scholarly journals Highly motile nanoscale magnetic artificial cilia

2021 ◽  
Vol 118 (35) ◽  
pp. e2104930118
Author(s):  
Tanveer ul Islam ◽  
Yves Bellouard ◽  
Jaap M. J. den Toonder

Among the many complex bioactuators functioning at different scales, the organelle cilium represents a fundamental actuating unit in cellular biology. Producing motions at submicrometer scales, dominated by viscous forces, cilia drive a number of crucial bioprocesses in all vertebrate and many invertebrate organisms before and after their birth. Artificially mimicking motile cilia has been a long-standing challenge while inspiring the development of new materials and methods. The use of magnetic materials has been an effective approach for realizing microscopic artificial cilia; however, the physical and magnetic properties of the magnetic material constituents and fabrication processes utilized have almost exclusively only enabled the realization of highly motile artificial cilia with dimensions orders of magnitude larger than their biological counterparts. This has hindered the development and study of model systems and devices with inherent size-dependent aspects, as well as their application at submicrometer scales. In this work, we report a magnetic elastomer preparation process coupled with a tailored molding process for the successful fabrication of artificial cilia with submicrometer dimensions showing unprecedented deflection capabilities, enabling the design of artificial cilia with high motility and at sizes equal to those of their smallest biological counterparts. The reported work crosses the barrier of nanoscale motile cilia fabrication, paving the way for maximum control and manipulation of structures and processes at micro- and nanoscales.

2021 ◽  
Vol 3 (2) ◽  
pp. 358-375
Author(s):  
Desi Karlina

Globalization has resulted in a shift in human morals, marked by the many cases of moral deviations that are rife in various parts of Indonesia so that the application of spiritual attitudes has not been maximized. The attitude of dishonesty is shown by the number of students who cheat on the test, and the attitude of indiscipline is shown by the number of students who are late so that the application of social attitudes does not seem to be visible. The role of PAI teachers is considered quite important for the development of these two attitudes. At SMPN 1 Darussalam, PAI teachers have played a role in fostering spiritual and social attitudes. Big. This research was conducted with a field study using a qualitative descriptive method. Data collection techniques were carried out through interviews and documentation. The results showed the role of PAI teachers in fostering spiritual attitudes by praying before and after lessons, praying in congregation, doing charity activities every Friday, and religious activities. The role of PAI teachers in fostering social attitudes is carried out through social service activities, visiting the Disabled Foundation and nursing homes, getting used to the 3S (smile, greeting, greeting), reporting to the teacher what items are found, punishing students who are late. Factors supporting the role of Islamic Education teachers in fostering spiritual and social attitudes are seen from adequate school facilities in the form of female/male prayer rooms, learning media such as LCD, the use of active methods. While the inhibiting factors include the lack of adequate facilities, especially LCDs, the lack of interest in teachers and knowledge, and the lack of interest in students to improve themselves.


1997 ◽  
Vol 8 (9) ◽  
pp. 1437-1442
Author(s):  
B Anderstam ◽  
K Katzarski ◽  
J Bergström

Nitric oxide (NO) is involved in blood pressure regulation, and its synthesis is inhibited by methylarginines. It has been hypothesized that one of these, asymmetrical dimethylarginine (ADMA), may contribute to dialysis-associated hypertension because it accumulates in the plasma of hemodialysis (HD) patients in a concentration high enough (4 mumol/L) to inhibit NO synthesis in experimental model systems. A precolumn HPLC technique was used to quantify methylarginines (ADMA and symmetrical dimethylarginine [SDMA]) in plasma from HD patients before and after dialysis, from continuous ambulatory peritoneal dialysis (CAPD) patients, and from healthy subjects. Plasma ADMA concentrations were 0.59 +/- 0.22 (SD) mumol/L in HD patients predialysis (n = 19) and 0.70 +/- 0.27 mumol/L in CAPD patients (n = 11), versus about half of the concentration in control subjects (0.36 +/- 0.08 mumol/L, n = 7). The concentrations of SDMA (not an inhibitor of NO formation) were approximately four to five times the ADMA concentrations in both HD and CAPD patients, in contrast to a ratio of 1:1 in the control subjects. Methylarginine concentrations were reduced by 23% and 40% postdialysis, as calculated from ADMA and SDMA values, respectively. No significant correlations were observed between ADMA concentrations, on the one had, and blood pressure, creatinine and dialysis dose (Kt/V urea), on the other hand. It is concluded that plasma levels of ADMA are considerably lower than those reported earlier in patients treated with HD and also below the levels that hitherto have been thought to have clinical relevance. The role of ADMA in inhibiting NO in dialysis-associated hypertension is questioned.


2019 ◽  
Vol 7 (2) ◽  
pp. 177
Author(s):  
Happy Sista Devy ◽  
Bahrain Pasha Irawan

<p>Goals of the research to analyze whether occurred abnormal return of ASIAN Games phenomena and see how investors react to the big ASIAN Games 2018 event in Indonesia. . This reseach uses a sample of companies included in the hotel, restaurant and tourism sub-sector on the Indonesia Stock Exchange (IDX) during the observation period, based on the purposive sampling method which obtained 22 companies and used the event study method. There is a significant abnormal return but not on the phenomenon of the Asian Games 2018. This shows that investors still wait and see to the organization of the Asian Games in 2018. No difference of abnormal return before and after the Asian Games 2018. This is because, as investors look to the many tourists who have started to flock to Indonesia before the Asian Games in 2018 took place.<em></em></p><p><strong><em></em></strong><em><br /></em></p>


2010 ◽  
Vol 14 (2) ◽  
pp. 431-447
Author(s):  
Zahra Fehresti

AbstractHuman trafficking, in particular the trafficking of women and children, is considered a syndicated international phenomenon, and numerous international agreements have consequently been signed to combat the crime. Iran is one of the many countries that passed legislated laws to battle this evil industry. In the present article, the author examines and compares Iran's legislative approaches towards human trafficking before and after the Islamic Revolution. The Iranian legislation combating human trafficking generally suffers from some serious shortcomings; particularly, the inconsistency regarding this issue between the civil and the Islamic Penal Codes and Iran's Constitution is its most prominent weakness.


Author(s):  
Jens Wolff

Luther was a point of reference in all three of the confessional cultures during the confessional age, though this was not something he had intended. His theological “self-fashioning” was not meant to secure, canonize, or stabilize his own works or his biography. Rather, he believed, and was convinced, that the hidden God rules in a strange way. He hides himself in the course of the world and realizes what we would have liked to realizes. Apart from this theological viewpoint, historiographic differentiation is needed: Luther had different impacts on each of the three confessions. Furthermore, one also has to differentiate between a deep impact and the unintended effects of Luther’s thinking. Luther was an extremely polarizing figure. From the beginning, he underwent a heroization and a diabolization by his contemporaries. Apart from this black-and-white reception of his person, it was, and still is, extremely difficult to analyze Luther, his work and medial effects. Historians have always been fixated on Luther: he was the one and only founder of Protestantism. His biography became a stereotype of writing and was an important element of Protestant (or anti-Protestant) identity politics. For some Protestants, his biography became identical with the history of salvation (Heilsgeschichte). For his enemies, his biography was identical with the history of the devil. In all historical fields, one has to differentiate between the different groups and people who protected or attacked Luther or shared his ideas. The history of Luther can only be written as a shared history with conflict and concordances: the so-called Anabaptists, for example, shared Luther’s antihierarchical ideal of Christian community, although on the other hand “they” were strongly opposed toward his theology and person. Luther or example, had conflicts with the humanists and with Erasmus especially; he argued about the Lord’s Supper with Zwingli, he criticized the Fuggers because of their financial transactions in an early capitalist society; and, last but not least, he was in conflict with the Roman Church. The legitimization of different pictures of Luther always depends upon the perspectives of the posterity: either Luther was intolerant against spiritualists, Anabaptists, or peasants who were willing to resort to violence; or he was defended by humanists like Sebastian Castellio for defending religious tolerance. During his lifetime Luther was an extremely polarizing figure. Hundreds of pro-Lutheran and polemical anti-Lutheran leaflets or texts were published. The many literary forms of parody, satire, caricature, the grotesque, and the absurd were cultivated during the confessional age. Luther’s biography was often used by Lutheran theologians as an instrument of heroization and identity politics in public discourse. Historically, one can differentiate between the time before and after Luther. The political and religious unity of the Holy Roman Empire was strongly disturbed, if not broken, through the Reformation. The end of the Universalist dreams of universal powers like theology and politics (pope and emperor) were some of the central preconditions for political, cultural, and theological differentiation of Europe. Religious differentiation was one of the unintended effects of theology and the interpretation of the scripture. Decades after Luther’s death, the Holy Roman Empire slowly and surprisingly turned into a poly-, multi- and interconfessional society.


2014 ◽  
Vol 624 ◽  
pp. 11-18
Author(s):  
Eva Coisson ◽  
Federica Ottoni

The use of composites in the field of architectural restoration is becoming more and more widespread, because of the great technical advantages they convey in many cases. But applying these materials to the Cultural Heritage poses not only technical issues, common to all the applications on the same materials, but also artistic, historical and, more generally, cultural ones. The present paper faces these issues, starting with some considerations on how they were dealt with in history, when the “new” materials were iron, steel and reinforced concrete. Then, the specific problems posed by the composite materials are discussed and some examples are shown in order to identify the correct approach to the many different cases that can arouse in the field of architectural restoration. There isn’t a single right solution for each problem, but there is a right approach that starts from the comprehension of the building’s behavior, passes through a comparison of all the possible solutions and aims at finding the best equilibrium among the technical and theoretical issues for the single case study.


2000 ◽  
Vol 639 ◽  
Author(s):  
E. D. Haberer ◽  
M. Woods ◽  
A. Stonas ◽  
C-H. Chen ◽  
S. Keller ◽  
...  

ABSTRACTIn this study, we use a quantum well (QW) probe structure to explore the size dependent effects of sidewall recombination in GaN. Mesas 0.8-7 μm in width with pitches of 4 μm, 8 μm, and 12 μm were etched into the QW probe structure, exposing the QW at the sidewalls. Several etch conditions were investigated. Room temperature photoluminescence (PL) measurements, using a He-Cd laser as an excitation source and laser spot size of approximately 230 μm, were taken before and after the mesas were etched. The effects of sidewall formation were quantified by comparing the maximum PL intensity of the QW before and after etch. Higher remaining PL intensity was observed for etch conditions which used both Ar ions and Cl2 gas instead of only Ar ions. The fraction of remaining PL decreased with decreasing mesa width, however the remaining PL intensity was relatively large even for small features. The preliminary data suggested that GaN is relatively insensitive to sidewall damage.


2007 ◽  
Vol 544-545 ◽  
pp. 821-824
Author(s):  
Indra ◽  
S.W. Oh ◽  
Hee Joon Kim

This work examined the mechanical properties of alumina that can directly be enhanced by ratio of nano sized alumina powders additives to micro size alumina powders (n/m ratio). These new materials have mechanical properties that are strongly grain size dependent and often significantly different from those of their coarser grained counter parts. The mechanical characteristics of samples were observed by using the indentation test system. This data shows that the relative density for the sample is increased with increasing Meyer hardness.


2012 ◽  
Vol 55 (2-3) ◽  
pp. 603-636 ◽  
Author(s):  
Filipa Lowndes Vicente

Abstract By analyzing the history of a photograph taken in a Bombay photo studio in 1885, this article explores notions of the production of knowledge on India and cultural dialogues, encounters, appropriations, and conflicts in colonial British India in the late nineteenth century. The photograph was taken after a Hindu religious ceremony in honour of the Italian Sanskritist Angelo de Gubernatis. Dressed as a Hindu Brahman, he is the only European photographed next to three Indian scholars, but what the image suggests of encounter and hybridity was challenged by the many written texts that reveal the conflicting dialogues that took place before and after the portrait was taken. Several factors were examined in order to decide who should and who should not be in the photograph: religion, cast, and even gender were successively discussed, before the category of “knowledge” became the bond that unified the four men who studied, taught, and wrote on India.


2021 ◽  
Author(s):  
Álvaro Galiana ◽  
Igor Paredes ◽  
Sebastián Ruiz ◽  
José Antonio Fernández Alén ◽  
Adolfo Gómez Grande ◽  
...  

Abstract PURPOSE: SSFS is an underdiagnosed complication of craniectomized patients, which mainly presents with headache, motor weakness, and cognitive impairments. In these patients, cranioplasty improves these symptoms. Furthermore, patients without a classical SSFS have been shown to improve their neurological functions after reconstructive surgery. Amongst the many different pathophysiological theories proposed, the changes of CBP caused by the cranial defect might have a role in the neurological deficiencies. We have studied CBP in twelve cortical areas of both hemispheres, using 99mTc-HMPAO SPECT-CT before and after cranioplasty.METHODS: Twenty-eight craniectomized patients subject to reconstructive surgery were studied with 99mTc- HMPAO in three different times, before cranioplasty, a week after, and three months later. The images were processed with quantification software comparing CBP of 24 cortical areas with a reference area , and with a database of normal individuals. A mixed effects model was used to determine the signification of CBP changes in the cortex regions of both the damaged and undamaged brain hemispheres.RESULTS: CBP increased significantly in both hemispheres after cranioplasty both in ratio (β=0.019 p-value=0,030 first post-surgical SPECT-CT and β=0.021 p-value=0,015 in the second study, vs. pre-surgical) and Z-score (β=0.220 p-value=0,026 and β=0.279 p-value=0,005 respectively). Nine of twelve areas of the damaged side had a significant lower CBP ratio and Z-score than the undamaged. Posterior cingulate showed an increased CBP ratio (p-value=0,034) and Z-score(p-value0,028) in the first post-surgical SPECT-CT.CONCLUSION: CBP changes significantly in specific cortical areas after cranioplasty, which might explain the clinical improvements observed. Posterior cingulate changes might explain some improvements in attention impairments described. 99mTc-HMPAO SPECT-CT might be a valid tool to assess CBP changes in these patients and could have a role in the management of craniectomized individuals.CLINICAL TRIAL REGISTRATIONNot applicable


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