别是配施(C+Ca)显著提高土壤活性碳含量及酶活性。PLFA分析表明,土壤微生物总PLFAs量的大小顺序为:C+CaCCaCK;各处理土壤细菌的相对丰度最大,大约占微生物总含量的80%,放线菌次之,大约占微生物总含量的13%～15%,而真菌和丛枝菌根真菌的相对丰度较低。生物质炭和过氧化钙增加了革兰氏阴性菌(GN)/革兰氏阳性菌(GP)值,尤以C+Ca处理增加幅度最大。主成分分析(PCA)表明,添加生物质炭和过氧化钙能够改善土壤微生物群落结构;计算主成分的综合得分,配施(C+Ca)处理的综合得分最高,对土壤微生物群落结构的影响最大。冗余分析(RDA)表明,土壤MBC、DOC和土壤INV酶活性是影响土壤微生物数量和结构的主要因子。因此,施用生物质炭和过氧化钙能够明显提高旱地红壤微生物生物量,改变红壤微生物群落结构以及激发红壤酶活性,且配施效果最显著。     

基于GIS的土壤风蚀模型软件构建

针对当前土壤风蚀监测的实际需求,提出基于GIS技术构建土壤风蚀模型软件的思路和方法。该软件基于DTGIS核心服务平台,以C#为主开发语言,Silverlight为界面开发工具,采用轻型数据库SQLite进行数据存储;该软件可为用户提供GIS查询功能、站点数据管理、风力因子计算、土壤侵蚀模数计算、土壤侵蚀强度分级、时间分析、空间分析等功能服务,支持远程客户端连接和多点同时上传数据;同时,该软件将风蚀模型与GIS系统有机地集成到一起,不仅支持风蚀运算过程的交互,而且可以直接将模型运行结果显示在软件中;软件亦可以制作土壤侵蚀模数专题图、土壤侵蚀强度分级专题图、时空分析图,实现土壤风蚀数据系统化管理和数据可视化管理,为评价土壤风蚀的危害提供科学依据。     

乙酰甲喹微乳的制备及其体外透皮释药研究

通过绘制伪三元相图优选处方,应用相转变法制备乙酰甲喹微乳,在透射电子显微镜(transmission electron microscope,TEM)下考察其形态,用Zetasizer Nano ZS分析仪以光子关联能谱法(photon correlation spectroscopy,PCS)测定其粒径和多分散系数(polydispersity index,PDI),并用上述仪器测定其zeta电位,通过恒温加速试验评价其稳定性,并研究其在小鼠皮肤上的体外经皮释药效果。结果显示:在所考察的油相中,肉桂醛对乙酰甲喹的溶解度最大,聚氧乙烯氢化蓖麻油(RH40)为最佳表面活性剂,用二者制备的乙酰甲喹微乳为黄色的澄清透明液体,流动性好;电镜观察微乳滴呈球形,纳米粒度仪测定其平均粒径为(13.9±0.3)nm,PDI为0.060±0.005;在25℃时,稀释5倍后的乙酰甲喹微乳的平均pH值为5.1±0.2,对应的平均zeta电位为(9.4±0.4)mV;高速离心、常温及低温下稳定,高温下颜色由黄色变为红色,但无药物析出,说明乙酰甲喹微乳符合微乳制剂的要求且稳定性较好;乙酰甲喹微乳配方中无氮酮和氮酮含量为2%及5%的表观透皮系数(Kp×10-3)分别为(12.701±0.012),(12.207±0.021)及(10.796±0.065)cm.h-1,而乙酰甲喹水溶液的表观透皮系数(Kp×10-3)是(4.908±0.034)cm.h-1,说明乙酰甲喹微乳的透皮效果优于其水溶液,且差异显著(P<0.01),其配方中无需透皮促进剂氮酮。     

猪卵母细胞第1极体与核相对位置变化对去核率的影响

为探讨猪受体卵母细胞体外成熟过程中第1极体(pbⅠ)与细胞核相对位置的动态变化规律及其对去核效率的影响,准确判定受体卵母细胞去核"窗口期"提供试验依据。将体外采集的GV(Germinal vesicle)期卵母细胞随机分为3组,分别成熟培养42～44 h、44～46 h、46～48 h,并采用Hoechst33342荧光染色法对成熟过程中pbⅠ与细胞核相对位置进行检测判定。结果显示,随着体外成熟时间的延长,卵母细胞的成熟率呈逐渐增加的趋势,但pbⅠ与细胞核的位置发生偏离的比率逐渐增加,而去核率则表现为逐渐降低的趋势,pbⅠ偏离率与去核率之间呈现一定程度的负相关;体外成熟44～46 h,既能获得较高的卵母细胞成熟率(80.2%),又可以保证理想的去核率(81.2%)。说明延长体外成熟时间所造成的去核率显著降低与pbⅠ发生偏离有关,体外成熟44～46 h是该试验条件下猪受体卵母细胞去核的最佳"窗口期"。     

Responses of soil dissolved organic matter to long-term plantations of three coniferous tree species

Tree species have significant effects on the availability and dynamics of soil organic matter. In the present study, the pool sizes of soil dissolved organic matter (DOM), potential mineralizable N (PMN) and bio-available carbon (C) (measured as cumulative CO₂ evolution over 63 days) were compared in soils under three coniferous species — 73 year old slash (Pinus elliottii), hoop (Araucaria cunninghamii) and kauri (Agathis robusta) pines. Results have shown that dissolved organic N (DON) in hot water extracts was 1.5–1.7 times lower in soils under slash pine than under hoop and kauri pines, while soil dissolved organic C (DOC) in hot water extracts tended to be higher under slash pine than hoop and kauri pines but this was not statistically significant. This has led to the higher DOC:DON ratio in soils under slash pine (32) than under hoop and kauri pines (17). Soil DOC and DON in 2 M KCl extracts were not significantly different among the three tree species. The DOC:DON ratio (hot water extracts) was positively and significantly correlated with soil C:N (R² = 0.886, P < 0.01) and surface litter C:N ratios (R² = 0.768, P < 0.01), indicating that DOM was mainly derived from litter materials and soil organic matter through dissolution and decomposition. Soil pH was lower under slash pine (4.5) than under hoop (6.0) and kauri (6.2) pines, and negatively correlated with soil total C, C:N ratio, DOC and DOC:DON ratio (hot water extracts), indicating the soil acidity under slash pine favored the accumulation of soil C. Moreover, the amounts of dissolved inorganic N, PMN and bio-available C were also significantly lower in soils under slash pine than under hoop and kauri pines. It is concluded that changes in the quantity and quality of surface litters and soil pH induced by different tree species largely determined the size and quality of soil DOM, and plantations of hoop and kauri pine trees may be better in maintaining long-term soil N fertility than slash pine plantations.     

猪卵泡闭锁过程中颗粒细胞凋亡和Fas/FasL变化

为了揭示猪卵巢卵泡选择性闭锁机制,采用Real time PCR和HE染色方法,检测猪各阶段卵泡颗粒细胞中Fas和FasLmRNA表达和形态学变化;分析比较不同发育阶段卵泡中颗粒细胞Fas和FasLmRNA表达差异及细胞凋亡程度。结果表明,健康的大(5 mm)、中(3～5 mm)、小(3 mm)卵泡,早期闭锁的大、中、小卵泡以及晚期闭锁的大、中、小卵泡壁层颗粒细胞都有Fas和FasLmRNA表达。早期闭锁卵泡颗粒细胞Fas和FasLmRNA相对表达量高于健康卵泡与晚期闭锁卵泡。早期闭锁小卵泡FasLmRNA相对表达量与大、中、小健康卵泡相比均有显著差异(P0.05);状态相同的大、中、小卵泡间Fas与FasLmRNA相对表达量均无显著差异(P0.05);表明Fas/FasL系统在猪卵巢卵泡选择性闭锁过程中,对颗粒细胞凋亡具有重要的调节作用。     

12-(取代苯氧异丁酰氧亚氨基)-1,15-十五内酯的合成及除草活性

通过取代苯氧异丁酸与12-(羟基亚氨基)十五内酯的反应,合成了取代苯氧异丁酰氧亚氨基十五内酯,并测定了其对苋菜的除草活性。所有化合物均经过1H NMR、13C NMR和元素分析确证。初步的生物活性测定结果表明,目标化合物 Ⅲa~Ⅲd 的EC50值分别为34.570、46.492、55.385、50.114 mg/L,其活性比对照药剂2,4-D(117.325 mg/L)高,而比苯磺隆(22.381 mg/L)低。     

Reduction of elasmobranch by-catch in the hake semipelagicnear-bottom longline fishery in the Algarve (Southern Portugal)

ABSTRACT:   Elasmobranch fish, particularly deep-sea sharks, are the mostimportant component of the by-catch of the hake semipelagic near-bottom 'pedra-e-bola' longlinefishery in the Algarve (South Portugal) and most of these fish arediscarded. The effects of the removal of the lower hooks were evaluated,in terms of target and by-catch reductions, by quantifying the catchesof each hook relative to the distance from the bottom. The analysisshowed that most European hake ( Merluccius merluccius ), thetarget species of this fishery, were caught in the middle rangeof the hooks, with very few individuals caught near the bottom,whereas for sharks the situation was the opposite, with most hookednear the bottom. The removal of the lower three pairs of hooks wouldresult in a small reduction in the catch of the target species,but a much more significant reduction in elasmobranch by-catch.In the specific case of the blackmouth catshark ( Galeus melastomus ),discard mortality would be further minimized due to the fact thatthe lower hooks capture significantly smaller animals that are alwaysdiscarded compared with hooks that are more distant from the bottom.     

Role of aloperine on ischemia-reperfusion-induced injury and inflammatory response in H9c2 cardiomyocytes

AIM: To explore the role of aloperine in ischemia-reperfusion (I/R)-induced H9c2 cardiomyocyte injury and inflammation.METHODS: The H9c2 cardiomyocytes were cultured under hypoxia and re-oxygenation conditions to simulate ischemia-reperfusion (SI/R) injury. After treatment with aloperine at various doses, the cell viability was measured by MTT assay. The cell apoptosis was analyzed by flow cytometry. Simultaneously, the levels of lactate dehydrogenase (LDH), malonaldehyde (MDA) and caspase-3 activity were detected by the commercial kits. The levels of inflammatory cytokines were also detected by ELISA. Moreover, the effects of aloperine on the activation of PI3K/AKT signaling pathway were determined by Western blot.RESULTS: Pre-treatment with aloperine remarkably abated the inhibitory effect of SI/R on H9c2 cell viability, and decreased the elevations of LDH and MDA triggered by SI/R (P<0.05). Pre-treatment with aloperine dramatically suppressed the cell apoptosis induced by SI/R treatment (P<0.05), concomitant with the decrease in caspase-3 activity and increase in Bcl-2/Bax ratio (P<0.05). In contrast to SI/R group, aloperine treatment notably restrained the concentrations of pro-inflammatory cytokines, including interleukin-6, tumor necrosis factor-α and interleukin-1β (P<0.05). Furthermore, aloperine remarkably increased the protein levels of p-PI3K and p-AKT. While blocking the PI3K/AKT pathway with its specific inhibitor LY294002, the viability-promoting, anti-apoptotic and anti-inflammatory effects of aloperine on the H9c2 cells were obviously attenuated (P<0.05).CONCLUSION: Alope-rine protects against cardiomyocytes from I/R injury and inhibits inflammatory responses by activating the PI3K/AKT signaling pathway, implying a potential benefic role of aloperine against myocardial I/R injury.     

Mixed‐method study on medicinal herb collection in relation to wildlife conservation: the case of giant pandas in China

Medicinal herb collection has historical and cultural roots in many rural communities in developing countries. Areas where herb collection occurs may overlap with biodiversity hotspots and crucial habitat of endangered and threatened species. However, impacts of such practices on wildlife are unknown and possibly underestimated, perhaps due to the elusive nature of such activities. We examined this phenomenon in Wolong Nature Reserve, China, a protected area in the South‐Central China biodiversity hotspot that also supports a community of Tibetan, Qiang and Han people who use herb collection as a supplementary source of livelihood. We adopted a participatory approach in which we engaged local people in outlining spatial and temporal dynamics of medicinal herb collection practices. We found that the overall spatial extent of herb collection increased in the past two decades. We then overlaid herb collection maps with localities of giant panda (Ailuropoda melanoleuca) feces collected over two time points in the reserve. Using a Bayesian parameter estimation, we found evidence for declined giant panda occurrence in the areas most recently impacted by emerging medicinal herb collection. Our methodology demonstrates the potential power of integrating participatory approaches with quantitative methods for processes like herb collection that may be difficult to examine empirically. We discuss future directions for improving explanatory power and addressing uncertainty in this type of mixed‐method, interdisciplinary research. This work has implications for future attempts to understand whether and how prevalent but subtle human activities may affect wildlife conservation.