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111.
Yingjie Victor Chen William Huynh Tim McGraw Zhenyu Cheryl Qian Raymond Hassan 《人机工程学与制造业中的人性因素》2018,28(5):250-259
In this work, we propose a new mode of interaction using hand gestures captured by the back camera of a mobile device. Using a simple intuitive two‐finger picking gesture, the user can perform mouse click and drag‐and‐drop operations from the back of the device, which provides an unobstructed touch‐free interaction. This method allows users to operate on a tablet and maintain full awareness of the display, which is especially suitable for certain working environments, such as the machine shop, garage, kitchen, gym, or construction site, where people's hands may be dirty, wet, or in gloves. The speed, accuracy, and error rate of this interaction have been evaluated and compared with the typical touch interaction in an empirical study. The results show that, although this method is not, in general, as efficient and accurate as direct touch, participants still consider it an effective and intuitive method of interacting with mobile devices in environments where direct touch is impractical. 相似文献
112.
Cheryl H. Rodriguez Wei-Li Yuan John F. Scamehorn Edgar A. O'Rear 《Journal of surfactants and detergents》2002,5(3):269-280
The overall time required for precipitation to occur can increase dramatically for surfactant mixtures compared to single
components. Atomic force microscopy (AFM) has been used in this study to examine the precipitated surfactant crystals, which
gives insight into both the thermodynamics and kinetics of surfactant precipitation. Calcium dodecyl sulfate, Ca(DS)2 shows regular, layered growth that is consistent with a screw-dislocation crystallization mechanism. Calcium octylbenzene
sulfonate, Ca(OBS)2, forms crystals with uneven, jagged edges. At high magnification, the head groups of both Ca(DS)2 and Ca(OBS)2 show hexagonal packing. For mixtures that have surprisingly slow precipitation kinetics, the jagged Ca(OBS)2 crystals were observed to grow on the layered Ca(DS)2 crystals. Other surfactant mixtures that exhibited a stepwise rate curve formed crystals with incomplete layers and holes
that are not observed with pure surfactants. In general, this type of crystal formation can occur when an impurity is present,
which in this case is most likely the second surfactant. This work indicates that interruption of crystal growth by crystallization
of a dissimilar supersaturated surfactant onto the first crystal is one explanation for the slower precipitation of surfactant
mixtures compared to single surfactants. Entrapment of the nonprecipitating surfactant (inclusion) in the forming crystal
of the precipitating surfactant in mixed surfactant systems is another mechanism responsible for the reduction in precipitation
rate. 相似文献
113.
Yong K. Kim A. William Frazier Cheryl L. Griffin 《Nutrient Cycling in Agroecosystems》1989,20(2):115-121
Solubility data were obtained in the system CO(NH2)2-NH4NO3-H3PO4-H2O at 0° and 15°C. The results show that high-analysis solution fertilizers can be produced from standard urea-ammonium nitrate (UAN) and phosphoric acid materials. These acidic solution fertilizers contain up to 35% total plant nutrient (TPN = N + P2O5 + K2O), with N:P2O5 ratios varying from 20:1 to 1.5:1. Potential liquid products having fertilizer grades of 23-12-0, 26-9-0, 28-6-0, and 31-3-0 are feasible. 相似文献
114.
Wu Tswei-Ping; Yee Vivien; Tulinksy A.; Chrusciel R.Alan; Nakanishi Hiroshi; Shen Richard; Priebe Cheryl; Kahn Michael 《Protein engineering, design & selection : PEDS》1993,6(5):471-478
Thrombin displays remarkable specificity, effecting the removalof fibrinopeptides A and B of fibrinogen through the selectivecleavage of two ArgGly bonds between the 181 Arg/LysXaabonds in fibrinogen. Significant advances have been made inrecent years towards understanding the origin of the specificityof cleavage of the Argl6Gly17 bond of the A-chain ofhuman fibrinogen. We have previously proposed a model for thebound structure of fibrinopeptide A716 (FPA), based uponNMR data, computer-assisted molecular modeling and the synthesisand study of peptidomimetic substrates and inhibitors of thrombin.We now report the structure of the ternary complex of an FPAmimetic (FPAM), hirugen and thrombin at 2.5 Å resolution(R-factor = 0.138) and specificity data for the inhibition ofthrombin and related trypsin-like proteinases by FPAM. The crystallographicstructures of FPA and its chloromethyl ketone derivative boundto thrombin were determined. Although there are differencesbetween these structures in the above modeled FPA structureand that of the crystal structure of FPAM bound to thrombin,the , angles in the critical region of P1P2P3in all of the structures are similar to those of bovine pancreatictrypsin inhibitor (BPTI) in the BPTItrypsin complex andDPheProArg (PPACK) in the PPACKthrombinstructure. A comparison between these and an NMR-derived structureis carried out and discussed. 相似文献
115.
Cheryl Hartfield Alasdair McDowall Bruce Loveland Kirsten Fischer Lindahl 《Microscopy research and technique》1991,18(2):148-156
Thymus-leukemia (TL) antigen is a class I molecule of the major histocompatibility complex that is expressed on the surface of mouse cortical thymocytes. Though not expected, it has been reported that TL antigen can be found on isolated mitochondria of TL+ cells. We used immuno-cryoultramicrotomy to look for TL on mitochondria in situ, thereby avoiding the plasma membrane contamination that occurs when isolating organelles. Establishing optimal fixation conditions was crucial, as mitochondrial structure was not preserved by the low concentrations of fixative needed for detection of antibody labeling. The plasma membranes of tissue culture and thymus cells were labeled well with anti-TL antibody and protein A-gold conjugate, while mitochondria within the cells were not labeled. Isolation of mitochondria on a one-step Ficoll gradient resulted in a purer organelle preparation than did isolation of mitochondria by centrifugation alone. Generally, mitochondria within this purer preparation were not labeled. Our data show that under conditions where contamination by plasma membrane is not a major concern, TL antigen cannot be detected on mitochondria. 相似文献
116.
To determine the potential importance of several unexplored covariates of everyday memory compensation, the authors examined relations between responses on the Memory Compensation Questionnaire (a self-report measure of everyday memory compensation) and cognitive reserve (education and verbal IQ), subjective memory, and life stress in 66 older adults (mean age = 70.55 years). Key results indicated that compensation occurred in people (a) whose IQ level was greater than their education level (representing cognitive reserve “discordance”) but not in people whose IQ was commensurate with their education (representing cognitive reserve “concordance”); (b) who had greater perceived memory errors; and (c) who experienced heightened stress. Further, high-stress older adults compensated whether perceived memory errors were low or high, but low-stress older adults compensated only if they perceived high memory errors. Bootstrapped confidence intervals around model betas provided further support for estimate reliability. These results suggest boundary conditions for the concept of cognitive reserve, and highlight the importance of subjective memory and life stress for defining contexts in which compensation may occur. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
117.
118.
Marina Zusman Amanda J. Gassett Kipruto Kirwa R. Graham Barr Christopher B. Cooper MeiLan K. Han Richard E. Kanner Kirsten Koehler Victor E. Ortega Robert Paine rd Laura Paulin Cheryl Pirozzi Ana Rule Nadia N. Hansel Joel D. Kaufman 《Indoor air》2021,31(3):702-716
Increased outdoor concentrations of fine particulate matter (PM2.5) and oxides of nitrogen (NO2, NOx) are associated with respiratory and cardiovascular morbidity in adults and children. However, people spend most of their time indoors and this is particularly true for individuals with chronic obstructive pulmonary disease (COPD). Both outdoor and indoor air pollution may accelerate lung function loss in individuals with COPD, but it is not feasible to measure indoor pollutant concentrations in all participants in large cohort studies. We aimed to understand indoor exposures in a cohort of adults (SPIROMICS Air, the SubPopulations and Intermediate Outcome Measures in COPD Study of Air pollution). We developed models for the entire cohort based on monitoring in a subset of homes, to predict mean 2-week–measured concentrations of PM2.5, NO2, NOx, and nicotine, using home and behavioral questionnaire responses available in the full cohort. Models incorporating socioeconomic, meteorological, behavioral, and residential information together explained about 60% of the variation in indoor concentration of each pollutant. Cross-validated R2 for best indoor prediction models ranged from 0.43 (NOx) to 0.51 (NO2). Models based on questionnaire responses and estimated outdoor concentrations successfully explained most variation in indoor PM2.5, NO2, NOx, and nicotine concentrations. 相似文献
119.
120.
Shashwat Bhakta Deepak K. Pattanayak Hiroaki Takadama Tadashi Kokubo Cheryl A. Miller Mehdi Mirsaneh Ian M. Reaney Ian Brook Richard van Noort Paul V. Hatton 《Journal of materials science. Materials in medicine》2010,21(11):2979-2988
Potassium fluorrichterite (KNaCaMg5Si8O22F2) glass-ceramics were modified by either increasing the concentration of calcium (GC5) or by the addition of P2O5 (GP2). The stoichiometric composition (GST), GC5 and GP2 were soaked in simulated body fluid (SBF) along with 45S5-type bioglass
as a control. After immersion, surface analyses were performed using thin-film X-ray diffraction (TF-XRD), scanning electron
microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared (reflection) spectroscopy (FT-IR).
All compositions showed the formation of a calcium phosphate rich surface layer in SBF; GST, GP2 and the bioglass control
within 7 days of immersion and GC5 after 14 days. It was concluded that all compositions were likely to be osteoconductive
in vivo, with GP2 providing the best performance in terms of the combination of rapid formation of the surface layer and superior
mechanical properties. This glass-ceramic system has potential as a load bearing bioceramic for fabrication of medical devices
intended for skeletal tissue repair. 相似文献