mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
胰腺癌的影像学研究进展

胰腺癌发病率逐年上升,据2009年美国癌症学会报道,胰腺癌的致死率居所有恶性肿瘤的第四位,消化道肿瘤的第二位。本病以中老年人为发病的高峰期人群。由于解剖学上胰腺位置较深的特点,再加上恶性程度较高,起病隐匿和早期转移等特点,常规手术切除并不能起到良好的治愈效果,5年内生存率仅为5%,所以对胰腺癌的早期诊断,及早治疗就显得尤为重要,近年来影像学技术的不断进步以及新技术、新方法的广泛应用已成为诊断胰腺癌不可或缺的重要检查手段。
二甲双胍在多囊卵巢综合征促排卵治疗中的作用

多囊卵巢综合征(PCOS)是育龄妇女常见的内分泌紊乱性疾病,持续无排卵、雄激素水平过高和胰岛素抵抗是其主要特征,是导致患者无排卵性不孕的首要原因,约占女性无排卵性不孕的50%~70%。本文就我院对PCOS促排卵治疗的患者应用二甲双胍的临床作用进行评价。
金属大头全髋关节置换术和半髋关节置换术治疗老年人股骨颈骨折的近期疗效比较

目的探讨半髋关节置换术和金属大头全髋关节置换术治疗老年人股骨颈骨折的疗效及其应用价值。方法回顾性分析43例老年人股骨颈骨折患者,其中行金属大头全髋关节置换术治疗患者23例,行半髋关节置换术20例,随访3~5年。对其手术时间、术中出血、术后失血、髋关节功能恢复时间、住院时间、疼痛率、术后髋关节Harris评分等作比较,评价2种手术方法的疗效。结果半髋关节置换术组与金属大头全髋关节置换术组相比较,在住院时间、髋关节功能恢复时间上未见明显差异;在手术时间、术中出血、术后失血方面均少于金属大头全髋关节置换术组;在术后疼痛率、患侧髋关节Harris评分方面,金属大头全髋关节置换术组优于半髋关节置换术组。结论半髋关节置换术和金属大头全髋关节置换术在治疗老年人股骨颈骨折方面各有优势。对于那些较年轻或者对术后髋关节功能要求较高的患者,金属大头全髋关节置换术更有优势。
Chinese product of constacyclic and cyclic codes over finite rings

In this paper, we study the Gray images of the Chinese product of constacyclic and cyclic codes over a finite ring. We first introduce the Chinese product of constacyclic and cyclic codes over the finite ring. We then define a Gray map between codes over the finite ring and a finite field. We prove that the Gray image of the Chinese product of constacyclic codes over the finite ring is a distance-invariant quasi-cyclic code over the finite field. We also prove that each code over the finite field, which is the Gray image of the Chinese product of cyclic codes over the finite ring, is permutation equivalent to a quasi-cyclic code.
经阴道超声诊断输卵管切除术后同侧间质部妊娠1例

患者女,40岁,已婚,孕2产1,因“停经38 d,下腹隐痛3 d”就诊,无阴道出血及肛门坠胀感,既往月经规律,持续3~5 d,月经周期29 d,量约40 ml。4年前因左侧输卵管妊娠行患侧输卵管切除术。妇科检查:外阴、阴道、宫颈未见明显异常;宫体:前位,稍增大,无压痛;附件:左侧附件增粗,无压痛。尿妊娠试验阳性,超声示左卵巢旁包块,临床拟诊为异位妊娠。入院后查血β-HCG 6328 mIU/ml,孕酮22.17 ng/ml。复查超声:宫腔内未见孕囊,左侧卵巢形态大小正常;左侧宫角部向外膨出一18 mm×15 mm 混合回声包块,其内见10 mm×15 mm 无回声,并见卵黄囊,包块与子宫内膜不通(图1A);右侧卵巢内见21 mm×18 mm 低回声型黄体(图1B)。超声诊断:左侧宫角部膨出性包块(输卵管间质部妊娠可能)。患者入院第2天突发下腹部急腹痛,立即于硬腰麻下开腹行左侧输卵管残端及左侧宫角切除术。术中见:子宫饱满,左侧卵巢及右侧附件外观正常,左侧输卵管峡部及其远端缺如,右侧卵巢表面见妊娠黄体。左输卵管间质部向外突起一4 cm×3 cm 包块,其表面见5 mm 破裂口并见活动性出血,盆腔内游离血约1400 ml,血块约100 g。切除宫角膨出性包块及部分宫角,包块内见绒毛。术后病理诊断:左侧输卵管残端妊娠。
Utilizing the dropped packets for data delivery in VANETs

Timely and cost-efficient multi-hop data delivery among vehicles is essential for vehicular ad-hoc networks (VANETs), and various routing protocols are envisioned for infrastructure-less vehicle-to-vehicle (V2V) communications. Generally, when a packet (or a duplicate) is delivered out of the routing path, it will be dropped. However, we observe that these packets (or duplicates) may also be delivered much faster than the packets delivered along the original routing path. In this paper, we propose a novel tree based routing scheme (TBRS) for ultilizing the dropped packets in VANETs. In TBRS, the packet is delivered along a routing tree with the destination as its root. And when the packet is delivered out its routing tree, it won't be dropt immediately and will be delivered for a while if it can arrive at another branch of the tree. We conduct the extensive simulations to evaluate the performance of TBRS based on the road map of a real city collected from Google Earth. The simulation results show that TBRS can outperform the existing protocols, especially when the network resources are limited.
Application of Kinetic Models in Describing Soil Potassium Release Characteristics and Their Correlations with Potassium Extracted by Chemical Methods

Potassium (K) release characteristics in soil play a significant role in supplying available K. Information on K-release characteristics in soils of central Iran is limited. The objectives of this study were to determine K release characteristics and correlations of K release rate constants with K extracted by different chemical methods in surface soils of ten calcareous soils of central Iran. The kinetics of K release in the soils was determined by successive extraction with 0.01 mol L~(?1) CaCl_2 in a period of 2-2 017 h at 25±1 ?C. Soil K was extracted by distilled water, 0.5 mol L~(?1) MgNO_3, 0.002 mol L~(?1) SrCl_2, 0.1 mol L~(?1) BaCl_2, 0.01 mol L~(?1) CaCl_2, 1 mol L~(?1) NaCl, 1 mol L~(?1) boiling HNO_3, 1 mol L~(?1) NH_4OAC, Mehlich 1, 0.002 mol L~(?1) SrCl_2 + 0.05 mol L~(?1) citric acid, and ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA). A plot of cumulative amounts of K released showed a discontinuity in slope at 168 h. Thus, two equations were applied to two segments of the total reaction time (2-168 and 168-2 017 h). Cumulative amounts of K released ranged from 55 to 299 mg kg~(?1) in 2-168 h and from 44 to 119 mg kg~(?1) in 168-2 017 h. Release kinetics of K in the two time segments conformed fairly well to parabolic diffusion, simplified Elovich, and power function models. There was a wide variation in the K release rate constants. Increasingly higher average concentrations of soil K were extracted by distilled water, Mehlich 1, SrCl_2, CaCl_2, SrCl_2 + citric acid, AB-DTPA, MgNO_3, NaCl, NH_4OAc, BaCl_2, and HNO_3. Potassium release rate constants were significantly correlated with K extracted. The results of this study showed that information obtained from mathematical modeling in two reaction time segments can help to estimate the K-supplying power of soils.
Effects of Earthworms and Ryegrass on the Removal of Fluoranthene from Soil

Earthworms can promote the bioremediation of contaminated soils through enhancing plant growth and microorganism development. The individual and combined effects of earthworms and ryegrass (Lolium multiflorum Lam.) on the removal of fluoranthene from a sandy-loam alluvial soil were investigated in a 70-d microcosm experiment. The experiment was set up in a complete factorial design with treatments in four replicates: without earthworms or ryegrass (control, CK), with earthworms only (E), with ryegrass only (P), and with both earthworms and ryegrass (EP). The residual fluoranthene, microbial biomass C, and polyphenol oxidase activity in the soil changed significantly (P < 0.01) with time. In general, the residual concentration of fluoranthene in the soil decreased sharply from 71.8-88.7 to 31.7-37.4 mg kg~(?1) in 14 d, and then decreased gradually to 19.7-30.5 mg kg~(?1) on the 70th d. The fluoranthene concentration left in the soil was the least with both earthworms and ryegrass, compared to the other treatments at the end of the experiment. Half-life times of fluoranthene in the E, P, and EP treatments were 17.8%-36.3% smaller than that of CK. More fluoranthene was absorbed by earthworms than ryegrass. However, the total amounts of fluoranthene accumulated in both the ryegrass and earthworms were small, only accounting for 0.01%-1.20% of the lost fluoranthene. Therefore, we assumed that microbial degradation would play a dominant functional role in fluoranthene removal from soil. We found that earthworms significantly increased microbial biomass C and polyphenol oxidase activity (P <0.01) in the presence of ryegrass at the end of the experiment. Furthermore,microbial biomass C and polyphenol oxidase activity were significantly (P <0.05) and negatively related to the residual fluoranthene concentration. This implied that earthworms might promote the removal of fluoranthene from soil via stimulating microbial biomass C and polyphenol oxidase activity.
Source Apportionment of Heavy Metals in Soils Using Multivariate Statistics and Geostatistics

The main objectives of this study were to introduce an integrated method for effectively identifying soil heavy metal pollution sources and apportioning their contributions, and apply it to a case study. The method combines the principal component analysis/ absolute principal component scores (PCA/APCS) receptor model and geostatistics. The case study was conducted in an area of 31 km2 in the urban-rural transition zone of Wuhan, a metropolis of central China. 124 topsoil samples were collected for measuring the concentrations of eight heavy metal elements (Mn, Cu, Zn, Pb, Cd, Cr, Ni and Co). PCA results revealed that three major factors were responsible for soil heavy metal pollution, which were initially identified as "steel production", "agronomic input" and "coal consumption". The APCS technique, combined with multiple linear regression analysis, was then applied for source apportionment. Steel production appeared to be the main source for Ni, Co, Cd, Zn and Mn, agronomic input for Cu, and coal consumption for Pb and Cr. Geostatistical interpolation using ordinary kriging was finally used to map the spatial distributions of the contributions of pollution sources and further confirm the result interpretations. The introduced method appears to be an effective tool in soil pollution source apportionment and identification, and might provide valuable reference information for pollution control and environmental management.
开展品管圈活动对患者外出检查运送安全的保障作用

目的探讨品管圈活动对患者外出检查运送安全的保障作用。方法成立品管圈小组,选定活动主题,分析影响患者外出检查安全的因素并采取相应的措施,实施质量持续改进。结果实施活动后患者和医务人员对中央运输科服务满意率分别为97.2%、93.3%,显著高于实施前(均P<0.05),运送患者差错发生率及投诉率显著下降(均P<0.01)。结论开展品管圈活动提高了患者外出检查的安全性,提升了医务人员和患者的满意率,增强了运送人员的管理意识。
一次性条形码手腕带在入职体检中的应用

入职体检既是对员工身心健康状况的全面了解,也是单位人力资源可持续发展的保证。而就业招录的竞争激烈,就要求体检必须提供公平、公正、客观的结果。然而随着现代科学科技的发展以及就业招录的激烈竞争,体检过程中出现的人为作弊、人为干扰等因素对体检结果的公平性、公正性、客观性提出了挑战。为加强就业招录体检的管理,确保各项体检指标的真实性与客观性,我院体检中心从2011年10月开始将附有条形码的一次性手腕带(下称手腕带)运用于就业招录体检中,暂未发生一起违规,介绍如下。
钒电池蓄势能发否

本刊2009年第2期发表的一篇题为《我国全钒液流储能电池研究取得新进展》短文,报道了中国科学院大连化学物理研究所研究员张华民领导的研究小组的研究动态,便引发了491次的下载(知网数据,截止2013年7月,在当期包括正式论文的所有文章下载量中,排名居第2位)。而发表于2010年第8期的《石墨烯的制备及研究现状》下载量更是高达2454次。数据显示了研究人员对新能源新材料的高度关注。读者的关注便是栏目服务的方向,本期行业资讯推出钒电池(同时参见本期P60《钒电池复合电极的制备及性能研究》)、石墨烯、OLED三个热点,供读者参考j同时热盼这三个研究领域的作者来稿,公布您的研究动态、发表您的独到见解。
HCMV IE2蛋白调控功能研究新进展

人巨细胞病毒(human cytomegalovirus, HCMV)属于β疱疹病毒亚科,是人类疱疹病毒中最大的一组病毒。在人群中,HCMV感染相当普遍,大多数感染呈临床隐性感染或潜伏感染;但在新生儿、 免疫抑制或免疫功能低下的人群中则可引起临床显性感染,出现明显症状, 甚至发生致死性疾病。而在孕妇,则可发生垂直传播,导致死胎、畸形以及婴幼儿神经系统发育障碍、智力低下等。HCMV基因组全长超过240 kb的双链DNA,整个基因组含有250个开放阅读框(ORF)。在病毒感染过程中,HCMV基因的表达表现一定的时序性,可分为早早期(IE)、早期(E)和晚期(L)基因。病毒穿入细胞后, IE基因被宿主细胞因子激活并最早表达, 编码两种重要的调控蛋白 IE1(IE72)和 IE2(IE86)。其中IE2(IE86)蛋白是从HCMV基因组的开放阅读框UL122上翻译过来的,是一种重要的反式激活因子并在HCMV感染中发挥了重要作用。已有研究表明,IE2(IE86)能反式激活细胞周期蛋白cyclinE启动子,并能延缓宿主细胞进入S期。近年有资料证实,IE2(IE86)调节许多与控制细胞周期相关的因子。IE2(IE86)是一种重要的病毒蛋白质,而缺少IE2(IE86)的HCMV子代突变体不能进行复制。下面主要就IE2(IE86)蛋白对病毒蛋白表达调控的作用作一综述。
内皮型一氧化氮合酶基因多态性与儿童体位性心动过速综合征的相关性

目的探讨内皮型一氧化氮合酶(eNOS)基因启动子-T786C、第7外显子G894T突变与儿童体位性心动过速综合征(POTS)的相关性。方法选择POTS患儿(POTS组)及健康儿童(健康对照组)各60例,提取静脉血基因组DNA,通过PCR扩增获得目的片段,限制性内切酶消化目的片段,计数基因型及突变基因频率。结果eNOS基因第7外显子的G894T位点有3种基因型:GG、GT、TT。健康对照组14例发生G894T突变,其中纯合子3例,杂合子11例;POTS组24例发生G894T突变,其中纯合子6例,杂合子18例。POTS组突变基因型频率(纯合子+杂合子)和T等位基因频率高于健康对照组(P<0.05)。eNOS基因启动子T786C位点有3种基因型:TT、CC、TC,健康对照组12例发生T298C突变,其中纯合子3例,杂合子9例;POTS组23例发生T786C突变,其中纯合子6例,杂合子17例。POTS组基因型频率(纯合子+杂合子)和C等位基因频率高于健康对照组(P<0.05)。结论G894T和T786C突变基因型频率可能为POTS发病的一个危险因子。
Effects of Cold Rolling Reduction on Retained Austenite Fraction and Mechanical Properties of High-Si TRIP Steel

Transformation-induced plasticity-aided steel was rolled at room temperature to different thickness reductions (0, 4%, 10%, 20%, 40%, and 60%). The mechanical properties, microstructure and austenite fractions of the rolled samples were measured by tensile test, electron back scattered diffraction (EBSD) and X-ray diffraction (XRD) for each rolling. The deformation behavior was studied based on the analysis of the mechanical properties and microstructure of steel after tensile deformation, aiming at understanding the effects of cold rolling reduction on the decay behavior of the austenite and the change of mechanical properties of the TRIP steels. It was found that increasing rolling reduction increases the yield stress gradually but decreases the total elongation significantly. It is very interesting that after 10% rolling reduction the yield stress is about 1 000 MPa but still with 20% total elongation, which gives an excellent combination of yield strength and ductility. Based on the XRD results, it was revealed that in both rolling and tension the austenite volume fraction monotonically decayed with the increase of rolling strain, but the decaying rate is faster in tension than in rolling, which may be ascribed to the higher temperature in rolled specimens than in the tensioned ones during deformation. Experimental results and theoretical reasoning indicate that the decreasing trend of austenite volume fraction with strain can be formulated by a unique equation.
HIF-1α对缺氧条件下人脐静脉内皮细胞ECV304增殖和凋亡的影响

缺氧是临床常见下肢静脉性疾病如静脉曲张、静脉血栓等形成与发展的重要原因之一。低氧诱导因子1α(hypoxia inducible factors-1α,HIF-1α)是最早发现的缺氧状态下特异性发挥作用的DNA结合蛋白,当缺氧发生时,HIF-1α多有特异性表达并引起一系列相关分子改变,在疾病发生进展过程中广泛作用于细胞增殖、细胞凋亡和细胞分化等过程。然而,缺氧状态下内皮细胞中HIF-1α表达与细胞凋亡和增殖关系的报道较少。本研究观察缺氧对人脐静脉内皮细胞ECV304 HIF-1α表达及细胞增殖与凋亡的影响,以期为临床靶向性治疗下肢静脉性疾病提供新的实验依据。
Integrated Risk Identification, Analysis, and Assessment: A Dynamic Household Economy Analysis Methodology and Example

Many methodologies identify, analyze, and assess static risks to quantify potential disaster losses based on past and current events. Static methodologies will not, however, capture how climate change and adaptation are rapidly affecting the natural and social systems in many areas. Local and global changes such as those associated with development investments, livelihood pressures, political stability, and demographic trends are also affecting many areas, especially in emerging economies. Risk identification, analysis, and assessment methodologies must integrate all changes dynamically so that risk reduction and development decisions can be based on future needs. After a theoretical explanation of how to integrate dynamic changes, a static Household Economy Analysis (HEA) completed for a rapidly changing area of East Timor was altered using current trends to make the analysis more dynamic. Some inherent difficulties exist with a more dynamic approach and recommendations for overcoming them are presented. Research, government, and non-government personnel interested in integrated approaches to risk reduction and development decision-making in areas subject to rapid change will find the study useful.
Analysis on the capacity degradation mechanism of a series lithium-ion power battery pack based on inconsistency of capacity

The lithium-ion battery has been widely used as an energy source. Charge rate, discharge rate, and operating temperature are very important factors for the capacity degradations of power batteries and battery packs. Firstly, in this paper we make use of an accelerated life test and a statistical analysis method to establish the capacity accelerated degradation model under three constant stress parameters according to the degradation data, which are charge rate, discharge rate, and operating temperature, and then we propose a capacity degradation model according to the current residual capacity of a Li-ion cell under dynamic stress parameters. Secondly, we analyze the charge and discharge process of a series power battery pack and interpret the correlation between the capacity degradations of the battery pack and its charge/discharge rate. According to this cycling condition, we establish a capacity degradation model of a series power battery pack under inconsistent capacity of cells, and analyze the degradation mechanism with capacity variance and operating temperature difference. The comparative analysis of test results shows that the inconsistent operating temperatures of cells in the series power battery pack are the main cause of its degradation; when the difference between inconsistent temperatures is narrowed by 5 ℃, the cycle life can be improved by more than 50%. Therefore, it effectively improves the cycle life of the series battery pack to reasonably assemble the batteries according to their capacities and to narrow the differences in operating temperature among cells.
Improved performance of InGaN light-emitting diodes with a novel sawtooth-shaped electron blocking layer

A sawtooth-shaped electron blocking layer is proposed to improve the performance of light-emitting diodes (LEDs). The energy band diagram, the electrostatic field in the quantum well, the carrier concentration, the electron leakage, and the internal quantum efficiency are systematically studied. The simulation results show that the LED with a sawtooth-shaped electron blocking layer possesses higher output power and a smaller efficiency droop than the LED with a conventional AlGaN electron blocking layer, which is because the electron confinement is enhanced and the hole injection efficiency is improved by the appropriately modified electron blocking layer energy band.
The design and simulation of a titanium oxide memristor-based programmable analog filter in a simulation program with integrated circuit emphasis

In many communication and signal routing applications, it is desirable to have a programmable analog filter. According to this practical demand, we consider the titanium oxide memristor, which is a kind of nano-scale electron device with low power dissipation and nonvolatile memory. Such characteristics could be suitable for designing the desired filter. However, both the non-analytical relation between the memristance and the charges that pass through it, and the changeable V-I characteristics in physical tests make it difficult to accurately set the memristance to the target value. In this paper, the conductive mechanism of the memristor is analyzed, a method of continuously programming the memristance is proposed and simulated in a simulation program with integrated circuit emphasis, and its feasibility and compatibility, both in simulations and physical realizations, are demonstrated. This method is then utilized in a first-order active filter as an example to show its applications in programmable filters. This work also provides a practical tool for utilizing memristors as resistance programmable devices.
Spin fluctuations and unconventional superconducting pairing in iron-based superconductors

In this article, we review the recent theoretical works on the spin fluctuations and superconductivity in iron-based superconductors. Using the fluctuation exchange approximation and multi-orbital tight-binding models, we study the characteristics of the spin fluctuations and the symmetries of the superconducting gaps for different iron-based superconductors. We explore the systems with both electron-like and hole-like Fermi surfaces (FS) and the systems with only the electron-like FS. We argue that the spin-fluctuation theories are successful in explaining at least the essential part of the problems, indicating that the spin fluctuation is the common origin of superconductivity in iron-based superconductors.
Electronic phase diagram of NaFe_(1-x)Co_xAs investigated by scanning tunneling microscopy

Our recent scanning tunneling microscopy (STM) studies of the NaFe_(1-x)Co_xAs phase diagram over a wide range of dopings and temperatures are reviewed. Similar to the high-T_c cuprates, the iron-based superconductors lie in close proximity to a magnetically ordered phase. Therefore, it is widely believed that magnetic interactions or fluctuations play an important role in triggering their Cooper pairings. Among the key issues regarding the electronic phase diagram are the properties of the parent spin density wave (SDW) phase and the superconducting (SC) phase, as well as the interplay between them. The NaFe_(1-x)Co_xAs is an ideal system for resolving these issues due to its rich electronic phases and the charge-neutral cleaved surface. In our recent work, we directly observed the SDW gap in the parent state, and it exhibits unconventional features that are incompatible with the simple Fermi surface nesting picture. The optimally doped sample has a single SC gap, but in the underdoped regime we directly viewed the microscopic coexistence of the SDW and SC orders, which compete with each other. In the overdoped regime we observed a novel pseudogap-like feature that coexists with superconductivity in the ground state, persists well into the normal state, and shows great spatial variations.The rich electronic structures across the phase diagram of NaFe_(1-x)Co_xAs revealed here shed important new light for defining microscopic models of the iron-based superconductors. In particular, we argue that both the itinerant electrons and local moments should be considered on an equal footing in a realistic model.
Photoemission study of iron-based superconductor

The iron-based superconductivity (IBSC) is a great challenge in correlated system. Angle-resolved photoemission spectroscopy (ARPES) provides electronic structure of the IBSCs, the pairing strength, and the order parameter symmetry. Here, we briefly review the recent progress in IBSCs and focus on the results from ARPES. The ARPES study shows the electronic structure of "122", "111", "11", and "122*" families of IBSCs. It has been agreed that the IBSCs are unconventional superconductors in strong coupling region. The order parameter symmetry basically follows s± form with considerable out-of-plane contribution.
Colossal magnetoresistance in manganites and related prototype devices

We review colossal magnetoresistance in single phase manganites, as related to the field sensitive spin-charge interactions and phase separation; the rectifying property and negative/positive magnetoresistance in manganite/Nb:SrTiO3 p-n junctions in relation to the special interface electronic structure; magnetoelectric coupling in manganite/ferroelectric structures that takes advantage of strain, carrier density, and magnetic field sensitivity; tunneling magnetoresistance in tunnel junctions with dielectric, ferroelectric, and organic semiconductor spacers using the fully spin polarized nature of manganites; and the effect of particle size on magnetic properties in manganite nanoparticles.
Exploration of iron-chalcogenide superconductors

Iron-chalcogenide compounds with FeSe(Te, S) layers did not attract much attention until the discovery of high-Tc superconductivity (SC) in the iron-pnictide compounds at the begining of 2008. Compared with FeAs-based superconductors, iron-chalcogenide superconductors have aroused enormous enthusiasm to study the relationship between SC and magnetisms with several distinct features, such as different antiferromagnetic ground states with relatively large moments in the parents, indicating possibly different superconducting mechanisms, the existence of the excess Fe atoms or Fe vacancies in the crystal lattice. Another reason is that the large single crystals are easily grown for the iron-chalcogenide compounds. This review will focus on our exploration for the iron-chalcogenide superconductors and discussion on several issues, including the crystal structure, magnetic properties, superconductivity, and phase separation. Some of them reach a consensus but some important questions still remain to be answered.