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排序方式: 共有312条查询结果,搜索用时 15 毫秒
101.
Adipose derived stem cells represent a readily available source of adult stem cells for various biomedical applications. In this study, the proliferation and osteogenic differentiation potential of lanthanum nitrate(La3+) on human adipose derived mesenchymal stem cells(hADSCs) were investigated for the first time and compared with that of dexamethasone(Dex). Our results provided evidence that La3+ at 50 μmol/L concentration promoted proliferation of hADSCs upto 2.4 fold when treated for 21 d in DMEM medium. Treatment of hADSCs with La3+ containing osteogenic induction medium(α-MEM with ascorbic acid and β-glycerophosphate) for 7 d resulted in higher calcium deposition than that in the presence of Dex(0.1 μmol/L) as shown by Alizarin red S and von Kossa staining. Scanning electron micrographs also showed more extracellular matrix mineralization in the presence of La3+. After 7 d of treatment with La3+(10 μmol/L) the expression of RunX2, osteopontin(OP) and osteocalcin(OC) increased 3.4, 5.5 and 2.7 fold respectively. Our results provided evidence that in the presence of La3+ osteogenic differentiation occurred earlier than that in the presence of Dex.  相似文献   
102.
Graph embedding problems have gained importance in the field of interconnection networks for parallel computer architectures. In this paper, we determine the exact wirelength of embedding hypercubes into necklace, windmill and snake graphs.  相似文献   
103.

Telecare medical communication system (TMCS) is an essential component in today’s fast moving era. Patients are privileged to have wireless online medical facilities from their remote locations. Probability of noscomial infections is absolutely zero in such wireless TMCS. Data Security of heterogeneous patients during the wireless communication is a big challenge. Patients’ data privacy is highly confidential and need enhanced encryption measures. Intruding leads to the medical data adulterations in such telecare systems. This paper proposes a modified Advanced Encryption Standards (AES) based on the biometric generated key. Binary biometric key were generated from the patients’ fingerprints. S-box of AES has been enhanced by the musical involvement of metaheuristic harmony search algorithm. Clinical electrocardiogram (ECG) signals were carried out to enhance the security mechanism of the TMCS. Different tests were carried on the proposed technique, which in turn gets wise bench-mark outcomes. Statistical analyses were conducted to counterfeit the intruding. This proposed technique is suitable for wireless TCMS with higher degree of patients’ privacy.

  相似文献   
104.
A highly energy efficient capacitor switching technique in a successive approximation register (SAR) analog to digital converter (ADC) for biomedical applications is presented. The proposed scheme based on new switching method, which combine the LSB split capacitive technique and monotonic method can reduce the average switching energy by 99.2% compared to the conventional SAR architecture. Besides reducing energy in each comparison cycle, the suggested method also achieves an 8× reduction in total capacitance used in the digital to analog converter over the conventional one with the same resolution. The proposed ADC can find application in biomedical engineering systems and other fields which low power consumption is needed.  相似文献   
105.
The recent wave of creating an interconnected world through satellites has renewed interest in satellite communications. Private and government-funded space agencies are making advancements in the creation of satellite constellations, and the introduction of 5G has brought a new focus to a fully connected world. Satellites are the proposed solutions for establishing high throughput and low latency links to remote, hard-to-reach areas. This has caused the injection of many satellites in Earth's orbit, which has caused many discrepancies. There is a need to establish highly adaptive and flexible satellite systems to overcome this. Machine Learning (ML) and Deep Learning (DL) have gained much popularity when it comes to communication systems. This review extensively provides insight into ML and DL's utilization in satellite communications. This review covers how satellite communication subsystems and other satellite system applications can be implemented through Artificial Intelligence (AI) and the ongoing open challenges and future directions.  相似文献   
106.
The application of two-dimensional (2-D) infinite impulse response (IIR) spatially-bandpass (SBP) filters as a digital beamformer for a wide spectrum of practical applications spanning wireless cognitive radio communications, doppler radar, and radio astronomy instrumentation is discussed. The paper starts with an introduction of the recently proposed 2-D SBP filter. The first application is a spectrum sensing scheme for dynamic spectrum access based cognitive radios. A 2-D IIR SBP filter is used in conjunction with a sub-Nyquist wideband signal reconstruction technique to achieve aperture-array directional spectrum sensing using sub-Nyquist sparse sampling based on the recently reported Eldar algorithm. The second application is related to wideband pulse and continuous-wave frequency modulated Doppler radar sensing. The SBP filter is integrated with a wideband radar back-end connected to an electronically-steerable aperture antenna. A a low-complexity directional localization algorithm is presented, which estimates the range and angle of a target scatterer with a signal to interference ratio improvement of 10 dB. We also present applications of 2-D IIR SBP in the fields of classification and remote sensing of unmanned aerial vehicles. Finally, a digital aperture-array wideband beamforming model using the 2-D IIR SBP filters is presented for radio telescope systems based on dense aperture arrays and time-domain beamforming. A well-known example is the study of pulsar astrophysics using a highly-directional aperture antenna system. The 2-D IIR SBP beamformer is simulated as the digital backend of the time-domain beamforming system with array signals synthesized using measured time-domain signatures from the Crab pulsar obtained from the GAVRT. The SBP filter shows a gain of 12.3 dB with an order of magnitude lower circuit complexity compared to traditional phased-array digital beamformers. To obtain comparable levels of SINR improvement, the wideband phased-array beamformers require 48-point FFTs per antenna. Assuming the optimum three real-multiplications per complex multiplication for the Gauss algorithm, it is discovered that the proposed 2-D IIR SBP beamformers are more than 97 % lower in digital multiplier complexity compared to traditional FIR phased-array FFT-beamformers.  相似文献   
107.
In this study an attempt has been made to incorporate the effect of transverse shear on the stability of moderately thick/very thick composite laminated plates under in-plane compressive and shear loading using a Simple Higher Order Shear Deformation Theory based on four unknown displacement functions (u0,v0,wb,ws) instead of five which is commonly used in most of the higher order theories. The finite element method is employed to study the initial buckling load of laminated plates. The change in initial buckling response of thick rectangular antisymmetric laminates with respect to the fibre orientation angle has been studied. The interaction curves (between Nx and Nxy for different parameters of the laminates) are studied in detail.  相似文献   
108.
The purpose of this investigation was to compare the bioavailability of three coenzyme Q10 (CoQ10) formulations in dogs using an open, randomized, multiple-dose crossover design. The formulations included a powder-filled capsule (A, control) and two soft gelatin formulations (Q-Gel as the water-miscible form of CoQ10, B and Q-Nol as the water-miscible form of ubiquinol, the reduced form of CoQ10, C). Formulations were evaluated in pairs, allowing a washout period of 14 days prior to crossing over. Blood samples were collected from each animal prior to dosing to determine the endogenous plasma CoQ10 concentrations. Serial blood samples were collected for 72 hr and plasma CoQ10 concentrations were determined by high-performance liquid chromatography. Plasma concentration-time profiles were corrected for endogenous CoQ10 concentrations. Results showed that the relative bioavailabilities of formulations B and C were approximately 3.6 and 6.2-fold higher than that of control formulation A. The AUC(microgram.hr/mL) +/- SD, Cmax(microgram/mL) +/- SD, and Tmax(hr) +/- SD for formulations A, B, and C were 1.695 +/- 0.06, 6.097 +/- 0.08, and 10.510 +/- 0.10; 0.096 +/- 0.035, 0.169 +/- 0.038, and 0.402 +/- 0.102; and 4.2 +/- 1.48, 4.1 +/- 1.57, and 4.5 +/- 0.58, respectively. While no significant differences were observed between Tmax values of the three formulations, the AUC and Cmax values for formulations B and C were significantly higher than those of the control (p < 0.05). The present investigation demonstrates that soft gelatin capsules containing water-miscible CoQ10 formulations B (Q-Gel) and C (Q-Nol) are superior to powder-filled formulations with regard to their biopharmaceutical characteristics.  相似文献   
109.
Yan J  Indra EM 《Analytical chemistry》2012,84(14):6122-6127
Sulfur anions and their derivatives have long been recognized for their high selectivity and reactivity toward Pb(2+) ions and formation of highly absorptive yet water-insoluble compounds with both acid and base media. This phenomenon has been used for qualitative analysis of lead ions in water. We demonstrate a new method to quantitatively determine the Pb(2+) concentration in the range of 0.5-500 ppm in water using colorimetric measurement, based on forming "soluble" lead sulfide in water enhanced with non-precious-metal nanoparticles. This method has inherent high selectivity for lead over other alkali-metal and alkaline-earth-metal ions. The colorimetric measurements of the absorptive solutions provide accurate determination of the lead concentration in water comparable to that measured using inductively coupled plasma mass spectrometry. To our knowledge, this is the simplest, lowest cost, and easiest-to-use method for detecting and determining the lead concentration in water.  相似文献   
110.
Nano Research - Natural killer (NK) cells are attractive effector cells of the innate immune system against human immunodeficiency virus (HIV) and cancer. However, NK cell therapies are limited by...  相似文献   
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