Relationship between roving behaviour and the diet and client composition of the cleaner fish Labroides bicolor

Diet analyses and observations of cleaning behaviour of two cleaner fishes revealed that Labroides bicolor fed more on client mucus, but Labroides dimidiatus fed more on ectoparasites, and that L. bicolor interacted with fewer species (36 species) compared with L. dimidiatus (44 species). The client species which contributed most to the dissimilarity between cleaner species were the dusky farmerfish Stegastes nigricans and bicolor chromis Chromis margaritifer damselfishes, which L. dimidiatus interacted with more often than L. bicolor, and the striated Ctenochaetus striatus and brown Acanthurus nigrofuscus surgeonfishes, which L. bicolor interacted with more; L. bicolor interacted with all parrotfishes (Scaridae) more. These results confirm the importance of repeated interactions and partner choice in determining the nature of interactions in mutualisms.     

中下段胆管癌的预后影响因素分析*

目的:探讨中下段胆管癌的预后影响因素。方法:对79例中下段胆管癌患者的临床资料进行回顾性分析,采用Kaplan-Meier分析对确定的单因素进行生存率的描述,用Cox回归进行多因素分析,采用log-rank法对单因素进行生存分析评价。结果:79例患者1、3、5年生存率分别为70.2%,36.2%,19.1%,中位生存时间为19.8个月。行根治性手术患者1年、3年、5年生存率分别为87.9%、45.5%和24.2%,分别显著高于姑息性手术患者1年、3年、5年生存率(28.9%、14.3%和7.1%);行根治性手术患者的中位生存时间为34.5个月,较姑息性手术患者显著延长(8个月),根治术与姑息性手术1、3、5年生存率及中位生存时间比较四项均P<0.01,差异具有统计学意义。单因素分析显示肿瘤病理分化,慢性病史,淋巴结转移为影响中下段胆管癌预后的因素。多因素分析显示慢性病史、手术切缘、肿瘤病理分化程度是影响中下段胆管癌预后的独立危险因素。结论:慢性病史、手术切缘、肿瘤病理分化程度为中、下段胆管癌行切除术后预后的独立危险因素,根治性手术可提高中、下段胆管癌患者的生存率和延长其生存时间。     

Application of an improved continuous parallel shaken bioreactor system for three microbial model systems

A continuous parallel shaken bioreactor system, combining the advantages of shaken bioreactors with the advantages of continuous fermentation, was specifically manufactured from quartz glass and provides a geometric accuracy of <1 mm. Two different model systems (facultative anaerobic bacterium C. glutamicum, and Crabtree-negative yeast P. stipitis), whose growth behaviour and metabolite formation are affected by dilution rate and oxygen availability, were studied. The transition from non-oxygen to limited conditions as function of the dilution rate could precisely be predicted applying the approach described by Maier et al. (Biochem Eng J 17:155–167, 2004). In addition, the Crabtree-positive yeast S. cerevisiae was simultaneously studied in the continuous parallel shaken bioreactor system and in a conventional 1-L bioreactor, for comparison. Essentially the same results were obtained in both types of bioreactors. However, many more reading points were obtained with the parallel shaken bioreactor system in the same time at much lower consumption of culture media.     

Toluene biodegradation by <Emphasis Type="Italic">Pseudomonas putida</Emphasis> F1: targeting culture stability in long-term operation

The stability of Pseudomonas putida F1, a strain harbouring the genes responsible for toluene degradation in the chromosome was evaluated in a bioscrubber under high toluene loadings and nitrogen limiting conditions at two dilution rates (0.11 and 0.27 h⁻¹). Each experiment was run for 30 days, period long enough for microbial instability to occur considering previously reported studies carried out with bacterial strains encoding the catabolic genes in the TOL plasmid. At all tested conditions, P. putida F1 exhibited stable performance as shown by the constant values of the specific toluene degradation yield, CO₂ produced versus toluene degraded yield, and biomass concentration within each steady state. Benzyl alcohol, a curing agent causing TOL plasmid deletion in Pseudomonas strains, was present in the cultivation medium as a result of the monooxygenation of toluene by the diooxygenase system of P. putida F1. However, no mutant population growing at the expense of the extracellular excreted carbon or lysis products was established in the chemostat as confirmed by the constant dissolved total organic carbon (TOC) concentration and fraction of toluene degrading cells (approx. 100%). In addition, batch experiments conducted with both lysis substrate and toluene simultaneously confirmed that P. putida F1 preferentially consumed toluene rather than extracellular excreted carbon.     

Methane production in an UASB reactor operated under periodic mesophilic-thermophilic conditions

Methane production was studied in a laboratory-scale 10 L anaerobic upflow sludge bed (UASB) reactor with periodic variations of the reactor temperature. On a daily basis the temperature was varied between 35 and 45 degrees C or 35 and 55 degrees C with a heating period of 6 h. Each temperature increase was accompanied by an increase in methane production and a decrease in the concentration of soluble organic matter in the effluent. In comparison to a reactor operated at 35 degrees C, a net increase in methane production of up to 22% was observed. Batch activity tests demonstrated a tolerance of mesophilic methanogenic populations to short-term, 2-6 h, temperature increases, although activity of acetoclastic methanogens decreased after 6 h exposure to a temperature of 55 degrees C. 16S sequencing of DGGE bands revealed proliferation of temperature-tolerant Methanospirillum hungatii sp. in the reactor.     

麻醉诱导时血压下降对术后恶心呕吐的影响

目的：观察麻醉诱导时血压下降与术后恶心呕吐的关系.方法：选择ASAⅠ-Ⅱ级的经腹胆囊切除术患者40例,按麻醉诱导时血压比基础值下降的程度分为2组,每组20例.A组：SBP比基础血压下降〉30%;B组：SBP比基础血压下降〈30%.术后随访病人48小时,记录病人恶心呕吐的发生情况.结果：麻醉诱导时血压下降对术后恶心呕吐有明显影响.结论：麻醉期间维持血流动力学稳定能降低PONV的发生.     

Biological detoxification of precious metal processing wastewaters

A biological treatment plant is utilized at the Homestake Mine in Lead, SD, to effect detoxification of a daily discharge of 4 million gallons of wastewater. The wastewater matrix requiring treatment contains cyanide, ammonia, toxic heavy metals, and a variable component of toxic chemicals associated with extractive metallurgy and mining operations. Rotating biological contactors (RBCs) are used to attach the biofilm. Cyanides and heavy metals concentrations are reduced by 95–98%. The treated discharge makes up as much as 60% of the total flow in a cold‐water trout fishery. This receiving stream, which remained lifeless for over 100 years as a mine drainage, has now become an established trout fishery and recently yielded a state record trout.     

Stability of aerobic granules during long-term bioreactor operation

Aerobic granular sludge technology has been extensively studied over the past 20 years and is regarded as the upcoming new standard for biological treatment of domestic and industrial wastewaters. Aerobic granules (AG) are dense, compact, self-immobilized microbial aggregates that allow better sludge-water separation and thereby higher biomass concentrations in the bioreactor than conventional activated sludge aggregates. This brings potential practical advantages in terms of investment cost, energy consumption and footprint. Yet, despite the relevant advances regarding the process of AG formation, instability of AG during long-term operation is still seen as a major barrier for a broad practical application of this technology. This paper presents an up-to-date review of the literature focusing on AG stability, aiming to contribute to the identification of key factors for promoting long-term stability of AG and to a better understanding of the underlying mechanisms. Operational conditions leading to AG disintegration are described, including high organic loads, particulate substrates in the influent, toxic feed components, aerobic feeding and too short famine periods. These operational and influent wastewater composition conditions were shown to influence the micro-environment of AG, consequently affecting their stability. Granule stability is generally favored by the presence of a dense core, with microbial growth throughout the AG depth being a crucial intrinsic factor determining its structural integrity. Accordingly, possible practical solutions to improve granule long-term stability are described, namely through the promotion of minimal substrate concentration gradients and control of microbial growth rates within AG, including anaerobic, plug-flow feeding and specific sludge removal strategies.     

清代北京皇家园林植物景观与园林经营体系研究

园林的管理与经营是清代皇家园林存续的重要支撑。本研究结合清代宫廷文献,以记录内务府规章制度的《钦定总管内务府现行则例》为主要依据,探讨清代管理机构职责、收入来源与经营方式、支出与盈余管理,归纳出一个以种植生产为核心的管理经营框架。认为清代皇家园林在多次改革基础上,逐渐形成了管理范围清晰的部门划分。各部门除对园林进行日常维护外,主要承担各园以植物生产为核心的经营任务。通过对资源的精细利用以及种植—租赁相结合的土地管理模式,基本实现皇家园林“以园养园”的收支平衡体系。而这种经营方式造就了园林沿水源布局的大面积的作物景观背景以及园林中点缀的生产性植物景观。最终得出结论,认为清代皇家园林植物景观不仅具有观赏功能,更是支持园林存续的物质基础。     

Ⅰ、Ⅱ期乳腺癌行保乳术的近期疗效观察

目的探讨Ⅰ、Ⅱ期乳腺癌行保乳术的近期疗效。方法选择2014年8月~2016年4月我院收治的Ⅰ、Ⅱ期乳腺癌患者104例为研究对象,依据患者治疗方法的不同分为治疗组和对照组各52例,对照组实施改良根治术治疗,治疗组实施保乳术治疗,观察比较两组患者近期疗效。结果治疗组平均手术时间、术中出血量以及住院时间均明显少于对照组(P0.05);而且治疗组术后乳房美容效果优良率达94.2%,对照组为76.9%,两组比较差异有统计学意义(P0.05);两组病灶局部复发和转移情况比较,差异无统计学意义(P0.05)。结论早期乳癌患者接受保乳术治疗具有显著疗效,病灶局部复发与转移发生率小,而且患者乳房外形良好,达到美学标准,值得临床推广。