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21.
A data-mining approach to biomarker identification from protein profiles using discrete stationary wavelet transform
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Hussain Montazery-Kordy Mohammad Hossein Miran-Baygi Mohammad Hassan Moradi 《浙江大学学报(自然科学英文版)》2008,9(11):863-870
Objective: To develop a new bioinformatic tool based on a data-mining approach for extraction of the most informative proteins that could be used to find the potential biomarkers for the detection of cancer. Methods: Two independent datasets from serum samples of 253 ovarian cancer and 167 breast cancer patients were used. The samples were examined by surfaceenhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The datasets were used to extract the informative proteins using a data-mining method in the discrete stationary wavelet transform domain. As a dimensionality reduction procedure, the hard thresholding method was applied to reduce the number of wavelet coefficients. Also, a distance measure was used to select the most discriminative coefficients. To find the potential biomarkers using the selected wavelet coefficients, we applied the inverse discrete stationary wavelet transform combined with a two-sided t-test. Results: From the ovarian cancer dataset, a set of five proteins were detected as potential biomarkers that could be used to identify the cancer patients from the healthy cases with accuracy, sensitivity, and specificity of 100%. Also, from the breast cancer dataset, a set of eight proteins were found as the potential biomarkers that could separate the healthy cases from the cancer patients with accuracy of 98.26%, sensitivity of 100%, and specificity of 95.6%. Conclusion: The results have shown that the new bioinformatic tool can be used in combination with the high-throughput proteomic data such as SELDI-TOF MS to find the potential biomarkers with high discriminative power. 相似文献
22.
Al composites are of interest due to their appropriate ratio of strength to weight. In our research, an Al/Co3O4 nanocomposite was generated using a sintering technique. The powders of Al with various Co3O4 nanoparticle contents (0wt%, 0.5wt%, 1.0wt%, 1.5wt%, 2.0wt%, and 2.5wt%) were first blended using planetary milling for 30 min, and compressed in a cylindrical steel mold with a diameter of 1 cm and a height of 5 cm at a pressure of 80 MPa. The samples were evaluated with X-ray diffractometry (XRD), scanning electron microscopy (SEM), Vickers hardness, and a vibrating sample magnetometer (VSM). Although the crystallite size of the Al particles remained constant at 7–10 nm, the accumulation of nanoparticles in the Al particle interspace increased the structural tensile strain from 0.0045 to 0.0063, the hardness from HV 28 to HV 52 and the magnetic saturation from 0.044 to 0.404 emu/g with an increase in Co3O4 nanoparticle content from 0wt% to 2.5wt%. 相似文献
23.
Masoumeh Malek Fatemeh Jafarifar Atabak Roohi Aminjan Hassan Salehi Hossein Parsa 《Journal of Natural History》2019,53(11-12):627-637
The increasing demands for medicinal leeches around the world has increased the need for new sources of leeches. To assess the feasibility of culturing a new medicinal leech species, growth, survival and reproduction of Hirudo orientalis was investigated under laboratory conditions (28°C; 9.5D:14.5L light regime; monthly feeding by sheep blood) from hatching until sexual maturity. Several interesting results emerged from this study. (1) The first copulation was observed in 5.5-month-old leeches and cocoon deposition started by six months. (2) Cocoon length and diameter did not differ significantly between six- and nine-month-old leeches, but the percentage of leeches depositing cocoons was significantly higher in the nine-month old group. (3) The growth curve was saltatory, similar to other sanguivorous species. The mean (±SE) wet weight of 6-month-old individuals was 4.70 (±0.86) g. (4) Weight gain rate decreased with increasing age. (5) Mortality only occurred in the one-, seven- and eight-month age groups at the rate of 5.7%, 23.1% and 14.3%, respectively. 相似文献
24.
A common CFH haplotype, with deletion of CFHR1 and CFHR3, is associated with lower risk of age-related macular degeneration 总被引:6,自引:0,他引:6
Hughes AE Orr N Esfandiary H Diaz-Torres M Goodship T Chakravarthy U 《Nature genetics》2006,38(10):1173-1177
Age-related macular degeneration (AMD; OMIM #603075) is the most frequent cause of visual impairment in the elderly population, with severe disease affecting nearly 10% of individuals of European descent over the age of 75 years. It is a complex disease in which genetic and environmental factors contribute to susceptibility. Complement factor H (CFH) has recently been identified as a major AMD susceptibility gene, and the Y402H polymorphism has been proposed as the likely causative factor. We genotyped polymorphisms spanning the cluster of CFH and five CFH-related genes on chromosome 1q23 in 173 individuals with severe neovascular AMD and 170 elderly controls with no signs of AMD. Detailed analysis showed a common haplotype associated with decreased risk of AMD that was present on 20% of chromosomes of controls and 8% of chromosomes of individuals with AMD. We found that this haplotype carried a deletion of CFHR1 and CFHR3, and the proteins encoded by these genes were absent in serum of homozygotes. The protective effect of the deletion haplotype cannot be attributed to linkage disequilibrium with Y402H and was replicated in an independent sample. 相似文献
25.
Reza Beygi Majid Zarezadeh Mehrizi Hossein Mostaan Mahdi Rafiei Ahmadreza Abbasian 《北京科技大学学报》2019,(3)
The aim of the present study was to investigate the phases formed during ball milling of Al–TiO_2–NiO. For this purpose, a mixture of Al–TiO_2–NiO with a molar ratio of 6:1:1 was used. Characterization of the milled powders by X-ray diffraction, differential thermal analysis, field-emission scanning electron microscopy, and transmission electron microscopy showed the formation of nanocrystalline NiTi_2 along with AlNi. A thermodynamical investigation confirmed that NiO was reduced by Al during ball milling, which consequently promoted TiO_2 reduction and the formation of NiTi_2. Al is capable of reducing NiO either during ball milling or at temperatures above the melting point of Al; by contrast, TiO_2 can be reduced by Al only by milling. 相似文献
26.
Hao Ye Hossein Lotfi Lu Li Robert T. Hinkey Rui Q. Yang Lin Lei Joel C. Keay Matthew B. Johnson Tetsuya D. Mıshıma Michael B. Santos 《科学通报(英文版)》2014,59(10):950-955
Interband cascade (IC) photovoltaic (PV)device structures, consisting of multiple discrete InAs/GaSb superlattice absorbers sandwiched between electronand hole barriers, were grown by molecular beam epitaxy.Details of the molecular beam epitaxy growth and materialcharacterization of the structures are presented. The dis-crete absorber architecture enables certain advantages, suchas high open-circuit voltage, high collection efficiency,high operating temperature, and smooth integration ofcascade stages with different bandgaps. The two- andthree-stage ICPV devices presented in this article operate atroom temperature with substantial open-circuit voltages ata cutoff wavelength of 5.3 μm (corresponding to a bandgapof 0.23 eV), the longest ever reported for room temperaturePV devices. The device characteristics indicate a high levelof current matching and demonstrate the advantages of theinterband cascade approach in thermophotovoltaic celldesign. 相似文献
27.
This paper applies the GARCH‐MIDAS (mixed data sampling) model to examine whether information contained in macroeconomic variables can help to predict short‐term and long‐term components of the return variance. A principal component analysis is used to incorporate the information contained in different variables. Our results show that including low‐frequency macroeconomic information in the GARCH‐MIDAS model improves the prediction ability of the model, particularly for the long‐term variance component. Moreover, the GARCH‐MIDAS model augmented with the first principal component outperforms all other specifications, indicating that the constructed principal component can be considered as a good proxy of the business cycle. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
28.
The inferior temporal cortex (IT) of primates is thought to be the final visual area in the ventral stream of cortical areas responsible for object recognition. Consistent with this hypothesis, single IT neurons respond selectively to highly complex visual stimuli such as faces. However, a direct causal link between the activity of face-selective neurons and face perception has not been demonstrated. In the present study of macaque monkeys, we artificially activated small clusters of IT neurons by means of electrical microstimulation while the monkeys performed a categorization task, judging whether noisy visual images belonged to 'face' or 'non-face' categories. Here we show that microstimulation of face-selective sites, but not other sites, strongly biased the monkeys' decisions towards the face category. The magnitude of the effect depended upon the degree of face selectivity of the stimulation site, the size of the stimulated cluster of face-selective neurons, and the exact timing of microstimulation. Our results establish a causal relationship between the activity of face-selective neurons and face perception. 相似文献
29.
New approach for assessing the weldability of precipitation-strengthened nickel-base superalloys
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Homam Naffakh Moosavy Mohammad-Reza Aboutalebi Seyed Hossein Seyedein Meisam Khodabakhshi Carlo Mapelli 《矿物冶金与材料学报》2013,20(12):1183-1191
A new procedure was proposed for evaluating the weldability of nickel-base superalloys. The theory is on the basis of two microstructural patterns. In pattern I, the weld microstructure exhibits severe alloying segregation, many low-melting eutectic structures, and low weldability. The weld requires a weaker etchant and a shorter time for etching. In pattern II, the weld microstructure displays less alloying segregation, low quantity of eutectic structures, and high weldability. The weld needs a stronger etchant and a longer time for etching. Five superalloys containing different amounts of Nb and Ti were designed to verify the patterns. After welding operations, the welds were etched by four etchants with different corrosivities. The weldability was determined by TG-DSC measurements. The metallography and weldability results confirmed the theoretic patterns. Finally, the etchant corrosivity and etching time were proposed as new criteria to evaluate the weldability of nickel-base superalloys. 相似文献
30.
Khalil Ganjehfard Reza Taghiabadi Mohammad Talafi Noghani Mohammad Hossein Ghoncheh 《矿物冶金与材料学报》2021,28(4):718-728
This study was undertaken to investigate the tensile properties and hot tearing susceptibility of cast Al–Cu alloys containing excess Fe (up to 1.5wt%) and Si (up to 2.5wt%). According to the results, the optimum tensile properties and hot tearing resistance were achieved at Fe/Si mass ratio of 1, where the α-Fe phase was the dominant Fe compound. Increasing the Fe/Si mass ratio above unity increased the amounts of detrimental β-CuFe platelets in the microstructure, deteriorating the tensile properties and hot tearing resistance. Decreasing the mass ratio below unity increased the size and fraction of Si needles and micropores in the microstructure, also impairing the tensile properties and hot tearing resistance. The investigation of hot-torn surfaces revealed that the β-CuFe platelets disrupted the tear healing phenomenon by blocking interdendritic feeding channels, while the α-Fe intermetallics improved the hot tearing resistivity due to their compact morphology and high melting point. 相似文献