Aortic heterogeneity across segments and under high fat/salt/glucose conditions at the single-cell level

The aorta, with ascending, arch, thoracic and abdominal segments, responds to the heartbeat, senses metabolites and distributes blood to all parts of the body. However, the heterogeneity across aortic segments and how metabolic pathologies change it are not known. Here, a total of 216 612 individual cells from the ascending aorta, aortic arch, and thoracic and abdominal segments of mouse aortas under normal conditions or with high blood glucose levels, high dietary salt, or high fat intake were profiled using single-cell RNA sequencing. We generated a compendium of 10 distinct cell types, mainly endothelial (EC), smooth muscle (SMC), stromal and immune cells. The distributions of the different cells and their intercommunication were influenced by the hemodynamic microenvironment across anatomical segments, and the spatial heterogeneity of ECs and SMCs may contribute to differential vascular dilation and constriction that were measured by wire myography. Importantly, the composition of aortic cells, their gene expression profiles and their regulatory intercellular networks broadly changed in response to high fat/salt/glucose conditions. Notably, the abdominal aorta showed the most dramatic changes in cellular composition, particularly involving ECs, fibroblasts and myeloid cells with cardiovascular risk factor-related regulons and gene expression networks. Our study elucidates the nature and range of aortic cell diversity, with implications for the treatment of metabolic pathologies.     

Cadaveric Dissection in Relation to Problem-Based Learning Case Sequencing: A Report of Medical Student Musculoskeletal Examination Performances and Self-Confidence

Mercer University School of Medicine utilizes a problem-based learning (PBL) curriculum for educating medical students in the basic clinical sciences. In 2014, an adjustment was piloted that enabled PBL cases to align with their corresponding cadaver dissection that reviewed the content of anatomy contained in the PBL cases. Faculty had the option of giving PBL cases in sequence with the cadaveric dissection schedule (sequential group) or maintaining PBL cases out of sequence with dissections (traditional group). During this adjustment, students’ academic performances were compared. Students’ perception of their own preparedness for cadaveric dissection, their perceived utility of the cadaver dissections, and free-response comments were solicited via an online survey. There were no statistically significant differences when comparing student mean examination score values between the sequential and traditional groups on both multidisciplinary examinations (79.39 ± 7.63 vs. 79.88 ± 7.31, P = 0.738) and gross anatomy questions alone (78.15 ± 10.31 vs. 79.98 ± 9.31, P = 0.314). A statistically significant difference was found between the sequential group's and traditional group's (63% vs. 29%; P = 0.005) self-perceived preparedness for cadaveric dissections in the 2017 class. Analysis of free-response comments found that students in the traditional group believed their performance in PBL group, participation in PBL group and examination performance was adversely affected when compared to students with the sequential schedule. This study provides evidence that cadaveric dissections scheduled in sequence with PBL cases can lead to increased student self-confidence with learning anatomy but may not lead to improved examination scores.     

脉冲异步时序逻辑电路的分析与设计探讨

本文以数字系统时最常用的计数器作为实例，介绍了如何对脉冲异步时序逻辑电路进行分析和设计。为电子技术人员在数字系统或计算机硬件的研发中提供了一个有序的思路。     

The planning illusion: does active planning of a learning route support learning as well as learners think it does?

Is actively planning one’s learning route through a learning domain beneficial for learning? Moreover, can learners accurately judge the extent to which planning has been beneficial for them? This study examined the effects of active planning on learning. Participants received a tool in which they created a learning route themselves before accessing learning material and, for comparison, also worked with a tool in which the route was planned automatically. Eighty-three participants participated in learning sessions with both tools over two topics in statistics. Both tools were found to influence the learning process. However, results indicate inconsistency between participants’ judgement of the relative effectiveness of the two types of tools and their actual learning outcomes. Although participants thought they had learned more when they actively created a plan themselves, knowledge tests showed no differences on performance between actively planning a learning route or receiving it ready-made.     

DNA storage: research landscape and future prospects

The global demand for data storage is currently outpacing the world''s storage capabilities. DNA, the carrier of natural genetic information, offers a stable, resource- and energy-efficient and sustainable data storage solution. In this review, we summarize the fundamental theory, research history, and technical challenges of DNA storage. From a quantitative perspective, we evaluate the prospect of DNA, and organic polymers in general, as a novel class of data storage medium.     

非对称R＆D／产品博弈实验研究

本文实验检验跨国公司大批进驻中国后其和国内企业在R＆D投入中的非对称博弈结果。经济学家借助博弈论研究得到：随着外溢的减弱，双方的博弈由序贯向同步转化，相应的R＆D投入也体现出不同的演变路径。本文实验模拟技术非对称的两类企业，在存在单向外溢时的R＆D投入决策行为，结果与非对称R＆D／产品博弈模型的预言结果一致，并与现实中所观察到的宏观结果相吻合，从而肯定了博弈模型研究结果对现实问题的解释力。     

运用高通量测序研究Alport综合征多能干细胞的microRNA及其靶基因(英文)

目的:寻找来源于Alport综合征患者与正常对照者的多能干细胞差异性表达的microR NA,并对差异性表达的microR NA靶基因进行预测。创新点:本研究不同于一般的试验标本,试验标本是来源于尿肾脏管细胞诱导而成的多能干细胞。基于Alport综合征是遗传疾病,我们对一遗传家系进行了系统的分析。寻找特异性的差异性表达microR NA及其靶基因,从基因水平对Alport综合征进行研究。方法:在前期工作中,成功地从实验者与对照者的尿肾脏管细胞诱导成多能干细胞。运用高通量测序技术分析并发现实验者与对照者之间差异性表达的microR NA。对差异性表达的microR NA靶基因进行预测,并进行靶基因聚集分析,研究靶基因主要参与的生物学过程。同时进行靶基因信号传导通路的分析,研究靶基因主要参与的细胞信号传导通路。结论:在实验组与对照组之间,发现了30个具有显著差异性表达的microR NAs,包括19个上调表达与11个下调表达。差异性表达的microR NA的靶基因主要聚集在细胞膜和细胞代谢过程;靶基因主要参与嘌呤代谢通路与丝裂原活化蛋白激酶(MAPK)通路。     

基于改进人工鱼群算法的船舶进港排序

针对我国绝大部分港口遵循先来先服务(first come first served, FCFS)调度方法引起的船舶进港总延误时间偏长的现象,提出一种基于改进人工鱼群算法(artificial fish swarm algorithm, AFSA)的船舶进港排序方法。改进算法的搜索精度更高和局部优化能力更强,利用这个改进算法得到的船舶进港排序使总延误时间更短。仿真结果显示,与FCFS调度方法和AFSA相比,改进算法的船舶进港总延迟时间分别减少了208%和52%。所提出的改进算法能为港口船舶进港排序提供有效支持。     

Characterization of the start-up period of single-step autotrophic nitrogen removal in a sequencing batch reactor

The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium to low ammonia-nitrogen concentration, with dissolved oxygen （DO）, hydraulic retention time （HRT） and temperature controlled. The experimental conditions were temperature at （30±2） ℃, ammonia concentration of （60 to 120） mg/L, DO of （0.8 to 1.0） mg/L, pH from 7.8 to 8.5 and HRT of 24 h. The rates of nitrification and nitrogen removal turn out to be 77% and 40%, respectively, after a start up period going through three stages divided according to nitrite accumulation： sludge domestication, nitrifying bacteria selection and sludge adaptation, It is demonstrated that dissolved oxygen is critical to nitrite accumulation and elastic YJZH soft compound packing is superior to polyhedral hollow balls in helping the bacteria adhere to the membrane.