oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 31 )

2018 ( 202 )

2017 ( 220 )

2016 ( 187 )

Custom range...

Search Results: 1 - 10 of 11732 matches for " Tielin Qin "
All listed articles are free for downloading (OA Articles)
Page 1 /11732
Display every page Item
Delta activity independent of its activity as a ligand of Notch
Lee-Peng Mok, Tielin Qin, Boris Bardot, Matthew LeComte, Asal Homayouni, Francois Ahimou, Cedric Wesley
BMC Developmental Biology , 2005, DOI: 10.1186/1471-213x-5-6
Abstract: Using Drosophila cultured cells we show that the full length Delta promotes accumulation of Daughterless protein, fringe RNA, and pangolin RNA in the absence of Scabrous or Notch. Scabrous binds Delta and suppresses this activity even though it increases the level of the Delta intracellular domain. We also show that Scabrous can promote Notch receptor activity, in the absence of Delta.Delta has activity that is independent of its activity as a ligand of Notch. Scabrous suppresses this Delta activity. Scabrous also promotes Notch activity that is dependent on Delta's ligand activity. Thus, Notch, Delta, and Scabrous might function in complex combinatorial or mutually exclusive interactions during development. The data reported here will be of significant help in understanding these interactions in vivo.Notch (N) and Delta (Dl) are cell surface proteins that are required for differentiation of almost all tissues in the fruit fly Drosophila melanogaster. They are evolutionarily conserved, functioning similarly in animals from worms to humans [1,2]. The best-known instance of their function is the process of lateral inhibition that initiates differentiation of the neuronal and epidermal tissues from proneural cells that are predisposed to making the neuronal tissue. Proneural cells express high levels of the neuronal transcription co-factors from the Achaete Scute Complex (ASC) or related genes [3,4]. These factors require their partner Daughterless (Da) to activate transcription of the neurogenesis genes [5-7]. Da is expressed at low levels in all Drosophila cells [8] and up regulated in proneural cells specified to differentiate the neurons [5]. Whether or not the up regulation of Da expression is part of lateral inhibition is not clear in Drosophila. In Caenorhabditis elegans, however, the differential accumulation of the Da homolog HLH-2 is the earliest detectable difference between the cells taking up alternate fates during lateral inhibition [9]. As N and Dl are k
Biological Neural Network Structure and Spike Activity Prediction Based on Multi-Neuron Spike Train Data  [PDF]
Tielin Zhang, Yi Zeng, Bo Xu
International Journal of Intelligence Science (IJIS) , 2015, DOI: 10.4236/ijis.2015.52010
Abstract: The micro-scale neural network structure for the brain is essential for the investigation on the brain and mind. Most of the previous studies typically acquired the neural network structure through brain slicing and reconstruction via nanoscale imaging. Nevertheless, this method still cannot scale well, and the observation on the neural activities based on the reconstructed neural network is not possible. Neuron activities are based on the neural network of the brain. In this paper, we propose that multi-neuron spike train data can be used as an alternative source to predict the neural network structure. And two concrete strategies for neural network structure prediction based on such kind of data are introduced, namely, the time-ordered strategy and the spike co-occurrence strategy. The proposed methods can even be applied to in vivo studies since it only requires neural spike activities. Based on the predicted neural network structure and the spreading activation theory, we propose a spike prediction method. For neural network structure reconstruction, the experimental results reveal a significantly improved accuracy compared to previous network reconstruction strategies, such as Cross-correlation, Pearson, and the Spearman method. Experiments on the spikes prediction results show that the proposed spreading activation based strategy is potentially effective for predicting neural spikes in the biological neural network. The predictions on the neural network structure and the neuron activities serve as foundations for large scale brain simulation and explorations of human intelligence.
An Effective Method of SNR Estimation for LDPC-CPM  [PDF]
Rui Xue, Bingbing Sun, Tielin Zhu
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2017, DOI: 10.4236/ijcns.2017.105B014
Abstract:
The technique of SNR estimation is one of the key technologies in adaptive frequency hopping system. The methods of channel quality estimation for non-linear continuous phase modulation (CPM) signals have some limitations. Therefore, the algorithm of channel quality estimation for CPM signals is worthy of further study. Some similar phase characteristics between sampling CPM and MPSK motivate us to propose a channel estimation algorithm with applications to nonlinear CPM using linear modulation signal processing. A comprehensive analysis of LDPC-CPM schemes using proposed algorithm is presented, and simulation results indicate that the proposed method can not only estimate channel quality well but also make the normalized MSE (NMSE) of SNR estimate close to/less than 0.1 dB at SNR of 4 dB using short block codes. It shows that the algorithm in this paper is effective enough to estimate the signal to noise ratio (SNR). Meanwhile, the algorithm in this paper reduces the complexity of computation compared with other traditional algorithms.
Application of Adaptive Coded Modulation Technology in UAV Data Link  [PDF]
Rui Xue, Deting Hu, Tielin Zhu
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2017, DOI: 10.4236/ijcns.2017.105B018
Abstract:
UAV data link has been considered as an important part of UAV communication system, through which the UAV could communicate with warships. However, constant coding and modulation scheme that UAV adopts does not make full use of the channel capacity when UAV communicates with warships in a good channel environment. In order to improve channel capacity and spectral efficiency, adaptive coded modulation technology is studied. Based on maritime channel model, SNR estimation technology and adaptive threshold determination technology, the simulation of UAV data link communication is carried out in this paper. Theoretic analysis and simulation results show that according to changes in maritime channel state, UAV can dynamically adjust the adaptive coded modulation scheme on the condition of meeting target Bit-Error-Rate (BER), the maximum amount of data transfer is non-adaptive systems three times.
The miR-17-92 cluster regulates FOG-2 expression and inhibits proliferation of mouse embryonic cardiomyocytes
Xiang, Rui;Lei, Han;Chen, Mianzhi;Li, Qinwei;Sun, Huan;Ai, Jianzhong;Chen, Tielin;Wang, Honglian;Fang, Yin;Zhou, Qin;
Brazilian Journal of Medical and Biological Research , 2012, DOI: 10.1590/S0100-879X2012007500007
Abstract: micrornas (mirnas) have gradually been recognized as regulators of embryonic development; however, relatively few mirnas have been identified that regulate cardiac development. a series of recent papers have established an essential role for the mirna-17-92 (mir-17-92) cluster of mirnas in the development of the heart. previous research has shown that the friend of gata-2 (fog-2) is critical for cardiac development. to investigate the possibility that the mir-17-92 cluster regulates fog-2 expression and inhibits proliferation in mouse embryonic cardiomyocytes we initially used bioinformatics to analyze 3’ untranslated regions (3’utr) of fog-2 to predict the potential of mir-17-92 to target it. we used luciferase assays to demonstrate that mir-17-5p and mir-20a of mir-17-92 interact with the predicted target sites in the 3’utr of fog-2. furthermore, rt-pcr and western blot were used to demonstrate the post-transcriptional regulation of fog-2 by mir-17-92 in embryonic cardiomyocytes from e12.5-day pregnant c57bl/6j mice. finally, edu cell assays together with the fog-2 rescue strategy were employed to evaluate the effect of proliferation on embryonic cardiomyocytes. we first found that the mir-17-5p and mir-20a of mir-17-92 directly target the 3’utr of fog-2 and post-transcriptionally repress the expression of fog-2. moreover, our findings demonstrated that over-expression of mir-17-92 may inhibit cell proliferation via post-transcriptional repression of fog-2 in embryonic cardiomyocytes. these results indicate that the mir-17-92 cluster regulates the expression of fog-2 protein and suggest that the mir-17-92 cluster might play an important role in heart development.
A Modified TALEN-Based Strategy for Rapidly and Efficiently Generating Knockout Mice for Kidney Development Studies
Yunhong Liu, Xiaoyan Lv, Ruizhi Tan, Tianming Liu, Tielin Chen, Mi Li, Yuhang Liu, Fang Nie, Xiaoyan Wang, Puhui Zhou, Mianzhi Chen, Qin Zhou
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084893
Abstract: The transcription activator-like effector nucleases (TALENs) strategy has been widely used to delete and mutate genes in vitro. This strategy has begun to be used for in vivo systemic gene manipulation, but not in an organ-specific manner. In this study, we developed a modified, highly efficient TALEN strategy using a dual-fluorescence reporter. We used this modified strategy and, within 5 weeks, we successfully generated kidney proximal tubule-specific gene Ttc36 homozygous knockout mice. Unilateral nephrectomy was performed on the 6-week-old founders (F0) to identify the knockout genotype prior to the birth of the offspring. This strategy was found to have little effect on reproduction in the knockout mice and inheritability of the knockout genotypes. The modified TALEN knockout strategy in combination with unilateral nephrectomy can be readily used for studies of gene function in kidney development and diseases.
Protein Palmitoylation Regulates Osteoblast Differentiation through BMP-Induced Osterix Expression
Wai Fook Leong, Tielin Zhou, Gek Liang Lim, Baojie Li
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0004135
Abstract: Osteoporosis is one of the most common diseases and can be treated by either anti-resorption drugs, anabolic drugs, or both. To search for anabolic drug targets for osteoporosis therapy, it is crucial to understand the biology of bone forming cells, osteoblasts, in terms of their proliferation, differentiation, and function. Here we found that protein palmitoylation participates in signaling pathways that control osterix expression and osteoblast differentiation. Mouse calvarial osteoblasts express most of the 24 palmitoyl transferases, with some being up-regulated during differentiation. Inhibition of protein palmitoylation, with a substrate-analog inhibitor, diminished osteoblast differentiation and mineralization, but not proliferation or survival. The decrease in differentiation capacity is associated with a reduction in osterix, but not Runx2 or Atf4. Inhibition of palmitoyl transferases had little effect in p53?/? osteoblasts that show accelerated differentiation due to overexpression of osterix, suggesting that osterix, at least partially, mediated the effect of inhibition of palmitoyl transferases on osteoblast differentiation. BMPs are the major driving force of osteoblast differentiation in the differentiation assays. We found that inhibition of palmitoyl transferases also compromised BMP2-induced osteoblast differentiation through down-regulating osterix induction. However, palmitoyl transferases inhibitor did not inhibit Smad1/5/8 activation. Instead, it compromised the activation of p38 MAPK, which are known positive regulators of osterix expression and differentiation. These results indicate that protein palmitoylation plays an important role in BMP-induced MAPK activation, osterix expression, and osteoblast differentiation.
Carbon-assisted growth and high visible-light optical reflectivity of amorphous silicon oxynitride nanowires
Zhang Lei,Shi Tielin,Tang Zirong,Liu Dan
Nanoscale Research Letters , 2011,
Abstract: Large amounts of amorphous silicon oxynitride nanowires have been synthesized on silicon wafer through carbon-assisted vapor-solid growth avoiding the contamination from metallic catalysts. These nanowires have the length of up to 100 μm, with a diameter ranging from 50 to 150 nm. Around 3-nm-sized nanostructures are observed to be homogeneously distributed within a nanowire cross-section matrix. The unique configuration might determine the growth of ternary amorphous structure and its special splitting behavior. Optical properties of the nanowires have also been investigated. The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance. These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle. Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.
Defect Inspection of Flip Chip Solder Bumps Using an Ultrasonic Transducer
Lei Su,Tielin Shi,Zhensong Xu,Xiangning Lu,Guanglan Liao
Sensors , 2013, DOI: 10.3390/s131216281
Abstract: Surface mount technology has spurred a rapid decrease in the size of electronic packages, where solder bump inspection of surface mount packages is crucial in the electronics manufacturing industry. In this study we demonstrate the feasibility of using a 230 MHz ultrasonic transducer for nondestructive flip chip testing. The reflected time domain signal was captured when the transducer scanning the flip chip, and the image of the flip chip was generated by scanning acoustic microscopy. Normalized cross-correlation was used to locate the center of solder bumps for segmenting the flip chip image. Then five features were extracted from the signals and images. The support vector machine was adopted to process the five features for classification and recognition. The results show the feasibility of this approach with high recognition rate, proving that defect inspection of flip chip solder bumps using the ultrasonic transducer has high potential in microelectronics packaging.
The Application of Organica Ecological Technology in Residential Sewage Treatment  [PDF]
Yuje Qin
Journal of Environmental Protection (JEP) , 2013, DOI: 10.4236/jep.2013.41B006
Abstract: Water is the basis in ecological residential area. It is very important to recycle the water resource in the designing and planning of the ecological residential quarter due to the critical way to realize the wastewater resource utilization. In this paper, a new technology of wastewater treatment is introduced, which is ORGANICA ecotechnology. We integrate the traditional wastewater treatment technology and modern ecological engineering technology together and apply the integrated technology in the treatment of domestic sewage. The treated water can be reused for landscape and greening, which can beautify the residential area and recycle wastewater.
Page 1 /11732
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.