MSC-exo一种新型细胞递送工具转运靶向基因调控胰腺癌增殖效应分析

目的 观察1种新型细胞递送工具(MSC-exo)转运靶向基因调控胰腺癌增殖效应。方法 透射电子显微镜(transmission electron microscope,TEM)和纳米颗粒跟踪分析技术(nanoparticle tracking analysis,NTA)鉴定人间充质干细胞外泌体(human mesenchymal stem cell exosomes,MSC-exo)并转运miR-450a-5p进入CFPAC-1,探讨miR-450a-5p靶向BZW2抑制胰腺癌细胞增殖效应。基因技术处理Pc-BZW2,CCK-8、EdU、细胞划痕、Transwell验证MSC-exo与MSC-exo-miR-450a-5p对细胞的抑制作用。结果 与胰腺正常组织相比miR-450a-5p在胰腺癌组织中低表达(P<0.05),CFPAC-1细胞MSC-exo-miR-450a-5p外泌体标记蛋白CD63、TSG101表达高于MSC-exo(P<0.05)。CCK-8、EdU、细胞划痕、Transwell实验显示MSC-exo-miR-450a-5p较MSC-exo可显著抑制CFPAC-1细胞增殖、侵袭和迁移(P<0.05)。通过双荧光素酶实验证实,miR-450a-5p靶向BZW2,并且RT-qPCR和免疫印迹检测miR-450a-5p和BZW2表达成负性相关(P<0.05)。过表达BZW2,CCK-8、EdU、细胞划痕、Transwell实验均证实,pc-BZW2逆转MSC-exo-miR-450a-5p对CFPAC-1的抑癌功能,免疫印迹检测PCNA、Ki-67、MMP2、MMP9,结果与上述实验一致(P<0.05)。结论 hMSC-exo是1种新的递送系统,靶向BZW2转运miR-450a-5p抑制胰腺癌细胞的生物学恶性,为胰腺癌靶向治疗研究提供了重要线索。

芙蓉不及美人妆——古代化妆品的奥秘

传统化妆产品看似与化学化工无关联,实际上却息息相关。本文从古代化妆美容的角度,着重选取具有代表性的胭脂、眉黛、澡豆三类化妆品,了解其背后的化学知识和制作工艺。在感受古代传统生活氛围,鉴赏古代物质世界的星星碎片的同时,体会化学与传统日用品间的密切关联。

Morphological characteristics and atomic evolution behavior of nanojoints in Ag nanowire interconnect network

Ag nanowires(AgNWs)have shown great application value in the field of flexible electronics due to their excellent optical and electrical properties,and the quality of its joints of AgNWs in the thin film network directly plays a key role in its performance.In order to further improve the joint quality of AgNWs under thermal excitation,the thermal welding process and atomic evolution behavior of AgNWs were investigated through a combination of in situ experimental and molecular dynamics simulations.The influence of processing time,temperature,and stress distribution due to spatial arrangement on nanojoints was systematically explored.What is more,the failure mechanisms and their atomic interface behavior of the nanojoints were also investigated.

Protective Effect of Ethanol Extract from Sweet Potato Leaves on CCL_(4)-Induced Liver Injury in Mice

[Objectives]To investigate the protective effect of ethanol extract from sweet potato leaves on liver injury induced by CCl_(4)in mice.[Methods]25 ICR mice were randomly divided into blank group,model group,high-dose extract group(200 mg/kg),low-dose extract group(100 mg/kg)and positive control group(2 mg/kg colchicine),with 5 mice in each group.All groups except the blank group were given intraperitoneal injection of 20%CCl 4 olive oil solution(2 mL/kg),and the blank group was given the same dose of olive oil solution three times a week.After 4 weeks,each administration group was given the corresponding dose of drugs(10 mL/kg),and the blank group and model group were given the corresponding amount of normal saline for 2 weeks.After the last intragastric administration,fasting was required,but water was allowed,blood was taken from eyeballs,and upper serum was taken by static centrifugation.Serum AST,ALT,CRP,IL-6 and SOD levels were detected by the kit.[Results]Compared with the blank group,the serum AST and ALT levels in the model group were significantly increased;compared with the model group,the ethanol extract of sweet potato leaves could decrease the levels of ALT,AST,CRP,IL-6 and increase the level of SOD in serum.[Conclusions]The ethanol extract of sweet potato leaves had protective effect on the mice with liver injury induced by CCl_(4),and its mechanism may be to protect the liver by lowering enzymes,inhibiting inflammation and antioxidant stress.

Therapeutic Effect of Daphnetin on Mastitis Induced by Staphylococcus aureus in Mice

[Objectives]To observe the effects of daphnetin on mastitis induced by Staphylococcus aureus in mice.[Methods]18 postpartum ICR female mice were used to establish mastitis animal model,and were randomly divided into three groups(A,B,and C)with 6 mice in each group.Group A:blank control group;group B:S.Aureus model group;group C:S.Aureus model+daphnetin group.The experimental groups were injected 1 mL of 1.0×104 CFU/100μL of S.aureus of along the nipple catheter.The suspension was placed in the 3 rd and 4 th pairs of mammary glands,and the control group was injected with the same dose of normal saline.On the second day after infection,the rats in group A,B and C were given drugs by gavage,while the rats in group A and B were given normal saline and the rats in group C were given daphnetin once a day for 6 consecutive days.Blood samples were collected from living eyeballs,and blood cells were analyzed by automatic flow cytometer after anticoagulation.[Results]The NLR and Systemie Immune Inflammati-on Index(SII)in the blood of mastitis mice induced by S.aureus were significantly higher than those in the control group(P<0.01),suggesting that neutrophil to lymphocyte ratio(NLR)and SII can be used as diagnostic indicators of mastitis,and the levels of NLR and SII decreased significantly after daphnetin intervention.[Conclusions]NLR and SII showed high levels in mastitis mice,which are valuable for the diagnosis of mastitis and the evaluation of its prognosis.After the intervention of daphnetin,both of them decreased significantly,indicating that daphnetin has a good prognosis trend in mastitis mice induced by S.aureus.

神奇化学之破译无字天书

从古至今,运用化学知识制作、解密隐形书的情况并不少见。本文通过孙特工和小孙特工的经历,一方面向大众科普隐形书中蕴含的化学知识,并介绍如何巧用生活中的物品制作隐形书;另一方面介绍有机荧光材料,并科普新型加密、防伪、解密的科研成果。本文可以让读者在体会化学趣味的同时感受信息安全、科技进步的重要性。

解密香水家族

香水——一种散发怡人香气的物质,丰富了人们的物质生活和精神文化生活。本文通过香水设计大赛,结合化学知识,以拟人的手法介绍了香水的发展历史、化学成分以及香气感觉中的个人差异。

Preparation and Electrorheological Response of PAL/TiO_(2)/PANI Nanorods

Using palygorskite(PAL)as template,the PAL/TiO_(2)/PANI nano-rods were synthesized by heterogeneous precipitation and in-situ polymerization.The synthesized PAL/TiO_(2)/PANI nanorods were used as a novel electrorheological(ER)fluid by mixing with silicone oil,which showed excellent ER effect.The yield stress of the PAL/TiO_(2)/PANI based ER fluid(15 vol%)reached 8.8 kPa under 4 kV mm^(−1) electric field.The dynamic shear stress of the PAL/TiO_(2)/PANI based ER fluid could maintain a stable level in the shear rate range of 0.1–100 s^(−1).Furthermore,the PAL/TiO_(2)/PANI ER fluid exhibited excellent suspension stability.

Properties of ABS/Organic-Attapulgite Nanocomposites Parts Fabricated by Fused Deposition Modeling

The paper discusses the mechanical and thermal performance manifested in natural nanorods attapulgite(ATP)reinforced Acrylonitrile butadiene styrene(ABS)nanocomposites in the process of fused deposition modeling(FDM).Molten extrusion technique was taken to manufacture the filaments of ABS/organic-attapulgite(OAT)nanocomposites with different mass fraction and the printing operation was made by one commercial FDM three-dimensional(3D)printer.Results indicate that the mechanical performance of these FDM 3D printed specimens are improved obviously via the introduction of OAT,and tensile strength of the ABS/OAT nanocomposites parts with only 2 wt%OAT addition is enhanced by 48.1%.At the same time,the addition OAT can reduce the linear expansion coefficient and creep flexibility,and improve the thermal stability and dimensional accuracy of these FDM 3D printed parts.

High-availability in-memory key-value store using RDMA and Optane DCPMM

1 Introduction and main contributiions Emerging hardwares like remote Direct Memory Access(RDMA)capable networks and persistent memory(PM)are promising to build fast high availability in-memory key-value stores.The recent advent of Intel Optane DC Persistent Memory Modules(Optane DCPMM)brings the future closer.However,existing studies to combine the two devices cannot deliver the desired performance due to their two-phase protocols for log shipping and most of them were based on emulation that perform sub-optimally on real PM hardware.

Partition pruning for range query on distributed log-structured merge-tree

Log-structured merge tree(LSM-tree)is adopted by many distributed storage systems.It contains a Memtable and a number of SSTables.The Memtable is an in-memory structure and the SSTable is a disk-based structure.Data records are horizontally partitioned over the primary key and stored in different SSTables.Data writes on records are first served by the Memtable and then compacted to SSTables periodically.Although this design optimizes data writes by avoiding random disk writes,it is unfriendly to read request since the results should be retrieved and merged from both Memtable and SSTables.In particular,when the Memtable and SSTables are distributed on different nodes,it incurs expensive costs to serve range queries.A range query on nonprimary key columns has to scan all partitions,which generates many network and I/O expenses.In this paper,we propose a partition pruning strategy to save cost for range queries.A statistics cache is designed to determine whether a partition contains the desired data or not,which enables read requests to avoid scanning useless partitions.As records can be updated in Memtable freely,to prevent incorrect filtering,a version-based cache synchronization strategy is proposed to ensure the queries to obtain the latest data state.We implement the proposed method in an open source distributed database and conduct comprehensive experiments.Experimental results reveal that the performance of range queries increased 30%~40%with our partition pruning technique.

RS-store:RDMA-enabled skiplist-based key-value store for efficient range query

Many key-value stores use RDMA to optimize the messaging and data transmission between application layer and the storage layer,most of which only provide point-wise operations.Skiplist-based store can support both point operations and range queries,but its CPU-intensive access operations combined with the high-speed network will easily lead to the storage layer reaches CPU bottlenecks.The common solution to this problem is offloading some operations into the application layer and using RDMA bypassing CPU to directly perform remote access,but this method is only used in the hash tablebased store.In this paper,we present RS-store,a skiplist-based key-value store with RDMA,which can overcome the CPU handle of the storage layer by enabling two access modes:local access and remote access.In RS-store,we redesign a novel data structure R-skiplist to save the communication cost in remote access,and implement a latch-free concurrency control mechanism to ensure all the concurrency during two access modes.RS-store also supports client-active range query which can reduce the storage layer’s CPU consumption.At last,we evaluate RS-store on an RDMA-capable cluster.Experimental results show that RS-store achieves up to 2x improvements over RDMA-enabled RocksDB on the throughput and application’s scalability.

Characterizing scientific elites:publication and citation patterns of outstanding scientists in biomedicine

Science is principally driven by the efforts of a small fraction of researchers publishing the m ajority of scientific research and garnering the m ajority of citations.The quantitative analysis of outstanding scientists’publication and citation patterns provides a new perspective fo r understanding of scientific talents.The study of outstanding scientists can enhance our understanding of the publication and citation patterns and their scientific careers more generally.Based on 35,315 research papers from the biomedical field,we analyzed the academic productivity and influence characteristics of 244 outstanding scientists in biomedical field.Several interesting patterns are observed as follows:as outstanding scientists’career age increased,(1)their scientific output shows a trend of decreasing after increasing,(2)their academic influence shows a trend of continuous growth,(3)their number of the co-authors in their scientific career first increases and then remains stable,and(4)the number of their research areas first decreases and then increases.