爆发型种群铜锤草增长的密度调节

“生态入侵”已成为国际上生态学领域关心的热点问题之一 ,尤其对引种引起的生态灾难已越来越受到人们的广泛关注。以引进种铜锤草为研究对象 ,通过实验从形态及数量动态、产量等方面考察铜锤草种群调控特点。研究表明 ,铜锤草种群的密度制约主要有以下特点 :①铜锤草单株构件具有随种群密度的增加调节自身数量和生物量的能力 ,以叶构件的数量和生物量对密度的反应最灵敏。②密度对种群数量动态的调节表现在个体和构件两个水平。铜锤草种群叶构件调节表现出各密度种群单株叶密度有如下趋势 :低密度种群 >中等密度种群 >高密度种群 ,而个体数量调节仅出现在高密种群。③密度对单株生物量和小鳞茎产量影响极显著 ;单株生物量与种群密度的关系基本符合 - 3/2幂定律 ,小鳞茎产量与种群密度也表现出近似的幂函数关系。     

核辐射对大深度快速上浮脱险致减压病大鼠相关指标的影响*

目的: 探讨不同剂量核暴露后不同时间对大深度快速上浮脱险致减压病大鼠模型的发病率、死亡率及损伤指标的影响。方法: 80只SD雄性大鼠,随机分成空白对照组、脱险对照组和6个干预组(4 Gy辐射后4 h脱险、6 Gy辐射后4 h脱险、12 Gy辐射后4 h脱险、4 Gy辐射后8 h脱险、6 Gy辐射后8 h脱险、12 Gy辐射8 h后脱险),每组10只。干预组动物先采用不同剂量γ射线外照射(4、6、12 Gy),再进行大深度快速上浮脱险实验(最大加压深度150 m),分析大鼠肺W/D、脾指数及血浆IL-1β的变化。结果: 与脱险对照组比较,核辐射后脱险大鼠的减压病发病率及死亡率明显上升。4 Gy、6 Gy照射4 h后上浮脱险的大鼠发病率和死亡率较照射8 h后高。12 Gy辐射后4 h及8 h脱险大鼠的减压病的发病率及死亡率均比低剂量照射组明显增高,死亡率尤其明显。和发病率及死亡率的变化相一致,肺组织湿/干比、肺组织病理损伤程度、脾指数下降也表现同样的变化趋势:较低剂量(4 Gy、6 Gy)辐射后4 h改变明显,8 h改变不明显,而高剂量(12 Gy)辐射后4、8 h均变化明显。和空白对照组及脱险对照组相比较,各辐射后脱险组的血浆IL-1β浓度均显著上升。结论: 核辐射引起放射性肺损伤、免疫功能下降及血浆炎症因子浓度升高,会增加大鼠快速上浮脱险致减压病的风险。     

Mitochondrial genomes and avian phylogeny: complex characters and resolvability without explosive radiations

We improve the taxon sampling for avian phylogeny by analyzing 7 new mitochondrial genomes (a toucan, woodpecker, osprey, forest falcon, American kestrel, heron, and a pelican). This improves inference of the avian tree, and it supports 3 major conclusions. The first is that some birds (including a parrot, a toucan, and an osprey) exhibit a complete duplication of the control region (CR) meaning that there are at least 4 distinct gene orders within birds. However, it appears that there are regions of continued gene conversion between the duplicate CRs, resulting in duplications that can be stable for long evolutionary periods. Because of this stable duplicated state, gene order can eventually either revert to the original order or change to the new gene order. The existence of this stable duplicate state explains how an apparently unlikely event (finding the same novel gene order) can arise multiple times. Although rare genomic changes have theoretical advantages for tree reconstruction, they can be compromised if these apparently rare events have a stable intermediate state. Secondly, the toucan and woodpecker improve the resolution of the 6-way split within Neoaves that has been called an "explosive radiation." An explosive radiation implies that normal microevolutionary events are insufficient to explain the observed macroevolution. By showing the avian tree is, in principle, resolvable, we demonstrate that the radiation of birds is amenable to standard evolutionary analysis. Thirdly, and as expected from theory, additional taxa breaking up long branches stabilize the position of some problematic taxa (like the falcon). In addition, we report that within the birds of prey and allies, we did not find evidence pairing New World vultures with storks or accipitrids (hawks, eagles, and osprey) with Falconids.     

Who can open the flower? Assessment of the flower opening force of mammal‐pollinated Mucuna macrocarpa

Effective pollinators in Fabaceae species with papillionaceous flowers should have sufficient force to open the petals and expose the stamens and pistils from the keel petals. Here, we assessed the force that is required (operative force) to open the petals of the mammal‐pollinated Mucuna macrocarpa, in parallel with estimating the force of bee species. The operative force of M. macrocarpa was quantified by a digital force gauge and the force of three bee species that frequent these flowers was estimated from body mass. The operative force was 1.635 ± 0.146 (mean ± SD) newton (N). This force was far larger than that estimated for the largest bee in the study area. In addition, the operative force of M. macrocarpa was 16–409 times greater than that of bee‐pollinated plants. Our results demonstrate that the operative force of M. macrocarpa flowers is adapted to mammalian openers, preventing potential nectar robbers.     

数字技术联合髓芯减压人工骨植入治疗早中期股骨头坏死

目的:回顾性分析在早中期股骨头坏死患者中,使用数字技术结合髓芯减压、人工骨植骨的临床疗效。方法:选取2013.01-2017.01符合纳入及排除标准的共计21名股骨头早中期患者。所有的股骨头坏死患者均统一按照国际股循环研究会标准,评定为ARCO Ⅰ期或者Ⅱ期。所有纳入患者均采用数字技术进行相关的术前准备,导板制作。然后术中行髓芯减压,死骨刮出,人工骨植骨术。术后通过视觉模拟评分和髋关节Harris评分系统对患者的疼痛和功能进行判定。结果:所有患者均接受至少半年的随访。患者在术后3个月及6月的Harris功能评分较术前具有显著的改善(P0.05)。21例患者中,优:12例,良:7例,尚可:2例。优良率为90.5%。股骨头保存率为100%。患者在术后1月、3月及6月的VAS疼痛评分较术前具有显著的降低(P0.05)。结论:与传统技术相比,使用数字技术结合髓芯减压,人工骨植骨在轻中度股骨头坏死患者的治疗中可显著改善功能,减轻疼痛,具有较明显的优势。     

胃肠减压对胃癌患者远端胃切除术围手术期效果的影响

目的:探讨胃癌患者远端胃大部切除术后放置鼻胃管引流的短期效果。方法:选取我科从2010年9月1日到2013年3月1日间318例胃癌行远端胃切除的患者,随机分为术后留置鼻胃管(NGT组)或不留置组(no NGT组),比较两组间围手术期的短期效果。结果:158例患者纳入NGT组,而160例患者纳入no NGT组。两组间在术后腹胀、持续呕吐、吻合口瘘、发热、肺部感染、伤口感染的发生率上无统计学差异(P0.05)。进一步分析65例既往有腹部手术史的患者(NGT组34例vs no NGT组31例),NGT组腹胀发生率(5.88%vs 29.03%,P0.05)显著低于no NGT组。结论:对于胃癌患者行远端胃切除术后不推荐放置鼻胃管;而对于既往有腹部手术史的患者,术后放置胃管可以降低腹胀的发生。     

髓芯减压联合干细胞移植治疗股骨头坏死患者的临床疗效及机制研究

目的:探讨采用髓芯减压与干细胞移植联合治疗股骨头坏死患者的临床疗效及可能机制。方法:选择我院确诊并治疗的股骨头患者76例作受试者,按随机数字表法分为两组,对照组38例采用干细胞移植治疗,治疗组38例在对照组基础上联合髓芯减压疗法。观察和比较两组患者的临床疗效、髋关节Harris评分及治疗前后血清PINP(Ⅰ型前胶原氨基端前肽)、CTX(Ⅰ型胶原C端肽)、OST(骨钙素)水平的变化情况。结果:治疗组总有效率及Harris评分均显著高于对照组(P0.05);治疗组患者血清PINP、CTX、OST水平较治疗前明显下降,并显著低于对照组,差异具有统计学意义(P0.05)。结论:髓芯减压与干细胞移植的联合应用可提高股骨头坏死患者的临床疗效和髋关节功能,可能与其降低患者血清PINP、CTX、OST水平有关。