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排序方式: 共有317条查询结果,搜索用时 15 毫秒
1.
Maja D. Markovic Vesna V. Panic Sanja I. Seslija Ana D. Milivojevic Pavle M. Spasojevic Nevenka M. Boskovic-Vragolovic Rada V. Pjanovic 《Polymer Engineering and Science》2020,60(8):2008-2022
Carriers for targeted delivery and controlled release of poorly water-soluble active substances (PWSAS) are facing three challenges: (a) the encapsulation issues, (b) limitations of PWSAS water solubility, and (c) burst drug release which can be pharmacologically dangerous and economically inefficient. The present study brings a novel strategy for encapsulation and controlled release of PWSAS—caffeine in concentrations which are higher than its maximal water solubility without the possibility of burst effect. The modification of hydrophilic carrier based on poly(methacylic acid) was done using casein and liposomes. To further increase the maximal caffeine loading inside the carrier nicotinamide was used. The release study of the encapsulated PWSAS was elaborated with respect to morphology of the carriers and interactions that could be established between its structural components. The carriers swelling and the release of caffeine and nicotinamide were also investigated depending on caffeine concentration, the presence of different liposomal formulations and the volume ratio of liposomal formulation, in three media with different pH simulating the path of the carrier through the human gastrointestinal tract. The synthesized carriers are promising candidates for encapsulation of PWSAS in concentrations which are higher than its maximal water solubility and for the targeted delivery of those dosages. 相似文献
2.
3.
Sanja Ramljak Matthias Schmitz Cendrine Repond Inga Zerr Luc Pellerin 《International journal of molecular sciences》2021,22(4)
The effect of a cellular prion protein (PrPc) deficiency on neuroenergetics was primarily analyzed via surveying the expression of genes specifically involved in lactate/pyruvate metabolism, such as monocarboxylate transporters (MCT1, MCT2, MCT4). The aim of the present study was to elucidate a potential involvement of PrPc in the regulation of energy metabolism in different brain regions. By using quantitative real-time polymerase chain reaction (qRT-PCR), we observed a marked reduction in MCT1 mRNA expression in the cortex of symptomatic Zürich I Prnp−/− mice, as compared to their wild-type (WT) counterparts. MCT1 downregulation in the cortex was accompanied with significantly decreased expression of the MCT1 functional interplayer, the Na+/K+ ATPase α2 subunit. Conversely, the MCT1 mRNA level was significantly raised in the cerebellum of Prnp−/− vs. WT control group, without a substantial change in the Na+/K+ ATPase α2 subunit expression. To validate the observed mRNA findings, we confirmed the observed change in MCT1 mRNA expression level in the cortex at the protein level. MCT4, highly expressed in tissues that rely on glycolysis as an energy source, exhibited a significant reduction in the hippocampus of Prnp−/− vs. WT mice. The present study demonstrates that a lack of PrPc leads to altered MCT1 and MCT4 mRNA/protein expression in different brain regions of Prnp−/− vs. WT mice. Our findings provide evidence that PrPc might affect the monocarboxylate intercellular transport, which needs to be confirmed in further studies. 相似文献
4.
Sanja Dogramadzi Maria Elena Giannaccini Christopher Harper Mohammad Sobhani Roger Woodman Jiyeon Choung 《Journal of Intelligent and Robotic Systems》2014,76(1):73-117
Robot manufacturers will be required to demonstrate objectively that all reasonably foreseeable hazards have been identified in any robotic product design that is to be marketed commercially. This is problematic for autonomous mobile robots because conventional methods, which have been developed for automatic systems do not assist safety analysts in identifying non-mission interactions with environmental features that are not directly associated with the robot’s design mission, and which may comprise the majority of the required tasks of autonomous robots. In this paper we develop a new variant of preliminary hazard analysis that is explicitly aimed at identifying non-mission interactions by means of new sets of guidewords not normally found in existing variants. We develop the required features of the method and describe its application to several small trials conducted at Bristol Robotics Laboratory in the 2011–2012 period. 相似文献
5.
Fourteen volatile compounds occurring in leaf trichomes of yellow squash (Cucurbita pepo L. cv. Early Prolific Straightneck) were identified. These compounds accounted for 83.5% of the volatile matrix. Ubiquitous constituents of the epidermis (myristic, palmitic, and stearic acids,n-tricosane, andn-pentacosane) accounted for 73.7%; these compounds were not bioassayed. The volatileso-,m-, andp-xylene, toluene, 2-heptanone, (R)-(+)- and (S)-(–)-limonene, and germacrene D were tested for their influence on attraction and oviposition by the pickleworm moth (Diaphania nitidalis Stoll.). No single compound, except germacrene D, was attractive. (R)-(+)-Limonene and 2-heptanone were weakly repellent. Mixtures of the highly volatile fractions were as attractive as volatiles emanating from whole, intact leaves. Oviposition levels on treated artificial sites corresponded with levels of visitation. Oviposition was significantly stimulated by whole-leaf volatiles, and (S)-(–)-limonene caused a slight but significant reduction.Mention of a trade name or proprietary product does not constitute a warranty or guarantee by the U.S. Department of Agriculture, nor does it imply exclusion of other products that may also be suitable. 相似文献
6.
A new method is presented for determining thecis/trans isomer content of edible vegetable oils. The intensities of Raman lines near 1656 and 1670 cm−1 are associated with thecis andtrans configuration, respectively. A precision of ca. 1% can be obtained in thecis/trans isomer analysis of binary mixtures of methyl esters and triglycerides of monoenes and dienes and of hydrogenated vegetable
oils. The spectroscopic data also provide the iodine value of vegetable oils or isolated fractions with precision for a single
determination of ca. 1%.
Presented at the AOCS meeting, Houston, May 1971.
W. Market. Nutr. Res. Div., ARS, USDA. 相似文献
7.
Validation of plant part measurements using a 3D reconstruction method suitable for high-throughput seedling phenotyping 总被引:2,自引:0,他引:2
Franck Golbach Gert Kootstra Sanja Damjanovic Gerwoud Otten Rick van de Zedde 《Machine Vision and Applications》2016,27(5):663-680
In plant phenotyping, there is a demand for high-throughput, non-destructive systems that can accurately analyse various plant traits by measuring features such as plant volume, leaf area, and stem length. Existing vision-based systems either focus on speed using 2D imaging, which is consequently inaccurate, or on accuracy using time-consuming 3D methods. In this paper, we present a computer-vision system for seedling phenotyping that combines best of both approaches by utilizing a fast three-dimensional (3D) reconstruction method. We developed image processing methods for the identification and segmentation of plant organs (stem and leaf) from the 3D plant model. Various measurements of plant features such as plant volume, leaf area, and stem length are estimated based on these plant segments. We evaluate the accuracy of our system by comparing the measurements of our methods with ground truth measurements obtained destructively by hand. The results indicate that the proposed system is very promising. 相似文献
8.
Scheduling plays a vital role in ensuring the effectiveness of the production control of a flexible manufacturing system (FMS). The scheduling problem in FMS is considered to be dynamic in its nature as new orders may arrive every day. The new orders need to be integrated with the existing production schedule immediately without disturbing the performance and the stability of existing schedule. Most FMS scheduling methods reported in the literature address the static FMS scheduling problems. In this paper, rescheduling methods based on genetic algorithms are described to address arrivals of new orders. This study proposes genetic algorithms for match-up rescheduling with non-reshuffle and reshuffle strategies which accommodate new orders by manipulating the available idle times on machines and by resequencing operations, respectively. The basic idea of the match-up approach is to modify only a part of the initial schedule and to develop genetic algorithms (GAs) to generate a solution within the rescheduling horizon in such a way that both the stability and performance of the shop floor are kept. The proposed non-reshuffle and reshuffle strategies have been evaluated and the results have been compared with the total-rescheduling method. 相似文献
9.
This paper deals with the problem of optimization of job sequence in a two-machine flow shop problem in the presence of uncertainty.
It is assumed that the processing times of jobs on the machines are described by triangular fuzzy sets. A new optimization
algorithm based on Johnson”s algorithm for deterministic processing times and on an improvement of McCahon and Lee”s algorithm
is developed and presented. In order to compare fuzzy processing times, McCahon and Lee use mean values of their corresponding
fuzzy sets. It is shown that this approach cannot fully explore possible relationships between fuzzy sets. In order to overcome
this drawback we consider different fuzzy sets determined by λ-cuts of the fuzzy processing times. Extensive experiments show
that the new algorithm gives better solutions with respect to makespan than existing McCahon and Lee's algorithm. 相似文献
10.
In recent years the processing speed of computers has increased dramatically. This in turn has allowed search algorithms to execute more iterations in a given amount of real-time. Does this necessarily always lead to an improvement in the quality of final solutions? This paper is devoted to the investigation of that question. We present two variants of local search where the search time can be set as an input parameter. These two approaches are: a time-predefined variant of simulated annealing and an adaptation of the “great deluge” method. We present a comprehensive series of experiments which show that these approaches significantly outperform the previous best results (in terms of solution quality) on a range of benchmark exam timetabling problems. Of course, there is a price to pay for such better results: increased execution time. We discuss the impact of this trade-off between quality and execution time. In particular we discuss issues involving the proper estimation of the algorithm's execution time and the assessment of its importance. 相似文献