Ultra-fast underwater suction traps

Carnivorous aquatic Utricularia species catch small prey animals using millimetre-sized underwater suction traps, which have fascinated scientists since Darwin's early work on carnivorous plants. Suction takes place after mechanical triggering and is owing to a release of stored elastic energy in the trap body accompanied by a very fast opening and closing of a trapdoor, which otherwise closes the trap entrance watertight. The exceptional trapping speed--far above human visual perception--impeded profound investigations until now. Using high-speed video imaging and special microscopy techniques, we obtained fully time-resolved recordings of the door movement. We found that this unique trapping mechanism conducts suction in less than a millisecond and therefore ranks among the fastest plant movements known. Fluid acceleration reaches very high values, leaving little chance for prey animals to escape. We discovered that the door deformation is morphologically predetermined, and actually performs a buckling/unbuckling process, including a complete trapdoor curvature inversion. This process, which we predict using dynamical simulations and simple theoretical models, is highly reproducible: the traps are autonomously repetitive as they fire spontaneously after 5-20 h and reset actively to their ready-to-catch condition.     

Functional morphology of the feeding apparatus and evolution of proboscis length in metalmark butterflies (Lepidoptera: Riodinidae)

An assessment of the anatomical costs of extremely long proboscid mouthparts can contribute to the understanding of the evolution of form and function in the context of insect feeding behaviour. An integrative analysis of expenses relating to an exceptionally long proboscis in butterflies includes all organs involved in fluid feeding, such as the proboscis plus its musculature, sensilla, and food canal, as well as organs for proboscis movements and the suction pump for fluid uptake. In the present study, we report a morphometric comparison of derived long‐tongued (proboscis approximately twice as long as the body) and short‐tongued Riodinidae (proboscis half as long as the body), which reveals the non‐linear scaling relationships of an extremely long proboscis. We found no elongation of the tip region, low numbers of proboscis sensilla, short sensilla styloconica, and no increase of galeal musculature in relation to galeal volume, but a larger food canal, as well as larger head musculature in relation to the head capsule. The results indicate the relatively low extra expense on the proboscis musculature and sensilla equipment but significant anatomical costs, such as reinforced haemolymph and suction pump musculature, as well as thick cuticular proboscis walls, which are functionally related to feeding performance in species possessing an extremely long proboscis. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 291–304.     

辽宁省近5年痰培养主要病原菌分布及临床意义

了解住院患者痰培养的病原菌分布及其对常用抗菌药物的耐药情况,为临床合理用药提供参考。回顾性分析辽宁省2015年1月至2019年12月共3 878份痰标本感染菌鉴定结果和铜绿假单胞菌(Pseudomonas aeruginosa)的药敏试验结果。采用法国梅里埃VITEK 2 Compact全自动微生物鉴定仪进行菌种鉴定,并对从门诊和住院下呼吸道感染患者中分离的785株铜绿假单胞菌进行药物敏感试验分析。结果表明,痰培养病原菌以革兰阴性杆菌为主,占68.9%,其次为真菌。在革兰阴性杆菌中,铜绿假单胞菌占20.2%。铜绿假单胞菌对氨苄西林、呋喃妥英、复方新诺明、头孢呋辛(酯)、头孢曲松、头孢替坦、头孢唑啉的耐药性较高,每年的耐药率均高于95%。而对于阿米卡星、环丙沙星、头孢吡肟、头孢他啶、左氧氟沙星则出现较低的耐药性,5年的耐药率均低于50%。铜绿假单胞菌对阿米卡星、哌拉西林、头孢吡肟、美罗培南、亚胺培南的耐药率有逐年下降的趋势,而对环丙沙星、左氧氟沙星的耐药率有逐年上升的趋势。以上结果表明辽宁省近5年痰培养主要致病菌为革兰阴性杆菌,其中铜绿假单胞菌占很大的比例。铜绿假单胞菌易产生多重耐药性,必须加强耐药性监测,为临床提供最新的耐药性资料,以便更好地控制铜绿假单胞菌的感染,同时也对临床合理使用抗生素有指导意义。     

膜下滴灌土壤湿润范围对棉花根层土壤水热环境和根系耗水的影响

为探明膜下滴灌土壤湿润范围对棉花根区水热环境及棉花根系耗水的影响,设置滴头流量1.69（W₁₆₉）、3.46（W₃₄₆）和6.33 L·h^-1（W₆₃₃）3个水平,观测分析了棉花生育期土壤基质势、土壤温度及棉花根系生长和耗水分布状况.结果表明： 膜下滴灌土壤温度主要受光照影响;不同类型土壤湿润区之间的土壤温度差异不明显,不同土壤湿润区的膜下土壤温度对棉花根系耗水也没有明显影响.但是随着土壤湿润区由窄深型向宽浅型过渡,棉花根区土壤基质吸力在水平方向上分布更趋于均匀,而棉花根系耗水强度主要受土壤基质吸力分布的影响.宽浅型土壤湿润区（W₆₃₃）的棉花膜下内、边行根系耗水强度差值平均为0.67 mm·d^-1,有利于内、边行棉株生长整齐;窄深型土壤湿润区（W₁₆₉）的内、边行根系耗水强度差值平均为0.88 mm·d^-1,不利于内、边行棉株均匀生长.可见,膜下滴灌技术设计中,土壤湿润区不应小于覆膜宽度,应使膜下土壤整体湿润.     

Anti-inflammatory deficiencies in neutrophilic asthma: reduced galectin-3 and IL-1RA/IL-1β

Background

Galectin-3 (gal-3), a member of the β-galactoside-binding animal lectins, is involved in the recruitment, activation and removal of neutrophils. Neutrophilic asthma is characterized by a persistent elevation of airway neutrophils and impaired efferocytosis. We hypothesized that sputum gal-3 would be reduced in neutrophilic asthma and the expression of gal-3 would be associated with other markers of neutrophilic inflammation.

Methods

Adults with asthma (n = 80) underwent a sputum induction following clinical assessment and blood collection. Sputum was dispersed for a differential cell count and ELISA assessment of gal-3, gal-3 binding protein (BP), interleukin (IL)-1β, IL-1 receptor antagonist (RA), IL-8 and IL-6. Gal-3 and gal-3BP immunoreactivity were assessed in mixed sputum cells.

Results

Sputum gal-3 (median, (q1,q3)) was significantly reduced in neutrophilic asthma (183 ng/mL (91,287)) compared with eosinophilic (293 ng/mL (188,471), p = 0.021) and paucigranulocytic asthma (399 ng/mL (213,514), p = 0.004). The gal-3/gal-3BP ratio and IL-1RA/IL-1β ratio were significantly reduced, while gal-3BP and IL-1β were significantly elevated in neutrophilic asthma compared with eosinophilic and paucigranulocytic asthma.

Conclusion

Patients with neutrophilic asthma have impairment in anti-inflammatory ratio of gal-3/gal-3BP and IL-1RA/IL-1β which provides a further framework for exploration into pathologic mechanisms of asthma phenotypes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0163-5) contains supplementary material, which is available to authorized users.     

经支气管镜氩离子凝固术治疗伴有咯血的晚期中心型肺癌的临床观察

目的:探讨经支气管镜氩离子凝固术治疗伴有咯血的晚期中心型肺癌的疗效。方法:选取2011年12月-2013年6月期间我院收治的晚期中心型肺癌咯血的患者60例,将其随机分为观察组(30例)和对照组(30例),观察组给予经支气管镜氩离子凝固术联合全身化疗,对照组给予经支气管镜介入局部用药联合全身化疗,对比两组患者治疗后的临床疗效、24h动脉血气分析、肺功能、止血有效率及治疗后3天、3~7天,7天复发率以及总复发率和不良反应情况。结果:治疗后两组患者的临床症状均得到一定的改善,观察组患者的临床有效率为80.0%(24/30)显著高于对照组的56.7%(17/30),差异具有统计学意义(P0.05);观察组患者在发热、呼吸困难、咳嗽、胸痛及咯血等方面的症状缓解率均显著高于对照组,比较差异均有统计学意义(均P0.05);治疗后观察组肺功能和24h动脉血气分析各项指标均显著优于治疗前,观察组患者的的以上指标均显著优于对照组,差异均有统计学意义(均P0.05);治疗后观察组患者的止血有效率为100%,显著高于对照组的56.7%(17/30),且观察组患者术后3天、3~7天,7天复发率以及总复发率均小于对照组,两组止血有效率和总复发率比较差异均有统计学意义(均P0.05);观察组患者不良反应的发生率为10.0%,对照组为13.3%,两组相比无显著差异(P0.05)。结论:经支气管镜氩离子凝固术联合全身化疗治疗老年晚期中心型肺癌咯血具有较好的临床疗效,止血迅速有效,且复发率低,能够缓解呼吸道阻塞症状,改善呼吸功能,是一种不错的选择,值得在临床普遍推广与应用。     

Angular roughshark Oxynotus centrina (Squaliformes: Oxynotidae) in captivity feeding exclusively on elasmobranch eggs: an overlooked feeding niche or a matter of individual taste?

A specimen of angular roughshark Oxynotus centrina has been kept successfully in captivity for the first time. Over a period of 24 months, the specimen preyed exclusively on the contents of elasmobranch egg cases, suggesting a specialized trophic niche.     

基于吸虫塔（Suction Trap）的蚜虫测报预警网络的构建

吸虫塔（suction trap）是用来监测麦类蚜虫和大豆蚜Aphis glycines迁飞种群动态的大型植保测报设备,在欧洲和北美洲已经呈网络安装分布,为蚜虫的预警和防控提供重要依据。作者借鉴欧美吸虫塔的工作原理和设计,设计并生产了符合我国地域特征的吸虫塔设备,在东北、华北、华中、华东、西北等地布点安装了21台,用于监控我国麦类蚜虫和大豆蚜的迁飞动态,初步形成覆盖我国小麦主产区和大豆主产区的吸虫塔网络系统。此吸虫塔总高8.8m,由底部轴流风机运转产生的负压在塔顶部形成吸力,将迁飞经附近的小型昆虫吸入塔管,最后落入下部的样品收集瓶中,以此获得其迁飞的动态数据。吸虫塔网络的构建和完善,不仅为麦类蚜虫和大豆蚜的监控提供支撑,同时也为其它小型迁飞性昆虫监测、种群动态、生物多样性、生物信息学等研究提供数据。     

Implications of short and long term critical flux experiments for laboratory-scale MBR operations

This paper evaluates the critical flux obtained by different techniques including tests with different flux step lengths (20 and 40 min and 7 days) and modes of operation (continuous and intermittent) under low and high MLSS concentrations. The paper also analyses a couple of long-term tests (flow rate of 40 and 20 L/day) to obtain the time required to reach the critical flux experimentally and compares those values with the results obtained numerically from a mathematical model. It was found that intermittent mode with membrane relaxation was useful in controlling the fouling of membrane and in restoring the membrane from fouling at lower MLSS.