mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
胸椎旁注射治疗对开胸术后慢性疼痛病人神经病理性疼痛发生的影响

开胸术后慢性疼痛(chronic post-thoracotomy pain, CPTP)发生率可达50%,位居所有手术后慢性疼痛之首,处理不当可能发展为神经病理性疼痛.依据不同评估方法,CPTP病人神经病理性疼痛发生率约为52% ~ 66%,严重影响病人外科康复和生活质量.如何为CPTP病人神经病理性疼痛提供有效的预防和治疗方法,仍是当前临床亟待解决的问题.随着超声引导神经阻滞技术的发展,胸椎旁阻滞成功率提高,并发症减少,可有效用于术后急性疼痛的治疗,但目前国内外尚无胸椎旁注射治疗用于预防CPTP病人神经病理性疼痛发生的相关报道.本研究拟通过与肋间神经注射治疗比较,评价胸椎旁注射治疗对CPTP病人神经病理性疼痛发生的影响.
豆纹动脉影像学特征与基底节区血管性病变关系的研究进展

豆纹动脉(lenticulostriate arteries, LSAs)是穿支动脉的一种,主要由大脑中动脉(middle cerebral artery, MCA)发出,并与其垂直的细小动脉。由于豆纹动脉形态及位置特殊,而且容易引起基底节区出血,因而也被称为“出血动脉”。豆纹动脉急性梗死在DWI上表现为深部白质高信号,以腔隙性梗死为主,但有部分患者出现进展性运动缺损(即神经功能恶化)。如何显示豆纹动脉对于影像学来说是一个巨大的挑战,目前的成像技术多种多样,这些技术在豆纹动脉的评估和诊断上发挥着巨大的作用。笔者旨在总结豆纹动脉的起源、分布及供血范围,研究豆纹动脉在解剖学和影像学上的数量、长度、管径及其临床意义,以及评价与豆纹动脉相关的病变的影像学特征。
肠道菌群与结直肠癌的发生发展

人体结肠中含有大量微生物,其中细菌占95%以上,大约有1014个,1000多种,以厚壁菌门及拟杆菌门为主.这些微生物与宿主消化道微环境共同构成了复杂的肠道微生态系统.肠道微生态失衡与胃肠道炎症、肿瘤、肥胖、糖尿病、过敏性哮喘以及神经精神性疾病等均有着密切关系,而宿主的饮食生活习惯、健康状况、遗传背景、抗生素使用及其生活环境中所接触的病原微生物又在一定程度上影响着肠道菌群的结构和功能.
Total plant performance evaluation based on big data: Visualization analysis of TE process

The performance evaluation of the process industry,which has been a popular topic nowadays, can not only find the weakness and verify the resilience and reliability of the process, but also provide some suggestions to improve the process benefits and efficiency. Nevertheless, the performance assessment principally concentrates upon some parts of the entire system at present, for example the controller assessment. Although some researches focus on the whole process, they aim at discovering the relationships between profit, society, policies and so forth, instead of relations between overall performance and some manipulated variables, that is, the total plant performance. According to the big data of different performance statuses, this paper proposes a hierarchical framework to select some structured logic rules frommonitored variables to estimate the current state of the process. The variables related to safety and profits are regarded as key factors to performance evaluation. To better monitor the process state and observe the performance variation trend of the process, a classificationvisualization method based on kernel principal component analysis (KPCA) and self-organizing map (SOM) is established. The dimensions of big data produced by the process are first reduced by KPCA and then the processed data will be mapped into a two-dimensional grid chart by SOM to evaluate the performance status. The monitoring method is applied to the Tennessee Eastman process. Monitoring results indicate that off-line and on-line performance status can be well detected in a two-dimensional diagram.
银川某综合管廊工程项目消防体系的构建与分析

综合管廊是集各专业管线于一体的市政隧道,发生火灾时人员的逃生、消防排烟及火灾扑救等不同于一般的工业与民用建筑。以实际案例为基础,从手提式灭火器的布置和自动灭火系统的设计两方面来构建综合管廊的消防体系,以确保综合管廊的安全运营。
浅析手抬泵与超高层建筑室内消防系统的连接方式

介绍了手抬泵的特点及其与超高层建筑室内消防系统的连接方式,通过国内城市消防站所需配备的消防车的技术性能及国产手抬泵的技术参数并结合工程实例,分析了消防系统设计中不同连接方式的限制条件及可行性,阐明了手抬泵的技术性能是工程设计中确定连接方式的重要依据。
Design & Beyond Design: Inspirations from the SPURS Program at MIT

As a SPURS fellow at the Massachusetts Institute of Technology (MIT) from August 2014 to June 2015, I had a great opportunity to participate in many MIT courses and professional trips and interviews offered by SPURS. Based on this experience, this paper discusses inspiration gotten from American planning practice and education, such as the Big-Dig of Boston the High Line Park of New York, involving complicated space shaping content, pre-simulation analysis, continuous post-evaluation of policy-making, and cross-disciplinary research for urban problem solving.
Research on Planning for Integrated Development of Marine and Terrestrial Industries in the Blue Economic Zone of Shandong Peninsula

The measuring of the integration degree between marine and terrestrial industries is a crucial part in formulating strategies of industrial adjustment and industrial development for coastal regions. Taking the Blue Economic Zone of Shandong Peninsula as an example, this paper conducted grey correlation analysis on the correlation between the three industrial sectors in marine and terrestrial areas, as well as on the internal interaction between main industries in marine and terrestrial areas. In the end, the paper puts forward related suggestions on the integrated development of marine and terrestrial industries in the Blue Economic Zone of the Shandong Peninsula.
时间序列分析在空气污染与健康领域的应用及其R软件实现

目的探讨时间序列分析在空气污染健康影响研究领域的应用与软件实现,为我国相关工作提供实用的操作方法参考.方法利用美国芝加哥市1987年至2000年大气污染与死亡数据,分别采用广义线性模型、广义相加模型,并结合分布滞后模型,介绍时间序列分析的基本理论与R软件实现步骤.结果时间序列分析可在R软件中方便实现.结论R软件为时间序列分析在空气污染流行病学研究中的应用提供了相对成熟的软件包,在实际研究中值得推广.
脓毒症:临床如何判别组织低灌注

脓毒症的定义为针对感染的宿主反应失调导致危及生命的器官功能障碍,是导致死亡的重要原因。脓毒性休克是脓毒症的特殊类型,出现严重的循环障碍及细胞代谢异常,导致病死率大幅增加。随着人口老龄化、侵入性医疗手段和免疫抑制剂的广泛应用,脓毒症的发病率不断增加,是临床工作中面临的重要问题之一。微循环功能障碍是导致脓毒症患者器官功能障碍和死亡的重要原因之一,早期识别组织低灌注,对于制定合理的血流动力学支持方案、防止不可逆的器官损伤至关重要。脓毒症患者是否存在组织低灌注可通过临床表现、血乳酸水平和组织氧供/氧耗(oxygen delivery/oxygen consumption,DO_2/VO_2)来进行临床判别。
食管结核并发食管瘘一例

讨论2015年WHO估算中国结核病的发病人数约为93万例,是全球22个结核病高负担国家之一,结核病仍是我国需要重点防控的重大传染病。食管结核临床极少见,好发于食管中下段,可有吞咽困难、胸痛、低热和消瘦等临床表现,是食管壁因MTB感染而出现的渗出、坏死和增生性病变。临床上原发食管结核极少见,多数食管结核继发于临近脏器,尤其是纵隔、肺门淋巴结和肺结核,这与MTB直接侵袭或经淋巴至食管黏膜下层有关。内镜下多将食管结核分为隆起型、溃疡型、窦道型、憩室和狭窄型4种类型,其中溃疡型和隆起型病例在内镜下较常见。近年来随着内镜技术的发展,食管结核的发病率逐渐增高。
bZIP73:影响粳稻耐低温的关键基因

水稻(Oryza sativa L.)是最主要的粮食作物之一,全球种植面积约1.6亿公顷,养活了世界约35亿人口。缘于水稻起源于亚热带地区,因此对低温非常敏感。世界上约1500万公顷的稻区(包括24个国家,如中国、日本和朝鲜等)遭遇过严重的冷害问题。冷害是高纬度高海拔稻区水稻生长发育的主要限制因素乊一,我国稻区南北分布相差约34度(最北端漠河53°27'N,最南端海南18°90'N),海拔分布相差2700 m (从东南沿海到云贵高原),因此平均每3~4年就会遭遇一次较大规模的冷害。除此乊外,每年秋季“寒露”节气前后,即9月中下旬,是华南及长江中下游一带水稻抽穗扬花的关键时期,如遇低温危害就会造成抽穗扬花受阻、授粉和受精无法正常迚行、空壳率增加,从而造成晚稻大幅减产。2010和2011年9月下旬,湖南省就发生了自1997年以来最严重的寒露风天气,导致晚稻产量大幅减产。近年来,极端气候频繁,倒春寒和寒露风等低温灾害逐年增加,每年我国因此造成的粮食损失高达3~5亿吨,严重影响粮食供给。
Characterization and acid-mobilization study for typical ironbearing clay mineral

In this study, iron speciation in five standard clay samples was characterized. Iron mobilization from these clays was then measured in acidic media. For comparison, a commercially available Arizona test dust (ATD) was also observed. The results showed that the free-Fe contents of clays were commonly lower than that of dust aerosols. The components of clays were dominant by the structural Fe held in the aluminosilicate lattice. The iron solubility of the clays were in the order of KGa-2 > SWy-2 > CCa-2 > IMt-2 > NAu- 2. Based upon the Mossbauer spectrum and transmission electron microscopy (TEM) analysis, the Fe(II) fraction and the Fe/Si ratio of clay particles changed after dissolution, suggesting the total Fe solubility depended on the Fe atom states existing within the aluminosilicate lattice. The Fe in KGa-2 and SWy-2 was most likely substituted for alkaline elements as the interlayer ions held by ionic bonds in the aluminosilicate, which are more liable to dissolution. However, the Fe in NAu-2 was more likely to be bound by strong covalent bonds in aluminosilicate mineral, which is less soluble. The much highly soluble Fe in ATD was not only linked to the dissolution of an appreciable fraction of Fe(II), but also could be attributed to the fact that the Fe bonds in the clay fraction of ATD were mainly present as ionic bonds. The TEM images showed that reacted clay particles displayed less aggregate particles, with nanoparticle aggregates and the Fe/S-rich tiny particles attached to the remains.
Size distribution and source of heavy metals in particulate matter on the lead and zinc smelting affected area

In order to understand the size distribution and the main kind of heavy metals in particulate matter on the lead and zinc smelting affected area, particulate matter (PM) and the source samples were collected in Zhuzhou, Hunan Province fromDecember 2011 to January 2012 and the results were discussed and interpreted. Atmospheric particles were collected with different sizes by a cascade impactor. The concentrations of heavy metals in atmospheric particles of different sizes, collected from the air and from factories, were measured using an inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that the average concentration of PM, chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) in PM was 177.3 ± 33.2 μg/m~3, 37.3 ± 8.8 ng/m~3, 17.3 ± 8.1 ng/m~3, 4.8 ± 3.1 ng/m~3 and 141.6 ± 49.1 ng/m~3, respectively. The size distribution of PM displayed a bimodal distribution; the maximum PM size distribution was at 1.1–2.1 μm, followed by 9–10 μm. The size distribution of As, Cd and Pb in PM was similar to the distribution of the PM mass, with peaks observed at the range of 1.1–2.1 μmand9–10 μmrangeswhile for Cr, only a single-mode at 4.7–5.8 μmwas observed. PM (64.7%), As (72.5%), Cd (72.2%) and Pb (75.8%) were associated with the finemode below 2.1 μm, respectively, while Cr (46.6%) was associated with the coarse mode. The size distribution characteristics, enrichment factor, correlation coefficient values, source information and the analysis of source samples showed that As, Cd and Pb in PM were the typical heavy metal in lead and zinc smelting affected areas, which originated mainly from lead and zinc smelting sources.
Understanding unusually high levels of peroxyacetyl nitrate (PAN) in winter in Urban Jinan, China

Peroxyacetyl nitrate (PAN), as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient levels of PAN were measured continuously by an automatic gas chromatograph equipped with an electron capture detector (GC–ECD) analyzer at an urban site in Jinan (China), with related parameters including concentrations of O_3, NO,NO_2, PM_(2.5), HONO, thephotolysis rate constant ofNO_2 andmeteorological factors observed concurrently. Themean and maximum values of PAN concentration were (1.89 ± 1.42) and 9.61 ppbv respectively in winter, and (2.54 ± 1.44) and 13.47 ppbv respectively in summer. Unusually high levels of PAN were observed during severe haze episodes in winter, and the formation mechanisms of them were emphatically discussed. Study showed that high levels of PAN in winter were mainly caused by local accumulation and strong photochemical reactions during haze episodes, while mass transport played only a minor role. Accelerated photochemical reactions (compared to winter days without haze) during haze episodes were deduced by the higher concentrations but shorter lifetimes of PAN, which was further supported by the sufficient solar radiation in the photolysis band alongwith the high concentrations of precursors (NO_2, VOCs) and HONO during haze episodes. In addition, significant PAN accumulation during calm weather of haze episodes was verified bymeteorological data.
胎儿脐尿管未闭合并脐部占位1例报告

本文报道1例胎儿脐尿管未闭患儿,早孕期超声发现脐部囊性占位且与膀胱相通,逐渐长大至中孕期末消失、代之以稍强回声团,晚孕期该稍强回声团长大且与腹腔内容物相通。出生后术后诊断为“脐膨出,脐尿管瘘伴膀胱部分膨出”等,术后预后较好。
Lithium/Silver-Doped Cu_2ZnSnS_4 with Tunable Band Gaps and Phase Structures: a First-Principles Study

Doping is an effective approach for improving the photovoltaic performance of Cu_2ZnSnS_4 (CZTS). The doping by substitution of Cu atoms in CZTS with Li and Ag atoms is investigated using density functional theory. The results show that the band gaps of Li_(2x)Cu_(2(1-x))ZnSnS_4 and Ag_(2x)Cu_(2(1-x))ZnSnS_4 can be tuned in the ranges of 1.30–3.43 and 1.30–1.63 eV, respectively. The calculation also reveals a phase transition from kesterite to wurtzite-kesterite for Li_(2x)Cu_(2(1-x))ZnSnS_4 as x is larger than 0.9. The tunable band gaps of Li_(2x)Cu_(2(1-x))ZnSnS_4 and Ag_(2x)Cu_(2(1-x))ZnSnS_4 make them beneficial for achieving band-gap-graded solar cells.
Friction surfacing of AISI 316 over mild steel: A characteriation study

An attempt has been made with overlaying of stain-less steel on mild steel by the technique of friction surfacing. This investigation elaborates the excellence acquired by different combination of the process parameters used in friction surfacing specifically traverse speed of the cross slide, speed of rotation of the spindle and the uniaxial compressive load. Excellent overlaying has been obtained amongst the chosen materials. To which, the coating can be done with various set of process parameters. It has been observed that the bond strength of the coating was found to be at a maximum of 502 MPa by ram tensile test. Based upon this results the surface methodology was characterized with scanning electron microscope. For authenticating the results, the coated specimen was subjected to salt spray test. The bonding microstructure was characterized using optical microscopy and X-ray diffraction. Corrosion resistance of surfaced coatings was found to be more inferior to that of mechtrode material and greater with the substrate.
Age hardening process modeling and optimization of aluminum alloy A356/Cow horn particulate composite for brake drum application using RSM, ANN and simulated annealing

Most conventional ceramic based aluminum metal matrix composites (MMCs) are either heavy, costly or combination of both. In order to reduce cost and weight, while at the same time maintaining quality, cow horn particles (CHp) was used with aluminum alloy A356 to produce MMC for brake drum application and other engineering uses. The aim of this research is to model the age hardening process of the produced composite using response surface methodology (RSM) and artificial neural network (ANN), and to use the developed ANN as fitness function for a simulated annealing optimization algorithm (SA-NN system) for optimization of age hardening process parameters. The results show that ANN modeled the age hardening data excellently and better than RSM with a correlation coefficient of experimental response with ANN predictions being 0.9921 as against 0.9583 for the RSM. The SA-NN system optimized process parameters were in very close agreement with the experimental values with the maximum relative error of 1.2%, minimum of 0.35% and average of 0.71%.
Pre-mRNA modifications and their role in nuclear processing

Background: Cellular non-coding RNAs are extensively modified post-transcriptionally, with more than 100 chemically distinct nucleotides identified to date. In the past five years, new sequencing based methods have revealed widespread decoration of eukaryotic messenger RNA with diverse RNA modifications whose functions in mRNA metabolism are only beginning to be known. Results: Since most of the identified mRNA modifying enzymes are present in the nucleus, these modifications have the potential to function in nuclear pre-mRNA processing including alternative splicing. Here we review recent progress towards illuminating the role of pre-mRNA modifications in splicing and highlight key areas for future investigation in this rapidly growing field. Conclusions: Future studies to identify which modifications are added to nascent pre-mRNA and to interrogate the direct effects of individual modifications are likely to reveal new mechanisms by which nuclear pre-mRNA processing is regulated.
Using partial evaluation in holistic subgraph search

Because of its wide application, the subgraph matching problem has been studied extensively during the past decade. However, most existing solutions assume that a data graph is a vertex/edge-labeled graph (i.e., each vertex/ edge has a simple label). These solutions build structural indices by considering the vertex labels. However, some real graphs contain rich-content vertices such as user profiles in social networks and HTML pages on the World Wide Web. In this study, we consider the problem of subgraph matching using a more general scenario. We build a structural index that does not depend on any vertex content. Based on the index, we design a holistic subgraph matching algorithm that considers the query graph as a whole and finds one match at a time. In order to further improve efficiency, we propose a “partial evaluation and assembly” framework to find subgraph matches over large graphs. Last but not least, our index has light maintenance overhead. Therefore, our method can work well on dynamic graphs. Extensive experiments on real graphs show that our method outperforms the state-of-the-art algorithms.
VBMq: pursuit baremetal performance by embracing block I/O parallelism in virtualization

Barely acceptable block I/O performance prevents virtualization from being widely used in the High- Performance Computing field. Although the virtio paravirtual framework brings great I/O performance improvement, there is a sharp performance degradation when accessing high-performance NAND-flash-based devices in the virtual machine due to their data parallel design. The primary cause of this fact is the deficiency of block I/O parallelism in hypervisor, such as KVM and Xen. In this paper, we propose a novel design of block I/O layer for virtualization, named VBMq. VBMq is based on virtio paravirtual I/O model, aiming to solve the block I/O parallelism issue in virtualization. It uses multiple dedicated I/O threads to handle I/O requests in parallel. In the meanwhile, we use polling mechanism to alleviate overheads caused by the frequent context switches of the VM's notification to and from its hypervisor. Each dedicated I/O thread is assigned to a non-overlapping core to improve performance by avoiding unnecessary scheduling. In addition, we configure CPU affinity to optimize I/O completion for each request. The CPU affinity setting is very helpful to reduce CPU cache miss rate and increase CPU efficiency. The prototype system is based on Linux 4.1 kernel and QEMU 2.3.1. Our measurements show that the proposed method scales graciously in the multi-core environment, and provides performance which is 39.6x better than the baseline at most, and approaches bare-metal performance.
Enhanced methane recovery and exoelectrogen-methanogen evolution from low-strength wastewater in an up-flow biofilm reactor with conductive granular graphite fillers

Methane production from low-strength wastewater (LSWW) is generally difficult because of the low metabolism rate of methanogens. Here, an up-flow biofilm reactor equipped with conductive granular graphite (GG) as fillers was developed to enhance direct interspecies electron transfer (DIET) between syntrophic electroactive bacteria and methanogens to stimulate methanogenesis process. Compared to quartz sand fillers, using conductive fillers significantly enhanced methane production and accelerated the start-up stage of biofilm reactor. At HRT of 6 h, the average methane production rate and methane yield of reactor with GG were 0.106 m~3/(m~3.d) and 74.5 L/kg COD, which increased by 34.3 times and 22.4 times respectively compared with the reactor with common quartz sand fillers. The microbial community analysis revealed that methanogens structure was significantly altered and the archaea that are involved in DIET (such as Methanobacterium) were enriched in GG filler. The beneficial effects of conductive fillers on methane production implied a practical strategy for efficient methane recovery from LSWW.
Proliferation of district heating using local energy resources through strategic building-stock management: A case study in Fukushima, Japan

District heating systems using cogeneration technology and renewable resources are considered as an effective approach to resources conservation and reduction of greenhouse gas (GHG) emissions. However, widespread aging and depopulation problems, as well as the popularization of energy-saving technologies in buildings, are estimated to greatly decrease energy consumption, leading to inefficiency in district heating and barriers to technology proliferation. From a long-term perspective, land use changes, especially the progression of compact city plans, have the potential to offset the decrement in energy consumption that maintains the efficiency of district heating systems. An integrated model is developed in this paper based on building cohort analysis to evaluate the economic feasibility and environmental impact of introducing district heating systems to a long-term compact city plan. As applied to a case in the Soma Region of Fukushima, Japan, potential migration from the suburbs to the central station districts is simulated, where district heating based on gas-fired cogeneration is expected to be introduced. The results indicate that guided migration to produce concentrated centers of population can substantially increase the heat demand density, which supports a wider application of district heating systems and better low-carbon performance. These results are further discussed in relation to technology innovation and related policies. It is concluded that policies related to urban land use planning and energy management should be integrated and quantitatively evaluated over the long-term with the aim of supporting urban low-carbon sustainable development.
Responding to the Paris Climate Agreement: global climate change mitigation efforts

Since the Paris Climate Agreement was adopted by consensus in December 2015, the global society has made various efforts to respond to this Agreement. The essential element of the Paris Climate Agreement is the so-called Nationally Determined Contributions (NDCs), specifying the long-term greenhouse gas (GHG) reduction targets beyond 2020. Unlike the different legal obligations of developed and developing countries specified in the precedent Kyoto Protocol, the NDCs under the Paris Climate Agreement apply equally to all countries. All the signed countries were asked to submit their Intended Nationally Determined Contributions (INDCs) before the 2015 Paris Climate Summit, which serve, unless otherwise provided, as the initial NDCs after the ratification of the Agreement. However, there is no mechanism to force a country to set a specific target by a specific date, but each target should go beyond previously set targets. Another challenge is that in June 2017, US President Donald Trump announced his intention to withdraw the US from the Agreement. Under the Agreement, the earliest effective date of withdrawal for the US is November 2020, shortly before the end of President Trump's current term. The US was responsible for 15.5% of global CO_2 emissions from fuel combustion in 2015 [1]. The US's withdrawal has brought a great uncertainty to the implementation of the Paris Climate Agreement and induced a lot of global disputes.
Microbial community dynamics at high organic loading rates revealed by pyrosequencing during sugar refinery wastewater treatment in a UASB reactor

The performance and microbial community structure in an upflow anaerobic sludge blanket reactor (UASB) treating sugar refinery wastewater were investigated. The chemical oxygen demand (COD) removal reached above 92.0% at organic loading rates (OLRs) of 12.0–54.0 kgCOD/(m~3·d). The volatile fatty acids (VFAs) in effluent were increased to 451.1 mg/L from 147.9 mg/L and the specific methane production rate improved by 1.2–2.2-fold as the OLR increased. The evolution of microbial communities in anaerobic sludge at three different OLRs was investigated using pyrosequencing. Operational taxonomic units (OTUs) at a 3% distance were 353, 337 and 233 for OLR12, OLR36 and OLR54, respectively. When the OLR was increased to 54.0 kgCOD /(m~3·d) from 12.0 kgCOD/ (m~3·d) by stepwise, the microbial community structure were changed significantly. Five genera (Bacteroides, Trichococcus, Chryseobacterium, Longilinea and Aerococcus) were the dominant fermentative bacteria at the OLR 12.0 kgCOD/(m~3·d). However, the sample of OLR36 was dominated by Lactococcus, Trichococcus, Anaeroarcus and Veillonella. At the last stage (OLR = 54.0 kgCOD/ (m~3·d)), the diversity and percentage of fermentative bacteria were markedly increased. Apart from fermentative bacteria, an obvious shift was observed in hydrogen-producing acetogens and nonacetotrophic methanogens as OLR increased. Syntrophobacter, Geobacter and Methanomethylovorans were the dominant hydrogen-producing acetogens and methylotrophic methanogens in the samples of OLR12 and OLR36. When the OLR was increased to 54.0 kgCOD/(m~3·d), the main hydrogen-producing acetogens and hydrogenotrophic methanogens were substituted with Desulfovibrio and Methanospirillum. However, the composition of acetotrophic methanogens (Methanosaeta) was relatively stable during the whole operation period of the UASB reactor.