256 research outputs found
DNA display for drug discovery
No full textA novel DNA display strategy, based on a new puromycin modifier, has been developed. The 5'-end puromycin-tethered oligonucleotide was synthesized to hybridize with mRNA, so that it could attack the nascent polypeptides during in vitro translation. The DNA-peptide fusion molecule can tolerate more harsh and stringent selection conditions, therefore, this DNA display may become a useful tool for in vitro display technologies for the selection of peptide drug candidates
Research on segmented mirror position error of optical system based on ZEMAX
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We have modeled a segmented mirror optical system by software ZEMAX, and analyzed influence of segmented mirror's position error to the optical system imaging for the first time to author's best knowledge. The primary mirror is composed of 18 segmented mirrors. By adjusting each one's position error of six freedoms, we get six relationship curves between position error and the optical system's image quality. The relationship curves show that some have different wave-front error RMS values when segmented mirrors have same position errors. The middle mirrors are sensitive to the movement along X axis direction, and the outer ones are sensitive to the movement along Y axis direction. The middle ones and outer ones are all sensitive to the tilt error, especially tilt along X, Y axis. (C) 2017 Elsevier GmbH. All rights reserved.</p
Sequence-specific RNA Photocleavage by Single-stranded DNA in Presence of Riboflavin
No full textConstant efforts have been made to develop new method to realize sequence-specific RNA degradation, which could cause inhibition of the expression of targeted gene. Herein, by using an unmodified short DNA oligonucleotide for sequence recognition and endogenic small molecue, vitamin B2 (riboflavin) as photosensitizer, we report a simple strategy to realize the sequence-specific photocleavage of targeted RNA. The DNA strand is complimentary to the target sequence to form DNA/RNA duplex containing a G.U wobble in the middle. The cleavage reaction goes through oxidative elimination mechanism at the nucleoside downstream of U of the G.U wobble in duplex to obtain unnatural RNA terminal, and the whole process is under tight control by using light as switch, which means the cleavage could be carried out according to specific spatial and temporal requirements. The biocompatibility of this method makes the DNA strand in combination with riboflavin a promising molecular tool for RNA manipulation
Fen CHEN,
No full textAbstract: This paper proposes a new adaptive image quality assessment (AIQA) method, which is based on distortion classifying. AIQA contains two parts, distortion classification and image quality assessment. Firstly, we analysis characteristics of the original and distorted images, including the distribution of wavelet coefficient, the ratio of edge energy and inner energy of the differential image block, we divide distorted images into White Noise distortion, JPEG compression distortion and fuzzy distortion. To evaluate the quality of first two type distortion images, we use pixel based structure similarity metric and DCT based structural similarity metric respectively. For those blurriness pictures, we present a new wavelet-based structure similarity algorithm. According to the experimental results, AIQA takes the advantages of different structural similarity metrics, and it’s able to simulate the human visual perception effectively. Copyright © 2014 IFSA Publishing, S. L
Clostridium perfringens Liver Abscess Disguised as Biliary Disease: A Report of Two Cases and a Review of the Literature
No full textJialun Peng,1,* Qilong Zhai,1,* Jinzheng Li,1 Xingyu Chen,1 Hongyu Wu,1 Tao Zhong,1 Gangyi Tang,2 Dajun Yu,2 Lixian He,2 Jinxu Li2 1Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, People’s Republic of China; 2Department of General Surgery, Wushan County People’s Hospital of Chongqing, Chongqing, 404700, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jinzheng Li; Gangyi Tang, Tel +86 138 9600 6584 ; +86 159 2387 3984, Fax +86 023 6369 3000, Email [email protected]; [email protected]: Liver abscesses caused by Clostridium perfringens are rare but rapidly fatal. In only a few days, patients progress from liver abscess to sepsis, intravascular hemolysis, multiple organ failure, and even death. These abscesses often occur in patients after trauma or surgery or in those with immunodeficiency. Because patients only show non-specific symptoms such as fever and abdominal pain in the early stage, they can easily be misdiagnosed and miss the therapeutic window, resulting in a poor prognosis. The diagnosis of Clostridium perfringens liver abscess mainly depends on computed tomography (CT), needle aspiration, and/or blood culture. After diagnosis, treatments such as antibiotic therapy, surgical abscess drainage, blood transfusion as needed, and correction of metabolic disturbances must be immediately administered to prevent severe complications. Here, we present two cases of liver abscess due to Clostridium perfringens infection. Both patients initially presented only with fever, abdominal pain, and jaundice, symptoms that were easily confused with cholangitis caused by cholelithiasis. The patients then progressed rapidly and, despite receiving antimicrobial and multimodal sepsis treatment, both eventually died of multiple organ dysfunction syndrome. Clinicians should be on high alert for Clostridium perfringens liver abscesses disguised as biliary disease. Early diagnosis and treatment with the appropriate antibiotics and surgery are fundamental for the survival of the affected patients.Keywords: intravascular hemolysis, biliary diseases, diagnosis, treatmen
SCALAR CURVATURE OF HYPERSURFACES WITH CONSTANT MEAN CURVATURE IN UNIT SPHERES
No full text Let M be an n-dimensional closed hypersurface with constant mean curvature H in a unit sphere Sn+1, n ≤ 8, and S the squared length of the second fundamental form of M. If |H| ≤ ε(n), then there exists a positive constant α(n, H), which depends only on n and H, such that if S0 ≤ S ≤ S0 + α(n, H), then S ≡ S0 and M is isometric to a Clifford hypersurface, where ε(n) is a positive constant depending only on n and [Formula: see text]. </jats:p
A Novel Colorimetric PCR-Based Biosensor for Detection and Quantification of Hepatitis B Virus（图书名：Biosensors and Biodetection--Methods and Protocols Volume 1:Optical-Based Detectors Second Edition）
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