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排序方式: 共有268条查询结果,搜索用时 15 毫秒
71.
Olli Seppänen Jake Evinger Christopher Mouflard 《Construction Management & Economics》2014,32(6):608-624
Location-based management systems (LBMSs) are becoming more commonly used to plan and control production in construction projects. The main use has been to compress durations and improve resource efficiency through real-time production control and forecasting. LBMS theory proposes that instead of continuously updating the plan with actualized completion dates, as with the critical path method (CPM), control actions can be used to manage an effective response to deviations in production in order to realign the schedule forecast with the approved plan. Three healthcare construction projects in California were monitored to document the effects of planning and control decisions on production rates, resources and labour consumption. First, the authors hypothesize that proposed control actions based on the system led to real actions in the field. Second, these control actions helped in controlling production rates. Third, control actions decreased subcontractor labour consumption. The results show that control actions were implemented as a response to production alarms and half of the implemented control actions were able to prevent production problems. Many control actions successfully improved production and labour consumption rates with a long-term impact. However, adding resources often increased labour consumption and negated part of the expected production rate benefit. 相似文献
72.
Mutharasu Gnanavel Akshaya Murugesan Saravanan Konda Mani Olli Yli-Harja Meenakshisundaram Kandhavelu 《International journal of molecular sciences》2021,22(2)
Glioblastoma (GBM) is the most common malignant brain tumor and its malignant phenotypic characteristics are classified as grade IV tumors. Molecular interactions, such as protein–protein, protein–ncRNA, and protein–peptide interactions are crucial to transfer the signaling communications in cellular signaling pathways. Evidences suggest that signaling pathways of stem cells are also activated, which helps the propagation of GBM. Hence, it is important to identify a common signaling pathway that could be visible from multiple GBM gene expression data. microRNA signaling is considered important in GBM signaling, which needs further validation. We performed a high-throughput analysis using micro array expression profiles from 574 samples to explore the role of non-coding RNAs in the disease progression and unique signaling communication in GBM. A series of computational methods involving miRNA expression, gene ontology (GO) based gene enrichment, pathway mapping, and annotation from metabolic pathways databases, and network analysis were used for the analysis. Our study revealed the physiological roles of many known and novel miRNAs in cancer signaling, especially concerning signaling in cancer progression and proliferation. Overall, the results revealed a strong connection with stress induced senescence, significant miRNA targets for cell cycle arrest, and many common signaling pathways to GBM in the network. 相似文献
73.
Mika Ihalainen Pasi Jalava Tuukka Ihantola Stefanie Kasurinen Oskari Uski Olli Sippula 《Aerosol science and technology》2019,53(2):133-145
In vitro, direct aerosol nanoparticle exposure of cells cultured at the air-liquid interface (ALI) has shown great potential over the conventional submerged cell exposure methods due to exposure relevancy and more accurate dose determination. Here, we present a design of an ALI cell exposure device, the thermocollector, which applies thermophoresis to deposit aerosol particles onto the cells. Computational numerical simulations were used to estimate the deposition flux and how it depended on particle properties. The deposition flux was approximately 250 particles/m2s for particles smaller than 100?nm, corresponding to an aerosol concentration of 1 #/cm3. This was also confirmed with experimental studies. For larger particles, the deposition rate depended more on particle properties; however, for fractal combustion derived soot particles, the deposition rate is practically size independent at the size range studied here. Finally, epithelial cells were exposed with wood combustion aerosol, and the toxicologic responses were investigated. The cell viability decrease and DNA damage were detected after the exposure. These effects were not detected in cells after the exposure to clean air in this cell exposure system.Copyright © 2019 American Association for Aerosol Research 相似文献
74.
Baral JK Majumdar HS Laiho A Jiang H Kauppinen EI Ras RH Ruokolainen J Ikkala O Osterbacka R 《Nanotechnology》2008,19(3):035203
We report a simple memory device in which the fullerene-derivative [6,6]-phenyl-C(61) butyric acid methyl ester (PCBM) mixed with inert polystyrene (PS) matrix is sandwiched between two aluminum (Al) electrodes. Transmission electron microscopy (TEM) images of PCBM:PS films showed well controlled morphology without forming any aggregates at low weight percentages (<10?wt%) of PCBM in PS. Energy dispersive x-ray spectroscopy (EDX) analysis of the device cross-sections indicated that the thermal evaporation of the Al electrodes did not lead to the inclusion of Al metal nanoparticles into the active PCBM:PS film. Above a threshold voltage of <3?V, independent of thickness, a consistent negative differential resistance (NDR) is observed in devices in the thickness range from 200 to 350?nm made from solutions with 4-10?wt% of PCBM in PS. We found that the threshold voltage (V(th)) for switching from the high-impedance state to the low-impedance state, the voltage at maximum current density (V(max)) and the voltage at minimum current density (V(min)) in the NDR regime are constant within this thickness range. The current density ratio at V(max) and V(min) is more than or equal to 10, increasing with thickness. Furthermore, the current density is exponentially dependent on the longest tunneling jump between two PCBM molecules, suggesting a tunneling mechanism between individual PCBM molecules. This is further supported with temperature independent NDR down to 240?K. 相似文献
75.
Xuelin Tian Hua Jin Jani Sainio Robin H. A. Ras Olli Ikkala 《Advanced functional materials》2014,24(38):6023-6028
The ability to gate (i.e., allow or block) droplet and fluid transport in a directional manner represents an important form of liquid manipulation and has tremendous application potential in fields involving intelligent liquid management. Inspired by passive transport across cell membranes which regulate permeability by transmembrane hydrophilic/hydrophobic interactions, macroscopic hydrophilic/hydrophobic Janus‐type membranes are prepared by facile vapor diffusion or plasma treatments for liquid gating. The resultant Janus membrane shows directional water droplet gating behavior in air‐water systems. Furthermore, membrane‐based directional gating of continuous water flow is demonstrated for the first time, enabling Janus membranes to act as facile fluid diodes for one‐way flow regulation. Additionally, in oil‐water systems, the Janus membranes show directional gating of droplets with integrated selectivity for either oil or water. The above remarkable gating properties of the Janus membranes could bring about novel applications in fluid rectifying, microchemical reaction manipulation, advanced separation, biomedical materials and smart textiles. 相似文献
76.
Healable,Stable and Stiff Hydrogels: Combining Conflicting Properties Using Dynamic and Selective Three‐Component Recognition with Reinforcing Cellulose Nanorods 下载免费PDF全文
Jason R. McKee Eric A. Appel Jani Seitsonen Eero Kontturi Oren A. Scherman Olli Ikkala 《Advanced functional materials》2014,24(18):2706-2713
Nanocomposite hydrogels are prepared combining polymer brush‐modified ‘hard’ cellulose nanocrystals (CNC) and ‘soft’ polymeric domains, and bound together by cucurbit[8]uril (CB[8]) supramolecular crosslinks, which allow dynamic host–guest interactions as well as selective and simultaneous binding of two guests, i.e., methyl viologen (the first guest) and naphthyl units (the second guest). CNCs are mechanically strong colloidal rods with nanometer‐scale lateral dimensions, which are functionalized by surface‐initiated atom transfer radical polymerization to yield a dense set of methacrylate polymer brushes bearing naphthyl units. They can then be non‐covalently cross‐linked through simple addition of poly(vinyl alcohol) polymers containing pendant viologen units as well as CB[8]s in aqueous media. The resulting supramolecular nanocomposite hydrogels combine three important criteria: high storage modulus (G′ > 10 kPa), rapid sol–gel transition (<6 s), and rapid self‐healing even upon aging for several months, as driven by balanced colloidal reinforcement as well as the selectivity and dynamics of the CB[8] three‐component supramolecular interactions. Such a new combination of properties for stiff and self‐healing hydrogel materials suggests new approaches for advanced dynamic materials from renewable sources. 相似文献
77.
Jin Shi Anu Ahlroos-Lehmus Taru K. Pilvi Riitta Korpela Olli Tossavainen Eero M. Mervaala 《Journal of Functional Foods》2012,4(2):440-449
Microfiltered native whey protein (MFNW) exerts superior in vitro functional properties compared to traditional cheese whey protein. We here investigated the metabolic effects of a novel MFNW, produced by economic polymeric membranes and rich in α-lactalbumin (α-lactalbumin 24% and β-lactoglobulin 65% of the protein), in a mice model of diet-induced obesity during weight gain and weight loss. Furthermore, the effects of MFNW were compared with those of α-lactalbumin. Replacement of casein in the diet (18% of energy) by MFNW prevented weight gain and body fat accumulation without influencing food intake, body temperature or glucose homeostasis. However, the anti-obesity effect of MFNW was inferior compared to α-lactalbumin (approximately 1/3). During weight loss (70% of ad libitum energy intake) the beneficial effects of both MFNW and α-lactalbumin were attenuated. Our findings indicate that MFNW protects against diet-induced obesity, and suggest that the beneficial effects of MFNW are due, to a great extent, to its α-lactalbumin content. 相似文献
78.
The personal computer equipped with a data acquisition board is a powerful tool for research and for routine data collection. Interference and noise often corrupt the data acquisition. This noise can be used as a dither signal for improving the resolution of the A/D converter. This paper discusses possibilities to decrease the uncertainty of measurement in cases when the measurand moves slowly enough to allow for averaging several dithered results. 相似文献
79.
We propose the use of bioluminescent whole cell biosensor combined with a pattern classification algorithm to automatically detect and identify β-lactam antibiotic substances. Escherichia coli cells with a plasmid harboring luxCDABE genes under the β-lactam sensitive promoter element are used as sensors. We present experimental measurements of light production of bioluminescent bacteria subject to 11 antibiotic substances. The patterns of measured light production are classified using a support vector machine classifier. The accuracy and reliability of the classification suggests that this method can be used in the future to probe for new antibiotic substances. 相似文献
80.
Bone morphogenetic protein 15 and growth differentiation factor 9 co-operate to regulate granulosa cell function 总被引:7,自引:0,他引:7
McNatty KP Juengel JL Reader KL Lun S Myllymaa S Lawrence SB Western A Meerasahib MF Mottershead DG Groome NP Ritvos O Laitinen MP 《Reproduction (Cambridge, England)》2005,129(4):473-480
The oocyte-secreted polypeptide growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15, also known as GDF9B) have both been shown to be essential for ovarian follicular growth and function. The effects of murine (m) and ovine (o) GDF9 as well as oBMP15, alone or together, on 3H-thymidine uptake and progesterone and inhibin production by granulosa cells from rats were determined. Murine GDF9 stimulated thymidine incorporation by granulosa cells whereas oGDF9 and oBMP15 alone had no effect. However, oBMP15 given together with mGDF9 or oGDF9 was very potent in stimulating 3H-thymidine incorporation by granulosa cells with a greater than 3-fold stimulation compared with any growth factor alone. The synergistic effect of oBMP15 and oGDF9 was almost completely blocked by antibodies generated against these growth factors when administered either alone or in combination. While neither GDF9 (murine or ovine) nor oBMP15 were able to modulate FSH-stimulated progesterone production on their own, FSH-stimulated progesterone production by granulosa cells was potently inhibited when BMP15 and GDF9 were administered together. Immunoreactive alpha-inhibin levels increased more than 15-fold from granulosa cells when BMP15 and GDF9 were given together whereas consistent stimulatory effects of either growth factor alone were not observed. The effects of GDF9 and BMP15, when added together, were different than those observed for the growth factors alone. Therefore, we hypothesize that within the ovary, these oocyte-secreted growth factors co-operate to regulate proliferation and gonadotropin-induced differentiation of granulosa cells in mammals. 相似文献