Chromatin modification mapping in nanochannels

We report the simultaneous mapping of multiple histone tail modifications on chromatin that has been confined to nanofluidic channels. In these channels, chromatin is elongated, and histone modification can be detected using fluorescently tagged monoclonal antibodies. Using reconstituted chromatin with three distinct histone sources and two histone tail modification probes (H3K4me3 and H3K9ac), we were able to distinguish chromatin from the different sources. Determined ratios of the two modifications were consistent with the bulk composition of histone mixtures. We determined that the major difficulty in transitioning the mapping method to site-specific profiling within single genomic molecules is the interference of naturally aggregating, off-the shelf antibodies with the internal structure of chromatin.     

Micro-/nanofluidics based cell electroporation

Non-viral gene delivery has been extensively explored as the replacement for viral systems. Among various non-viral approaches, electroporation has gained increasing attention because of its easy operation and no restrictions on probe or cell type. Several effective systems are now available on the market with reasonably good gene delivery performance. To facilitate broader biological and medical applications, micro-/nanofluidics based technologies were introduced in cell electroporation during the past two decades and their advances are summarized in this perspective. Compared to the commercially available bulk electroporation systems, they offer several advantages, namely, (1) sufficiently high pulse strength generated by a very low potential difference, (2) conveniently concentrating, trapping, and regulating the position and concentration of cells and probes, (3) real-time monitoring the intracellular trafficking at single cell level, and (4) flexibility on cells to be transfected (from single cell to large scale cell population). Some of the micro-devices focus on cell lysis or fusion as well as the analysis of cellular properties or intracellular contents, while others are designed for gene transfection. The uptake of small molecules (e.g., dyes), DNA plasmids, interfering RNAs, and nanoparticles has been broadly examined on different types of mammalian cells, yeast, and bacteria. A great deal of progress has been made with a variety of new micro-/nanofluidic designs to address challenges such as electrochemical reactions including water electrolysis, gas bubble formation, waste of expensive reagents, poor cell viability, low transfection efficacy, higher throughput, and control of transfection dosage and uniformity. Future research needs required to advance micro-/nanofluidics based cell electroporation for broad life science and medical applications are discussed.     

智慧农业模式对农业信息服务的挑战与机遇

[目的/意义]将大数据、云计算、物联网、人工智能等新兴技术应用到农业生产的全过程,形成智慧农业模式,从而实现信息需求和信息提供的精准对接,更好提升农业信息服务。[方法/过程]通过实地调研、专家咨询、以及相关数据的统计分析,从大数据服务平台、自动化农作物保护、农业机械智能操作和精准养殖等几个方面进行探讨。并从技术和人才方面对智慧农业未来发展所面临的挑战进行了展望。[结果/结论]智慧农业模式实现了农业数据的高效收集,生产过程的实时监控,生产灾害的提前预测等功能,提高了农业信息服务的效率。提高农业生产规模化和集约化程度,降低技术使用成本,是提高我国农业智慧化程度的关键之一。核心技术的自主研发和推广应用也是我国智慧农业发展的一个重大挑战。     

Aberrant methylation patterns in cancer: a clinical view

Epigenetic mechanisms, such as DNA methylation, DNA hydroxymethylation, post-translational modifications (PTMs) of histone proteins affecting nucleosome remodelling, and regulation by small and large non-coding RNAs (ncRNAs) work in concert with cis and trans acting elements to drive appropriate gene expression. Advances in detection methods and development of dedicated platforms and methylation arrays resulted in an explosion of information on aberrantly methylated sequences linking deviations in epigenetic landscape with the initiation and progression of complex diseases. Here, we consider how DNA methylation changes in malignancies, such as breast, pancreatic, colorectal, and gastric cancer could be exploited for the purpose of developing specific diagnostic tools. DNA methylation changes can be applicable as biomarkers for detection of malignant disease in easily accessible tissues. Methylation signatures are already proving to be an important marker for determination of drug sensitivity. Even more, promoter methylation patterns of some genes, such as MGMT, SHOX2, and SEPT9, have already been translated into commercial clinical assays aiding in patient assessment as adjunct diagnostic tools. In conclusion, the changes in DNA methylation patterns in tumour cells are slowly gaining entrance into routine diagnostic tests as promising biomarkers and as potential therapeutic targets.Key words: biomarkers, CpG islands, DNA methylation, molecular diagnostics, epigenetics     

Together they shall not fade away: Opportunities and challenges of self-tracking for dementia care

Dementia is a major public health concern, and mobile technologies have been identified as having the potential to improve the quality of life for individuals with dementia and their caregivers. Recent research, however, suggests that technology-based solutions are frequently driven by and beneficial to caregivers, not both. Emerging personal technologies that are equipped with self-tracking are an ideal option for accommodating person-centered care in light of the collaborative nature of dementia care. However, there is a lack of investigation on how tracking occurs in the context of dementia care. This article presents a thematic analysis of the types of tracking-related information desired in dementia care online communities, as well as how and by whom they are desired through adapting the Conceptual Model of Shared Health Informatics (CoMSHI) for tracking in chronic illness management. Our findings show that four types of tracking metrics are desired for nine types of information: safety alert for wandering, falls, and strangers, reminders of daily life activities and medical and health related activities, monitoring data related to daily life activities and data related to health status, and remote control for patients' daily life activities and financial safety. Family members, caregivers, community members, and persons with dementia involved in work with tracked data face specific challenges. We recommend that self-tracking technologies be implemented in dementia care through collaboration, with the recognition of different types of information as well as different roles involved and with particular attention paid to different types of data work and related roles in data work.     

技术-市场双元性组合对破坏性创新的影响——以科技型小微企业为研究对象

为厘清技术推动力和市场拉动力对于科技型小微企业破坏性创新的影响机理,本研究基于技术和市场领域中探索与利用的组合分别探讨了单一探索、单一利用、技术双元、市场双元、技术开发和市场开发六种可能的双元性组合策略对科技型小微企业低端破坏性创新和新市场破坏性创新的影响。通过对佛山地区364家科技型小微企业的调查研究,实证分析结果显示基于“技术利用×市场利用”组合的单一利用策略和基于“技术探索×市场利用”组合的技术开发策略对科技型小微企业的低端破坏性创新具有显著的正向影响;而基于“技术利用×市场探索”组合的市场开发策略和基于“技术探索×市场探索”组合的单一探索策略对于科技型小微企业的新市场破坏性创新具有显著的正向影响。     

Institutions for Civic Technoscience: How Critical Making is Transforming Environmental Research

This article explores the changing relationship between the academy and new public formations of scientific research, which we term “civic technoscience.” Civic technoscience leverages tactics seen in critical making communities to question and transform how and who can make credible and actionable knowledge. A comparison of two case studies is used. The first is a grassroots mapping process that allows communities to generate high-quality aerial imagery. The second is an academic-led project using environmental sensors to engage disparate audiences in scientific practice. These two projects were found to differ in their ability to form strategic spaces for community-based science, and suggest pathways to foster more robust relationships across the public–academic divide. By altering power dynamics in material, literary, and social technologies used for scientific research, we argue that civic technoscience enables citizens to question expert knowledge production through critical making tactics, and creates opportunities to generate credible public science.     

Measurements of DNA barcode label separations in nanochannels from time-series data

We analyzed time-series data for fluctuations of intramolecular segments of barcoded E. coli genomic DNA molecules confined in nanochannels with sizes near the persistence length of DNA. These dynamic data allowed us to measure the probability distribution governing the distance between labels on the DNA backbone, which is a key input into the alignment methods used for genome mapping in nanochannels. Importantly, this dynamic method does not require alignment of the barcode to the reference genome, thereby removing a source of potential systematic error in a previous study of this type. The results thus obtained support previous evidence for a left-skewed probability density for the distance between labels, albeit at a lower magnitude of skewness. We further show that the majority of large fluctuations between labels are short-lived events, which sheds further light upon the success of the linearized DNA genome mapping technique. This time-resolved data analysis will improve existing genome map alignment algorithms, and the overall idea of using dynamic data could potentially improve the accuracy of genome mapping, especially for complex heterogeneous samples such as cancer cells.     

Putting to (information) work: A Stengersian perspective on how information technologies and people influence information practices

Instead of merely subscribing to an unspecific inseparability in the co-constitution or mangle of information technologies and human-actors, there is a need for conceptual tools to describe and explicate the mechanics of how the enmeshment of technologies and human-beings is occurring in information contexts: how information technologies are both setting standards of the social conduct of information practices, and how people are using information technologies to regulate the social process. Building on an empirical study of human-technology relations in the context of archaeological information work, this article discusses how the imaginary of putting Stengers to work can make a contribution to such an end. Stengers describes an ideal system of human-actors and technology working seamlessly —World-as-Clock—that is unattainable but can serve as a benchmark and a lens for understanding frictions and discrepancies in the cohesion of the two.     

新兴技术对传统管理的挑战和特殊市场开拓的思路

新兴技术的发展正在给传统管理思想带来挑战,与传统技术相比,新兴技术具有显著的特点。本文将重点讨论新兴技术对传统管理的挑战,新兴技术的管理思维,新兴技术的市场特点和新兴技术特殊的市场开拓思路。     

浅论信息化环境下微观经济学课程的教学改革

随着信息技术时代的到来,微观经济学传统的教学模式和方法得到挑战。多媒体、计算机和互联网等现代教育技术在教学资源和教学模式等方面起到了积极推动作用,然而在实际的教学过程中如多媒体应用、教师信息技术掌握力度不够等方面存在着问题。在探讨信息环境下．微观经济学课程教学改革必要性的基础上,分析当今存在的问题,并为教师能更好地运用现代教育技术提高教学质量,深化教育改革,提出解决对策。     

Modeling the relaxation time of DNA confined in a nanochannel

Using a mapping between a Rouse dumbbell model and fine-grained Monte Carlo simulations, we have computed the relaxation time of λ-DNA in a high ionic strength buffer confined in a nanochannel. The relaxation time thus obtained agrees quantitatively with experimental data [Reisner et al., Phys. Rev. Lett. 94, 196101 (2005)] using only a single O(1) fitting parameter to account for the uncertainty in model parameters. In addition to validating our mapping, this agreement supports our previous estimates of the friction coefficient of DNA confined in a nanochannel [Tree et al., Phys. Rev. Lett. 108, 228105 (2012)], which have been difficult to validate due to the lack of direct experimental data. Furthermore, the model calculation shows that as the channel size passes below approximately 100 nm (or roughly the Kuhn length of DNA) there is a dramatic drop in the relaxation time. Inasmuch as the chain friction rises with decreasing channel size, the reduction in the relaxation time can be solely attributed to the sharp decline in the fluctuations of the chain extension. Practically, the low variance in the observed DNA extension in such small channels has important implications for genome mapping.     

工业过程绿色低碳技术

针对钢铁、有色、化工、建材四大高碳排放行业,通过调研和分析,提出了绿氢/绿电替代、原料/产品结构调整、工艺流程再造、数字化和智能化的4个低碳化策略。结合不同行业的技术发展现状和趋势,建议了若干拟重点发展的先进低碳技术,凝练出需解决的关键科学技术难题,并提出了加快新技术应用及产业转型升级的建议和举措,以期为工业低碳绿色发展提供支撑。     

学科知识图谱及其构建机理

目前有关学科知识图谱构建存在目标不明确、视角不明晰、方法较单一、流程不规范等问题,难以有效支持学科建设发展,因此,研究学科建设和学科知识图谱的内涵、价值和类型,提出学科知识图谱构建目标、原则、思路及机理。学科知识图谱按学科建设内涵可分为学科流派图谱、学科交流图谱和学科脉络图谱,在遵循数据时效性、可靠度、标准性和简洁性,知识单元支持度和简洁度,以及流程普适性、步骤规范性、类型多样性、图谱易懂性等原则的基础上,综合运用引文分析、多元统计分析、社会网络分析等方法,从空间维度识别学科核心知识单元及其交流、从时间维度确定学科同类单元结构关系及其演化等,从而辅助精准识别学科建设内涵及结构,科学定位学科发展阶段及特征,立体呈现学科主体间合作关系,动态揭示学科知识演化、研究方向以及前沿趋势,最终辅助学科内涵建设、学科建设决策。     

Co-ownership of intellectual property: Exploring the value-appropriation and value-creation implications of co-patenting with different partners

Combining both interview data and empirical analyses at the patent and firm levels, we explore the value-appropriation and value-creation implications of R&D collaboration resulting in the co-ownership of intellectual property (i.e. co-patents). We make an explicit distinction between three different types of co-patenting partners: intra-industry partners, inter-industry partners, and universities. Our findings indicate that the value-appropriation challenges of IP sharing are clearly evident with intra-industry co-patenting, where partners are more likely to encounter overlapping exploitation domains. Co-patenting with universities is associated with higher market value, since appropriation challenges are unlikely to play a role and collaboration may signal novel technological opportunities. Although we find some evidence that co-patenting corresponds to higher (patent) value, patents co-owned with firms are significantly less likely to receive self-citations, indicating constraints on the future exploitation and development of co-owned technologies.     

Drop-to-drop liquid–liquid extraction of DNA in an electrowetting-on-dielectric digital microfluidics

Recent advancements in microfluidics and lab-on-a-chip technologies enabled miniaturization and automation of many downstream nucleic acid analysis steps such as PCR. However, DNA extraction/isolation protocol remains a stand-alone sample preparation step. For a quick sample-to-result solution, downstream protocols and sample preparation protocols need to be seamlessly integrated into a single lab-on-a-chip platform. As a step toward such integration, this paper introduces microfluidic DNA isolation using the liquid–liquid extraction (LLE) method in the drop-to-drop (DTD) format. The electrowetting-on-dielectric digital microfluidic platform is capable of handling a two-phase liquid system easily, which enables DTD LLE. In this study, the extraction of plasmid DNA (pDNA) from an aqueous sample to an ionic liquid is demonstrated. Prior to pDNA extraction study, the DTD LLE protocol was developed and optimized using organic dyes as solutes. The selective extraction of pDNA in the presence of proteins as interfering molecules is also demonstrated. This work implies that DTD LLE can substitute for magnetic beads steps in standard DNA isolation protocols.     

技术多元化对创新绩效的双中介作用机理研究

随着知识经济时代的到来，如何通过技术多元化提升企业创新绩效引起重点关注，但对两者间的内在机理尚缺乏深入剖析。为此，本文从组织能力视角出发，构建“技术广度多元化、技术深度多元化--吸收能力、技术整合能力--创新绩效”的理论框架，采用回归分析等方法，以沪深两市6个制造行业303家上市公司为样本进行实证检验，研究发现：（1）技术广度多元化与技术深度多元化对创新绩效呈现显著正向影响：（2）吸收能力与技术整合能力在技术多元化与创新绩效间所起作用各不相同，技术广度多元化主要通过吸收能力提升创新绩效，而技术深度多元化主要通过技术整合能力对创新绩效起作用。     

现代钢结构建筑设计与表现探讨

随着科技的发展新型材料的运用越来越广泛,其中钢材是其中普遍采用的一种。我国目前不仅能生产各种类型的建筑钢材,同时钢材生产的新技术、新工艺、新产品日益也增多,如彩钢压型板、彩钢复合板、彩钢扣板、拱形厂房及彩钢制品等的生产,使建筑结构充满现代化时代气息,实际证明现代钢结构建筑在我国更具有广阔的发展前景。     

双曲拱坝体型优化设计

采用改进的复合型法对某双曲拱坝进行了体型优化设计，优化过程中结构重分析采用线弹性有限单元法，本文分别三心圆、地数螺旋线，抛物线，双曲线，椭圆和一般二次曲线六种体型进行了研究，结果表明，一般二次曲线体型的坝体方量，最大拉应力较其它几种体型均为最小，其优化后拱坝的混凝土方量和最大拉应力比原设计方案分别降低约8．77％和20％。