129 research outputs found
OPTIMIZING PROTEIN PURIFICATION FOR RNA-BINDING RECOMBINANT FUSION PROTEINS
There has been great interest in delivering short interfering RNA (siRNA) and microRNA (miRNA) for therapeutic applications. However, the delivery of small RNAs remains challenging due to its inefficient cellular uptake and instability under physiological conditions. Here, we engineered a CXCR4-targeting RNA-protein nanoplex that consists of a CXCR4-targeting single-chain variable fragment (scFv) antibody, which is fused to an RNA-binding protamine peptide (RSQSRSRYYRQRQRSRRRRRRS). To obtain a functional RNA-binding protein, the removal of external nucleic acids is essential. This study aims to optimize the purification process of RNA-binding fusion proteins to free up RNA-binding domains and study if protein/siRNA complexes could successfully protect and deliver siRNA to silence cellular genes. After testing out different nucleic-acid removal methods, the high-salt-wash assisted immobilized metal affinity column purification method showed a great reduction of bound nucleic-acid contaminants. The purified fusion proteins showed a successful complexation with siRNAs and could deliver siRNA to the targeted cells.Master of Scienc
Protein quality control and aggregation in the endoplasmic reticulum: From basic to bedside
Endoplasmic reticulum (ER) is the largest membrane-bound compartment in all cells and functions as a key regulator in protein biosynthesis, lipid metabolism, and calcium balance. Mammalian endoplasmic reticulum has evolved with an orchestrated protein quality control system to handle defective proteins and ensure endoplasmic reticulum homeostasis. Nevertheless, the accumulation and aggregation of misfolded proteins in the endoplasmic reticulum may occur during pathological conditions. The inability of endoplasmic reticulum quality control system to clear faulty proteins and aggregates from the endoplasmic reticulum results in the development of many human disorders. The efforts to comprehensively understand endoplasmic reticulum quality control network and protein aggregation will benefit the diagnostics and therapeutics of endoplasmic reticulum storage diseases. Herein, we overview recent advances in mammalian endoplasmic reticulum protein quality control system, describe protein phase transition model, and summarize the approaches to monitor protein aggregation. Moreover, we discuss the therapeutic applications of enhancing endoplasmic reticulum protein quality control pathways in endoplasmic reticulum storage diseases
Memetic reinforcement learning based maximum power point tracking design for PV systems under partial shading condition
Spatially controlled electrostatic doping in graphene p-i-n junction for hybrid silicon photodiode
Sufficiently large depletion region for photocarrier generation and
separation is a key factor for two-dimensional material optoelectronic devices,
but few device configurations has been explored for a deterministic control of
a space charge region area in graphene with convincing scalability. Here we
investigate a graphene-silicon p-i-n photodiode defined in a foundry processed
planar photonic crystal waveguide structure, achieving visible - near-infrared,
zero-bias and ultrafast photodetection. Graphene is electrically contacting to
the wide intrinsic region of silicon and extended to the p an n doped region,
functioning as the primary photocarrier conducting channel for electronic gain.
Graphene significantly improves the device speed through ultrafast out-of-plane
interfacial carrier transfer and the following in-plane built-in electric field
assisted carrier collection. More than 50 dB converted signal-to-noise ratio at
40 GHz has been demonstrated under zero bias voltage, with quantum efficiency
could be further amplified by hot carrier gain on graphene-i Si interface and
avalanche process on graphene-doped Si interface. With the device architecture
fully defined by nanomanufactured substrate, this study is the first
demonstration of post-fabrication-free two-dimensional material active silicon
photonic devices.Comment: NPJ 2D materials and applications (2018
Understanding Translationese in Cross-Lingual Summarization
Given a document in a source language, cross-lingual summarization (CLS) aims
at generating a concise summary in a different target language. Unlike
monolingual summarization (MS), naturally occurring source-language documents
paired with target-language summaries are rare. To collect large-scale CLS
data, existing datasets typically involve translation in their creation.
However, the translated text is distinguished from the text originally written
in that language, i.e., translationese. In this paper, we first confirm that
different approaches of constructing CLS datasets will lead to different
degrees of translationese. Then we systematically investigate how
translationese affects CLS model evaluation and performance when it appears in
source documents or target summaries. In detail, we find that (1) the
translationese in documents or summaries of test sets might lead to the
discrepancy between human judgment and automatic evaluation; (2) the
translationese in training sets would harm model performance in real-world
applications; (3) though machine-translated documents involve translationese,
they are very useful for building CLS systems on low-resource languages under
specific training strategies. Lastly, we give suggestions for future CLS
research including dataset and model developments. We hope that our work could
let researchers notice the phenomenon of translationese in CLS and take it into
account in the future.Comment: Accepted to the Findings of EMNLP 202
Erratum: Jiang et al. Localization accuracy of ultrasound-actuated needle with color doppler imaging. :<i>Diagnostics</i> 2020, <i>10</i>, 1020
Localization Accuracy of Ultrasound-Actuated Needle with Color Doppler Imaging
An ultrasonic needle-actuating device for tissue biopsy and regional anaesthesia offers enhanced needle visibility with color Doppler imaging. However, its specific performance is not yet fully determined. This work investigated the influence on needle visibility of the insertion angle and drive voltage, as well as determined the accuracy and agreement of needle tip localization by comparing color Doppler measurements with paired photographic and B-mode ultrasound measurements. Needle tip accuracy measurements in a gelatin phantom gave a regression trend, where the slope of trend is 0.8808; coefficient of determination (R2) is 0.8877; bias is −0.50 mm; and the 95% limits of agreement are from −1.31 to 0.31 mm when comparing color Doppler with photographic measurements. When comparing the color Doppler with B-mode ultrasound measurements, the slope of the regression trend is 1.0179; R2 is 0.9651; bias is −0.16 mm; and the 95% limits of agreement are from −1.935 to 1.605 mm. The results demonstrate the accuracy of this technique and its potential for application to biopsy and ultrasound guided regional anaesthesia
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