1,631 research outputs found
VISIBLE WAVELENGTH MALDI STUDY
Since its inception over two decades ago matrix-assisted laser/desorption ionization (MALDI) mass spectrometry (MS) using either ultraviolet (UV) or infrared (IR) lasers, has become an important tool for the analysis of molecules of chemical and biological interest. Primarily, this is because MALDI-MS is a relatively soft methodology which allows the ionization and detection of intact analytes with minimal fragmentation. Although MALDI mass spectrometry using visible wavelength lasers has been less studied it is expected to have several advantages over UV-MALDI and IR- MALDI. Many macromolecules of interest absorb UV-light but are transparent at visible wavelengths. In principle, visible-MALDI should be softer than UV-MALDI. Like UV- MALDI, visible-MALDI is also expected to require lower pulse energies than IR- MALDI. Furthermore, readily available pulsed visible laser sources such as the solid- state frequency-doubled Nd:YAG laser (532 nm output) are becoming relatively inexpensive and have longer operational lifetimes compared to standard UV devices. This thesis describes an exploration of possible organic molecules that can absorb 532 nm laser light and serve as matrices. Two classes of compounds considered: pyrromethene and Rhodamine laser dyes. The experiments carried out established that the Rhodamine (R) 610 laser dye is relatively stable; that is, it exhibits minimal fragmentation under 532 nm laser irradiation, and can ionize a selection of analytes. The chloride salt of R610 yielded the cleanest spectra making it a particularly good MALDI matrix candidate for detecting small molecular weight analytes. R575, a neutral laser dye, was found to be an effective absorber in binary matrices. Analyte ionization was achieved by combining this specific laser dye with either a proton donor (HC1 or CHCA), proton acceptor (NaOH), or alkali donor (NaTFA). A detection sensitivity as low as ~12 femtomole was determined using R575 as a component of an acidic or basic binary matrix
Power Efficient Visible Light Communication (VLC) with Unmanned Aerial Vehicles (UAVs)
A novel approach that combines visible light communication (VLC) with
unmanned aerial vehicles (UAVs) to simultaneously provide flexible
communication and illumination is proposed. To minimize the power consumption,
the locations of UAVs and the cell associations are optimized under
illumination and communication constraints. An efficient sub-optimal solution
that divides the original problem into two sub-problems is proposed. The first
sub-problem is modeled as a classical smallest enclosing disk problem to obtain
the optimal locations of UAVs, given the cell association. Then, assuming fixed
UAV locations, the second sub-problem is modeled as a min-size clustering
problem to obtain the optimized cell association. In addition, the obtained UAV
locations and cell associations are iteratively optimized multiple times to
reduce the power consumption. Numerical results show that the proposed approach
can reduce the total transmit power consumption by at least 53.8% compared to
two baseline algorithms with fixed UAV locations.Comment: 4 pages, 4 figures. Accepted for publication in IEEE Communications
Letter
Combining Channel Theory, HowNet and Extension Model to Analyze Big Data
AbstractBecause the diversity of unstructured data has brought new challenges to big data analysis, this paper proposes to combine Channel theory, HowNet and extension model to improve big data analysis ability. The paper proposes a new method to process big data, which is based on the Channel theory idea and HowNet structure, in order to overcome the semantic conflicts of big data. In view of the problems that people are difficult to analyze their big data in order to get profits, the paper proposes a case study to show the effective of our method
A Novel Received Signal Strength Assisted Perspective-three-Point Algorithm for Indoor Visible Light Positioning
In this paper, a received signal strength assisted Perspective-three-Point
positioning algorithm (R-P3P) is proposed for visible light positioning (VLP)
systems. The basic idea of R-P3P is to joint visual and strength information to
estimate the receiver position using 3 LEDs regardless of the LEDs'
orientations. R-P3P first utilizes visual information captured by the camera to
estimate the incidence angles of visible lights. Then, R-P3P calculates the
candidate distances between the LEDs and the receiver based on the law of
cosines and the Wu-Ritt's zero decomposition method. Based on the incidence
angles, the candidate distances and the physical characteristics of the LEDs,
R-P3P can select the exact distances from all the candidate distances. Finally,
the linear least square (LLS) method is employed to estimate the position of
the receiver. Due to the combination of visual and strength information of
visible light signals, R-P3P can achieve high accuracy using 3 LEDs regardless
of the LEDs' orientations. Simulation results show that R-P3P can achieve
positioning accuracy within 10 cm over 70% indoor area with low complexity
regardless of LEDs orientations.Comment: arXiv admin note: substantial text overlap with arXiv:2004.0629
External application of Ruyi Jinhuang powder for phlebitis: A systematic review and meta-analysis
Purpose: To systematically review the effectiveness of the external application, Ruyi Jinhuang powder, on phlebitis
Methods: Relevant literature was retrieved from Medline, Embase, China National Knowledge Infrastructure database (CNKI), Cochrane Central Register, Chongqing Vip, Wanfang Data and SinoMed using the search terms “Ruyi Jinhuang San”, “Ruyi Jinhuang powder”, “Ruyi Jinhuang cream”, “Agreeable golden powder”, “satisfactory golden powder”, “Jinhuang cream”, “phlebitis”, “prevention and (or) treatment”, “randomized controlled trials” and “RCRs”. Two researchers independently arranged and analyzed the data.
Results: Significant differences were observed in the total effectiveness rate of Ruyi Jinhuang powder [relative risk (RR) = 1.27, 95% confidence interval (CI) = 1.19 to 1.36, and p < 0.0001). Ruyi Jinhuang powder can reduce the incidence of phlebitis versus conventional therapy in preventing phlebitis (RR = 0.32, 95 % CI 0.24 to 0.42, and p < 0.0001). Shorten the average healing time [mean difference (MD) =- 32.17, 95 % CI= -48.39 to -15.94, and p = 0.0001). Reduced pain relief time for phlebitis (MD = -3.29, 95% CI -5.42 to -1.16, and p = 0.002). However, no statistical difference was observed with regard to the onset time of phlebitis (MD = -0.62, 95 % CI -1.76 to 0.52, and p = 0.29).
Conclusion: Clinicians consider Ruyi Jinhuang powder a viable complementary and alternative medicine for phlebitis following the stronger evidence being offered
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