高等学校分层与社会各阶层入学机会均等问题研究

我国高等学校初始分层动因源于20世纪50年代国家重点大学政策的诞生,除"文化大革命"时期外,高等教育系统等级界线一直比较明显,各类学校在办学经费、师资配备、招生条件、社会声望等方面存在较大差异。这意味着学生进入不同层级的大学将获得不同质量的入学机会。研究表明,父母社会阶层高、文化程度高、行政职务高、经济条件好的学生,在国家重点大学等高层级院校中,获得更多的入学机会,而父母社会阶层低、文化程度低、行政职务低、经济条件差的学生,大多数聚集在二本、三本、大专等低层级院校中。这种高等学校分层状况与当前社会分层具有同构性,这在一定程度上固化了现有的社会阶层结构,造成学生隔离现象,影响社会和谐,需要借助国家政策干预加以消解。     

试论新形势下思想政治教育学科的创新发展

新形势下思想政治教育学科创新发展面临着＂四个急需＂的形势与挑战。目前思想政治教育学科还存在着学科认同感缺乏、学科研究对象认识不统一、学科范畴的界定存在分歧、学科建设的力量亟待整合等问题。推进思想政治教育学科的创新发展,必须进一步深化对学科研究对象与基本范畴的研究,积极建构理论与实践并重的大学科体系,大力提升学科协同创新发展力。     

《桃夭》的多重隐喻意象

《桃夭》是《诗经》中一首轻快活泼的祝婚诗。全诗三章均以茂盛而美丽的桃树起兴,从修辞学角度讲,属于以物喻人的比喻;从《诗经》的艺术表现手段看则属于兴中兼比,具有明显的隐喻性质。作者选取桃树作诗的整体隐喻意象,以桃花、桃子、桃叶作多重隐喻,层层递进地对新娘婚后生活幸福、早生子女、家业兴旺做了巧妙暗示,同时结合"之子于归,宜其室家"的写实,表达了对新娘幸福美满的婚后生活的热情祝愿。《桃夭》的这种多重隐喻既源于作者对生活的细致观察,又与当时的社会文化背景密切相关。     

SOFT HANDOFF ALGORITHM BASED ONSIGNAL LEVEL STRENGTH

ＳＯＦＴＨＡＮＤＯＦＦＡＬＧＯＲＩＴＨＭＢＡＳＥＤＯＮＳＩＧＮＡＬＬＥＶＥＬＳＴＲＥＮＧＴＨＳｉＹｉ（侣毅）ＣｈｅｎｇＳｈｉｘｉｎ（程时昕）（ＤｅｐａｒｔｍｅｎｔｏｆＲａｄｉｏＥｎｇｉｎｅｅｒｉｎｇ）ＳＯＦＴＨＡＮＤＯＦＦＡＬＧＯＲＩＴＨＭＢＡＳＥＤ...     

掌握新的教育技术 推进院校教育现代化

现代教育技术应用在教育教学实践上,是充分发挥现代教育技术对院校教育发展的促进作用的一项基本的途径。深化教育教学改革就和发展现代教育技术相辅相成,是院校教育技术发展的根本问题。因此,深刻认识现代教育技术的发展对院校教育教学活动的影响,就成为占领现代教育制高点的前提和基础。     

关于我国基础研究和前沿技术科技评价问题研究

本文对我国科技评价现状及存在问题进行了分析,科技评价主要存在的问题包括科技评价过多、过泛;科技评价方法科学性有待提高;部分科技评价不够透明公开等.并在充分调研基础上,针对基础研究和前沿技术科技评价过程中存在的主要问题提出了相应解决措施和建议.     

主要国家应对气候变化的新举措及对我国的启示

气候变化会导致自然灾害频发、经济下滑、农业减产以及气候移民等一系列问题,为此,各国政府当前已经把气候变化作为当前的重要问题来应对,他们采取的主要措施包括:制定应对气候变化的政策框架,重视科技在应对气候变化中的作用,强调国际科技合作,建立碳排放交易机制和碳税,利用经济刺激计划力挺低碳发展路径等等.这些措施对于我国制定相关政策有一定的启示.     

Re-examining and developing the notion of academic citizenship: A critical literature review

The notion of academic citizenship has been largely associated with the service role which is a part of academic work seen as additional to teaching and research. The changing landscapes of higher education and the increasing diversity of academic work have prompted debates on what academic citizenship means. This paper challenges the conventional association of academic citizenship with the service role and presents a critical review of the key themes and issues explored in extant literature on the subject. Drawing upon the general view of citizenship as practice, it proposes that the different dimensions of academic work be seen integratively, with academic citizenship reframed beyond the service role. We argue that academic citizenship needs to be conceptualised as a practice of enactment, that is, by the values, processes and means by which it is enacted and asserted as academics draw on freedoms, autonomy and individual motivations.     

An integrated microfluidic device for rapid serodiagnosis of amebiasis

A microfluidic device was successfully fabricated for the rapid serodiagnosis of amebiasis. A micro bead-based immunoassay was fabricated within integrated microfluidic chip to detect the antibody to Entamoeba histolytica in serum samples. In this assay, a recombinant fragment of C terminus of intermediate subunit of galactose and N-acetyl-_D-galactosamine-inhibitable lectin of Entamoeba histolytica (C-Igl, aa 603-1088) has been utilized instead of the crude antigen. This device was validated with serum samples from patients with amebiasis and showed great sensitivity. The serodiagnosis can be completed within 20 min with 2 μl sample consumption. The device can be applied for the rapid and cheap diagnosis of other infectious disease, especially for the developing countries with very limited medical facilities.Entamoeba histolytica is the causative agent of amebiasis and is globally considered a leading parasitic cause of human mortality.¹ It has been estimated that 50 × 10⁶ people develop invasive disease such as amebic dysentery and amebic liver abscess, resulting in 100 000 deaths per annum.^{2, 3} High sensitive diagnosis method for early stage amebiasis is quite critical to prevent and cure this disease. To date, various serological tests have been used for the immune diagnosis of amebiasis, such as the indirect fluorescent antibody test (IFA) and enzyme-linked immunosorbent assay (ELISA).We have recently identified a 150-kDa surface antigen of E. histolytica as an intermediate subunit (Igl) of galactose and N-acetyl-_D-galactosamine-inhibitable lectin.^{4, 5} In particular, it has been shown that the C-terminus of Igl (C-Igl, aa 603-1088) was an especially useful antigen for the serodiagnosis of amebiasis. ELISA using C-Igl is more specific than the traditional ELISA using crude antigen.⁶ However, the ELISA process usually takes several hours, which is still labor-intensive and requires experienced operators to perform. More economic and convenient filed diagnosis methods are still in need, especially for the developing countries with limited medical facilities.Among all the bioanalytical techniques, microfluidics has been attracting more and more attention because of its low reagent/power consumption, the rapid analysis speed as well as easy automation.^{7, 8, 9, 10, 11} Especially with the development of the fabrication technique, microfluidics chip can include valves, mixers, pumps, heating devices, and even micro sensors, so many traditional bioanalytical methods can be performed in the microfluidics. Qualitative and quantitative immune analysis on the microfluidic chip was successfully proved by plenty of research with improved sensitivity, shorten reaction time, and less sample consumption.^{8, 10, 11, 12, 13, 14, 15, 16, 17} Moreover, with the intervention of other physical, chemical, biology, and electronic technology, microfluidic technique has been successfully utilized in protein crystallization, protein and gene analysis, cell capture and culturing and analysis as well as in the rapid and quantitative detection of microbes.^{13, 14, 15, 16, 17, 18, 19, 20}Herein, we report a new integrated microfluidic device, which is capable of rapid serodiagnosis of amebiasis with little sample consumption. The microfluidic device was fabricated from polydimethysiloxane (PDMS) following standard soft lithography.^{21, 22} The device was composed of two layers (shown in Figure ​Figure1)1) including upper fluidic layer (in green and blue) and bottom control layer (in red).Open in a separate windowFigure 1Structure illustration of microfluidic chip.To create the fluidic layer and the control layer, two different molds with different patterns have fabricated by photolithographic processes. The mold to create the fluidic channels was made by positive photoresist (AZ-50 XT), while the control pneumatic mold was made by negative photoresist (SU8 2025). For the chip fabrication, the fluidic layer is made from PDMS (RTV 615 A: B in ratio 5:1), and the pattern was transferred from the respective mold. The control layer is made from PDMS (RTV 615 A:B in ratio 20:1). The two layers were assembled and bonded together accurately, and there is elastic PDMS membrane about 30 μm thick between the fluidic layer channels and control layer.^{21, 22} The elastic membrane at the intersection can deform to block the fluid inside the fluidic channels, functioning as valves under the pressures introduced though control channels. There are two types of channels in fluidic layer, the rectangular profiled (in green, 200 μm wide, 35 μm thick) channel and round profiled channels (in blue, 200 μm wide, 25 μm center height). Because of the position of the valves on the fluidic channels, two types of valves (Figure ​(Figure2a)2a) were built, working as a standard valve and a sieve valve. The standard valves (on blue fluidic channels) can totally block the fluid because of the round profile of fluidic channel; the sieve valve can only half close because of the rectangular profile. The sieve valve can be used to trap the microspheres (beads) filled inside the green fluidic channels, while letting the fluid pass through. By this sieve valve, a micro column (in green) is constructed, where the entire ELISA reaction happens. The micrograph of the fabricated micro device is shown in Figure ​Figure2b.2b. The channels were filled with food dyes in different colors to show the relative positions of the channels. The pressures though different control channels are individually controlled by solenoid valves, connected to a computer through relay board. By programming the status (on/off) of various valves at different time periods, all the microfluidic chip operation can be digitally controlled by the computer in manual, semi-automatic, or automatic manner.Open in a separate windowFigure 2(a) Structure illustration of micro column, standard valve and sieve valve; (b) photograph of the microfluidic chip.To validate this device, 12 patient serum samples were collected. Sera from 9 patients (Nos. 1–9) with an amebic liver abscess or amebic colitis were used as symptomatic cases. The diagnosis of these patients was based on their clinical symptoms, ultrasound examination (liver abscess) and endoscopic or microscopic examination (colitis). We also identified the clinical samples using PCR amplification of rRNA genes.²⁴ As negative control, sera obtained from 3 healthy individuals with no known history of amebiasis were mixed into pool sera. The serum was positive for E. histolytica with a titer of 1:64 (borderline positive), as determined by an indirect fluorescent-antibody (IFA) test.^{23, 24} In our previously study, the sensitivity and specificity of the recombinant C-Igl in the ELISA were 97% and 99%.^{6, 25} In the current study, the serodiagnosis of amebiasis was also examined by ELISA using C-Igl.²⁶ The cut-off for a positive result was defined as an ELISA value > 3 SD above the mean for healthy negative controls²⁷ (shown in Figure ​Figure3).3). The seropositivity to C-Igl was 100% in patients with amebiasis.Open in a separate windowFigure 3ELISA reactivity of sera from patients against C-Igl. ELISA plate was coated with 100 ng per well of C-Igl. Serum samples from patients and healthy controls were used at 1:400 dilutions. The dashed line indicates the cut-off value. Data are representative of results from three independent experiments.In the diagnosis process with microfluidic chip, the 4 micro immuno-columns filled with C-Igl-coated microspheres were the key components of the device. The C-Igl was prepared in E. coli as inclusion bodies. After expression, the recombinant protein was purified and analyzed by SDS-PAGE. The apparent molecular mass was 85 kDa.²⁶The immune-reaction mechanism is illustrated in Figure ​Figure4.4. The anti-His monocolonal antibody was immobilized onto the microspheres (beads, 9 μm diameter) coated with protein A. The C-Igl was then immobilized onto the beads through the binding between the His tag and C-Igl. For the diagnosis, the microspheres immobilized with C-Igl and blocked by 5% BSA were preloaded into the columns for the rapid analysis of the patient serum samples. Generally, serum samples which were diluted 100 times were first loaded into the reaction column and incubated at room temperature for 5 min. After being washed by PBS buffer, FITC-conjugated goat anti-human polyclonal antibody was added into the column for 4 min incubation. The fluorescence image can be collected by the fluorescence microscope after the micro column was washed with PBS buffer. From loading diluted serum samples into column to collecting fluorescence images, the total time to complete the immunoassay is less than 10 min. The final fluorescence results were analyzed by Image Pro Plus 6.0.Open in a separate windowFigure 4Schematic representation of the ELISA in the chip.Different reaction conditions have been investigated to find the optimized ones. For each patient, 2 μl sample is enough for the analysis. The designed microfluidic chip with 4 micro columns is capable for 4 parallel analyses at the same time. More micro columns can be integrated into the device if more parallel tests are needed.Different incubating time for the diagnosis has also been investigated and no significant difference has been found for various time periods. It is enough to incubate the chip for only 5 min. The total diagnosis time for one sample is less than 10 min. The detection result appeared as the fluorescence intensity of the reaction column. As shown in Figure ​Figure5,5, the negative sample showed relatively low fluorescence intensity, because little FITC-conjugated goat anti-human polyclonal antibody could attach to the surface of microspheres; on the contrast, the positive sample showed much brighter fluorescence. The fluorescence intensity can be transferred to digital data (Table

数字治理格局研判的理论与方法探索

在世界各国围绕数字治理领域的竞争日趋激烈的背景下,对数字治理格局做出科学研判已十分紧迫且重要。文章首先阐述了对数字治理及数字治理格局的理解,并在回顾了既有关于数字治理格局研究的两种视角基础上,提出了用于研判数字治理格局的数字生态理论视角。文章认为,由于生态视角对关联性、层次性、聚集性、整体性和动态性等更为关注,在把握数字治理格局问题上,具备匹配数字时代高度互联、复杂互动总体特征,关联更宽阔、广泛的问题域等优势。文章还介绍了应用数字生态视角研判数字治理格局的主要方法与具体技术路线。