Synthesis of nanomaterials using various top-down and bottom-up approaches, influencing factors, advantages, and disadvantages: A review

Top-down and bottom-up theorem proving approaches each have specific advantages and disadvantages. Bottom-up provers profit from strong redundancy control but suffer from the lack of goal-orientation, whereas top-down provers are goal-oriented but often have weak calculi when their proof lengths are considered. In order to integrate both approaches, we try to achieve cooperation between a top-down and a bottom-up prover in two different ways: The first technique aims at supporting a bottom-up with a top-down prover. A top-down prover generates subgoal clauses, they are then processed by a bottom-up prover. The second technique deals with the use of bottom-up generated lemmas in a top-down prover. We apply our concept to the areas of model elimination and superposition. We discuss the ability of our techniques to shorten proofs as well as to reorder the search space in an appropriate manner. Furthermore, in order to identify subgoal clauses and lemmas which are actually relevant for the proof task, we develop methods for a relevancy-based filtering. Experiments with the provers SETHEO and SPASS performed in the problem library TPTP reveal the high potential of our cooperation approaches.

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Radiographic Evaluation of Children with Febrile Urinary Tract Infection: Bottom-Up, Top-Down, or None of the Above?

Advances in Urology ◽

10.1155/2012/716739 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 16

Author(s):

Michaella M. Prasad ◽

Earl Y. Cheng

Keyword(s):

Urinary Tract Infection ◽

Urinary Tract ◽

Tract Infection ◽

Renal Scarring ◽

Radiographic Evaluation ◽

Voiding Cystourethrogram ◽

Top Down ◽

Febrile Urinary Tract Infection ◽

Bottom Up ◽

Advantages And Disadvantages

The proper algorithm for the radiographic evaluation of children with febrile urinary tract infection (FUTI) is hotly debated. Three studies are commonly administered: renal-bladder ultrasound (RUS), voiding cystourethrogram (VCUG), and dimercapto-succinic acid (DMSA) scan. However, the order in which these tests are obtained depends on the methodology followed: bottom-up or top-down. Each strategy carries advantages and disadvantages, and some groups now advocate even less of a workup (none of the above) due to the current controversies about treatment when abnormalities are diagnosed. New technology is available and still under investigation, but it may help to clarify the interplay between vesicoureteral reflux, renal scarring, and dysfunctional elimination in the future.

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A Critical Review of Graphene Quantum Dots: Synthesis and Application in Biosensors

NANO ◽

10.1142/s1793292021300012 ◽

2021 ◽

pp. 2130001

Author(s):

Jialu Shen ◽

Weifeng Chen ◽

Zihan Yang ◽

Guo Lv ◽

Jie Cao ◽

...

Keyword(s):

Quantum Dots ◽

Critical Review ◽

Graphene Quantum Dots ◽

Top Down ◽

Bottom Up ◽

Advantages And Disadvantages ◽

Future Developments ◽

Potential Applications

Graphene quantum dots (GQDs) have aroused widespread attention because of their remarkable properties and potential applications. Herein, we discuss both the top-down and bottom-up strategies for the synthesis of GQDs. Different processes are presented to study their characteristics and the influence on the final properties of GQDs. The respective advantages and disadvantages of these methods are summarized. With regard to some important or novel ones, mechanisms are proposed for reference. In addition, the application of GQDs in biosensors is highlighted in detail. At last, we put forward some problems to be solved and give a brief prospect in their future developments. This review is very useful for quickly gaining knowledge and experience for synthesizing GQDs and designing the related novel biosensors.

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Engineered Microgels—Their Manufacturing and Biomedical Applications

Micromachines ◽

10.3390/mi12010045 ◽

2021 ◽

Vol 12 (1) ◽

pp. 45

Author(s):

Hamzah Alzanbaki ◽

Manola Moretti ◽

Charlotte A. E. Hauser

Keyword(s):

Biomedical Applications ◽

Attractive Alternative ◽

Top Down ◽

Bottom Up ◽

Advantages And Disadvantages ◽

Hydrogel Particles ◽

Self Assembling ◽

Synthetic Materials ◽

Micrometer Scale ◽

Cell Carriers

Microgels are hydrogel particles with diameters in the micrometer scale that can be fabricated in different shapes and sizes. Microgels are increasingly used for biomedical applications and for biofabrication due to their interesting features, such as injectability, modularity, porosity and tunability in respect to size, shape and mechanical properties. Fabrication methods of microgels are divided into two categories, following a top-down or bottom-up approach. Each approach has its own advantages and disadvantages and requires certain sets of materials and equipments. In this review, we discuss fabrication methods of both top-down and bottom-up approaches and point to their advantages as well as their limitations, with more focus on the bottom-up approaches. In addition, the use of microgels for a variety of biomedical applications will be discussed, including microgels for the delivery of therapeutic agents and microgels as cell carriers for the fabrication of 3D bioprinted cell-laden constructs. Microgels made from well-defined synthetic materials with a focus on rationally designed ultrashort peptides are also discussed, because they have been demonstrated to serve as an attractive alternative to much less defined naturally derived materials. Here, we will emphasize the potential and properties of ultrashort self-assembling peptides related to microgels.

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The Anxiety of Educational Reform and Innovation: Bridging of Top-Down and Bottom-Up Strategies within Practice Educational Reform of Curriculum in Indonesia

Studies in Philosophy of Science and Education ◽

10.46627/sipose.v1i2.30 ◽

2020 ◽

Vol 1 (2) ◽

pp. 87-96 ◽

Cited By ~ 3

Author(s):

Beni Setiawan

Keyword(s):

Educational Reform ◽

National Curriculum ◽

Field Education ◽

Top Down ◽

Bottom Up ◽

Advantages And Disadvantages ◽

School Based ◽

Points Of View ◽

Reform And Innovation ◽

The Government

Reform and innovation are important issues in the educational field. Education is dynamic and changing depends on globalization demands. To counterbalance for these changes, there are two strategies to make education change. Top down and bottom up strategies. Top down and bottom up have advantages and disadvantages to the reform and innovation of educational. For instance, the advantage of top-down is the government have the power to make policy, do research about national curriculum and implement that policy in the education area, especially at school but for making policy, regulation, research and implement government have spent more money without significant result. In another hand, the benefit of bottom-up is the innovation of education easily to find and grow up because they have involved directly in the change in school, also understand what they need in education because the teachers and the principle have strong connection with the students and indirectly evaluate the national curriculum which is appropriate or not. Nevertheless, school community as the representative of bottom-up did not have the power to bring that innovation in the top level because there is no connecting purpose between government and school. In addition, the big effect is the top-down, bottom-up has the different points of view to look into education. Furthermore, to solve that problem, there are some approaches could be bond to both strategies such as the collaborative, negotiate, conceptual, and strategic clarification, school-based management and strong site councils. Based on several previous researchers that approach is the best option for bridging the educational purpose between top down and bottom up.

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