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排序方式： 共有1145条查询结果，搜索用时 15 毫秒
91.
Dariush Nasrollahzadeh Gholamreza Roshandel Tiffany Myriam Delhomme Patrice Hodonou Avogbe Matthieu Foll Farrokh Saidi Hossein Poustchi Masoud Sotoudeh Reza Malekzadeh Paul Brennan James Mckay Pierre Hainaut Behnoush Abedi-Ardekani 《International journal of molecular sciences》2021,22(11)
Circulating cell-free DNA (cfDNA) is emerging as a potential tumor biomarker. CfDNA-based biomarkers may be applicable in tumors without an available non-invasive screening method among at-risk populations. Esophageal squamous cell carcinoma (ESCC) and residents of the Asian cancer belt are examples of those malignancies and populations. Previous epidemiological studies using cfDNA have pointed to the need for high volumes of good quality plasma (i.e., >1 mL plasma with 0 or 1 cycles of freeze-thaw) rather than archival serum, which is often the main available source of cfDNA in retrospective studies. Here, we have investigated the concordance of TP53 mutations in tumor tissue and cfDNA extracted from archival serum left-over from 42 cases and 39 matched controls (age, gender, residence) in a high-risk area of Northern Iran (Golestan). Deep sequencing of TP53 coding regions was complemented with a specialized variant caller (Needlestack). Overall, 23% to 31% of mutations were concordantly detected in tumor and serum cfDNA (based on two false discovery rate thresholds). Concordance was positively correlated with high cfDNA concentration, smoking history (p-value = 0.02) and mutations with a high potential of neoantigen formation (OR; 95%CI = 1.9 (1.11–3.29)), suggesting that tumor DNA release in the bloodstream might reflect the effects of immune and inflammatory context on tumor cell turnover. We identified TP53 mutations in five controls, one of whom was subsequently diagnosed with ESCC. Overall, the results showed that cfDNA mutations can be reliably identified by deep sequencing of archival serum, with a rate of success comparable to plasma. Nonetheless, 70% non-identifiable mutations among cancer patients and 12% mutation detection in controls are the main challenges in applying cfDNA to detect tumor-related variants when blindly targeting whole coding regions of the TP53 gene in ESCC. 相似文献
92.
This paper concentrates on the issues with the aim of providing a constant dc‐link voltage and desired power sharing for a distributed energy storage system (DESS)‐based hybrid microgrid under load variations. The hybrid microgrid which is consisted of PV system, lithium battery‐based storage system and a grid‐connected dc/ac converter are controlled by designing a controller based on the zero dynamics‐based mathematical equations of all used converters. Two buck and bidirectional buck‐boost dc/dc converters employed in PV and DESS systems, respectively, are responsible for damping the dc‐link voltage fluctuations, and also the grid‐connected converter is set to enhance the grid power quality and supply continuously the grid‐connected loads. The main contributions of the proposed control technique are simplicity and providing the simultaneous stable performance for both DC and AC sides under both DC and grid‐connected loads variations. Moreover, another contribution of the proposed control technique is providing accurate coordination in both steady‐state and dynamic conditions. To analyze the proposed controller, the dynamic operations of the converters in various operating conditions are evaluated. In this evaluation, several curves based on their zero dynamics are achieved, and their desired operations are completely investigated in different operating conditions. Simulation results in MATLAB/SIMULINK verify the proposed controller ability at reaching the desired zero dynamics and the stable performance of the proposed hybrid microgrid. 相似文献
93.
Masoud Ghahremanloo Mohammad Reza Mobasheri Meisam Amani 《International journal of remote sensing》2019,40(1):104-117
Soil Temperature (ST) data, obtained from either field works or satellite imagery, has frequently been studied for Soil Moisture (SM) estimation. However, a combination of ST data at different depths and soil surface temperature, i.e., Surface Radiometric Temperature (SRT) or Land Surface Temperature (LST), has not yet been well investigated for accurate SM prediction. In this study, an empirical model was first developed to estimate SM at 5 cm Depth (SM5D) over areas with no or sparse vegetation cover using the field SRT and field ST data at 5 cm Depth (ST5D). A Root Mean Square Error (RMSE) and a correlation coefficient (r) of 0.037 m3 m?3 and 0.8 were obtained using this model, respectively. Then, the SRT was substituted by the LST obtained from Landsat thermal bands and ST5D was estimated using the ST data collected at the nearest weather station to the study area by developing a regression equation. The second model demonstrated an RMSE and r of 0.035 m3 m?3 and 0.71, respectively. Overall, it was concluded that the proposed models had high potential for SM estimation using the ST data at different depths collected in the field or acquired by optical satellites. 相似文献
94.
Masoud Shokrnezhad Siavash Khorsandi 《Transactions on Emerging Telecommunications Technologies》2019,30(1)
Internet of things (IoT) is a global infrastructure, providing ubiquitous intelligence by enabling seamless data flows between physical and virtual objects based on existing and evolving interoperable communication technologies. It is expected that the demand for wireless resources will rapidly increase in future IoT networks, and hence, the utilization of the wireless medium needs to be highly improved by efficiently allocating the resources. In this work, we investigate the problem of allocating wireless network resources in a multicarrier code‐division multiple access relay‐aided wireless IoT network, considering both channel assignment and power control, to satisfy the signal‐to‐interference ratio requirement of the devices with the objective of supporting as many devices as possible. The primary problem, named power control and channel assignment, is formulated as a mixed integer linear programming problem. Due to its complexity, three practical suboptimal solution approaches with different applications are developed. First, the Lagrangian relaxation and the dual decomposition methods are employed, and the problem is divided into two pure integer programming and linear programming subproblems, which are then solved using an iterative subgradient‐based algorithm that converges to a near‐optimal solution. Next, a greedy heuristic algorithm based on the Gaussian elimination method is proposed to efficiently find a suboptimal solution. In addition, a two‐phase second‐price auction‐based channel assignment and noncooperative game‐based power control algorithm is proposed to allocate resources in an iterative, distributed, and scalable manner. In the distributed scheme, no information about path gains is required. The numerical results show that the difference between the optimal solution and our approaches is negligible, so they can be efficiently employed in real‐world scenarios. 相似文献
95.
96.
Masoud Homayouni&#x;Tabrizi Mozhgan Soltani Ehsan Karimi Farideh Namvar Vahid Pouresmaeil Ali Es&#x;haghi 《IET nanobiotechnology / IET》2019,13(6):617
One of the most important challenges in treating cancer is the invasion and the angiogenesis of cancer cells. The synthesis of green nanoparticles (NPs) and their use in therapeutic fields is one of the most effective methods with minimal side effects in cancer treatment. In this study, cytotoxic and anti‐angiogenic effects of silver NPs (AgNPs) coated with palm pollen extract [Ag–PP(NPs)] were evaluated. For this purpose, the cells were treated with NPs and then were subjected to trypan blue testing (48 h). Then, the cancer invasion was evaluated by the scratch procedure and the expressions of the vascular endothelial growth factor (VEGF) and its receptor (VEGF‐R) genes were estimated using real‐time PCR assay. Also, the angiogenesis effect of the NPs was investigated with chick chorioallantoic membrane (CAM) assay. The Ag–PP(NPs) induced cytotoxicity on MCF7 cells. The findings also showed that Ag–PP(NPs) inhibit invasive cancer cells and reduce the expression of VEGF and VEGF‐R and significantly reduced the number and vessels lengths and the lengths and weights of the embryos in CAM assay. Ag–PP(NPs) with the induction of cytotoxic effects, metastatic inhibition and anti‐angiogenesis properties should be considered as an appropriate option for treatment of cancerInspec keywords: nanomedicine, genetics, cellular biophysics, toxicology, patient treatment, silver, cancer, biochemistry, biomedical materials, nanoparticles, nanofabrication, membranesOther keywords: minimal side effects, cancer treatment, silver NPs, cancer invasion, vascular endothelial growth factor, receptor genes, VEGF‐R, real‐time polymerase chain reaction assay, angiogenesis effect, chick chorioallantoic membrane assay, MCF7 cells, invasive cancer cells, cytotoxic effects, putative mechanism, anticancer properties, antiangiogenic effects, antiangiogenesis properties, Ag–PP‐induced cytotoxicity, metastatic inhibition, palm pollen extraction, trypan blue testing, time 48.0 hour, Ag 相似文献
97.
Omid Amiri Amir Ehsan Rezaee Hakimeh Teymourinia Masoud Salavati‐Niasari L. Jay Guo Ardashir Baktash 《Advanced Materials Interfaces》2019,6(9)
Current efficiency of perovskite solar cells has reached 23.7%, which is comparable with silicon solar cells. However commercial development is seriously hindered by the instability of the perovskite, especially under moisture conditions. Therefore it is crucial to gain clear understanding of the mechanism of degradation of organic–inorganic perovskite in order to achieve stable perovskite devices. In this paper, the formation and the degradation of perovskite film on different charge transport layers such as a compact TiO2 layer, compact ZnO layer, and ZnO foil, Si nanowires, and porous Si are studied. In addition, density functional theory studies are carried out to better understand the interaction between the perovskite film and substrates. Experimental and theoretical results are combined to draw more reliable conclusion regarding the degradation mechanism. Most notably, the investigations show that the interaction between the iodine (I) atom in the perovskite layer and substrate determine the stability of perovskite cells. As a result, Si has minimum interaction with I atoms and shows maximum stability, while perovskite film degrades on TiO2 film almost immediately. 相似文献
98.
99.
Tapan K. Sarkar Pallab Midya Zoran A. Maricevic Masoud Kahrizi Sadasiva M. Rao Antonije R. Djordjevic 《国际射频与微波计算机辅助工程杂志》1992,2(3):168-178
Triangular patch modeling is used for analysis of arbitrarily shaped microstrip patch antennas over a single lossy dielectric medium. Since the Sommerfeld formulation is used, both the single dielectric layer (over which the microstrip patch is located) and the ground plane are considered to be infinitely wide. Typical numerical results are presented for rectangular, circular, semicircular, pentagonal, and triangular patch antennas. © 1992 John Wiley & Sons, Inc. 相似文献
100.
Mohammad Hossein&#x;Keshavarz Mohammad&#x;Hassan Moghadas Masoud Kavosh&#x;Tehrani 《Propellants, Explosives, Pyrotechnics》2009,34(2):136-141
In this paper, a new approach is introduced to predict the electrostatic sensitivity of nitramines on the basis of their molecular structure. The ratio of carbon to oxygen and the existence of two specific structural parameters can be used for the prediction of the electrostatic sensitivity of nitramines. The results are also compared with quantum mechanical computations from [9] so that the new method gives better predictions with respect to the measured data. Electrostatic sensitivities calculated by the new method for two new nitramines CL‐20 [2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane] and TNAZ [1,3,3‐trinitroazatidine] are also close to the experimental data. 相似文献