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排序方式: 共有993条查询结果,搜索用时 15 毫秒
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Bram H. Frohock Jessica M. Gilbertie Dr. Jennifer C. Daiker Dr. Lauren V. Schnabel Dr. Joshua G. Pierce 《Chembiochem : a European journal of chemical biology》2020,21(7):933-937
The failure of frontline antibiotics in the clinic is one of the most serious threats to human health and requires a multitude of novel therapeutics and innovative approaches to treatment so as to curtail the growing crisis. In addition to traditional resistance mechanisms resulting in the lack of efficacy of many antibiotics, most chronic and recurring infections are further made tolerant to antibiotic action by the presence of biofilms. Herein, we report an expanded set of 5-benzylidene-4-oxazolidinones that are able to inhibit the formation of Staphylococcus aureus biofilms, disperse preformed biofilms, and, in combination with common antibiotics, are able to significantly reduce the bacterial load in a robust collagen-matrix model of biofilm infection. 相似文献
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Packaging engineers need to be able to accurately determine the forces present in the shipping environment in order to protect packaged goods. The purpose of this study was to determine the vertical vibration levels measured in three separate truck-trailer suspension systems; conventional leaf-spring, conventional air-ride and damaged air-ride. The main conclusion reached in this study is that the air-ride suspension when maintained gives lower power density (PD) levels on all road surfaces studied. A damaged air-ride suspension and leaf-spring suspension are very similar in response frequencies, although the damaged air-ride produces higher vibration levels at lower frequencies. 相似文献
5.
Patrick N. Troy 《Housing Studies》1992,7(3):216-233
This paper sets out the development of four main threads of housing policy in New South Wales from the latter part of the 19th century through the first 40 years of the 20th century. Following a discussion of the social and political circumstances and debate surrounding government policy regarding landlord/tenant relations, housing quality and supply, and owner occupancy, it concludes that policy evolution is irregular and a product of the exigencies of the political process. It also suggests that although government policy did little to improve the housing situation for the underprivileged, there was nevertheless a growing acceptance by both Labor and conservative parties of the increased need for government intervention in the housing market. 相似文献
6.
T. H. Pierce 《国际能源研究杂志》1987,11(2):203-231
A preliminary experimental and theorotical investigation of the feasibility of detonation-induced pulverized coal gasification is described. The concept envisions a closed annular detonation duct through which a hydrogen/oxygen gasphase detonation propagates continuously. Coal particles injected into the violent and rapidly changing atmosphere produced by the detonation would undergo gasification reactions and be subsequently expelled from the duct. These events would occur in a time period compatible with one revolution of the detonation. A one-dimensional analysis of the response of a single coal particle within the expansion-wave region behind the detonation front is presented. Independent variables include particle diameter, initial H2/O2 stoichiometry and expansion wavelength (at the time the particle is overtaken by the detonation front). The most significant result of this analysis is the prediction of relative gas/particle velocities ranging between 125 and 1500m/s, which are sustained throughout particle residence times of 1–15 ms corresponding to 10–1000 μm diameter particles. An experimental facility comprising a 47 m ‘single-shot’ detonation duct that was built for this study is discussed. The duct was 2.54 cm square and was terminated at each end by a 0.36 m diameter × 2.44 m long cylindrical tank which contained helium gas during a test. Sized coal particles were placed at a point within the first 3.7 m length of the duct, and thin brass diaphragms initially separated the duct from the two helium-filled tanks. Detonation was initiated at the duct, end closest to these particles. The diaphragm at that end burst, allowing combustion and gasification products to exhaust into the adjoining tank where they were quenched and decelerated. When the detonation reached the far end of the duct the second diaphragm burst, minimizing wave reflections which would otherwise return to the ‘test section’ end and interfere with the flow field there. After a test the contents of both tanks and the duct were circulated and mixed. A gas sample was then drawn and analysed for yield. Results from preliminary experiments using this facility are presented. Although too few tests were conducted for conclusive observations to be reported, in two experiments yields of CO + CH4 representing 40 per cent of the total initial carbon content in the coal samples were obtained. 相似文献
7.
George Chryssolouris James E. Pierce Kristian Dicke 《International Journal of Flexible Manufacturing Systems》1992,4(3-4):309-330
This paper introduces a generic decision-making framework for assigning resources of a manufacturing system to production tasks. Resources are broadly defined production units, such as machines, human operators, or material handling vehicles; and tasks are activities performed by resources. In the specific context of FMS, resources correspond to individual machines; tasks correspond to operations to be performed on parts. The framework assumes a hierarchical structure of the system and calls for the execution of four consecutive steps to make a decision for the assignment of a resource to a task. These steps are 1) establishment of decision-making criteria, 2) formation of alternative assignments, 3) estimation of the consequences of the assignments, and 4) selection of the best alternative assignment. This framework has been applied to an existing FMS as an operational policy that decides what task will be executed on which resource of this FMS. Simulation runs provide some initial results of the application of this policy. It is shown that the policy provides flexibility in terms of system performance and computational effort. 相似文献
8.
The Cones synthesis system for automatic generation of VLSI implementations is discussed. Named for the cones in sequential logic, Cones takes behavioral models written in C and produces gate-level implementations in technologies such as standard cells and programmable logic arrays or programmable logic devices. The overall design is produced faster, more efficiently, and with fewer errors. Designers are free to concentrate on functions, instead of on the details of the implementation technology 相似文献
9.
Keirnan R. LaMarche Stephen L. Conway Benjamin J. Glasser Troy Shinbrot 《Granular Matter》2007,9(3-4):219-229
A cellular automata model is used to simulate a variety of granular chute flows. The model is tested against several case
studies: flow down a chute, flow past an obstacle, chute flow in which complex, counter-rotating vortices result in streamwise
surface stripes and flow near a boundary. The model successfully reproduces experimental observations in all of these cases.
These results lead us to propose that simple, rule-based, models such as this can improve our detailed understanding of dynamics
and flow within an opaque granular bed. 相似文献
10.
Investigated, in 4 experiments, the time course of semantic priming effects during 2 forms of visual word identification, lexical decision and pronunciation. On each trial, a target letter string was preceded by a single-word priming context. The effects of varying the stimulus onset asynchrony between the prime and the target indicated that the time course of semantic priming was equivalent for young and older adults. There were no consistent differences between lexical decision and pronunciation in the time course of semantic priming. The age differences associated with response selection were greater than would be predicted by generalized age-related slowing. The semantic priming effects were also inconsistent with a generalized slowing model, but the reliability of these effects was substantially lower than the reliability of the other task-related variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献