Photoregulation of Gene Expression with Ligand-Modified Caged siRNAs through Host/Guest Interaction

Small interfering RNA (siRNA) can effectively silence target genes through Argonate 2 (Ago2)-induced RNA interference (RNAi). It is very important to control siRNA activity in both spatial and temporal modes. Among different masking strategies, photocaging can be used to regulate gene expression through light irradiation with spatiotemporal and dose-dependent resolution. Many different caging strategies and caging groups have been reported for light-activated siRNA gene silencing. Herein, we describe a novel caging strategy that increases the blocking effect of RISC complex formation/process through host/guest (including ligand/receptor) interactions, thereby enhancing the inhibition of caged siRNA activity until light activation. This strategy can be used as a general approach to design caged siRNAs for the photomodulation of gene silencing of exogenous and endogenous genes.     

One step method of structure engineering porous graphitic carbon nitride for efficient visible-light photocatalytic reduction of Cr(Ⅵ)

Porous g-C3N4 nanosheets (PCN) were prepared by the nickel-assisted one-step thermal polymerization method.Hydrogen (H2) which was produced by the reaction between nickel (Ni) foam and ammonia (NH3) defined the structure and properties of PCN.During the formation of PCN,the participation of H2 not only enhanced the spacing between layers but also boosted the specific surface area that more active sites were exposed.Additionally,H2 promoted pores formation in the nanosheets,which was beneficial to the transfer of photons through lamellar structure and improved the absorption efficiency of visible light.Remarkably,the obtained PCN possessed better Cr(Ⅵ) photocatalytic reduction efficiency than pure g-C3N4.The reaction rate constant (k) of PCN (0.013 min-1) was approximately twice that of bare g-C3N4 (0.007 min-1).Furthermore,the effects of original pH and concentration of Cr(Ⅵ)-containing solution on removal efficiency of Cr(Ⅵ) were explored.A possible photocatalytic mechanism was proposed based on the experiments of radical scavengers and photoelectrochemical characterizations.     

Hydrogen Production from Catalytic Steam Reforming of Bio-Oils: A Critical Review

In the future, hydrogen will be an important energy carrier and industrial raw material. Catalytic steam reforming of bio-oils is a promising and economically viable technology for hydrogen production. However, during the reforming process, the catalysts are rapidly deactivated due to coke formation and sintering. Thus, maintaining the activity and stability of catalysts is the key issue in this process. Optimized operation conditions could extend the catalyst lifetime by affecting the coke morphology or promoting coke gasification. This article summarizes the recent developments in the field of catalytic steam reforming of bio-oils, focusing on the operation conditions, the properties of the catalysts, and the effects of the catalyst supports. The expected insights into the catalytic steam reforming of bio-oils will provide further guidance for hydrogen production from bio-oils.     

iRGD-reinforced,photo-transformable nanoclusters toward cooperative enhancement of intratumoral penetration and antitumor efficacy

Nano Research - Insufficient intratumoral penetration greatly hurdles the anticancer performance of nanomedicine. To realize highly efficient tumor penetration in a precisely and spatiotemporally...     

Reconstructing gene regulatory networks with a memetic-neural hybrid based on fuzzy cognitive maps

Reconstructing gene regulatory networks (GRNs) plays an important role in identifying the complicated regulatory relationships, uncovering regulatory patterns in cells, and gaining a systematic view for biological processes. In order to reconstruct large-scale GRNs accurately, in this paper, we first use fuzzy cognitive maps (FCMs), which are a kind of cognition fuzzy influence graphs based on fuzzy logic and neural networks, to model GRNs. Then, a novel hybrid method is proposed to reconstruct GRNs from time series expression profiles using memetic algorithm (MA) combined with neural network (NN), which is labeled as MANN_FCM-GRN. In MANN_FCM-GRN, the MA is used to determine regulatory connections in GRNs and the NN is used to determine the interaction strength of the regulatory connections. In the experiments, the performance of MANN_FCM-GRN is validated on both synthetic data and the benchmark dataset DREAM3 and DREAM4. The experimental results demonstrate the efficacy of MANN_FCM-GRN and show that MANN_FCM-GRN can reconstruct GRNs with high accuracy without expert knowledge. The comparison with existing algorithms also shows that MANN_FCM-GRN outperforms ant colony optimization, non-linear Hebbian learning, and real-coded genetic algorithms.

     

Chemotherapy response of pancreatic cancer by diffusion-weighted imaging (DWI) and intravoxel incoherent motion DWI (IVIM-DWI) in an orthotopic mouse model

Magnetic Resonance Materials in Physics, Biology and Medicine - To investigate the value of using diffusion-weighted imaging (DWI) and intravoxel incoherent motion DWI (IVIM-DWI) to assess the...     

亲子乐园空调送风方式的数值模拟研究

大型综合室内亲子乐园属于高大空间,设有游乐设施和游戏的特殊性使得对空间的舒适性要求一致,但是送风气流遇阻严重,室内存在较多气流死角,影响室内空气质量和儿童健康。因此其空调设计不仅需要考虑温度、风速的空间均匀度,还要考虑各点的空气龄和PMV-PPD指标。以天津某亲子乐园为研究对象,利用scSTREAM软件对适用于该房间的辐射供冷加新风、置换通风、混合通风三种空调方式的送风效果进行数值模拟分析,从流场的均匀性、人员的热舒适性等方面对模拟结果进行探讨,研究结果表明辐射供冷加新风方式的空间均匀性和PMV指标最佳,混合通风方式的空气龄最小。     

300M超高强钢在中性盐雾环境中的腐蚀行为及机制

摘要：为了研究300M超高强钢在中性盐雾环境中的腐蚀行为及腐蚀机制，采用失重法，宏观、微观腐蚀形貌分析，三维表面轮廓分析及电化学分析的研究方法，来表征腐蚀实验现象并进行分析。结果表明：300M超高强钢在中性盐雾环境中的腐蚀产物为FeOOH、Fe2O3、Fe(OH)3和Fe3O4；腐蚀速率随着腐蚀时间逐渐降低，腐蚀后期（72h）腐蚀速率降低50%；腐蚀初期以点蚀为主，点蚀坑通过横向扩展，逐渐发展为后期的均匀腐蚀，腐蚀表面形貌呈沟壑状；外腐蚀层对基体的保护能力很弱，Cr元素在锈层靠近基体的一侧偏聚使内腐蚀层具有一定的抗腐蚀性。     

Precise Extraction of Charge Carrier Mobility for Organic Transistors

Unreliable mobility values, and particularly greatly overestimated values and severely distorted temperature dependences, have recently hampered the development of the organic transistor field. Given that organic field‐effect transistors (OFETs) have been routinely used to evaluate mobility, precise parameter extraction using the electrical properties of OFETs is thus of primary importance. This review examines the origins of the various mobilities that must be determined for OFET applications, the relevant extraction methods, and the data selection limitations, which help in avoiding conceptual errors during mobility extraction. For increased precision, the review also discusses device fabrication considerations, calibration of both the specific gate‐dielectric capacitance and the threshold voltage, the contact effects, and the bias and temperature dependences, which must actually be handled with great care but have mostly been overlooked to date. This review serves as a systematic overview of the OFET mobility extraction process to ensure high precision and will also aid in improving future research.     

荷电细水雾对管道瓦斯爆炸超压的影响规律研究

为了研究荷电细水雾对瓦斯爆炸超压的影响规律和机理,采用小尺寸管道模拟瓦斯爆炸,研究不同荷电电压作用下的瓦斯爆炸超压和平均压升速率,以及不同雾通量作用下的瓦斯爆炸超压.结果表明:随着荷电电压的升高,瓦斯爆炸超压和平均压升速率受到明显的抑制;随着雾通量的增加,瓦斯爆炸超压明显降低.在实验条件下,和普通细水雾相比,当雾通量为4L、荷电电压为8kV时,瓦斯爆炸超压峰值降低10.798kPa,降幅达49.78%;平均压升速率峰值降低180.468kPa/s,降幅达49.90%.