scholarly journals Gecko-Like Dry Adhesive Surfaces and Their Applications: A Review

Author(s):  
Wei Wang ◽  
Yang Liu ◽  
Zongwu Xie

AbstractGecko has the ability to climb flexibly on various natural surfaces because of its fine layered adhesion system of foot, which has motivated researchers to carry out a lot of researches on it. Significant progresses have been made in the gecko-like dry adhesive surfaces in the past 2 decades, such as the mechanical measurement of adhesive characteristics, the theoretical modeling of adhesive mechanism and the production of synthetic dry adhesive surfaces. Relevant application researches have been carried out as well. This paper focuses on the investigations made in recent years on the gecko-like dry adhesive surfaces, so as to lay the foundation for further research breakthroughs. First, the adhesion system of gecko’s foot and its excellent adhesive characteristics are reviewed, and the adhesive models describing the gecko adhesion are summarily reviewed according to the different contact modes. Then, some gecko-like dry adhesive surfaces with outstanding adhesive characteristics are presented. Next, some application researches based on the gecko-like dry adhesive surfaces are introduced. Finally, the full text is summarized and the problems to be solved on the gecko-like dry adhesive surfaces are prospected.

Slovene ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 526-540
Author(s):  
Irina V. Fedorova

The abundance of apocryphal material in the text of the Pilgrimage by Daniel the Traveler has become the subject of several special studies in the past, by Ya. I. Gorozhansky, M. A. Venevitinov, P. A. Zabolotsky, V. P. Adrianova-Peretts, and M. Garzaniti. All of these studies, however, were based on the text of the First Redaction of the Pilgrimage (according to Venevitinov’s classification) and they did not consider the work’s literary history. The present study reveals the various ways in which the reproduction of apocryphal subjects appears in different redactions of the Pilgrimage (both full-text and abridged) and its later adaptations made in the 16th and 17th centuries. One of the examples is the description of Nazareth, which is accompanied by an apocryphal version of the Annunciation in the Pilgrimage. This version differs from the Bible text (Mt 1:18–25, Lk 1:26–28) in that it tells about the events directly preceding the Annunciation: the pre-Annunciation at the well, where Mary comes to draw water, and the appearance of the Archangel Gabriel to her in a cave. In the group of abridged copies of the 16th century from the Kirillo-Belozersky Monastery, this information is missing, and the only thing said about Nazareth is that “Archangel Gabriel announced to Her [Mary] there.” Thus, the complete story appearing in the full-text redactions of Daniel’s Pilgrimage was replaced by a compact report consistent with the Bible narrative. The nature of the variant readings presented in this paper remains to be interpreted, as these variants may be later interpolations in the text made by redactors or they may represent traces of the earlier period of the history of the text. At the same time, any reconstruction of the literary history of the Pilgrimage has to take into account the peculiarities of the reproduction of apocryphal subjects in different redactions of the text.


1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.


Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.


Author(s):  
John Hunsley ◽  
Eric J. Mash

Evidence-based assessment relies on research and theory to inform the selection of constructs to be assessed for a specific assessment purpose, the methods and measures to be used in the assessment, and the manner in which the assessment process unfolds. An evidence-based approach to clinical assessment necessitates the recognition that, even when evidence-based instruments are used, the assessment process is a decision-making task in which hypotheses must be iteratively formulated and tested. In this chapter, we review (a) the progress that has been made in developing an evidence-based approach to clinical assessment in the past decade and (b) the many challenges that lie ahead if clinical assessment is to be truly evidence-based.


1970 ◽  
Vol 2 (3) ◽  
pp. 17-19 ◽  
Author(s):  
Jack D Ives

Preview of Himalayan perceptions: Environmental change and the well-being of mountain peoples by JD Ives Routledge, London and New York To be published in August 2004 Himalayan Perspectives returns to the enormously popular development paradigm that Ives dubbed the ‘Theory of Himalayan Degradation’. According to this seductive construct, poverty and overpopulation in the Himalayas was leading to degradation of highland forests, erosion, and downstream flooding. In the ‘Himalayan Dilemma’, Ives and Messerli exposed this “Theory” as a dangerous collection of assumptions and misrepresentations. While most scholars in the field promptly conceded Ives and Messerli’s points, the Theory has somehow survived as the guiding myth of development planners and many government agencies. In his new book, Ives returns to drive a stake through the heart of this revenant. His book not only reviews the research that, over the past 15 years, has confirmed the arguments of the ‘Himalayan Dilemma’; it also takes a close look at all those destructive factors that were overlooked by the conveniently simplistic ‘Theory of Himalayan Environmental Degradation’: government mismanagement, oppression of mountain minorities, armed conflict, and inappropriate tourism development. Himalayan Journal of Sciences 2(3): 17-19, 2004 The full text is of this article is available at the Himalayan Journal of Sciences website


2021 ◽  
pp. 088506662199232
Author(s):  
Xiaojuan Zhang ◽  
Xin Li

Septic shock with multiple organ failure is a devastating situation in clinical settings. Through the past decades, much progress has been made in the management of sepsis and its underlying pathogenesis, but a highly effective therapeutic has not been developed. Recently, macromolecules such as histones have been targeted in the treatment of sepsis. Histones primarily function as chromosomal organizers to pack DNA and regulate its transcription through epigenetic mechanisms. However, a growing body of research has shown that histone family members can also exert cellular toxicity once they relocate from the nucleus into the extracellular space. Heparin, a commonly used anti-coagulant, has been shown to possess life-saving capabilities for septic patients, but the potential interplay between heparin and extracellular histones has not been investigated. In this review, we summarize the pathogenic roles of extracellular histones and the therapeutic roles of heparin in the development and management of sepsis and septic shock.


1939 ◽  
Vol 17 (2) ◽  
pp. 69-82 ◽  
Author(s):  
D. W. Fenwick

Numerous attempts have been made in the past to induce the eggs of Ascaris suum to hatch outside the body of the host. Extra-corporeal hatching has been observed under a variety of conditions by different workers. Kondo (1920, 1922), Asada (1921) and others record hatching in water, charcoal and sand cultures. Wharton (1915) states that hatching will occur in alkaline digestive juices, while Martin (1913) records a similar phenomenon in pancreatic fluid. Many different explanations have been offered to explain this hatching. Wharton suggested that the interaction of algae and sand might have some effect. Ohba (1923), who found that hatching would occur in 0·2% hydrochloric acid and 0·2% sodium carbonate believed that extra-corporeal hatching was limited to very old cultures of eggs. Many workers are of the opinion that some stimulus normally present in the digestive tract is necessary for hatching.


2015 ◽  
Vol 370 (1681) ◽  
pp. 20140267 ◽  
Author(s):  
Paul J. Ferraro ◽  
Merlin M. Hanauer

To develop effective protected area policies, scholars and practitioners must better understand the mechanisms through which protected areas affect social and environmental outcomes. With strong evidence about mechanisms, the key elements of success can be strengthened, and the key elements of failure can be eliminated or repaired. Unfortunately, empirical evidence about these mechanisms is limited, and little guidance for quantifying them exists. This essay assesses what mechanisms have been hypothesized, what empirical evidence exists for their relative contributions and what advances have been made in the past decade for estimating mechanism causal effects from non-experimental data. The essay concludes with a proposed agenda for building an evidence base about protected area mechanisms.


1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.


Author(s):  
Wei Chen ◽  
S.L. Yuen ◽  
R.H.Y. So

This paper summarizes the progress made in the quest to establish a Cybersickness Dose Value (CSDV). The Motion Sickness Dose Value (MSDV), reported in the British Standard BS6841, has been used to predict the severity of seasickness since 1987. In 1999, the authors of this paper proposed a CSDV formulation with a structure similar to that of the MSDV (So, 1999). Since then, several experiments and simulation studies have been conducted to modify and develop the proposed CSDV formula. In particular, progress has been made in (i) the methods to measure CSDV, (ii) the determination of a frequency weighting curve to equalize the non-linear relationship between the navigation velocity and levels of cybersickness, and (iii) the detailed formulation of CSDV. This paper summarizes the past progress and reports on the current effort in developing a CSDV.


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