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排序方式: 共有240条查询结果,搜索用时 15 毫秒
1.
QP Wang E Escudier F Roudot-Thoraval I Abd-Al Samad R Peynegre A Coste 《Canadian Metallurgical Quarterly》1997,107(7):926-931
Myofibroblasts that express alpha-smooth muscle actin (alpha-SMA) are detected in many chronic inflammatory diseases. Transforming growth factor-beta (TGF-beta) is a potent inducer of myofibroblast accumulation in tissues. In this study, scattered myofibroblasts and TGF-beta were quantified and localized in nasal polyps (NPs) and normal nasal mucosa (NM). NPs were sampled in 16 patients during ethmoidectomy and NM was obtained from 10 control subjects during rhinoplasty. alpha-SMA and TGF-beta were detected using immunohistochemistry and the numbers of labeled cells were quantified (alpha-SMA and TGF-beta indices) and compared between NPs and NM. In eight NPs, in which the pedicle was preserved, alpha-SMA and TGF-beta were evaluated and compared in the pedicle, central, and tip areas. Finally, TGF-beta expression was compared between low (zone 1), moderate (zone 2), and high (zone 3) zones of alpha-SMA positivity. alpha-SMA and TGF-beta indices were significantly higher in NPs than in NM. In the eight selected NPs, alpha-SMA-positive cells were significantly more abundant in the pedicle than in the central and tip areas, whereas TGF-beta-positive cells were significantly more numerous in the pedicle than in the tip area. The number of TGF-beta-positive cells was significantly higher in zone 3 than in zone 1 of alpha-SMA positivity. Myofibroblasts, which are abundant in NPs but rare in NM, could be involved in the growth of NPs by inducing extracellular matrix accumulation. The local development of myofibroblasts in NPs could be controlled by TGF-beta, locally produced by inflammatory cells. 相似文献
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Maryam Gharaei Jomehei Samad Sheikhaei 《Analog Integrated Circuits and Signal Processing》2014,78(2):489-499
Reducing the power consumption of a passive radio frequency identification (RFID) tag is the key in many applications. As the modulator is usually the most power-hungry block in an RFID tag, this paper proposes a power-saving modulator. The proposed modulator uses phase shift keying (PSK) backscatter modulation which allows tag to communicate data from its memory to a reader by PSK modulation. The proposed modulator uses a MOSCAP as a variable impedance and is designed in a new one-inverter structure in compare to the conventional varactor-based modulators designed in two-inverter structure, as this modulator needs just a low voltage swing to drive its MOSCAP. Using MOSCAP as the variable capacitance leads to a low voltage design. Also, the fundamental equations required for determination of the capacitive impedance seen by the antenna is presented. This impedance is the master key in modulator design. The modulator has been designed, simulated and optimized in 0.18 μm CMOS technology. All possible simulation results are presented to approve its compatible operation with C1 G2 EPC global standard. The power consumption of less than 46 nW is achieved in all process corner cases at 0.8 V power supply. 相似文献
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Masoud Ayat Behjat Forouzandeh Samad Sheikhaei 《Analog Integrated Circuits and Signal Processing》2013,77(2):307-314
Communication systems require a wide gain range. For example the code-division multiple access system (CDMA) requires more than 80 dB of gain range so that, many variable gain amplifiers (VGAs) must be used, resulting in high power consumption and low linearity because of VGA non-linearity factors. In this paper, a one-stage VGA in 0.18 μm technology is presented. The VGA based on the class AB power amplifier is designed and simulated for a high linearity and an 80 dB tuning range. For the linear-in-decibel tuning range, transistors in sub-threshold region is used. The current control circuit of the VGA changes gain continuously from ?68 to 18 dB at 0.5 GHz and ?60 to 20 dB at 1 GHz with gain error of less than 2 dB. The power consumption enjoys a highest value about 13.5 mW in the maximum gain and P1dB is also about ?3.4 dBm at 0.5 GHz and 2.2 dBm at 1 GHz. 相似文献
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A millimeter‐wave (mm‐wave) high‐linear low‐noise amplifier (LNA) is presented using a 0.18 µm standard CMOS process. To improve the linearity of mm‐wave LNAs, we adopted the multiple‐gate transistor (MGTR) topology used in the low frequency range. By using an MGTR having a different gate‐source bias at the last stage of LNAs, third‐order input intercept point (IIP3) and 1‐dB gain compression point (P1dB) increase by 4.85 dBm and 4 dBm, respectively, without noise figure (NF) degradation. At 33 GHz, the proposed LNAs represent 9.5 dB gain, 7.13 dB NF, and 6.25 dBm IIP3. 相似文献
7.
Single Molecule with Dual Function on Nanogold: Biofunctionalized Construct for In Vivo Photoacoustic Imaging and SERS Biosensing 下载免费PDF全文
U. S. Dinish Zhegang Song Chris Jun Hui Ho Ghayathri Balasundaram Amalina Binte Ebrahim Attia Xianmao Lu Ben Zhong Tang Bin Liu Malini Olivo 《Advanced functional materials》2015,25(15):2316-2325
Multimodal imaging provides complimentary information that is advantageous in studying both cellular and molecular mechanisms in vivo, which has tremendous potential in pre‐clinical research and clinical translational imaging. It is desirable to design probes for multimodal imaging that can be administered minimally but provides multifaceted information. Herein, we demonstrate the complementary dual functional ability of a nanoconstruct for molecular imaging in both photoacoustic (PA) and surface‐enhanced Raman scattering (SERS) biosensing simultaneously in tandem. To realize this, a group of NIR active organic molecules are designed and synthesized that possess both SERS and PA activity. Nanoconstructs realized by anchoring such molecules onto gold nanoparticles are demonstrated for targeting cancer biomarkers in vivo while providing complimentary information about biodistribution and targeting efficiency. In future, such nanoconstructs could play a major role in identifying surgical margins and also for disease monitoring in translational medicine. 相似文献
8.
Hosein Mohamadi Abdul Samad Ismail Shaharuddin Salleh Ali Nodehi 《Wireless Personal Communications》2013,73(3):1309-1330
Recently, directional sensor networks have received a great deal of attention due to their wide range of applications in different fields. A unique characteristic of directional sensors is their limitation in both sensing angle and battery power, which highlights the significance of covering all the targets and, at the same time, extending the network lifetime. It is known as the target coverage problem that has been proved as an NP-complete problem. In this paper, we propose four learning automata-based algorithms to solve this problem. Additionally, several pruning rules are designed to improve the performance of these algorithms. To evaluate the performance of the proposed algorithms, several experiments were carried out. The theoretical maximum was used as a baseline to which the results of all the proposed algorithms are compared. The obtained results showed that the proposed algorithms could solve efficiently the target coverage problem. 相似文献
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Abdol‐Samad Abedi Marjan Rismanchi Mehrnoush Shahdoostkhany Abdorreza Mohammadi Hedayat Hosseini 《International Journal of Food Science & Technology》2016,51(10):2280-2289
The present work reports on the microencapsulation of Nigella sativa seeds oil containing thymoquinone (TQ) by spray‐drying, using modified starch (MS) and maltodextrin (MD) mixture as wall materials aimed at producing functional yogurt. First, the impact of different ratios of MS/MD on microencapsulation efficiency (ME) and TQ retention was investigated. The highest ME (90.10%) was found in microcapsules prepared from emulsion with 80/20 ratio of MS/MD; however, the microcapsules prepared with 50/50 ratio was selected for considering TQ stability under storage conditions and functional yogurt production due to an acceptable ME (89.48%) and better TQ retention (61.12%). The results showed that the microcapsules stored at refrigerator temperature had the highest content of TQ after 4 weeks. Moreover, the results of chemical and sensory analysis suggest that N. sativa seeds oil microcapsules can be used for producing functional yogurt due to high stability of TQ and proper chemical and sensory properties. 相似文献