mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Response of ground beetles (Coleoptera: Carabidae) to forest gaps formed by a typhoon in a red pine forest at Gwangneung Forest, Republic of Korea

In Korea, damaging typhoons related to climate change have increased steadily since the 1990s. Red pine (Pinus densiflora) forests in Gwangneung Forest were greatly disturbed by typhoon Kompasu in 2010. A survey was carried out to clarify differences in ground beetle (Coleoptera: Carabidae) communities between forest gaps and undamaged forests. Ground beetles were sampled using pitfall traps from early May to late October 2011. Vegetation changes, litter layer, organic matter layer, and soil conditions were also measured. A total of 1035 ground beetles of 32 species were collected. Contrary to our expectation, species richness, abundance, and community structure of the ground beetles in forest gaps were similar to those in undamaged forests. Species richness and abundance of habitat type were also similar. However, species diversity and estimated species richness in forest gaps were significantly higher than in undamaged forests. These findings suggest that forest gaps formed by a typhoon did not lead to great change in ground beetle communities.
Relationships between tree-ring cell features of Pinus koraiensis and climate factors in the Changbai Mountains,Northeastern China

Anatomical characteristics have been proven useful for extracting climatic signals. To examine the climatic signals recorded by tree-ring cell features in the Changbai Mountains, we measured cell number and cell lumen diameter, in addition to ring widths, of Korean pine (Pinus koraiensis) tree rings at sites of varied elevation, and we developed chronologies of cell number (CN), mean lumen diameter (MLD),maximum lumen diameter (MAXLD) and tree-ring width (TRW). The chronologies were correlated with climatic factors monthly mean temperature and the sum of precipitation. As shown by our analysis, the cell parameter chronologies were suitable for dendroclimatology studies. CN and TRW shared relatively similar climatic signals which differed from MLD and MAXLD, and growth-climate relationships were elevationdependent, as shown by the following findings: (1) at each elevation, MLD and MAXLD recorded different monthly climatic signals from those recorded by TRW for the same climatic factors; and (2) MLD and MAXLD recorded climatic factors that were absent from TRW at lower and middle elevations. Cell lumen diameter proved to be an effective archive for improving the climate reconstruction for this study area.
Shoot multiplication of Syringa reticulata var. mandshurica from in vitro cultured seedlings

We developed a shoot multiplication protocol for Syringa reticulata Blume var. mandshurica Hara from in vitro cultured seedlings that derived from in vitro germinated seeds. The shoots could be induced on Murashige and Skoog (MS) medium with proper plant growth regulator combinations of 6-benzylaminopurine (BA) and indole-3-butyric acid (IBA). The better medium for shoot multiplication and growth was MS + 5 mg L~(-1) BA + 0.5 mg L~(-1) IBA + 20 g L~(-1) sucrose + 7 g L~(-1) agar, and the corresponding shoot induction rate was 75 %. The plantlets grew well after rooting on 1/2MS medium (macro-elements of MS medium are at half-strength) supplemented with 1 mg L~(-1) IBA, and the survival percentage was >80 % at 16 weeks after transplanting.
指背筋膜蒂皮瓣联合V-Y皮瓣修复拇指掌侧缺损

拇指指腹缺损临床上常见,传统的一侧近节指背逆行筋膜皮瓣修复指腹缺损获得满意的治疗效果。自2013年1月至2014年6月,我们利用拇指多源供血的尺侧指背筋膜蒂皮瓣联合桡侧V-Y推移皮瓣,修复拇指掌侧缺损患者8例,效果满意。
Enhanced Capacitive Desalination Performance of Porous Carbon Spheres@MnO_2 Composite

A porous carbon spheres@MnO_2 composite is prepared and used as the electrosorption electrode. The MnO_2 nanoparticles are evenly distributed on the porous carbon spheres. The as-prepared composite possesses high specific surface area of 258.6 m~2·g~(-1). Its electrochemical evaluations confirm that the composite has high specific capacitance of 175 F·g~(-1) at a current density of 1 A·g~(-1) in 0.5 mol·L~(-1) NaCl aqueous solution, and shows good conductivity and excellent cycling performance. Electrosorption capacity for the porous carbon spheres@MnO_2 composite is 6.28 mg·g~(-1). Moreover, the composite electrode exhibits excellent recyclability with an efficient regeneration process.
Sequence-based genetic mapping of Ds-tagged insertions to characterize malting-related traits in barley

Among various functional genomics tools used to characterize genes in plants, transposonbased mutagenesis approaches offer great potential, especially in barley and wheat, which possess large genomes and in which genetic transformation is not routine. Two Ds transposon flanking sequences (TNPs),TNP-29 (27.4 cM(centiMorgan)) andTNP-79 (70.3 cM), weremapped in the vicinity of amalting qualityQTL located on chromosome4Hof barley. Reactivation of the Ds transposon sequence from these TNP lines led to the identification of genes in the malting QTL regions. Several Ds (dissociation) lines were generated by crossing TNP-29 and TNP-79 with an AcTPase (activator) expressing line (25-B), and F_2 progenieswere subsequently screened for Ds insertions at new locations. To further characterize these Ds mutants, we mapped the new Ds flanking sequences on a barley genetic map and found that 29% of Ds were located in regions associated with the malting QTL located on chromosome 4H and in close proximity to other important malting-associated QTL across the barley chromosome. Using a sequence based approach, a linkage map was generated that confirmed the position of Ds loci in the barley genome map. Locating these Ds loci on the barley map opens avenues to dissect important malting QTL for facilitating identification of candidate malting genes.
Slope stability analysis of Balia Nala landslide, Kumaun Lesser Himalaya, Nainital, Uttarakhand, India

Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socio-economic importance. This study presents the stability analysis of a ravine/valley along Balia Nala. Variegated slates (lower Krol and upper Blaini formations) are the main rock types, wherever the outcrop does exist and rest of the area is covered by slope wash and river borne materials. Three sets of joints are presented in the area, but 4 sets of joints also exist at some locations. Nainital lake fault intersected by Manora fault from southwest direction passes through eastern side of the study area, and some small faults, which are sub-branches of Nainital lake fault, are observed (with 10 m offset) and promote the landslide in the area. This study shows that different kinds of discontinuities (joints, faults and shear zones) and rapid down cutting by the stream due to neotectonic activity affect the stability of the slope. The fragile lithology and deep V-shaped valley further accelerate the mass movement in the study area. In addition, rock mass rating (RMR), factor of safety (FOS) and graphical analysis of the joints indicate the study area as landslide-prone zone. This study will be helpful in not only reducing the risk on life of people, but also in assisting the ongoing civil work in the study area.
CO_2 seasonal variation and global change:Test global warming from another point of view

CO_2 and temperature records at Mauna Loa, Hawaii, and other observation stations show that the correlation between CO_2 and temperature is not significant. These stations are located away from big cities, and in various latitudes and hemispheres. But the correlation is significant in global mean data. Over the last five decades, CO_2 has grown at an accelerating rate with no corresponding rise in temperature in the stations. This discrepancy indicates that CO_2 probably is not the driving force of temperature change globally but only locally (mainly in big cities). We suggest that the Earth's atmospheric concentration of CO_2 is too low to drive global temperature change. Our empirical perception of the global warming record is due to the urban heat island effect:temperature rises in areas with rising population density and rising industrial activity. This effect mainly occurs in the areas with high population and intense human activities, and is not representative of global warming. Regions far from cities, such as the Mauna Loa highland, show no evident warming trend. The global monthly mean temperature calculated by record data, widely used by academic researchers, shows R~2=0.765, a high degree of correlation with CO_2. However, the R~2 shows much less significance (mean R~2=0.024) if calculated by each record for 188 selected stations over the world. This test suggests that the inflated high correlation between CO_2 and temperature (mean R~2=0.765-0.024=0.741) used in reports from the Intergovernmental Panel on Climate Change (IPCC) was very likely produced during data correction and processing. This untrue global monthly mean temperature has created a picture:human emission drives global warming.
调节性T细胞在乳腺癌免疫治疗中的作用

免疫治疗是利用免疫系统来治疗疾病。近年来,随着免疫学的深入研究,免疫治疗开始应用于包括肿瘤在内的多种疾病,并显示出其独特的疗效。相关研究发现,调节性T细胞(Treg)是一群具有免疫抑制功能的T细胞,是肿瘤浸润性淋巴细胞中起到免疫抑制作用的关键细胞。乳腺癌免疫治疗包括主动免疫治疗和被动免疫治疗。笔者重点阐述以Treg为靶点的免疫治疗最新研究成果及其在免疫治疗中的地位,以期为乳腺癌的进一步相关研究提供参考。
Drug resistance mechanisms and novel drug targets for tuberculosis therapy

Drug-resistant tuberculosis (TB) poses a significant challenge to the successful treatment and control of TB worldwide. Resistance to anti-TB drugs has existed since the beginning of the chemotherapy era. New insights into the resistant mechanisms of anti-TB drugs have been provided. Better understanding of drug resistance mechanisms helps in the development of new tools for the rapid diagnosis of drug-resistant TB. There is also a pressing need in the development of new drugs with novel targets to improve the current treatment of TB and to prevent the emergence of drug resistance in Mycobacterium tuberculosis. This review summarizes the anti-TB drug resistance mechanisms, furnishes some possible novel drug targets in the development of new agents for TB therapy and discusses the usefulness using known targets to develop new anti-TB drugs. Whole genome sequencing is currently an advanced technology to uncover drug resistance mechanisms in M. tuberculosis. However, further research is required to unravel the significance of some newly discovered gene mutations in their contribution to drug resistance.
Towards human-like and transhuman perception in AI 2.0:a review

Perception is the interaction interface between an intelligent system and the real world. Without sophisticated and flexible perceptual capabilities, it is impossible to create advanced artificial intelligence (AI) systems. For the next-generation AI, called 'AI 2.0', one of the most significant features will be that AI is empowered with intelligent perceptual capabilities, which can simulate human brain's mechanisms and are likely to surpass human brain in terms of performance. In this paper, we briefly review the state-of-the-art advances across different areas of perception, including visual perception, auditory perception, speech perception, and perceptual information processing and learning engines. On this basis, we envision several R&D trends in intelligent perception for the forthcoming era of AI 2.0, including:(1) human-like and transhuman active vision; (2) auditory perception and computation in an actual auditory setting; (3) speech perception and computation in a natural interaction setting; (4) autonomous learning of perceptual information; (5) large-scale perceptual information processing and learning platforms; and (6) urban omnidirectional intelligent perception and reasoning engines. We believe these research directions should be highlighted in the future plans for AI 2.0.
Climate change impact in theWestern Himalaya:people's perception and adaptive strategies

The Himalaya represents a vast mountain system and globally valued for its significant role in regulation of global as well as regional climate that has direct impact on biodiversity and ecosystem services crucial for sustenance of millions of people in Himalaya and adjoining areas. However, mountain regions worldwide are impacted by climate change and at the same time represent distinctive area for the assessment of climate related impacts. Climate change impacts in Himalayan region have its implications on food production, natural ecosystems, retreat of glacier, water supply, human and animal health and overall human well being. The livelihood and food security of the people inhabited in region largely depend on climate sensitive sectors i.e. agriculture, livestock, forestry and their interlinkages with each other, and has the potential to break down food and nutritional security as well as livelihood support systems. People's perception and understanding of climate can be an important asset when it comes to adaptation to climate change impact; however it is not taken into consideration for the development of policy design and implementation of modern mitigation and adaptation strategies by governments and other civil society organizations. The knowledge of local people and farming communities for rural landscape management and sustainable use of bioresources is gaining credence as a key strategy to cope up with the climate change. Therefore, the present study analyzes the indigenous knowledge of local people and their perceptions on climate change, and also documented adaptation approaches at local level in mountain ecosystem of western Himalaya. The study could be useful to policy makers to design appropriate adaptation strategies to cope up with the impacts of climate change.
3D打印技术在精准微创治疗中的应用进展

近年来,随着3D打印(3D printing, 3DP)技术临床转化的快速推进,其在医疗领域,尤其是精准微创治疗中的应用价值逐渐得到重视。精准治疗,即针对病人的个性化特征量体裁衣地提供治疗方案。基于影像数据三维重建及计算机辅助设计,3D打印技术不仅为临床提供了立体可触的个性化解剖模型,更成为辅助完成手术方案设计、精确术前模拟、精准手术导航的重要工具。微创介入手术是治疗慢性疼痛的重要手段,而3D打印技术在该领域的应用相对较少,本文将就3D打印技术在精准微创治疗中的临床应用进行综述,并对其在慢性疼痛领域的应用前景进行展望。
金世元学术思想传承特色探析

在明确传承学术思想概念的基础上,理清中药传承研究思路,分析金世元学术思想传承特色。传承是中药大家传授和弟子继承的有机组合;学术是中药学科学问、知识和实践中应用的技术、手段;思想是中药大家经过思维活动而产生的对专业学问、知识、技术、方法事物本质和规律性的认识。金世元传承的是经过自身70余年从业经验打磨并反复思考形成的"学"与"术"。在此基础上,明确传承其学术思想研究的基本目标是全面记录、整理金世元学术内容,提出解决其认可标本收集这一难点的方法;最高目标是凝练、实践中药专家学术思想。与中医学术传承比较,总结金世元中药学术传承模式特点,一是补经典学习,传大家衣钵;二是传承实践内容多元化、形式多样化。通过概念梳理、目标确定、模式特色凝练,总结对国医大师金世元学术传承研究体会、浅析特色,以期为研究中药专家学术传承提供参考。
《素问·上古天真论》"登天"与"天师"解诂

结合《素问·上古天真论》"登天"、"天师"二语出自王冰之手的事实,对其含义做了详细考辨,提出"登天"当依王冰注,作"白日升天"解,指的是成仙之事; "天师"本是对通晓道术之人的尊称,王冰将其作为"岐伯"的专称,而此改动似既有《庄子》旧典的影响,又与王冰信奉道教成仙之说有密切关联。
超级稻德香4103在湖北省孝感市种植表现及高产栽培技术

德香4103是2012年农业部确认的超级稻品种, 2014-2015年在孝感市4个县市作一季中稻栽培,产量平均10.7 t/hm~2,在2014年10个参试品种和2015年12个参试品种中均位居第1位。2015年作中稻+再生稻栽培,中稻产量10.5 t/hm~2,再生稻产量5.39 t/hm~2,田间表现为穗大粒重、产量高、抗病性较强等特点。介绍了德香4103在各试验点的种植表现和高产栽培技术。
三系杂交晚稻贺优50母本直播高产制种技术

2015年贺优50在湖南临澧制种30 hm~2,母本采取直播方式,平均产量3.3 t/hm~2,种子纯度99%以上。介绍了该组合亲本的特征特性,总结了母本直播高产制种技术,为该组合母本直播高产制种提供参考。
改良关节镜下缝线内固定治疗前交叉韧带胫骨止点骨折

目的总结改良关节镜下缝线内固定治疗前交叉韧带(anterior cruciate ligament,ACL)胫骨止点骨折的疗效。方法2011年4月-2015年4月,收治28例ACL胫骨止点骨折患者。男21例,女7例;年龄11~47岁,平均28.6岁。致伤原因:运动伤19例,交通事故伤9例。受伤至手术时间1~5 d,平均2.1 d。膝关节Lysholm评分为(42.7±7.6)分。按照Meyers-Mckeever-Zaircznyj分型标准:Ⅱ型3例,Ⅲ型17例,Ⅳ型8例。合并半月板损伤3例。采用改良关节镜下缝线内固定治疗,术后正规康复锻炼。结果术后X线片示骨折均达解剖复位;切口均 Ⅰ期愈合。患者均获随访,随访时间12~18个月,平均14.2个月。X线片复查示,术后6个月骨折均达骨性愈合。术后12个月,膝关节Lysholm评分为(93.2 ±6.5)分,与术前比较差异有统计学意义(t=26.721,P=0.000)。Lachman试验及前抽屉试验均为阴性。胫骨结节内侧内固定缝线经皮处无瘢痕或仅遗留点状瘢痕。结论改良关节镜下缝线内固定治疗ACL胫骨止点骨折,更微创,操作简便,疗效良好。
In situ observation of austenite grain growth and transformation temperature in coarse grain heat affected zone of Ce-alloyed weld metal

Laser scanning confocal microscopy (LSCM) was used to study the inhibition of austenite grain growth by the inclusions and the effect of cerium on the trend of acicular ferrite (AF) and ferrite side plate (FSP) transformation temperature in coarse grain heat affected zone (CGHAZ) of Ce-alloyed weld metals. The results showed there were lots of tiny cerium oxides and sulfides inclusions in the CGHAZ of Ce-alloyed weld metals. When the concentration of Ce was 0.021%, the volume fraction of inclusions in weld metal CGHAZ was higher and the inclusion size was smaller, therefore austenite grain size was smaller with the increase of hightemperature residence time. Cerium tended to segregate at austenite grain boundaries, so FSP transformation temperature decreased and FSP transformation was suppressed. On the contrary, AF transformation temperature increased because AF transformation was promoted in CGHAZ of the Ce-alloyed weld metal, especially when the concentration of Ce was 0.021%.
心电信号小波去噪的改进算法研究

对心电信号(ECG)中的基线漂移、工频干扰和肌电干扰等噪声进行去除,在波形识别、医疗诊断和治疗等领域具有重要意义。提出用sym5小波函数对心电信号进行8层小波分解。根据有用信号强度在每一层平均分配而噪声强度随分解层数增加而减少的规律,将分解得到的每一层的小波细节系数设置不同的阈值,最后用所提出的新阈值函数进行小波阈值去噪。该阈值函数既能克服硬阈值函数在阈值附近不连续的缺点,又可弥补软阈值函数与原函数之间存在固定差值的不足。以MIT-BIH心电数据库中的101号文件作为原始数据,将整个数据文件进行平均分段,每段有1 200个数据点,对每段数据进行加噪仿真分析,结果表明所提出的去噪算法得到的去噪信号信噪比比硬阈值函数和软阈值函数分别提高2.31%和8.04%,从而证明所提算法的有效性。
Effects of Shengjiangxiexin decoction on irinotecan-induced toxicity in patients with UGT1A1*28 and UGT1A1*6 polymorphisms

OBJECTIVE:To evaluate the efficacy of Shengjiangxiexin decoction (SXD), prepared with a formula from Traditional Chinese Medicine (TCM), in reducing irinotecan-induced hematological and gastrointestinal toxicities in patients with UDP-glucuronosyltransferase (UGT)1A1*28 and UGT1A1*6 polymorphisms. METHODS:This clinical trial included 115 patients receiving irinotecan combined with 5-fluorouracil plus l-leucovorin (FOLFIRI) treatment. All patients consented to UGT1A1*28 and *6 gene polymorphism detection prior to chemotherapy. SXD were administered from 1 day prior to chemotherapy to 6 day post chemotherapy. Chemotherapy induced adverse reactions (neutropenia, diarrhea, nausea, vomiting, anorexia and infection) were recorded, and short-term effect of chemotherapy was evaluated regularly. RESULTS:A total of 50 patients had *1/*1 wild genotype, 58 patients had single allele variants with genotype *1/*6 or *1/*28, and 7 patients had two alleles variants with genotype *6/*6, *28/*28 or *6/* 28. In *1/*6 or *1/*28 patients (high risk group), 9 patients (15.5%) developed Ⅰ-Ⅱ grade diarrhea and no patient developed severe diarrhea; neutropenia occurred in 19 patients (32.8%) and only 3 patients (8.6%) developed sever neutropenia. There were no significant differences in any toxic effects (neutropenia, diarrhea, nausea, vomiting, anorexia or infection) between *6 or *28 variant patients (high risk group) and wild type patients. No sever toxicity was found in high risk two alleles variants patients (*6/*6, *6/*28 or *28/*28). No significant differences were observed between UGT1A1*6/*28 polymorphisms and clinical response of chemotherapy. CONCLUSION:SXD could significantly reduce irinotecan-induced hematological and gastrointestinal toxicities in UGT1A1*28 or *6 variant patients (high risk group), while this treatment didn't affect clinical response of chemotherapy.
Sini decoction as an adjuvant therapy for angina pectoris:a systematic review of randomized controlled trials

OBJECTIVE:To systematically assess the effects and safety of Sini decoction as an adjuvant therapy for patients with angina pectoris. METHODS:We searched PubMed, Excerpt Medica Database, the Cochrane library, Wanfang Database, China National Knowledge Infrastructure Database, China Science and Technology Journal Database from the date of its inception until August 1, in 2014. Available literatures were selected according to the inclusion criteria. Two reviewers finished data extraction, checked the data and assessed the methodological quality of studies, independently. The Review Manage Software 5.1.0 was used for data analysis. RESULTS:Six trials involving 453 participants were eligible. None of the trials reported the mortality due to angina pectoris. The secondary outcomes showed that Sini decoction, together with nitroglycerin when necessary, may have some effects on reducing the number of angina attacks and the amount of nitroglycerin. But in terms of reducing the duration of angina and improvement of electrocardiogram, there were no statistical differences between Sini decoction group and isosorbide dinitrate group. Only one reported that no adverse events were found. CONCLUSION:Based on this systematic review, Sini decoction can reduce the dosage of nitroglycerin, when compared with isosorbide dinitrate group. And there were no enough evidence in the papers to draw any conclusions for the safety of Sini decoction.
Level and characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans in feed and feed additives

Feed security is a prerequisite for safe animal food products. In this study, 13 groups of feed and feed ingredients, totaling 2067 samples, were collected in the period of 2011 to 2014 from China. The highest mean level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was found in fish meals and shell powders, with a concentration of 60.35 ng/kg, followed by mineral origin materials. In terms of the toxicity equivalent concentration, the fish oil group showed the highest PCDD/F levels because of their bio-accumulation through the aquatic food chain, with an average concentration of 1.26 ng WHO-TEQ/kg, while the lowest level was observed in compound feed for chickens and pigs, with an average value of 0.16 ng WHO-TEQ/kg. OCDD and OCDF were the predominant congeners in all groups except fish oils, in which the primary congeners were 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF. For zinc chloride samples, different from other zinc-based compound samples, the main congeners were 1,2,3,4,6,7,8-HpCDF (17%), 1,2,3,4,7,8,9-HpCDF (15%), 1,2,3,4,7,8-HxCDF (12%) and OCDF (30%). Considering toxicity equivalency factors, the dominant congeners were 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 2,3,7,8-TCDF and 1,2,3,7,8-PeCDD, and the contribution to the total TEQwas 29%, 16%, 14% and 12%, respectively. Overall, 2.1% (43 out of 2067) of all the analyzed samples exceeded the different individual 'European Union maximum limited levels for PCDD/Fs. This study is beneficial for the determination of the status of contamination levels of feed and feed ingredients.
Effects of ionic strength and temperature on the aggregation and deposition of multi-walled carbon nanotubes

The aggregation and deposition of carbon nanotubes (CNTs) determines their transport and fate in natural waters. Therefore, the aggregation kinetics of humic-acid treated multi-walled carbon nanotubes (HA-MWCNTs) was investigated by time-resolved dynamic light scattering in NaCl and CaCl_2 electrolyte solutions. Increased ionic strength induced HA-MWCNT aggregation due to the less negative zeta potential and the reduced electrostatic repulsion. The critical coagulation concentration (CCC) values of HA-MWCNTs were 80 mmol/L in NaCl and 1.3 mmol/L in CaCl_2 electrolyte, showing that Ca~(2+) causes more serious aggregation than Na~+. The aggregation behavior of HA-MWCNTs was consistent with Derjaguin-Landau-Verwey-Overbeek theory. The deposition kinetics of HA-MWCNTs was measured by the optical absorbance at 800 nm. The critical deposition concentrations for HA-MWCNT in NaCl and CaCl_2 solutions were close to the CCC values, therefore the rate of deposition cannot be increased by changing the ionic strength in the diffusion-limited aggregation regime. The deposition process was correlated to the aggregation since larger aggregates increased gravitational deposition and decreased random Brownian diffusion. HA-MWCNTs hydrodynamic diameters were evaluated at 5, 15 and 25°C. Higher temperature caused faster aggregation due to the reduced electrostatic repulsion and increased random Brownian motion and collision frequency. HA-MWCNTs aggregate faster at higher temperature in either NaCl or CaCl_2 electrolyte due to the decreased electrostatic repulsion and increased random Brownian motion. Our results suggest that CNT aggregation and deposition are two correlated processes governed by the electrolyte, and CNT transport is favored at low ionic strength and low temperature.