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101.
This study examined the use of a low-cost incentive program to decrease the rate of unanticipated no-shows in a nontreatment study of the genetics of substance dependence. Low-cost retail items (such as calling cards or gift certificates) were offered contingent on attendance at the first scheduled research appointment. Although the intervention did not result in an increase in the rate of attendance at appointments, it reduced the likelihood of unanticipated no-shows by almost 50%. This reduction was accompanied by a significant increase in advance cancellations. Despite limitations due to the study's A-B design, this research demonstrates that it may be possible to use modest incentives to increase the efficiency of research enrollment and increase service provision for substance abusers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
This paper provides a framework for process design to achieve simultaneous improvement of the multiple features of the product. The methodology provides a way to integrate process parameters with the product features. Many of the features may be conflicting in nature, and thus may limit the use of a particular setting of design parameter of the process to produce the quality product. In this paper we discuss how to resolve the conflicting objectives of the process design problem. A case study for the design of vacuum-sealed molding process using the proposed methodology is included.  相似文献   
103.
A study was conducted to verify the efficacy of a fracture mechanics methodology to model the crack growth behavior of fretting fatigue-nucleated cracks obtained under test conditions similar to those found in turbine engine blade attachments. Experiments were performed to produce cracked samples, and fretting fatigue crack propagation lives were calculated for each sample. Cracks were generated at 106 cycles (10%-of-life) under applied stress conditions previously identified as the fretting fatigue limit conditions for a 107 cycle fatigue life. Resulting cracks, ranging in size from 30 to 1200 μm, were identified and measured using scanning electron microscopy. Uniaxial fatigue limit stresses were determined experimentally for the fretting fatigue-cracked samples, using a step loading technique, for R=0.5 at 300 Hz. Fracture surfaces were inspected to characterize the fretting fatigue crack front indicated by heat tinting. The shape and size of the crack front were then used in calculating ΔKth values for each crack. The resulting uniaxial fatigue limit and ΔKth values compared favorably with the baseline fatigue strength (660 MPa) for this material and the ΔKth value (2.9 MPa√m) for naturally initiated cracks tested at R=0.5 on a Kitagawa diagram.Crack propagation lives were calculated using stress results of FEM analysis of the contact conditions and a weight function method for determination of ΔK. Resulting lives were compared with the nine million-cycle propagation life that would have been expected in the experiments, if the contact conditions had not been removed. Scatter in the experimental results for fatigue limit stresses and fatigue lives had to be considered as part of an explanation why the fatigue life calculations were unable to match the experiments that were modeled. Analytical life prediction results for the case where propagation life is observed to be very short experimentally were most accurate when using a coefficient of friction, μ=1.0, rather than for the calculations using μ=0.3  相似文献   
104.
105.
Aniline has been polymerized in the presence of a novel dopant sodio‐5‐sulfo‐isophthallic acid (NaSIPA), via the chemical oxidative polymerization route. The thermal stability and processability of polyaniline prepared by indirect method (PD1) have been improved significantly (290°C) as compared to polyaniline doped with conventional inorganic dopants like HCl or H2SO4, without much loss of electronic conductivity (5.07 S/cm in PD1). This suggests its use for melt blending with engineering thermoplastics. However, polyaniline prepared by direct method (PD2) can be melt‐blended only with conventional thermoplastics like polyethylene, polypropylene, polystyrene, etc. Low‐temperature studies reveal the 1‐D variable range hopping as a conduction mechanism for direct polymer (PD2), with parameters To and σo as 4112 K and 15.1 S/cm, respectively. However, for indirectly doped polymer (PD1) Arrhenius‐type model, having parameters |(EF ? EC)| and σC as 0.04 eV and 28.4 S/cm, respectively, it suited well. The coherence length as found from XRD data was around 28.8 nm for PD1 and 25.2 nm for PD2. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008  相似文献   
106.
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection in children and infants. To date, there is no effective vaccine available against RSV. Heparan sulfate is a type of glycosaminoglycan that aids in the attachment of the RSV to the host cell membrane via the G protein. In the present study, the effect of amino acid substitution on the structure and stability of the ectodomain G protein was studied. Further, it was investigated whether mutation (K117A) in the CX3C motif of G protein alters the binding with heparan sulfate. The point mutation significantly affects the conformational stability of the G protein. The mutant protein showed a low binding affinity with heparan sulfate as compared to the wild-type G protein, as determined by fluorescence quenching, isothermal titration calorimetry (ITC), and molecular docking studies. The low binding affinity and decreased stability suggested that this mutation may play an important role in prevention of attachment of virion to the host cell receptors. Collectively, this investigation suggests that mutation in the CX3C motif of G protein may likely improve the efficacy and safety of the RSV vaccine.  相似文献   
107.
Casein kinase II (CK2) and cyclin-dependent kinases (CDKs) frequently interact within multiple pathways in pancreatic ductal adenocarcinoma (PDAC). Application of CK2- and CDK-inhibitors have been considered as a therapeutic option, but are currently not part of routine chemotherapy regimens. We investigated ten PDAC cell lines exposed to increasing concentrations of silmitasertib and dinaciclib. Cell proliferation, metabolic activity, biomass, and apoptosis/necrosis were evaluated, and bioinformatic clustering was used to classify cell lines into sensitive groups based on their response to inhibitors. Furthermore, whole exome sequencing (WES) and RNA sequencing (RNA-Seq) was conducted to assess recurrent mutations and the expression profile of inhibitor targets and genes frequently mutated in PDAC, respectively. Dinaciclib and silmitasertib demonstrated pronounced and limited cell line specific effects in cell death induction, respectively. WES revealed no genomic variants causing changes in the primary structure of the corresponding inhibitor target proteins. RNA-Seq demonstrated that the expression of all inhibitor target genes was higher in the PDAC cell lines compared to non-neoplastic pancreatic tissue. The observed differences in PDAC cell line sensitivity to silmitasertib or dinaciclib did not depend on target gene expression or the identified gene variants. For the PDAC hotspot genes kirsten rat sarcoma virus (KRAS) and tumor protein p53 (TP53), three and eight variants were identified, respectively. In conclusion, both inhibitors demonstrated in vitro efficacy on the PDAC cell lines. However, aberrations and expression of inhibitor target genes did not appear to affect the efficacy of the corresponding inhibitors. In addition, specific aberrations in TP53 and KRAS affected the efficacy of both inhibitors.  相似文献   
108.
Supporting Mobile Commerce Applications Using Dependable Wireless Networks   总被引:1,自引:0,他引:1  
Mobile commerce (m-commerce) is an emerging discipline involving applications, mobile devices, middleware, and wireless networks. While most of existing e-commerce applications can be modified to run in a wireless environment, m-commerce also involves many more new applications that become possible only due to the wireless infrastructure. These applications include mobile financial services, user and location specific mobile advertising, mobile inventory management, wireless business re-engineering, and mobile interactive games. In addition to device and wireless constraints, mobile commerce would also be impacted by the dependability of wireless infrastructure. Unlike e-commerce applications that usually run on fixed networking infrastructure of fairly high dependability (approaching to about 100%), m-commerce applications may not receive such high dependability from the existing and emerging wireless infrastructure. So far, most of the m-commerce research focuses on applications, devices, and security issues. We believe that some work is necessary in addressing the dependability challenges of the wireless infrastructure. In this paper, we present (a) the dependability issues of wireless infrastructure, (b) several architectures to improve the dependability of wireless networks, and (c) a simulation model and results on wireless dependability for m-commerce. The results show that a significant improvement is possible in wireless dependability for supporting m-commerce applications.  相似文献   
109.
Published information about insect pest infestation in dried or preserved animal products comprising food items like dried fish and milk powder and non-food materials such as hides and skins, silkworm cocoons, wool and woollen materials, honeybee combs, fishmeal and museum collections/exhibits and control measures has been summarised in this review. Beetle and moth pests belonging to the Dermestidae and Tineidae, respectively, attack the animal products, during the processing or manufacturing stage as well as in storage. The insects cause considerable loss or damage to the commodity in terms of quantity, quality and market value. Silk, apiculture and leather industries are particularly affected by the pests. Data on the extent of losses due to insect pests in various preserved animal products are lacking. Insect control measures in these products differ depending on the conditions of storage or processing and the relevant cost factor. Phosphine fumigation plays an important role in insect pest elimination in the majority of the stored animal products. For disinfesting museum objects and honeycombs, freezing (for artefacts) or modified atmosphere application of CO2 or nitrogen is preferred. Commodities such as woollen materials, dried fish, fishmeal and feeds containing animal products and their storage premises are sometimes treated with residual contact insecticides such as deltamethrin, pirimiphos-methyl, permethrin and synergised pyrethrins. For protecting animal products, especially dried fish, different countries have examined alternatives including plant extracts and vegetable oils.The need for detailed studies on (i) fumigation with alternatives to methyl bromide such as sulphuryl fluoride, ethyl formate and ozone, (ii) disinfestation methods involving the active principles from natural products and (iii) exploitation of insect traps for pest management in museums has been highlighted.  相似文献   
110.
Material series with compositional formula Ba1·0?x Pb x Ti0·90Zr0·10O3 (0 ≤ x ≤ 0·20, in steps of 0·05) were prepared by conventional solid state method. All the samples were subjected to X-ray diffraction (XRD) studies and found to be single phase with perovskite structure. SEM measurements were done in order to collect micro-structural information. Different transition temperatures were found to depend on the Pb content. Tetragonality (c/a) and Curie temperature (T c) increase with increase in lead content x. Dielectric properties were studied as a function of temperature and frequencies.  相似文献   
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